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BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
readpng2_init
int readpng2_init(mainprog_info *mainprog_ptr) { png_structp png_ptr; /* note: temporary variables! */ png_infop info_ptr; /* could also replace libpng warning-handler (final NULL), but no need: */ png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr, readpng2_error_handler, NULL); if (!png_ptr) return 4; /* out of memory */ info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { png_destroy_read_struct(&png_ptr, NULL, NULL); return 4; /* out of memory */ } /* we could create a second info struct here (end_info), but it's only * useful if we want to keep pre- and post-IDAT chunk info separated * (mainly for PNG-aware image editors and converters) */ /* setjmp() must be called in every function that calls a PNG-reading * libpng function, unless an alternate error handler was installed-- * but compatible error handlers must either use longjmp() themselves * (as in this program) or exit immediately, so here we are: */ if (setjmp(mainprog_ptr->jmpbuf)) { png_destroy_read_struct(&png_ptr, &info_ptr, NULL); return 2; } #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED /* prepare the reader to ignore all recognized chunks whose data won't be * used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT, * IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */ { /* These byte strings were copied from png.h. If a future version * of readpng2.c recognizes more chunks, add them to this list. */ static PNG_CONST png_byte chunks_to_process[] = { 98, 75, 71, 68, '\0', /* bKGD */ 103, 65, 77, 65, '\0', /* gAMA */ 115, 82, 71, 66, '\0', /* sRGB */ }; /* Ignore all chunks except for IHDR, PLTE, tRNS, IDAT, and IEND */ png_set_keep_unknown_chunks(png_ptr, -1 /* PNG_HANDLE_CHUNK_NEVER */, NULL, -1); /* But do not ignore chunks in the "chunks_to_process" list */ png_set_keep_unknown_chunks(png_ptr, 0 /* PNG_HANDLE_CHUNK_AS_DEFAULT */, chunks_to_process, sizeof(chunks_to_process)/5); } #endif /* PNG_HANDLE_AS_UNKNOWN_SUPPORTED */ /* instead of doing png_init_io() here, now we set up our callback * functions for progressive decoding */ png_set_progressive_read_fn(png_ptr, mainprog_ptr, readpng2_info_callback, readpng2_row_callback, readpng2_end_callback); /* make sure we save our pointers for use in readpng2_decode_data() */ mainprog_ptr->png_ptr = png_ptr; mainprog_ptr->info_ptr = info_ptr; /* and that's all there is to initialization */ return 0; }
/* returns 0 for success, 2 for libpng problem, 4 for out of memory */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/readpng2.c#L98-L176
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
readpng2_decode_data
int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length) { png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr; png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr; /* setjmp() must be called in every function that calls a PNG-reading * libpng function */ if (setjmp(mainprog_ptr->jmpbuf)) { png_destroy_read_struct(&png_ptr, &info_ptr, NULL); mainprog_ptr->png_ptr = NULL; mainprog_ptr->info_ptr = NULL; return 2; } /* hand off the next chunk of input data to libpng for decoding */ png_process_data(png_ptr, info_ptr, rawbuf, length); return 0; }
/* returns 0 for success, 2 for libpng (longjmp) problem */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/readpng2.c#L183-L205
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
readpng_init
int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight) { static uch ppmline[256]; int maxval; saved_infile = infile; fgets(ppmline, 256, infile); if (ppmline[0] != 'P' || ppmline[1] != '6') { fprintf(stderr, "ERROR: not a PPM file\n"); return 1; } /* possible color types: P5 = grayscale (0), P6 = RGB (2), P8 = RGBA (6) */ if (ppmline[1] == '6') { color_type = 2; channels = 3; } else if (ppmline[1] == '8') { color_type = 6; channels = 4; } else /* if (ppmline[1] == '5') */ { color_type = 0; channels = 1; } do { fgets(ppmline, 256, infile); } while (ppmline[0] == '#'); sscanf(ppmline, "%lu %lu", &width, &height); do { fgets(ppmline, 256, infile); } while (ppmline[0] == '#'); sscanf(ppmline, "%d", &maxval); if (maxval != 255) { fprintf(stderr, "ERROR: maxval = %d\n", maxval); return 2; } bit_depth = 8; *pWidth = width; *pHeight = height; return 0; }
/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/readppm.c#L81-L125
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
readpng_get_bgcolor
int readpng_get_bgcolor(uch *red, uch *green, uch *blue) { return 1; }
/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error; * scales values to 8-bit if necessary */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/readppm.c#L133-L136
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
rpng2_win_init
static void rpng2_win_init() { ulg i; ulg rowbytes = rpng2_info.rowbytes; Trace((stderr, "beginning rpng2_win_init()\n")) Trace((stderr, " rowbytes = %d\n", rpng2_info.rowbytes)) Trace((stderr, " width = %ld\n", rpng2_info.width)) Trace((stderr, " height = %ld\n", rpng2_info.height)) rpng2_info.image_data = (uch *)malloc(rowbytes * rpng2_info.height); if (!rpng2_info.image_data) { readpng2_cleanup(&rpng2_info); return; } rpng2_info.row_pointers = (uch **)malloc(rpng2_info.height * sizeof(uch *)); if (!rpng2_info.row_pointers) { free(rpng2_info.image_data); rpng2_info.image_data = NULL; readpng2_cleanup(&rpng2_info); return; } for (i = 0; i < rpng2_info.height; ++i) rpng2_info.row_pointers[i] = rpng2_info.image_data + i*rowbytes; /*--------------------------------------------------------------------------- Do the basic Windows initialization stuff, make the window, and fill it with the user-specified, file-specified or default background color. ---------------------------------------------------------------------------*/ if (rpng2_win_create_window()) { readpng2_cleanup(&rpng2_info); return; } rpng2_info.state = kWindowInit; }
/* this function is called by readpng2_info_callback() in readpng2.c, which * in turn is called by libpng after all of the pre-IDAT chunks have been * read and processed--i.e., we now have enough info to finish initializing */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/rpng2-win.c#L641-L679
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
rpng2_win_load_bg_image
static int rpng2_win_load_bg_image() { uch *src, *dest; uch r1, r2, g1, g2, b1, b2; uch r1_inv, r2_inv, g1_inv, g2_inv, b1_inv, b2_inv; int k, hmax, max; int xidx, yidx, yidx_max = (bgscale-1); int even_odd_vert, even_odd_horiz, even_odd; int invert_gradient2 = (bg[pat].type & 0x08); int invert_column; ulg i, row; /*--------------------------------------------------------------------------- Allocate buffer for fake background image to be used with transparent images; if this fails, revert to plain background color. ---------------------------------------------------------------------------*/ bg_rowbytes = 3 * rpng2_info.width; bg_data = (uch *)malloc(bg_rowbytes * rpng2_info.height); if (!bg_data) { fprintf(stderr, PROGNAME ": unable to allocate memory for background image\n"); bg_image = 0; return 1; } /*--------------------------------------------------------------------------- Vertical gradients (ramps) in NxN squares, alternating direction and colors (N == bgscale). ---------------------------------------------------------------------------*/ if ((bg[pat].type & 0x07) == 0) { uch r1_min = rgb[bg[pat].rgb1_min].r; uch g1_min = rgb[bg[pat].rgb1_min].g; uch b1_min = rgb[bg[pat].rgb1_min].b; uch r2_min = rgb[bg[pat].rgb2_min].r; uch g2_min = rgb[bg[pat].rgb2_min].g; uch b2_min = rgb[bg[pat].rgb2_min].b; int r1_diff = rgb[bg[pat].rgb1_max].r - r1_min; int g1_diff = rgb[bg[pat].rgb1_max].g - g1_min; int b1_diff = rgb[bg[pat].rgb1_max].b - b1_min; int r2_diff = rgb[bg[pat].rgb2_max].r - r2_min; int g2_diff = rgb[bg[pat].rgb2_max].g - g2_min; int b2_diff = rgb[bg[pat].rgb2_max].b - b2_min; for (row = 0; row < rpng2_info.height; ++row) { yidx = row % bgscale; even_odd_vert = (row / bgscale) & 1; r1 = r1_min + (r1_diff * yidx) / yidx_max; g1 = g1_min + (g1_diff * yidx) / yidx_max; b1 = b1_min + (b1_diff * yidx) / yidx_max; r1_inv = r1_min + (r1_diff * (yidx_max-yidx)) / yidx_max; g1_inv = g1_min + (g1_diff * (yidx_max-yidx)) / yidx_max; b1_inv = b1_min + (b1_diff * (yidx_max-yidx)) / yidx_max; r2 = r2_min + (r2_diff * yidx) / yidx_max; g2 = g2_min + (g2_diff * yidx) / yidx_max; b2 = b2_min + (b2_diff * yidx) / yidx_max; r2_inv = r2_min + (r2_diff * (yidx_max-yidx)) / yidx_max; g2_inv = g2_min + (g2_diff * (yidx_max-yidx)) / yidx_max; b2_inv = b2_min + (b2_diff * (yidx_max-yidx)) / yidx_max; dest = bg_data + row*bg_rowbytes; for (i = 0; i < rpng2_info.width; ++i) { even_odd_horiz = (i / bgscale) & 1; even_odd = even_odd_vert ^ even_odd_horiz; invert_column = (even_odd_horiz && (bg[pat].type & 0x10)); if (even_odd == 0) { /* gradient #1 */ if (invert_column) { *dest++ = r1_inv; *dest++ = g1_inv; *dest++ = b1_inv; } else { *dest++ = r1; *dest++ = g1; *dest++ = b1; } } else { /* gradient #2 */ if ((invert_column && invert_gradient2) || (!invert_column && !invert_gradient2)) { *dest++ = r2; /* not inverted or */ *dest++ = g2; /* doubly inverted */ *dest++ = b2; } else { *dest++ = r2_inv; *dest++ = g2_inv; /* singly inverted */ *dest++ = b2_inv; } } } } /*--------------------------------------------------------------------------- Soft gradient-diamonds with scale = bgscale. Code contributed by Adam M. Costello. ---------------------------------------------------------------------------*/ } else if ((bg[pat].type & 0x07) == 1) { hmax = (bgscale-1)/2; /* half the max weight of a color */ max = 2*hmax; /* the max weight of a color */ r1 = rgb[bg[pat].rgb1_max].r; g1 = rgb[bg[pat].rgb1_max].g; b1 = rgb[bg[pat].rgb1_max].b; r2 = rgb[bg[pat].rgb2_max].r; g2 = rgb[bg[pat].rgb2_max].g; b2 = rgb[bg[pat].rgb2_max].b; for (row = 0; row < rpng2_info.height; ++row) { yidx = row % bgscale; if (yidx > hmax) yidx = bgscale-1 - yidx; dest = bg_data + row*bg_rowbytes; for (i = 0; i < rpng2_info.width; ++i) { xidx = i % bgscale; if (xidx > hmax) xidx = bgscale-1 - xidx; k = xidx + yidx; *dest++ = (k*r1 + (max-k)*r2) / max; *dest++ = (k*g1 + (max-k)*g2) / max; *dest++ = (k*b1 + (max-k)*b2) / max; } } /*--------------------------------------------------------------------------- Radial "starburst" with azimuthal sinusoids; [eventually number of sinu- soids will equal bgscale?]. This one is slow but very cool. Code con- tributed by Pieter S. van der Meulen (originally in Smalltalk). ---------------------------------------------------------------------------*/ } else if ((bg[pat].type & 0x07) == 2) { uch ch; int ii, x, y, hw, hh, grayspot; double freq, rotate, saturate, gray, intensity; double angle=0.0, aoffset=0.0, maxDist, dist; double red=0.0, green=0.0, blue=0.0, hue, s, v, f, p, q, t; fprintf(stderr, "%s: computing radial background...", PROGNAME); fflush(stderr); hh = rpng2_info.height / 2; hw = rpng2_info.width / 2; /* variables for radial waves: * aoffset: number of degrees to rotate hue [CURRENTLY NOT USED] * freq: number of color beams originating from the center * grayspot: size of the graying center area (anti-alias) * rotate: rotation of the beams as a function of radius * saturate: saturation of beams' shape azimuthally */ angle = CLIP(angle, 0.0, 360.0); grayspot = CLIP(bg[pat].bg_gray, 1, (hh + hw)); freq = MAX((double)bg[pat].bg_freq, 0.0); saturate = (double)bg[pat].bg_bsat * 0.1; rotate = (double)bg[pat].bg_brot * 0.1; gray = 0.0; intensity = 0.0; maxDist = (double)((hw*hw) + (hh*hh)); for (row = 0; row < rpng2_info.height; ++row) { y = row - hh; dest = bg_data + row*bg_rowbytes; for (i = 0; i < rpng2_info.width; ++i) { x = i - hw; angle = (x == 0)? PI_2 : atan((double)y / (double)x); gray = (double)MAX(ABS(y), ABS(x)) / grayspot; gray = MIN(1.0, gray); dist = (double)((x*x) + (y*y)) / maxDist; intensity = cos((angle+(rotate*dist*PI)) * freq) * gray * saturate; intensity = (MAX(MIN(intensity,1.0),-1.0) + 1.0) * 0.5; hue = (angle + PI) * INV_PI_360 + aoffset; s = gray * ((double)(ABS(x)+ABS(y)) / (double)(hw + hh)); s = MIN(MAX(s,0.0), 1.0); v = MIN(MAX(intensity,0.0), 1.0); if (s == 0.0) { ch = (uch)(v * 255.0); *dest++ = ch; *dest++ = ch; *dest++ = ch; } else { if ((hue < 0.0) || (hue >= 360.0)) hue -= (((int)(hue / 360.0)) * 360.0); hue /= 60.0; ii = (int)hue; f = hue - (double)ii; p = (1.0 - s) * v; q = (1.0 - (s * f)) * v; t = (1.0 - (s * (1.0 - f))) * v; if (ii == 0) { red = v; green = t; blue = p; } else if (ii == 1) { red = q; green = v; blue = p; } else if (ii == 2) { red = p; green = v; blue = t; } else if (ii == 3) { red = p; green = q; blue = v; } else if (ii == 4) { red = t; green = p; blue = v; } else if (ii == 5) { red = v; green = p; blue = q; } *dest++ = (uch)(red * 255.0); *dest++ = (uch)(green * 255.0); *dest++ = (uch)(blue * 255.0); } } } fprintf(stderr, "done.\n"); fflush(stderr); } /*--------------------------------------------------------------------------- Blast background image to display buffer before beginning PNG decode; calling function will handle invalidation and UpdateWindow() call. ---------------------------------------------------------------------------*/ for (row = 0; row < rpng2_info.height; ++row) { src = bg_data + row*bg_rowbytes; dest = wimage_data + row*wimage_rowbytes; for (i = rpng2_info.width; i > 0; --i) { r1 = *src++; g1 = *src++; b1 = *src++; *dest++ = b1; *dest++ = g1; /* note reverse order */ *dest++ = r1; } } return 0; }
/* end function rpng2_win_create_window() */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/rpng2-win.c
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
main
int main(int argc, char **argv) { #ifndef DOS_OS2_W32 FILE *keybd; #endif #ifdef sgi FILE *tmpfile; /* or we could just use keybd, since no overlap */ char tmpline[80]; #endif char *inname = NULL, outname[256]; char *p, pnmchar, pnmline[256]; char *bgstr, *textbuf = NULL; ulg rowbytes; int rc, len = 0; int error = 0; int text = FALSE; int maxval; double LUT_exponent; /* just the lookup table */ double CRT_exponent = 2.2; /* just the monitor */ double default_display_exponent; /* whole display system */ double default_gamma = 0.0; wpng_info.infile = NULL; wpng_info.outfile = NULL; wpng_info.image_data = NULL; wpng_info.row_pointers = NULL; wpng_info.filter = FALSE; wpng_info.interlaced = FALSE; wpng_info.have_bg = FALSE; wpng_info.have_time = FALSE; wpng_info.have_text = 0; wpng_info.gamma = 0.0; /* First get the default value for our display-system exponent, i.e., * the product of the CRT exponent and the exponent corresponding to * the frame-buffer's lookup table (LUT), if any. If the PNM image * looks correct on the user's display system, its file gamma is the * inverse of this value. (Note that this is not an exhaustive list * of LUT values--e.g., OpenStep has a lot of weird ones--but it should * cover 99% of the current possibilities. This section must ensure * that default_display_exponent is positive.) */ #if defined(NeXT) /* third-party utilities can modify the default LUT exponent */ LUT_exponent = 1.0 / 2.2; /* if (some_next_function_that_returns_gamma(&next_gamma)) LUT_exponent = 1.0 / next_gamma; */ #elif defined(sgi) LUT_exponent = 1.0 / 1.7; /* there doesn't seem to be any documented function to * get the "gamma" value, so we do it the hard way */ tmpfile = fopen("/etc/config/system.glGammaVal", "r"); if (tmpfile) { double sgi_gamma; fgets(tmpline, 80, tmpfile); fclose(tmpfile); sgi_gamma = atof(tmpline); if (sgi_gamma > 0.0) LUT_exponent = 1.0 / sgi_gamma; } #elif defined(Macintosh) LUT_exponent = 1.8 / 2.61; /* if (some_mac_function_that_returns_gamma(&mac_gamma)) LUT_exponent = mac_gamma / 2.61; */ #else LUT_exponent = 1.0; /* assume no LUT: most PCs */ #endif /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */ default_display_exponent = LUT_exponent * CRT_exponent; /* If the user has set the SCREEN_GAMMA environment variable as suggested * (somewhat imprecisely) in the libpng documentation, use that; otherwise * use the default value we just calculated. Either way, the user may * override this via a command-line option. */ if ((p = getenv("SCREEN_GAMMA")) != NULL) { double exponent = atof(p); if (exponent > 0.0) default_gamma = 1.0 / exponent; } if (default_gamma == 0.0) default_gamma = 1.0 / default_display_exponent; /* Now parse the command line for options and the PNM filename. */ while (*++argv && !error) { if (!strncmp(*argv, "-i", 2)) { wpng_info.interlaced = TRUE; } else if (!strncmp(*argv, "-time", 3)) { wpng_info.modtime = time(NULL); wpng_info.have_time = TRUE; } else if (!strncmp(*argv, "-text", 3)) { text = TRUE; } else if (!strncmp(*argv, "-gamma", 2)) { if (!*++argv) ++error; else { wpng_info.gamma = atof(*argv); if (wpng_info.gamma <= 0.0) ++error; else if (wpng_info.gamma > 1.01) fprintf(stderr, PROGNAME " warning: file gammas are usually less than 1.0\n"); } } else if (!strncmp(*argv, "-bgcolor", 4)) { if (!*++argv) ++error; else { bgstr = *argv; if (strlen(bgstr) != 7 || bgstr[0] != '#') ++error; else { unsigned r, g, b; /* this way quiets compiler warnings */ sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b); wpng_info.bg_red = (uch)r; wpng_info.bg_green = (uch)g; wpng_info.bg_blue = (uch)b; wpng_info.have_bg = TRUE; } } } else { if (**argv != '-') { inname = *argv; if (argv[1]) /* shouldn't be any more args after filename */ ++error; } else ++error; /* not expecting any other options */ } } /* open the input and output files, or register an error and abort */ if (!inname) { if (isatty(0)) { fprintf(stderr, PROGNAME ": must give input filename or provide image data via stdin\n"); ++error; } else { #ifdef DOS_OS2_W32 /* some buggy C libraries require BOTH setmode() and fdopen(bin) */ setmode(fileno(stdin), O_BINARY); setmode(fileno(stdout), O_BINARY); #endif if ((wpng_info.infile = fdopen(fileno(stdin), "rb")) == NULL) { fprintf(stderr, PROGNAME ": unable to reopen stdin in binary mode\n"); ++error; } else if ((wpng_info.outfile = fdopen(fileno(stdout), "wb")) == NULL) { fprintf(stderr, PROGNAME ": unable to reopen stdout in binary mode\n"); fclose(wpng_info.infile); ++error; } else wpng_info.filter = TRUE; } } else if ((len = strlen(inname)) > 250) { fprintf(stderr, PROGNAME ": input filename is too long [%d chars]\n", len); ++error; } else if (!(wpng_info.infile = fopen(inname, "rb"))) { fprintf(stderr, PROGNAME ": can't open input file [%s]\n", inname); ++error; } if (!error) { fgets(pnmline, 256, wpng_info.infile); if (pnmline[0] != 'P' || ((pnmchar = pnmline[1]) != '5' && pnmchar != '6' && pnmchar != '8')) { fprintf(stderr, PROGNAME ": input file [%s] is not a binary PGM, PPM or PAM file\n", inname); ++error; } else { wpng_info.pnmtype = (int)(pnmchar - '0'); if (wpng_info.pnmtype != 8) wpng_info.have_bg = FALSE; /* no need for bg if opaque */ do { fgets(pnmline, 256, wpng_info.infile); /* lose any comments */ } while (pnmline[0] == '#'); sscanf(pnmline, "%ld %ld", &wpng_info.width, &wpng_info.height); do { fgets(pnmline, 256, wpng_info.infile); /* more comment lines */ } while (pnmline[0] == '#'); sscanf(pnmline, "%d", &maxval); if (wpng_info.width <= 0L || wpng_info.height <= 0L || maxval != 255) { fprintf(stderr, PROGNAME ": only positive width/height, maxval == 255 allowed \n"); ++error; } wpng_info.sample_depth = 8; /* <==> maxval 255 */ if (!wpng_info.filter) { /* make outname from inname */ if ((p = strrchr(inname, '.')) == NULL || (p - inname) != (len - 4)) { strcpy(outname, inname); strcpy(outname+len, ".png"); } else { len -= 4; strncpy(outname, inname, len); strcpy(outname+len, ".png"); } /* check if outname already exists; if not, open */ if ((wpng_info.outfile = fopen(outname, "rb")) != NULL) { fprintf(stderr, PROGNAME ": output file exists [%s]\n", outname); fclose(wpng_info.outfile); ++error; } else if (!(wpng_info.outfile = fopen(outname, "wb"))) { fprintf(stderr, PROGNAME ": can't open output file [%s]\n", outname); ++error; } } } if (error) { fclose(wpng_info.infile); wpng_info.infile = NULL; if (wpng_info.filter) { fclose(wpng_info.outfile); wpng_info.outfile = NULL; } } } /* if we had any errors, print usage and die horrible death...arrr! */ if (error) { fprintf(stderr, "\n%s %s: %s\n", PROGNAME, VERSION, APPNAME); writepng_version_info(); fprintf(stderr, "\n" "Usage: %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] pnmfile\n" "or: ... | %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] | ...\n" " exp \ttransfer-function exponent (``gamma'') of the image in\n" "\t\t floating-point format (e.g., ``%.5f''); if image looks\n" "\t\t correct on given display system, image gamma is equal to\n" "\t\t inverse of display-system exponent, i.e., 1 / (LUT * CRT)\n" "\t\t (where LUT = lookup-table exponent and CRT = CRT exponent;\n" "\t\t first varies, second is usually 2.2, all are positive)\n" " bg \tdesired background color for alpha-channel images, in\n" "\t\t 7-character hex RGB format (e.g., ``#ff7700'' for orange:\n" "\t\t same as HTML colors)\n" " -text\tprompt interactively for text info (tEXt chunks)\n" " -time\tinclude a tIME chunk (last modification time)\n" " -interlace\twrite interlaced PNG image\n" "\n" "pnmfile or stdin must be a binary PGM (`P5'), PPM (`P6') or (extremely\n" "unofficial and unsupported!) PAM (`P8') file. Currently it is required\n" "to have maxval == 255 (i.e., no scaling). If pnmfile is specified, it\n" "is converted to the corresponding PNG file with the same base name but a\n" "``.png'' extension; files read from stdin are converted and sent to stdout.\n" "The conversion is progressive (low memory usage) unless interlacing is\n" "requested; in that case the whole image will be buffered in memory and\n" "written in one call.\n" "\n", PROGNAME, PROGNAME, default_gamma); exit(1); } /* prepare the text buffers for libpng's use; note that even though * PNG's png_text struct includes a length field, we don't have to fill * it out */ if (text && #ifndef DOS_OS2_W32 (keybd = fdopen(fileno(stderr), "r")) != NULL && #endif (textbuf = (char *)malloc((5 + 9)*75)) != NULL) { int i, valid, result; fprintf(stderr, "Enter text info (no more than 72 characters per line);\n"); fprintf(stderr, "to skip a field, hit the <Enter> key.\n"); /* note: just <Enter> leaves len == 1 */ do { valid = TRUE; p = textbuf + TEXT_TITLE_OFFSET; fprintf(stderr, " Title: "); fflush(stderr); if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) { if (p[len-1] == '\n') p[--len] = '\0'; wpng_info.title = p; wpng_info.have_text |= TEXT_TITLE; if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) { fprintf(stderr, " " PROGNAME " warning: character code" " %u is %sdiscouraged by the PNG\n specification " "[first occurrence was at character position #%d]\n", (unsigned)p[result], (p[result] == 27)? "strongly " : "", result+1); fflush(stderr); #ifdef FORBID_LATIN1_CTRL wpng_info.have_text &= ~TEXT_TITLE; valid = FALSE; #else if (p[result] == 27) { /* escape character */ wpng_info.have_text &= ~TEXT_TITLE; valid = FALSE; } #endif } } } while (!valid); do { valid = TRUE; p = textbuf + TEXT_AUTHOR_OFFSET; fprintf(stderr, " Author: "); fflush(stderr); if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) { if (p[len-1] == '\n') p[--len] = '\0'; wpng_info.author = p; wpng_info.have_text |= TEXT_AUTHOR; if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) { fprintf(stderr, " " PROGNAME " warning: character code" " %u is %sdiscouraged by the PNG\n specification " "[first occurrence was at character position #%d]\n", (unsigned)p[result], (p[result] == 27)? "strongly " : "", result+1); fflush(stderr); #ifdef FORBID_LATIN1_CTRL wpng_info.have_text &= ~TEXT_AUTHOR; valid = FALSE; #else if (p[result] == 27) { /* escape character */ wpng_info.have_text &= ~TEXT_AUTHOR; valid = FALSE; } #endif } } } while (!valid); do { valid = TRUE; p = textbuf + TEXT_DESC_OFFSET; fprintf(stderr, " Description (up to 9 lines):\n"); for (i = 1; i < 10; ++i) { fprintf(stderr, " [%d] ", i); fflush(stderr); if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) p += len; /* now points at NULL; char before is newline */ else break; } if ((len = p - (textbuf + TEXT_DESC_OFFSET)) > 1) { if (p[-1] == '\n') { p[-1] = '\0'; --len; } wpng_info.desc = textbuf + TEXT_DESC_OFFSET; wpng_info.have_text |= TEXT_DESC; p = textbuf + TEXT_DESC_OFFSET; if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) { fprintf(stderr, " " PROGNAME " warning: character code" " %u is %sdiscouraged by the PNG\n specification " "[first occurrence was at character position #%d]\n", (unsigned)p[result], (p[result] == 27)? "strongly " : "", result+1); fflush(stderr); #ifdef FORBID_LATIN1_CTRL wpng_info.have_text &= ~TEXT_DESC; valid = FALSE; #else if (p[result] == 27) { /* escape character */ wpng_info.have_text &= ~TEXT_DESC; valid = FALSE; } #endif } } } while (!valid); do { valid = TRUE; p = textbuf + TEXT_COPY_OFFSET; fprintf(stderr, " Copyright: "); fflush(stderr); if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) { if (p[len-1] == '\n') p[--len] = '\0'; wpng_info.copyright = p; wpng_info.have_text |= TEXT_COPY; if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) { fprintf(stderr, " " PROGNAME " warning: character code" " %u is %sdiscouraged by the PNG\n specification " "[first occurrence was at character position #%d]\n", (unsigned)p[result], (p[result] == 27)? "strongly " : "", result+1); fflush(stderr); #ifdef FORBID_LATIN1_CTRL wpng_info.have_text &= ~TEXT_COPY; valid = FALSE; #else if (p[result] == 27) { /* escape character */ wpng_info.have_text &= ~TEXT_COPY; valid = FALSE; } #endif } } } while (!valid); do { valid = TRUE; p = textbuf + TEXT_EMAIL_OFFSET; fprintf(stderr, " E-mail: "); fflush(stderr); if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) { if (p[len-1] == '\n') p[--len] = '\0'; wpng_info.email = p; wpng_info.have_text |= TEXT_EMAIL; if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) { fprintf(stderr, " " PROGNAME " warning: character code" " %u is %sdiscouraged by the PNG\n specification " "[first occurrence was at character position #%d]\n", (unsigned)p[result], (p[result] == 27)? "strongly " : "", result+1); fflush(stderr); #ifdef FORBID_LATIN1_CTRL wpng_info.have_text &= ~TEXT_EMAIL; valid = FALSE; #else if (p[result] == 27) { /* escape character */ wpng_info.have_text &= ~TEXT_EMAIL; valid = FALSE; } #endif } } } while (!valid); do { valid = TRUE; p = textbuf + TEXT_URL_OFFSET; fprintf(stderr, " URL: "); fflush(stderr); if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) { if (p[len-1] == '\n') p[--len] = '\0'; wpng_info.url = p; wpng_info.have_text |= TEXT_URL; if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) { fprintf(stderr, " " PROGNAME " warning: character code" " %u is %sdiscouraged by the PNG\n specification " "[first occurrence was at character position #%d]\n", (unsigned)p[result], (p[result] == 27)? "strongly " : "", result+1); fflush(stderr); #ifdef FORBID_LATIN1_CTRL wpng_info.have_text &= ~TEXT_URL; valid = FALSE; #else if (p[result] == 27) { /* escape character */ wpng_info.have_text &= ~TEXT_URL; valid = FALSE; } #endif } } } while (!valid); #ifndef DOS_OS2_W32 fclose(keybd); #endif } else if (text) { fprintf(stderr, PROGNAME ": unable to allocate memory for text\n"); text = FALSE; wpng_info.have_text = 0; } /* allocate libpng stuff, initialize transformations, write pre-IDAT data */ if ((rc = writepng_init(&wpng_info)) != 0) { switch (rc) { case 2: fprintf(stderr, PROGNAME ": libpng initialization problem (longjmp)\n"); break; case 4: fprintf(stderr, PROGNAME ": insufficient memory\n"); break; case 11: fprintf(stderr, PROGNAME ": internal logic error (unexpected PNM type)\n"); break; default: fprintf(stderr, PROGNAME ": unknown writepng_init() error\n"); break; } exit(rc); } /* free textbuf, since it's a completely local variable and all text info * has just been written to the PNG file */ if (text && textbuf) { free(textbuf); textbuf = NULL; } /* calculate rowbytes on basis of image type; note that this becomes much * more complicated if we choose to support PBM type, ASCII PNM types, or * 16-bit-per-sample binary data [currently not an official NetPBM type] */ if (wpng_info.pnmtype == 5) rowbytes = wpng_info.width; else if (wpng_info.pnmtype == 6) rowbytes = wpng_info.width * 3; else /* if (wpng_info.pnmtype == 8) */ rowbytes = wpng_info.width * 4; /* read and write the image, either in its entirety (if writing interlaced * PNG) or row by row (if non-interlaced) */ fprintf(stderr, "Encoding image data...\n"); fflush(stderr); if (wpng_info.interlaced) { long i; ulg bytes; ulg image_bytes = rowbytes * wpng_info.height; /* overflow? */ wpng_info.image_data = (uch *)malloc(image_bytes); wpng_info.row_pointers = (uch **)malloc(wpng_info.height*sizeof(uch *)); if (wpng_info.image_data == NULL || wpng_info.row_pointers == NULL) { fprintf(stderr, PROGNAME ": insufficient memory for image data\n"); writepng_cleanup(&wpng_info); wpng_cleanup(); exit(5); } for (i = 0; i < wpng_info.height; ++i) wpng_info.row_pointers[i] = wpng_info.image_data + i*rowbytes; bytes = fread(wpng_info.image_data, 1, image_bytes, wpng_info.infile); if (bytes != image_bytes) { fprintf(stderr, PROGNAME ": expected %lu bytes, got %lu bytes\n", image_bytes, bytes); fprintf(stderr, " (continuing anyway)\n"); } if (writepng_encode_image(&wpng_info) != 0) { fprintf(stderr, PROGNAME ": libpng problem (longjmp) while writing image data\n"); writepng_cleanup(&wpng_info); wpng_cleanup(); exit(2); } } else /* not interlaced: write progressively (row by row) */ { long j; ulg bytes; wpng_info.image_data = (uch *)malloc(rowbytes); if (wpng_info.image_data == NULL) { fprintf(stderr, PROGNAME ": insufficient memory for row data\n"); writepng_cleanup(&wpng_info); wpng_cleanup(); exit(5); } error = 0; for (j = wpng_info.height; j > 0L; --j) { bytes = fread(wpng_info.image_data, 1, rowbytes, wpng_info.infile); if (bytes != rowbytes) { fprintf(stderr, PROGNAME ": expected %lu bytes, got %lu bytes (row %ld)\n", rowbytes, bytes, wpng_info.height-j); ++error; break; } if (writepng_encode_row(&wpng_info) != 0) { fprintf(stderr, PROGNAME ": libpng problem (longjmp) while writing row %ld\n", wpng_info.height-j); ++error; break; } } if (error) { writepng_cleanup(&wpng_info); wpng_cleanup(); exit(2); } if (writepng_encode_finish(&wpng_info) != 0) { fprintf(stderr, PROGNAME ": error on final libpng call\n"); writepng_cleanup(&wpng_info); wpng_cleanup(); exit(2); } } /* OK, we're done (successfully): clean up all resources and quit */ fprintf(stderr, "Done.\n"); fflush(stderr); writepng_cleanup(&wpng_info); wpng_cleanup(); return 0; }
/* lone global */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/wpng.c#L154-L783
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
writepng_init
int writepng_init(mainprog_info *mainprog_ptr) { png_structp png_ptr; /* note: temporary variables! */ png_infop info_ptr; int color_type, interlace_type; /* could also replace libpng warning-handler (final NULL), but no need: */ png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr, writepng_error_handler, NULL); if (!png_ptr) return 4; /* out of memory */ info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { png_destroy_write_struct(&png_ptr, NULL); return 4; /* out of memory */ } /* setjmp() must be called in every function that calls a PNG-writing * libpng function, unless an alternate error handler was installed-- * but compatible error handlers must either use longjmp() themselves * (as in this program) or some other method to return control to * application code, so here we go: */ if (setjmp(mainprog_ptr->jmpbuf)) { png_destroy_write_struct(&png_ptr, &info_ptr); return 2; } /* make sure outfile is (re)opened in BINARY mode */ png_init_io(png_ptr, mainprog_ptr->outfile); /* set the compression levels--in general, always want to leave filtering * turned on (except for palette images) and allow all of the filters, * which is the default; want 32K zlib window, unless entire image buffer * is 16K or smaller (unknown here)--also the default; usually want max * compression (NOT the default); and remaining compression flags should * be left alone */ png_set_compression_level(png_ptr, Z_BEST_COMPRESSION); /* >> this is default for no filtering; Z_FILTERED is default otherwise: png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY); >> these are all defaults: png_set_compression_mem_level(png_ptr, 8); png_set_compression_window_bits(png_ptr, 15); png_set_compression_method(png_ptr, 8); */ /* set the image parameters appropriately */ if (mainprog_ptr->pnmtype == 5) color_type = PNG_COLOR_TYPE_GRAY; else if (mainprog_ptr->pnmtype == 6) color_type = PNG_COLOR_TYPE_RGB; else if (mainprog_ptr->pnmtype == 8) color_type = PNG_COLOR_TYPE_RGB_ALPHA; else { png_destroy_write_struct(&png_ptr, &info_ptr); return 11; } interlace_type = mainprog_ptr->interlaced? PNG_INTERLACE_ADAM7 : PNG_INTERLACE_NONE; png_set_IHDR(png_ptr, info_ptr, mainprog_ptr->width, mainprog_ptr->height, mainprog_ptr->sample_depth, color_type, interlace_type, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); if (mainprog_ptr->gamma > 0.0) png_set_gAMA(png_ptr, info_ptr, mainprog_ptr->gamma); if (mainprog_ptr->have_bg) { /* we know it's RGBA, not gray+alpha */ png_color_16 background; background.red = mainprog_ptr->bg_red; background.green = mainprog_ptr->bg_green; background.blue = mainprog_ptr->bg_blue; png_set_bKGD(png_ptr, info_ptr, &background); } if (mainprog_ptr->have_time) { png_time modtime; png_convert_from_time_t(&modtime, mainprog_ptr->modtime); png_set_tIME(png_ptr, info_ptr, &modtime); } if (mainprog_ptr->have_text) { png_text text[6]; int num_text = 0; if (mainprog_ptr->have_text & TEXT_TITLE) { text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; text[num_text].key = "Title"; text[num_text].text = mainprog_ptr->title; ++num_text; } if (mainprog_ptr->have_text & TEXT_AUTHOR) { text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; text[num_text].key = "Author"; text[num_text].text = mainprog_ptr->author; ++num_text; } if (mainprog_ptr->have_text & TEXT_DESC) { text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; text[num_text].key = "Description"; text[num_text].text = mainprog_ptr->desc; ++num_text; } if (mainprog_ptr->have_text & TEXT_COPY) { text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; text[num_text].key = "Copyright"; text[num_text].text = mainprog_ptr->copyright; ++num_text; } if (mainprog_ptr->have_text & TEXT_EMAIL) { text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; text[num_text].key = "E-mail"; text[num_text].text = mainprog_ptr->email; ++num_text; } if (mainprog_ptr->have_text & TEXT_URL) { text[num_text].compression = PNG_TEXT_COMPRESSION_NONE; text[num_text].key = "URL"; text[num_text].text = mainprog_ptr->url; ++num_text; } png_set_text(png_ptr, info_ptr, text, num_text); } /* write all chunks up to (but not including) first IDAT */ png_write_info(png_ptr, info_ptr); /* if we wanted to write any more text info *after* the image data, we * would set up text struct(s) here and call png_set_text() again, with * just the new data; png_set_tIME() could also go here, but it would * have no effect since we already called it above (only one tIME chunk * allowed) */ /* set up the transformations: for now, just pack low-bit-depth pixels * into bytes (one, two or four pixels per byte) */ png_set_packing(png_ptr); /* png_set_shift(png_ptr, &sig_bit); to scale low-bit-depth values */ /* make sure we save our pointers for use in writepng_encode_image() */ mainprog_ptr->png_ptr = png_ptr; mainprog_ptr->info_ptr = info_ptr; /* OK, that's all we need to do for now; return happy */ return 0; }
/* returns 0 for success, 2 for libpng problem, 4 for out of memory, 11 for * unexpected pnmtype; note that outfile might be stdout */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/writepng.c#L84-L251
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
writepng_encode_image
int writepng_encode_image(mainprog_info *mainprog_ptr) { png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr; png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr; /* as always, setjmp() must be called in every function that calls a * PNG-writing libpng function */ if (setjmp(mainprog_ptr->jmpbuf)) { png_destroy_write_struct(&png_ptr, &info_ptr); mainprog_ptr->png_ptr = NULL; mainprog_ptr->info_ptr = NULL; return 2; } /* and now we just write the whole image; libpng takes care of interlacing * for us */ png_write_image(png_ptr, mainprog_ptr->row_pointers); /* since that's it, we also close out the end of the PNG file now--if we * had any text or time info to write after the IDATs, second argument * would be info_ptr, but we optimize slightly by sending NULL pointer: */ png_write_end(png_ptr, NULL); return 0; }
/* returns 0 for success, 2 for libpng (longjmp) problem */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/writepng.c#L259-L289
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
writepng_encode_row
int writepng_encode_row(mainprog_info *mainprog_ptr) /* NON-interlaced only! */ { png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr; png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr; /* as always, setjmp() must be called in every function that calls a * PNG-writing libpng function */ if (setjmp(mainprog_ptr->jmpbuf)) { png_destroy_write_struct(&png_ptr, &info_ptr); mainprog_ptr->png_ptr = NULL; mainprog_ptr->info_ptr = NULL; return 2; } /* image_data points at our one row of image data */ png_write_row(png_ptr, mainprog_ptr->image_data); return 0; }
/* returns 0 if succeeds, 2 if libpng problem */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/writepng.c#L297-L319
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
writepng_encode_finish
int writepng_encode_finish(mainprog_info *mainprog_ptr) /* NON-interlaced! */ { png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr; png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr; /* as always, setjmp() must be called in every function that calls a * PNG-writing libpng function */ if (setjmp(mainprog_ptr->jmpbuf)) { png_destroy_write_struct(&png_ptr, &info_ptr); mainprog_ptr->png_ptr = NULL; mainprog_ptr->info_ptr = NULL; return 2; } /* close out PNG file; if we had any text or time info to write after * the IDATs, second argument would be info_ptr: */ png_write_end(png_ptr, NULL); return 0; }
/* returns 0 if succeeds, 2 if libpng problem */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/gregbook/writepng.c#L327-L350
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
parse_color
static void parse_color(char *arg, unsigned int *colors) { unsigned int ncolors = 0; while (*arg && ncolors < 4) { char *ep = arg; unsigned long ul = strtoul(arg, &ep, 0); if (ul > 65535) { fprintf(stderr, "makepng --color=...'%s': too big\n", arg); exit(1); } if (ep == arg) { fprintf(stderr, "makepng --color=...'%s': not a valid color\n", arg); exit(1); } if (*ep) ++ep; /* skip a separator */ arg = ep; colors[++ncolors] = (unsigned int)ul; /* checked above */ } if (*arg) { fprintf(stderr, "makepng --color=...'%s': too many values\n", arg); exit(1); } *colors = ncolors; }
/* This is a not-very-good parser for a sequence of numbers (including 0). It * doesn't accept some apparently valid things, but it accepts all the sensible * combinations. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/makepng.c#L1238-L1274
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
make_random_bytes
static void make_random_bytes(png_uint_32* seed, void* pv, size_t size) { png_uint_32 u0 = seed[0], u1 = seed[1]; png_bytep bytes = voidcast(png_bytep, pv); /* There are thirty three bits, the next bit in the sequence is bit-33 XOR * bit-20. The top 1 bit is in u1, the bottom 32 are in u0. */ size_t i; for (i=0; i<size; ++i) { /* First generate 8 new bits then shift them in at the end. */ png_uint_32 u = ((u0 >> (20-8)) ^ ((u1 << 7) | (u0 >> (32-7)))) & 0xff; u1 <<= 8; u1 |= u0 >> 24; u0 <<= 8; u0 |= u; *bytes++ = (png_byte)u; } seed[0] = u0; seed[1] = u1; }
/* Generate random bytes. This uses a boring repeatable algorithm and it * is implemented here so that it gives the same set of numbers on every * architecture. It's a linear congruential generator (Knuth or Sedgewick * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and * Hill, "The Art of Electronics". */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L77-L100
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
closestinteger
static double closestinteger(double x) { return floor(x + .5); }
/* Math support - neither Cygwin nor Visual Studio have C99 support and we need * a predictable rounding function, so make one here: */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L112-L116
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
u8d
static png_byte u8d(double d) { d = closestinteger(d); return (png_byte)d; }
/* Cast support: remove GCC whines. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L119-L124
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
unpremultiply
static png_byte unpremultiply(int component, int alpha) { if (alpha <= component) return 255; /* Arbitrary, but consistent with the libpng code */ else if (alpha >= 65535) return isRGB(component); else return sRGB((double)component / alpha); }
/* not used */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L168-L179
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
power_law_error8
static int power_law_error8(int value) { if (value > 0 && value < 255) { double vd = value / 255.; double e = fabs( pow(sRGB_to_d[value], 1/2.2) - sRGB_from_linear(pow(vd, 2.2))); /* Always allow an extra 1 here for rounding errors */ e = 1+floor(255 * e); return (int)e; } return 0; }
/* The error that results from using a 2.2 power law in place of the correct * sRGB transform, given an 8-bit value which might be either sRGB or power-law. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L221-L236
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
power_law_error16
static int power_law_error16(int value) { if (value > 0 && value < 65535) { /* Round trip the value through an 8-bit representation but using * non-matching to/from conversions. */ double vd = value / 65535.; double e = fabs( pow(sRGB_from_linear(vd), 2.2) - linear_from_sRGB(pow(vd, 1/2.2))); /* Always allow an extra 1 here for rounding errors */ e = error_in_sRGB_roundtrip+floor(65535 * e); return (int)e; } return 0; }
/* by experiment */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L239-L257
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
formatof
static png_uint_32 formatof(const char *arg) { char *ep; unsigned long format = strtoul(arg, &ep, 0); if (ep > arg && *ep == 0 && format < FORMAT_COUNT) return (png_uint_32)format; else for (format=0; format < FORMAT_COUNT; ++format) { if (strcmp(format_names[format], arg) == 0) return (png_uint_32)format; } fprintf(stderr, "pngstest: format name '%s' invalid\n", arg); return FORMAT_COUNT; }
/* Decode an argument to a format number. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L426-L443
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
format_clear
static void format_clear(format_list *pf) { int i; for (i=0; i<FORMAT_SET_COUNT; ++i) pf->bits[i] = 0; }
/* currently unused */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L461-L466
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
format_unset
static int format_unset(format_list *pf, png_uint_32 format) { if (format < FORMAT_COUNT) return pf->bits[format >> 5] &= ~((png_uint_32)1) << (format & 31); return 0; }
/* currently unused */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L488-L494
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
newimage
static void newimage(Image *image) { memset(image, 0, sizeof *image); }
/* Initializer: also sets the permitted error limit for 16-bit operations. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L558-L562
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
resetimage
static void resetimage(Image *image) { if (image->input_file != NULL) rewind(image->input_file); }
/* Reset the image to be read again - only needs to rewind the FILE* at present. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L566-L571
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
freebuffer
static void freebuffer(Image *image) { if (image->buffer) free(image->buffer); image->buffer = NULL; image->bufsize = 0; image->allocsize = 0; }
/* Free the image buffer; the buffer is re-used on a re-read, this is just for * cleanup. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L576-L583
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
freeimage
static void freeimage(Image *image) { freebuffer(image); png_image_free(&image->image); if (image->input_file != NULL) { fclose(image->input_file); image->input_file = NULL; } if (image->input_memory != NULL) { free(image->input_memory); image->input_memory = NULL; image->input_memory_size = 0; } if (image->tmpfile_name[0] != 0 && (image->opts & KEEP_TMPFILES) == 0) { remove(image->tmpfile_name); image->tmpfile_name[0] = 0; } }
/* Delete function; cleans out all the allocated data and the temporary file in * the image. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L588-L612
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
initimage
static void initimage(Image *image, png_uint_32 opts, const char *file_name, int stride_extra) { freeimage(image); memset(&image->image, 0, sizeof image->image); image->opts = opts; image->file_name = file_name; image->stride_extra = stride_extra; }
/* This is actually a re-initializer; allows an image structure to be re-used by * freeing everything that relates to an old image. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L617-L625
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
check16
static int check16(png_const_bytep bp, int b) { int i = 16; do if (*bp != b) return 1; while (--i); return 0; }
/* Make sure 16 bytes match the given byte. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L657-L667
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
checkbuffer
static void checkbuffer(Image *image, const char *arg) { if (check16(image->buffer, 95)) { fflush(stdout); fprintf(stderr, "%s: overwrite at start of image buffer\n", arg); exit(1); } if (check16(image->buffer+16+image->allocsize, 95)) { fflush(stdout); fprintf(stderr, "%s: overwrite at end of image buffer\n", arg); exit(1); } }
/* Check for overwrite in the image buffer. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L670-L686
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
logerror
static int logerror(Image *image, const char *a1, const char *a2, const char *a3) { fflush(stdout); if (image->image.warning_or_error) fprintf(stderr, "%s%s%s: %s\n", a1, a2, a3, image->image.message); else fprintf(stderr, "%s%s%s\n", a1, a2, a3); if (image->image.opaque != NULL) { fprintf(stderr, "%s: image opaque pointer non-NULL on error\n", image->file_name); png_image_free(&image->image); } return 0; }
/* ERROR HANDLING */ /* Log a terminal error, also frees the libpng part of the image if necessary. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L691-L709
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
logclose
static int logclose(Image *image, FILE *f, const char *name, const char *operation) { int e = errno; fclose(f); return logerror(image, name, operation, strerror(e)); }
/* Log an error and close a file (just a utility to do both things in one * function call.) */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L714-L721
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
checkopaque
static int checkopaque(Image *image) { if (image->image.opaque != NULL) { png_image_free(&image->image); return logerror(image, image->file_name, ": opaque not NULL", ""); } else if (image->image.warning_or_error != 0 && (image->opts & STRICT) != 0) return logerror(image, image->file_name, " --strict", ""); else return 1; }
/* Make sure the png_image has been freed - validates that libpng is doing what * the spec says and freeing the image. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L726-L740
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gp_g8
static void gp_g8(Pixel *p, png_const_voidp pb) { png_const_bytep pp = voidcast(png_const_bytep, pb); p->r = p->g = p->b = pp[0]; p->a = 255; }
/* Read a Pixel from a buffer. The code below stores the correct routine for * the format in a function pointer, these are the routines: */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L771-L778
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_noop
static void gpc_noop(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = in->r; out->g = in->g; out->b = in->b; out->a = in->a; }
/* Convertion between pixel formats. The code above effectively eliminates the * component ordering changes leaving three basic changes: * * 1) Remove an alpha channel by pre-multiplication or compositing on a * background color. (Adding an alpha channel is a no-op.) * * 2) Remove color by mapping to grayscale. (Grayscale to color is a no-op.) * * 3) Convert between 8-bit and 16-bit components. (Both directtions are * relevant.) * * This gives the following base format conversion matrix: * * OUT: ----- 8-bit ----- ----- 16-bit ----- * IN G GA RGB RGBA G GA RGB RGBA * 8 G . . . . lin lin lin lin * 8 GA bckg . bckc . pre' pre pre' pre * 8 RGB g8 g8 . . glin glin lin lin * 8 RGBA g8b g8 bckc . gpr' gpre pre' pre * 16 G sRGB sRGB sRGB sRGB . . . . * 16 GA b16g unpg b16c unpc A . A . * 16 RGB sG sG sRGB sRGB g16 g16 . . * 16 RGBA gb16 sGp cb16 sCp g16 g16' A . * * 8-bit to 8-bit: * bckg: composite on gray background * bckc: composite on color background * g8: convert sRGB components to sRGB grayscale * g8b: convert sRGB components to grayscale and composite on gray background * * 8-bit to 16-bit: * lin: make sRGB components linear, alpha := 65535 * pre: make sRGB components linear and premultiply by alpha (scale alpha) * pre': as 'pre' but alpha := 65535 * glin: make sRGB components linear, convert to grayscale, alpha := 65535 * gpre: make sRGB components grayscale and linear and premultiply by alpha * gpr': as 'gpre' but alpha := 65535 * * 16-bit to 8-bit: * sRGB: convert linear components to sRGB, alpha := 255 * unpg: unpremultiply gray component and convert to sRGB (scale alpha) * unpc: unpremultiply color components and convert to sRGB (scale alpha) * b16g: composite linear onto gray background and convert the result to sRGB * b16c: composite linear onto color background and convert the result to sRGB * sG: convert linear RGB to sRGB grayscale * sGp: unpremultiply RGB then convert to sRGB grayscale * sCp: unpremultiply RGB then convert to sRGB * gb16: composite linear onto background and convert to sRGB grayscale * (order doesn't matter, the composite and grayscale operations permute) * cb16: composite linear onto background and convert to sRGB * * 16-bit to 16-bit: * A: set alpha to 65535 * g16: convert linear RGB to linear grayscale (alpha := 65535) * g16': as 'g16' but alpha is unchanged */ /* Simple copy: */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1125-L1133
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_bckg
static void gpc_bckg(Pixel *out, const Pixel *in, const Background *back) { if (in->a <= 0) out->r = out->g = out->b = back->ig; else if (in->a >= 255) out->r = out->g = out->b = in->g; else { double a = in->a / 255.; out->r = out->g = out->b = sRGB(sRGB_to_d[in->g] * a + back->dg * (1-a)); } out->a = 255; }
/* 8-bit to 8-bit conversions */ /* bckg: composite on gray background */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1175-L1192
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_bckc
static void gpc_bckc(Pixel *out, const Pixel *in, const Background *back) { if (in->a <= 0) { out->r = back->ir; out->g = back->ig; out->b = back->ib; } else if (in->a >= 255) { out->r = in->r; out->g = in->g; out->b = in->b; } else { double a = in->a / 255.; out->r = sRGB(sRGB_to_d[in->r] * a + back->dr * (1-a)); out->g = sRGB(sRGB_to_d[in->g] * a + back->dg * (1-a)); out->b = sRGB(sRGB_to_d[in->b] * a + back->db * (1-a)); } out->a = 255; }
/* bckc: composite on color background */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1195-L1222
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_g8
static void gpc_g8(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->r == in->g && in->g == in->b) out->r = out->g = out->b = in->g; else out->r = out->g = out->b = sRGB(YfromRGB(sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); out->a = in->a; }
/* g8: convert sRGB components to sRGB grayscale */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1225-L1238
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_g8b
static void gpc_g8b(Pixel *out, const Pixel *in, const Background *back) { if (in->a <= 0) out->r = out->g = out->b = back->ig; else if (in->a >= 255) { if (in->r == in->g && in->g == in->b) out->r = out->g = out->b = in->g; else out->r = out->g = out->b = sRGB(YfromRGB( sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); } else { double a = in->a/255.; out->r = out->g = out->b = sRGB(a * YfromRGB(sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b]) + back->dg * (1-a)); } out->a = 255; }
/* g8b: convert sRGB components to grayscale and composite on gray background */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1241-L1266
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_lin
static void gpc_lin(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = ilinear(in->r); if (in->g == in->r) { out->g = out->r; if (in->b == in->r) out->b = out->r; else out->b = ilinear(in->b); } else { out->g = ilinear(in->g); if (in->b == in->r) out->b = out->r; else if (in->b == in->g) out->b = out->g; else out->b = ilinear(in->b); } out->a = 65535; }
/* 8-bit to 16-bit conversions */ /* lin: make sRGB components linear, alpha := 65535 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1270-L1303
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_pre
static void gpc_pre(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = ilineara(in->r, in->a); if (in->g == in->r) { out->g = out->r; if (in->b == in->r) out->b = out->r; else out->b = ilineara(in->b, in->a); } else { out->g = ilineara(in->g, in->a); if (in->b == in->r) out->b = out->r; else if (in->b == in->g) out->b = out->g; else out->b = ilineara(in->b, in->a); } out->a = in->a * 257; }
/* pre: make sRGB components linear and premultiply by alpha (scale alpha) */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1306-L1339
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_preq
static void gpc_preq(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = ilineara(in->r, in->a); if (in->g == in->r) { out->g = out->r; if (in->b == in->r) out->b = out->r; else out->b = ilineara(in->b, in->a); } else { out->g = ilineara(in->g, in->a); if (in->b == in->r) out->b = out->r; else if (in->b == in->g) out->b = out->g; else out->b = ilineara(in->b, in->a); } out->a = 65535; }
/* pre': as 'pre' but alpha := 65535 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1342-L1375
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_glin
static void gpc_glin(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->r == in->g && in->g == in->b) out->r = out->g = out->b = ilinear(in->g); else out->r = out->g = out->b = u16d(65535 * YfromRGB(sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); out->a = 65535; }
/* glin: make sRGB components linear, convert to grayscale, alpha := 65535 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1378-L1391
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_gpre
static void gpc_gpre(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->r == in->g && in->g == in->b) out->r = out->g = out->b = ilineara(in->g, in->a); else out->r = out->g = out->b = u16d(in->a * 257 * YfromRGB(sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); out->a = 257 * in->a; }
/* gpre: make sRGB components grayscale and linear and premultiply by alpha */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1394-L1407
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_gprq
static void gpc_gprq(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->r == in->g && in->g == in->b) out->r = out->g = out->b = ilineara(in->g, in->a); else out->r = out->g = out->b = u16d(in->a * 257 * YfromRGB(sRGB_to_d[in->r], sRGB_to_d[in->g], sRGB_to_d[in->b])); out->a = 65535; }
/* gpr': as 'gpre' but alpha := 65535 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1410-L1423
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_Lin
static void gpc_Lin(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = ilinear_g22(in->r); if (in->g == in->r) { out->g = out->r; if (in->b == in->r) out->b = out->r; else out->b = ilinear_g22(in->b); } else { out->g = ilinear_g22(in->g); if (in->b == in->r) out->b = out->r; else if (in->b == in->g) out->b = out->g; else out->b = ilinear_g22(in->b); } out->a = 65535; }
/* 8-bit to 16-bit conversions for gAMA 45455 encoded values */ /* Lin: make gAMA 45455 components linear, alpha := 65535 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1427-L1460
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_Pre
static void gpc_Pre(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = ilineara_g22(in->r, in->a); if (in->g == in->r) { out->g = out->r; if (in->b == in->r) out->b = out->r; else out->b = ilineara_g22(in->b, in->a); } else { out->g = ilineara_g22(in->g, in->a); if (in->b == in->r) out->b = out->r; else if (in->b == in->g) out->b = out->g; else out->b = ilineara_g22(in->b, in->a); } out->a = in->a * 257; }
/* Pre: make gAMA 45455 components linear and premultiply by alpha (scale alpha) */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1465-L1498
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_Preq
static void gpc_Preq(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = ilineara_g22(in->r, in->a); if (in->g == in->r) { out->g = out->r; if (in->b == in->r) out->b = out->r; else out->b = ilineara_g22(in->b, in->a); } else { out->g = ilineara_g22(in->g, in->a); if (in->b == in->r) out->b = out->r; else if (in->b == in->g) out->b = out->g; else out->b = ilineara_g22(in->b, in->a); } out->a = 65535; }
/* Pre': as 'Pre' but alpha := 65535 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1503-L1536
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_Glin
static void gpc_Glin(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->r == in->g && in->g == in->b) out->r = out->g = out->b = ilinear_g22(in->g); else out->r = out->g = out->b = u16d(65535 * YfromRGB(g22_to_d[in->r], g22_to_d[in->g], g22_to_d[in->b])); out->a = 65535; }
/* Glin: make gAMA 45455 components linear, convert to grayscale, alpha := 65535 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1542-L1555
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_Gpre
static void gpc_Gpre(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->r == in->g && in->g == in->b) out->r = out->g = out->b = ilineara_g22(in->g, in->a); else out->r = out->g = out->b = u16d(in->a * 257 * YfromRGB(g22_to_d[in->r], g22_to_d[in->g], g22_to_d[in->b])); out->a = 257 * in->a; }
/* Gpre: make gAMA 45455 components grayscale and linear and premultiply by * alpha. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1562-L1575
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_Gprq
static void gpc_Gprq(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->r == in->g && in->g == in->b) out->r = out->g = out->b = ilineara_g22(in->g, in->a); else out->r = out->g = out->b = u16d(in->a * 257 * YfromRGB(g22_to_d[in->r], g22_to_d[in->g], g22_to_d[in->b])); out->a = 65535; }
/* Gpr': as 'Gpre' but alpha := 65535 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1580-L1593
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_sRGB
static void gpc_sRGB(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = isRGB(in->r); if (in->g == in->r) { out->g = out->r; if (in->b == in->r) out->b = out->r; else out->b = isRGB(in->b); } else { out->g = isRGB(in->g); if (in->b == in->r) out->b = out->r; else if (in->b == in->g) out->b = out->g; else out->b = isRGB(in->b); } out->a = 255; }
/* 16-bit to 8-bit conversions */ /* sRGB: convert linear components to sRGB, alpha := 255 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1598-L1631
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_unpg
static void gpc_unpg(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->a <= 128) { out->r = out->g = out->b = 255; out->a = 0; } else { out->r = out->g = out->b = sRGB((double)in->g / in->a); out->a = u8d(in->a / 257.); } }
/* unpg: unpremultiply gray component and convert to sRGB (scale alpha) */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1634-L1650
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_unpc
static void gpc_unpc(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->a <= 128) { out->r = out->g = out->b = 255; out->a = 0; } else { out->r = sRGB((double)in->r / in->a); out->g = sRGB((double)in->g / in->a); out->b = sRGB((double)in->b / in->a); out->a = u8d(in->a / 257.); } }
/* unpc: unpremultiply color components and convert to sRGB (scale alpha) */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1653-L1671
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_b16g
static void gpc_b16g(Pixel *out, const Pixel *in, const Background *back) { if (in->a <= 0) out->r = out->g = out->b = back->ig; else { double a = in->a/65535.; double a1 = 1-a; a /= 65535; out->r = out->g = out->b = sRGB(in->g * a + back->dg * a1); } out->a = 255; }
/* b16g: composite linear onto gray background and convert the result to sRGB */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1674-L1690
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_b16c
static void gpc_b16c(Pixel *out, const Pixel *in, const Background *back) { if (in->a <= 0) { out->r = back->ir; out->g = back->ig; out->b = back->ib; } else { double a = in->a/65535.; double a1 = 1-a; a /= 65535; out->r = sRGB(in->r * a + back->dr * a1); out->g = sRGB(in->g * a + back->dg * a1); out->b = sRGB(in->b * a + back->db * a1); } out->a = 255; }
/* b16c: composite linear onto color background and convert the result to sRGB*/
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1693-L1715
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_sG
static void gpc_sG(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = out->g = out->b = sRGB(YfromRGBint(in->r, in->g, in->b)/65535); out->a = 255; }
/* sG: convert linear RGB to sRGB grayscale */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1718-L1725
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_sGp
static void gpc_sGp(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->a <= 128) { out->r = out->g = out->b = 255; out->a = 0; } else { out->r = out->g = out->b = sRGB(YfromRGBint(in->r, in->g, in->b)/in->a); out->a = u8d(in->a / 257.); } }
/* sGp: unpremultiply RGB then convert to sRGB grayscale */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1728-L1744
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_sCp
static void gpc_sCp(Pixel *out, const Pixel *in, const Background *back) { (void)back; if (in->a <= 128) { out->r = out->g = out->b = 255; out->a = 0; } else { out->r = sRGB((double)in->r / in->a); out->g = sRGB((double)in->g / in->a); out->b = sRGB((double)in->b / in->a); out->a = u8d(in->a / 257.); } }
/* sCp: unpremultiply RGB then convert to sRGB */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1747-L1765
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_gb16
static void gpc_gb16(Pixel *out, const Pixel *in, const Background *back) { if (in->a <= 0) out->r = out->g = out->b = back->ig; else if (in->a >= 65535) out->r = out->g = out->b = isRGB(in->g); else { double a = in->a / 65535.; double a1 = 1-a; a /= 65535; out->r = out->g = out->b = sRGB(in->g * a + back->dg * a1); } out->a = 255; }
/* gb16: composite linear onto background and convert to sRGB grayscale */ /* (order doesn't matter, the composite and grayscale operations permute) */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1769-L1788
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_cb16
static void gpc_cb16(Pixel *out, const Pixel *in, const Background *back) { if (in->a <= 0) { out->r = back->ir; out->g = back->ig; out->b = back->ib; } else if (in->a >= 65535) { out->r = isRGB(in->r); out->g = isRGB(in->g); out->b = isRGB(in->b); } else { double a = in->a / 65535.; double a1 = 1-a; a /= 65535; out->r = sRGB(in->r * a + back->dr * a1); out->g = sRGB(in->g * a + back->dg * a1); out->b = sRGB(in->b * a + back->db * a1); } out->a = 255; }
/* cb16: composite linear onto background and convert to sRGB */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1791-L1820
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_A
static void gpc_A(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = in->r; out->g = in->g; out->b = in->b; out->a = 65535; }
/* 16-bit to 16-bit conversions */ /* A: set alpha to 65535 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1824-L1832
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_g16
static void gpc_g16(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = out->g = out->b = u16d(YfromRGBint(in->r, in->g, in->b)); out->a = 65535; }
/* g16: convert linear RGB to linear grayscale (alpha := 65535) */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1835-L1841
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gpc_g16q
static void gpc_g16q(Pixel *out, const Pixel *in, const Background *back) { (void)back; out->r = out->g = out->b = u16d(YfromRGBint(in->r, in->g, in->b)); out->a = in->a; }
/* g16': as 'g16' but alpha is unchanged */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L1844-L1850
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
transform_from_formats
static void transform_from_formats(Transform *result, Image *in_image, const Image *out_image, png_const_colorp background, int via_linear) { png_uint_32 in_format, out_format; png_uint_32 in_base, out_base; memset(result, 0, sizeof *result); /* Store the original images for error messages */ result->in_image = in_image; result->out_image = out_image; in_format = in_image->image.format; out_format = out_image->image.format; if (in_format & PNG_FORMAT_FLAG_LINEAR) result->in_opaque = 65535; else result->in_opaque = 255; result->output_8bit = (out_format & PNG_FORMAT_FLAG_LINEAR) == 0; result->is_palette = 0; /* set by caller if required */ result->accumulate = (in_image->opts & ACCUMULATE) != 0; /* The loaders (which need the ordering information) */ result->in_gp = get_pixel(in_format); result->out_gp = get_pixel(out_format); /* Remove the ordering information: */ in_format &= BASE_FORMATS | PNG_FORMAT_FLAG_COLORMAP; in_base = in_format & BASE_FORMATS; out_format &= BASE_FORMATS | PNG_FORMAT_FLAG_COLORMAP; out_base = out_format & BASE_FORMATS; if (via_linear) { /* Check for an error in this program: */ if (out_format & (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLORMAP)) { fprintf(stderr, "internal transform via linear error 0x%x->0x%x\n", in_format, out_format); exit(1); } result->transform = gpc_fn[in_base][out_base | PNG_FORMAT_FLAG_LINEAR]; result->from_linear = gpc_fn[out_base | PNG_FORMAT_FLAG_LINEAR][out_base]; result->error_ptr = gpc_error_via_linear[in_format][out_format]; } else if (~in_format & out_format & PNG_FORMAT_FLAG_COLORMAP) { /* The input is not colormapped but the output is, the errors will * typically be large (only the grayscale-no-alpha case permits preserving * even 8-bit values.) */ result->transform = gpc_fn[in_base][out_base]; result->from_linear = NULL; result->error_ptr = gpc_error_to_colormap[in_base][out_base]; } else { /* The caller handles the colormap->pixel value conversion, so the * transform function just gets a pixel value, however because libpng * currently contains a different implementation for mapping a colormap if * both input and output are colormapped we need different conversion * functions to deal with errors in the libpng implementation. */ if (in_format & out_format & PNG_FORMAT_FLAG_COLORMAP) result->transform = gpc_fn_colormapped[in_base][out_base]; else result->transform = gpc_fn[in_base][out_base]; result->from_linear = NULL; result->error_ptr = gpc_error[in_format][out_format]; } /* Follow the libpng simplified API rules to work out what to pass to the gpc * routines as a background value, if one is not required pass NULL so that * this program crashes in the even of a programming error. */ result->background = NULL; /* default: not required */ /* Rule 1: background only need be supplied if alpha is to be removed */ if (in_format & ~out_format & PNG_FORMAT_FLAG_ALPHA) { /* The input value is 'NULL' to use the background and (otherwise) an sRGB * background color (to use a solid color). The code above uses a fixed * byte value, BUFFER_INIT8, for buffer even for 16-bit output. For * linear (16-bit) output the sRGB background color is ignored; the * composition is always on the background (so BUFFER_INIT8 * 257), except * that for the colormap (i.e. linear colormapped output) black is used. */ result->background = &result->background_color; if (out_format & PNG_FORMAT_FLAG_LINEAR || via_linear) { if (out_format & PNG_FORMAT_FLAG_COLORMAP) { result->background_color.ir = result->background_color.ig = result->background_color.ib = 0; result->background_color.dr = result->background_color.dg = result->background_color.db = 0; } else { result->background_color.ir = result->background_color.ig = result->background_color.ib = BUFFER_INIT8 * 257; result->background_color.dr = result->background_color.dg = result->background_color.db = 0; } } else /* sRGB output */ { if (background != NULL) { if (out_format & PNG_FORMAT_FLAG_COLOR) { result->background_color.ir = background->red; result->background_color.ig = background->green; result->background_color.ib = background->blue; /* TODO: sometimes libpng uses the power law conversion here, how * to handle this? */ result->background_color.dr = sRGB_to_d[background->red]; result->background_color.dg = sRGB_to_d[background->green]; result->background_color.db = sRGB_to_d[background->blue]; } else /* grayscale: libpng only looks at 'g' */ { result->background_color.ir = result->background_color.ig = result->background_color.ib = background->green; /* TODO: sometimes libpng uses the power law conversion here, how * to handle this? */ result->background_color.dr = result->background_color.dg = result->background_color.db = sRGB_to_d[background->green]; } } else if ((out_format & PNG_FORMAT_FLAG_COLORMAP) == 0) { result->background_color.ir = result->background_color.ig = result->background_color.ib = BUFFER_INIT8; /* TODO: sometimes libpng uses the power law conversion here, how * to handle this? */ result->background_color.dr = result->background_color.dg = result->background_color.db = sRGB_to_d[BUFFER_INIT8]; } /* Else the output is colormapped and a background color must be * provided; if pngstest crashes then that is a bug in this program * (though libpng should png_error as well.) */ else result->background = NULL; } } if (result->background == NULL) { result->background_color.ir = result->background_color.ig = result->background_color.ib = -1; /* not used */ result->background_color.dr = result->background_color.dg = result->background_color.db = 1E30; /* not used */ } /* Copy the error values into the Transform: */ result->error[0] = result->error_ptr[0]; result->error[1] = result->error_ptr[1]; result->error[2] = result->error_ptr[2]; result->error[3] = result->error_ptr[3]; }
/* Return a 'transform' as above for the given format conversion. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L2134-L2322
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
init_error_via_linear
static void init_error_via_linear(void) { int alpha; error_via_linear[0] = 255; /* transparent pixel */ for (alpha=1; alpha<=255; ++alpha) { /* 16-bit values less than 128.5 get rounded to 8-bit 0 and so the worst * case error arises with 16-bit 128.5, work out what sRGB * (non-associated) value generates 128.5; any value less than this is * going to map to 0, so the worst error is floor(value). * * Note that errors are considerably higher (more than a factor of 2) * because libpng uses a simple power law for sRGB data at present. * * Add .1 for arithmetic errors inside libpng. */ double v = floor(255*pow(.5/*(128.5 * 255 / 65535)*/ / alpha, 1/2.2)+.1); error_via_linear[alpha] = (int)v; } /* This is actually 14.99, but, despite the closeness to 15, 14 seems to work * ok in this case. */ error_in_libpng_gamma = 14; }
/* Indexed by 8-bit alpha */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L2356-L2384
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
compare_two_images
static int compare_two_images(Image *a, Image *b, int via_linear, png_const_colorp background) { ptrdiff_t stridea = a->stride; ptrdiff_t strideb = b->stride; png_const_bytep rowa = a->buffer+16; png_const_bytep rowb = b->buffer+16; const png_uint_32 width = a->image.width; const png_uint_32 height = a->image.height; const png_uint_32 formata = a->image.format; const png_uint_32 formatb = b->image.format; const unsigned int a_sample = PNG_IMAGE_SAMPLE_SIZE(formata); const unsigned int b_sample = PNG_IMAGE_SAMPLE_SIZE(formatb); int alpha_added, alpha_removed; int bchannels; int btoa[4]; png_uint_32 y; Transform tr; /* This should never happen: */ if (width != b->image.width || height != b->image.height) return logerror(a, a->file_name, ": width x height changed: ", b->file_name); /* Set up the background and the transform */ transform_from_formats(&tr, a, b, background, via_linear); /* Find the first row and inter-row space. */ if (!(formata & PNG_FORMAT_FLAG_COLORMAP) && (formata & PNG_FORMAT_FLAG_LINEAR)) stridea *= 2; if (!(formatb & PNG_FORMAT_FLAG_COLORMAP) && (formatb & PNG_FORMAT_FLAG_LINEAR)) strideb *= 2; if (stridea < 0) rowa += (height-1) * (-stridea); if (strideb < 0) rowb += (height-1) * (-strideb); /* First shortcut the two colormap case by comparing the image data; if it * matches then we expect the colormaps to match, although this is not * absolutely necessary for an image match. If the colormaps fail to match * then there is a problem in libpng. */ if (formata & formatb & PNG_FORMAT_FLAG_COLORMAP) { /* Only check colormap entries that actually exist; */ png_const_bytep ppa, ppb; int match; png_byte in_use[256], amax = 0, bmax = 0; memset(in_use, 0, sizeof in_use); ppa = rowa; ppb = rowb; /* Do this the slow way to accumulate the 'in_use' flags, don't break out * of the loop until the end; this validates the color-mapped data to * ensure all pixels are valid color-map indexes. */ for (y=0, match=1; y<height && match; ++y, ppa += stridea, ppb += strideb) { png_uint_32 x; for (x=0; x<width; ++x) { png_byte bval = ppb[x]; png_byte aval = ppa[x]; if (bval > bmax) bmax = bval; if (bval != aval) match = 0; in_use[aval] = 1; if (aval > amax) amax = aval; } } /* If the buffers match then the colormaps must too. */ if (match) { /* Do the color-maps match, entry by entry? Only check the 'in_use' * entries. An error here should be logged as a color-map error. */ png_const_bytep a_cmap = (png_const_bytep)a->colormap; png_const_bytep b_cmap = (png_const_bytep)b->colormap; int result = 1; /* match by default */ /* This is used in logpixel to get the error message correct. */ tr.is_palette = 1; for (y=0; y<256; ++y, a_cmap += a_sample, b_cmap += b_sample) if (in_use[y]) { /* The colormap entries should be valid, but because libpng doesn't * do any checking at present the original image may contain invalid * pixel values. These cause an error here (at present) unless * accumulating errors in which case the program just ignores them. */ if (y >= a->image.colormap_entries) { if ((a->opts & ACCUMULATE) == 0) { char pindex[9]; sprintf(pindex, "%lu[%lu]", (unsigned long)y, (unsigned long)a->image.colormap_entries); logerror(a, a->file_name, ": bad pixel index: ", pindex); } result = 0; } else if (y >= b->image.colormap_entries) { if ((a->opts & ACCUMULATE) == 0) { char pindex[9]; sprintf(pindex, "%lu[%lu]", (unsigned long)y, (unsigned long)b->image.colormap_entries); logerror(b, b->file_name, ": bad pixel index: ", pindex); } result = 0; } /* All the mismatches are logged here; there can only be 256! */ else if (!cmppixel(&tr, a_cmap, b_cmap, 0, y)) result = 0; } /* If reqested copy the error values back from the Transform. */ if (a->opts & ACCUMULATE) { tr.error_ptr[0] = tr.error[0]; tr.error_ptr[1] = tr.error[1]; tr.error_ptr[2] = tr.error[2]; tr.error_ptr[3] = tr.error[3]; result = 1; /* force a continue */ } return result; } /* else the image buffers don't match pixel-wise so compare sample values * instead, but first validate that the pixel indexes are in range (but * only if not accumulating, when the error is ignored.) */ else if ((a->opts & ACCUMULATE) == 0) { /* Check the original image first, * TODO: deal with input images with bad pixel values? */ if (amax >= a->image.colormap_entries) { char pindex[9]; sprintf(pindex, "%d[%lu]", amax, (unsigned long)a->image.colormap_entries); return logerror(a, a->file_name, ": bad pixel index: ", pindex); } else if (bmax >= b->image.colormap_entries) { char pindex[9]; sprintf(pindex, "%d[%lu]", bmax, (unsigned long)b->image.colormap_entries); return logerror(b, b->file_name, ": bad pixel index: ", pindex); } } } /* We can directly compare pixel values without the need to use the read * or transform support (i.e. a memory compare) if: * * 1) The bit depth has not changed. * 2) RGB to grayscale has not been done (the reverse is ok; we just compare * the three RGB values to the original grayscale.) * 3) An alpha channel has not been removed from an 8-bit format, or the * 8-bit alpha value of the pixel was 255 (opaque). * * If an alpha channel has been *added* then it must have the relevant opaque * value (255 or 65535). * * The fist two the tests (in the order given above) (using the boolean * equivalence !a && !b == !(a || b)) */ if (!(((formata ^ formatb) & PNG_FORMAT_FLAG_LINEAR) | (formata & (formatb ^ PNG_FORMAT_FLAG_COLOR) & PNG_FORMAT_FLAG_COLOR))) { /* Was an alpha channel changed? */ const png_uint_32 alpha_changed = (formata ^ formatb) & PNG_FORMAT_FLAG_ALPHA; /* Was an alpha channel removed? (The third test.) If so the direct * comparison is only possible if the input alpha is opaque. */ alpha_removed = (formata & alpha_changed) != 0; /* Was an alpha channel added? */ alpha_added = (formatb & alpha_changed) != 0; /* The channels may have been moved between input and output, this finds * out how, recording the result in the btoa array, which says where in * 'a' to find each channel of 'b'. If alpha was added then btoa[alpha] * ends up as 4 (and is not used.) */ { int i; png_byte aloc[4]; png_byte bloc[4]; /* The following are used only if the formats match, except that * 'bchannels' is a flag for matching formats. btoa[x] says, for each * channel in b, where to find the corresponding value in a, for the * bchannels. achannels may be different for a gray to rgb transform * (a will be 1 or 2, b will be 3 or 4 channels.) */ (void)component_loc(aloc, formata); bchannels = component_loc(bloc, formatb); /* Hence the btoa array. */ for (i=0; i<4; ++i) if (bloc[i] < 4) btoa[bloc[i]] = aloc[i]; /* may be '4' for alpha */ if (alpha_added) alpha_added = bloc[0]; /* location of alpha channel in image b */ else alpha_added = 4; /* Won't match an image b channel */ if (alpha_removed) alpha_removed = aloc[0]; /* location of alpha channel in image a */ else alpha_removed = 4; } } else { /* Direct compare is not possible, cancel out all the corresponding local * variables. */ bchannels = 0; alpha_removed = alpha_added = 4; btoa[3] = btoa[2] = btoa[1] = btoa[0] = 4; /* 4 == not present */ } for (y=0; y<height; ++y, rowa += stridea, rowb += strideb) { png_const_bytep ppa, ppb; png_uint_32 x; for (x=0, ppa=rowa, ppb=rowb; x<width; ++x) { png_const_bytep psa, psb; if (formata & PNG_FORMAT_FLAG_COLORMAP) psa = (png_const_bytep)a->colormap + a_sample * *ppa++; else psa = ppa, ppa += a_sample; if (formatb & PNG_FORMAT_FLAG_COLORMAP) psb = (png_const_bytep)b->colormap + b_sample * *ppb++; else psb = ppb, ppb += b_sample; /* Do the fast test if possible. */ if (bchannels) { /* Check each 'b' channel against either the corresponding 'a' * channel or the opaque alpha value, as appropriate. If * alpha_removed value is set (not 4) then also do this only if the * 'a' alpha channel (alpha_removed) is opaque; only relevant for * the 8-bit case. */ if (formatb & PNG_FORMAT_FLAG_LINEAR) /* 16-bit checks */ { png_const_uint_16p pua = aligncastconst(png_const_uint_16p, psa); png_const_uint_16p pub = aligncastconst(png_const_uint_16p, psb); switch (bchannels) { case 4: if (pua[btoa[3]] != pub[3]) break; case 3: if (pua[btoa[2]] != pub[2]) break; case 2: if (pua[btoa[1]] != pub[1]) break; case 1: if (pua[btoa[0]] != pub[0]) break; if (alpha_added != 4 && pub[alpha_added] != 65535) break; continue; /* x loop */ default: break; /* impossible */ } } else if (alpha_removed == 4 || psa[alpha_removed] == 255) { switch (bchannels) { case 4: if (psa[btoa[3]] != psb[3]) break; case 3: if (psa[btoa[2]] != psb[2]) break; case 2: if (psa[btoa[1]] != psb[1]) break; case 1: if (psa[btoa[0]] != psb[0]) break; if (alpha_added != 4 && psb[alpha_added] != 255) break; continue; /* x loop */ default: break; /* impossible */ } } } /* If we get to here the fast match failed; do the slow match for this * pixel. */ if (!cmppixel(&tr, psa, psb, x, y) && (a->opts & KEEP_GOING) == 0) return 0; /* error case */ } } /* If reqested copy the error values back from the Transform. */ if (a->opts & ACCUMULATE) { tr.error_ptr[0] = tr.error[0]; tr.error_ptr[1] = tr.error[1]; tr.error_ptr[2] = tr.error[2]; tr.error_ptr[3] = tr.error[3]; } return 1; }
/* Compare two images, the original 'a', which was written out then read back in * to * give image 'b'. The formats may have been changed. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L2665-L3002
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
read_file
static int read_file(Image *image, png_uint_32 format, png_const_colorp background) { memset(&image->image, 0, sizeof image->image); image->image.version = PNG_IMAGE_VERSION; if (image->input_memory != NULL) { if (!png_image_begin_read_from_memory(&image->image, image->input_memory, image->input_memory_size)) return logerror(image, "memory init: ", image->file_name, ""); } else if (image->input_file != NULL) { if (!png_image_begin_read_from_stdio(&image->image, image->input_file)) return logerror(image, "stdio init: ", image->file_name, ""); } else { if (!png_image_begin_read_from_file(&image->image, image->file_name)) return logerror(image, "file init: ", image->file_name, ""); } /* This must be set after the begin_read call: */ if (image->opts & sRGB_16BIT) image->image.flags |= PNG_IMAGE_FLAG_16BIT_sRGB; /* Have an initialized image with all the data we need plus, maybe, an * allocated file (myfile) or buffer (mybuffer) that need to be freed. */ { int result; png_uint_32 image_format; /* Print both original and output formats. */ image_format = image->image.format; if (image->opts & VERBOSE) { printf("%s %lu x %lu %s -> %s", image->file_name, (unsigned long)image->image.width, (unsigned long)image->image.height, format_names[image_format & FORMAT_MASK], (format & FORMAT_NO_CHANGE) != 0 || image->image.format == format ? "no change" : format_names[format & FORMAT_MASK]); if (background != NULL) printf(" background(%d,%d,%d)\n", background->red, background->green, background->blue); else printf("\n"); fflush(stdout); } /* 'NO_CHANGE' combined with the color-map flag forces the base format * flags to be set on read to ensure that the original representation is * not lost in the pass through a colormap format. */ if ((format & FORMAT_NO_CHANGE) != 0) { if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0 && (image_format & PNG_FORMAT_FLAG_COLORMAP) != 0) format = (image_format & ~BASE_FORMATS) | (format & BASE_FORMATS); else format = image_format; } image->image.format = format; image->stride = PNG_IMAGE_ROW_STRIDE(image->image) + image->stride_extra; allocbuffer(image); result = png_image_finish_read(&image->image, background, image->buffer+16, (png_int_32)image->stride, image->colormap); checkbuffer(image, image->file_name); if (result) return checkopaque(image); else return logerror(image, image->file_name, ": image read failed", ""); } }
/* Read the file; how the read gets done depends on which of input_file and * input_memory have been set. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L3007-L3094
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
read_one_file
static int read_one_file(Image *image) { if (!(image->opts & READ_FILE) || (image->opts & USE_STDIO)) { /* memory or stdio. */ FILE *f = fopen(image->file_name, "rb"); if (f != NULL) { if (image->opts & READ_FILE) image->input_file = f; else /* memory */ { if (fseek(f, 0, SEEK_END) == 0) { long int cb = ftell(f); if (cb > 0 && (unsigned long int)cb < (size_t)~(size_t)0) { png_bytep b = voidcast(png_bytep, malloc((size_t)cb)); if (b != NULL) { rewind(f); if (fread(b, (size_t)cb, 1, f) == 1) { fclose(f); image->input_memory_size = cb; image->input_memory = b; } else { free(b); return logclose(image, f, image->file_name, ": read failed: "); } } else return logclose(image, f, image->file_name, ": out of memory: "); } else if (cb == 0) return logclose(image, f, image->file_name, ": zero length: "); else return logclose(image, f, image->file_name, ": tell failed: "); } else return logclose(image, f, image->file_name, ": seek failed: "); } } else return logerror(image, image->file_name, ": open failed: ", strerror(errno)); } return read_file(image, FORMAT_NO_CHANGE, NULL); }
/* Reads from a filename, which must be in image->file_name, but uses * image->opts to choose the method. The file is always read in its native * format (the one the simplified API suggests). */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L3100-L3167
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
main
int main(void) { fprintf(stderr, "pngstest: no read support in libpng, test skipped\n"); /* So the test is skipped: */ return 77; }
/* !PNG_SIMPLIFIED_READ_SUPPORTED */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngstest.c#L3736-L3741
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
fix
static png_fixed_point fix(double d) { d = floor(d * PNG_FP_1 + .5); return (png_fixed_point)d; }
/* Convert a double precision value to fixed point. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L182-L187
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
row_copy
static void row_copy(png_bytep toBuffer, png_const_bytep fromBuffer, unsigned int bitWidth) { memcpy(toBuffer, fromBuffer, bitWidth >> 3); if ((bitWidth & 7) != 0) { unsigned int mask; toBuffer += bitWidth >> 3; fromBuffer += bitWidth >> 3; /* The remaining bits are in the top of the byte, the mask is the bits to * retain. */ mask = 0xff >> (bitWidth & 7); *toBuffer = (png_byte)((*toBuffer & mask) | (*fromBuffer & ~mask)); } }
/* Copy a complete row of pixels, taking into account potential partial * bytes at the end. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L482-L499
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
pixel_cmp
static int pixel_cmp(png_const_bytep pa, png_const_bytep pb, png_uint_32 bit_width) { #if PNG_LIBPNG_VER < 10506 if (memcmp(pa, pb, bit_width>>3) == 0) { png_uint_32 p; if ((bit_width & 7) == 0) return 0; /* Ok, any differences? */ p = pa[bit_width >> 3]; p ^= pb[bit_width >> 3]; if (p == 0) return 0; /* There are, but they may not be significant, remove the bits * after the end (the low order bits in PNG.) */ bit_width &= 7; p >>= 8-bit_width; if (p == 0) return 0; } #else /* From libpng-1.5.6 the overwrite should be fixed, so compare the trailing * bits too: */ if (memcmp(pa, pb, (bit_width+7)>>3) == 0) return 0; #endif /* Return the index of the changed byte. */ { png_uint_32 where = 0; while (pa[where] == pb[where]) ++where; return 1+where; } }
/* Compare pixels - they are assumed to start at the first byte in the * given buffers. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L504-L543
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
random_32
static png_uint_32 random_32(void) { for(;;) { png_byte mark[4]; png_uint_32 result; store_pool_mark(mark); result = png_get_uint_32(mark); if (result != 0) return result; } }
/* Use this for random 32 bit values; this function makes sure the result is * non-zero. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L659-L674
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
internal_error
static void internal_error(png_store *ps, png_const_charp message) { store_log(ps, NULL, message, 1 /* error */); /* And finally throw an exception. */ { struct exception_context *the_exception_context = &ps->exception_context; Throw ps; } }
/* Internal error function, called with a png_store but no libpng stuff. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L883-L893
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
store_read_buffer_avail
static size_t store_read_buffer_avail(png_store *ps) { if (ps->current != NULL && ps->next != NULL) { png_store_buffer *next = &ps->current->data; size_t cbAvail = ps->current->datacount; while (next != ps->next && next != NULL) { next = next->prev; cbAvail += STORE_BUFFER_SIZE; } if (next != ps->next) png_error(ps->pread, "buffer read error"); if (cbAvail > ps->readpos) return cbAvail - ps->readpos; } return 0; }
/* Return total bytes available for read. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L1111-L1133
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
store_read_imp
static void store_read_imp(png_store *ps, png_bytep pb, png_size_t st) { if (ps->current == NULL || ps->next == NULL) png_error(ps->pread, "store state damaged"); while (st > 0) { size_t cbAvail = store_read_buffer_size(ps) - ps->readpos; if (cbAvail > 0) { if (cbAvail > st) cbAvail = st; memcpy(pb, ps->next->buffer + ps->readpos, cbAvail); st -= cbAvail; pb += cbAvail; ps->readpos += cbAvail; } else if (!store_read_buffer_next(ps)) png_error(ps->pread, "read beyond end of file"); } }
/* Need separate implementation and callback to allow use of the same code * during progressive read, where the io_ptr is set internally by libpng. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L1162-L1184
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
set_store_for_read
static png_structp set_store_for_read(png_store *ps, png_infopp ppi, png_uint_32 id, PNG_CONST char *name) { /* Set the name for png_error */ safecat(ps->test, sizeof ps->test, 0, name); if (ps->pread != NULL) png_error(ps->pread, "read store already in use"); store_read_reset(ps); /* Both the create APIs can return NULL if used in their default mode * (because there is no other way of handling an error because the jmp_buf * by default is stored in png_struct and that has not been allocated!) * However, given that store_error works correctly in these circumstances * we don't ever expect NULL in this program. */ if (ps->speed) ps->pread = png_create_read_struct(PNG_LIBPNG_VER_STRING, ps, store_error, store_warning); else ps->pread = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, ps, store_error, store_warning, &ps->read_memory_pool, store_malloc, store_free); if (ps->pread == NULL) { struct exception_context *the_exception_context = &ps->exception_context; store_log(ps, NULL, "png_create_read_struct returned NULL (unexpected)", 1 /*error*/); Throw ps; } store_read_set(ps, id); if (ppi != NULL) *ppi = ps->piread = png_create_info_struct(ps->pread); return ps->pread; }
/* The main interface for reading a saved file - pass the id number of the file * to retrieve. Ids must be unique or the earlier file will be hidden. The API * returns a png_struct and, optionally, a png_info. Both of these will be * destroyed by store_read_reset above. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L1599-L1642
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
outerr
static double outerr(PNG_CONST png_modifier *pm, int in_depth, int out_depth) { /* There is a serious error in the 2 and 4 bit grayscale transform because * the gamma table value (8 bits) is simply shifted, not rounded, so the * error in 4 bit grayscale gamma is up to the value below. This is a hack * to allow pngvalid to succeed: * * TODO: fix this in libpng */ if (out_depth == 2) return .73182-.5; if (out_depth == 4) return .90644-.5; if (out_depth == 16 && (in_depth == 16 || !pm->calculations_use_input_precision)) return pm->maxout16; /* This is the case where the value was calculated at 8-bit precision then * scaled to 16 bits. */ else if (out_depth == 16) return pm->maxout8 * 257; else return pm->maxout8; }
/* Output error - the error in the encoded value. This is determined by the * digitization of the output so can be +/-0.5 in the actual output value. In * the expand_16 case with the current code in libpng the expand happens after * all the calculations are done in 8 bit arithmetic, so even though the output * depth is 16 the output error is determined by the 8 bit calculation. * * This limit is not determined by the bit depth of internal calculations. * * The specified parameter does *not* include the base .5 digitization error but * it is added here. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2053-L2080
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
outlog
static double outlog(PNG_CONST png_modifier *pm, int in_depth, int out_depth) { /* The command line parameters are either 8 bit (0..255) or 16 bit (0..65535) * and so must be adjusted for low bit depth grayscale: */ if (out_depth <= 8) { if (pm->log8 == 0) /* switched off */ return 256; if (out_depth < 8) return pm->log8 / 255 * ((1<<out_depth)-1); return pm->log8; } if (out_depth == 16 && (in_depth == 16 || !pm->calculations_use_input_precision)) { if (pm->log16 == 0) return 65536; return pm->log16; } /* This is the case where the value was calculated at 8-bit precision then * scaled to 16 bits. */ if (pm->log8 == 0) return 65536; return pm->log8 * 257; }
/* This does the same thing as the above however it returns the value to log, * rather than raising a warning. This is useful for debugging to track down * exactly what set of parameters cause high error values. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2086-L2118
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
output_quantization_factor
static int output_quantization_factor(PNG_CONST png_modifier *pm, int in_depth, int out_depth) { if (out_depth == 16 && in_depth != 16 && pm->calculations_use_input_precision) return 257; else return 1; }
/* This complements the above by providing the appropriate quantization for the * final value. Normally this would just be quantization to an integral value, * but in the 8 bit calculation case it's actually quantization to a multiple of * 257! */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2125-L2133
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
modifier_total_encodings
static unsigned int modifier_total_encodings(PNG_CONST png_modifier *pm) { return 1 + /* (1) nothing */ pm->ngammas + /* (2) gamma values to test */ pm->nencodings + /* (3) total number of encodings */ /* The following test only works after the first time through the * png_modifier code because 'bit_depth' is set when the IHDR is read. * modifier_reset, below, preserves the setting until after it has called * the iterate function (also below.) * * For this reason do not rely on this function outside a call to * modifier_reset. */ ((pm->bit_depth == 16 || pm->assume_16_bit_calculations) ? pm->nencodings : 0); /* (4) encodings with gamma == 1.0 */ }
/* Iterate through the usefully testable color encodings. An encoding is one * of: * * 1) Nothing (no color space, no gamma). * 2) Just a gamma value from the gamma array (including 1.0) * 3) A color space from the encodings array with the corresponding gamma. * 4) The same, but with gamma 1.0 (only really useful with 16 bit calculations) * * The iterator selects these in turn, the randomizer selects one at random, * which is used depends on the setting of the 'test_exhaustive' flag. Notice * that this function changes the colour space encoding so it must only be * called on completion of the previous test. This is what 'modifier_reset' * does, below. * * After the function has been called the 'repeat' flag will still be set; the * caller of modifier_reset must reset it at the start of each run of the test! */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2231-L2247
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
modifier_set_encoding
static void modifier_set_encoding(png_modifier *pm) { /* Set the encoding to the one specified by the current encoding counter, * first clear out all the settings - this corresponds to an encoding_counter * of 0. */ pm->current_gamma = 0; pm->current_encoding = 0; pm->encoding_ignored = 0; /* not ignored yet - happens in _ini functions. */ /* Now, if required, set the gamma and encoding fields. */ if (pm->encoding_counter > 0) { /* The gammas[] array is an array of screen gammas, not encoding gammas, * so we need the inverse: */ if (pm->encoding_counter <= pm->ngammas) pm->current_gamma = 1/pm->gammas[pm->encoding_counter-1]; else { unsigned int i = pm->encoding_counter - pm->ngammas; if (i >= pm->nencodings) { i %= pm->nencodings; pm->current_gamma = 1; /* Linear, only in the 16 bit case */ } else pm->current_gamma = pm->encodings[i].gamma; pm->current_encoding = pm->encodings + i; } } }
/* The following must be called before anything else to get the encoding set up * on the modifier. In particular it must be called before the transform init * functions are called. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2306-L2342
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
modifier_color_encoding_is_sRGB
static int modifier_color_encoding_is_sRGB(PNG_CONST png_modifier *pm) { return pm->current_encoding != 0 && pm->current_encoding == pm->encodings && pm->current_encoding->gamma == pm->current_gamma; }
/* Enquiry functions to find out what is set. Notice that there is an implicit * assumption below that the first encoding in the list is the one for sRGB. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2347-L2352
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
modifier_crc
static void modifier_crc(png_bytep buffer) { /* Recalculate the chunk CRC - a complete chunk must be in * the buffer, at the start. */ uInt datalen = png_get_uint_32(buffer); uLong crc = crc32(0, buffer+4, datalen+4); /* The cast to png_uint_32 is safe because a crc32 is always a 32 bit value. */ png_save_uint_32(buffer+datalen+8, (png_uint_32)crc); }
/* The guts of modification are performed during a read. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2372-L2383
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
modifier_read_imp
static void modifier_read_imp(png_modifier *pm, png_bytep pb, png_size_t st) { while (st > 0) { size_t cb; png_uint_32 len, chunk; png_modification *mod; if (pm->buffer_position >= pm->buffer_count) switch (pm->state) { static png_byte sign[8] = { 137, 80, 78, 71, 13, 10, 26, 10 }; case modifier_start: store_read_imp(&pm->this, pm->buffer, 8); /* size of signature. */ pm->buffer_count = 8; pm->buffer_position = 0; if (memcmp(pm->buffer, sign, 8) != 0) png_error(pm->this.pread, "invalid PNG file signature"); pm->state = modifier_signature; break; case modifier_signature: store_read_imp(&pm->this, pm->buffer, 13+12); /* size of IHDR */ pm->buffer_count = 13+12; pm->buffer_position = 0; if (png_get_uint_32(pm->buffer) != 13 || png_get_uint_32(pm->buffer+4) != CHUNK_IHDR) png_error(pm->this.pread, "invalid IHDR"); /* Check the list of modifiers for modifications to the IHDR. */ mod = pm->modifications; while (mod != NULL) { if (mod->chunk == CHUNK_IHDR && mod->modify_fn && (*mod->modify_fn)(pm, mod, 0)) { mod->modified = 1; modifier_setbuffer(pm); } /* Ignore removal or add if IHDR! */ mod = mod->next; } /* Cache information from the IHDR (the modified one.) */ pm->bit_depth = pm->buffer[8+8]; pm->colour_type = pm->buffer[8+8+1]; pm->state = modifier_IHDR; pm->flush = 0; break; case modifier_IHDR: default: /* Read a new chunk and process it until we see PLTE, IDAT or * IEND. 'flush' indicates that there is still some data to * output from the preceding chunk. */ if ((cb = pm->flush) > 0) { if (cb > st) cb = st; pm->flush -= cb; store_read_imp(&pm->this, pb, cb); pb += cb; st -= cb; if (st == 0) return; } /* No more bytes to flush, read a header, or handle a pending * chunk. */ if (pm->pending_chunk != 0) { png_save_uint_32(pm->buffer, pm->pending_len); png_save_uint_32(pm->buffer+4, pm->pending_chunk); pm->pending_len = 0; pm->pending_chunk = 0; } else store_read_imp(&pm->this, pm->buffer, 8); pm->buffer_count = 8; pm->buffer_position = 0; /* Check for something to modify or a terminator chunk. */ len = png_get_uint_32(pm->buffer); chunk = png_get_uint_32(pm->buffer+4); /* Terminators first, they may have to be delayed for added * chunks */ if (chunk == CHUNK_PLTE || chunk == CHUNK_IDAT || chunk == CHUNK_IEND) { mod = pm->modifications; while (mod != NULL) { if ((mod->add == chunk || (mod->add == CHUNK_PLTE && chunk == CHUNK_IDAT)) && mod->modify_fn != NULL && !mod->modified && !mod->added) { /* Regardless of what the modify function does do not run * this again. */ mod->added = 1; if ((*mod->modify_fn)(pm, mod, 1 /*add*/)) { /* Reset the CRC on a new chunk */ if (pm->buffer_count > 0) modifier_setbuffer(pm); else { pm->buffer_position = 0; mod->removed = 1; } /* The buffer has been filled with something (we assume) * so output this. Pend the current chunk. */ pm->pending_len = len; pm->pending_chunk = chunk; break; /* out of while */ } } mod = mod->next; } /* Don't do any further processing if the buffer was modified - * otherwise the code will end up modifying a chunk that was * just added. */ if (mod != NULL) break; /* out of switch */ } /* If we get to here then this chunk may need to be modified. To * do this it must be less than 1024 bytes in total size, otherwise * it just gets flushed. */ if (len+12 <= sizeof pm->buffer) { store_read_imp(&pm->this, pm->buffer+pm->buffer_count, len+12-pm->buffer_count); pm->buffer_count = len+12; /* Check for a modification, else leave it be. */ mod = pm->modifications; while (mod != NULL) { if (mod->chunk == chunk) { if (mod->modify_fn == NULL) { /* Remove this chunk */ pm->buffer_count = pm->buffer_position = 0; mod->removed = 1; break; /* Terminate the while loop */ } else if ((*mod->modify_fn)(pm, mod, 0)) { mod->modified = 1; /* The chunk may have been removed: */ if (pm->buffer_count == 0) { pm->buffer_position = 0; break; } modifier_setbuffer(pm); } } mod = mod->next; } } else pm->flush = len+12 - pm->buffer_count; /* data + crc */ /* Take the data from the buffer (if there is any). */ break; } /* Here to read from the modifier buffer (not directly from * the store, as in the flush case above.) */ cb = pm->buffer_count - pm->buffer_position; if (cb > st) cb = st; memcpy(pb, pm->buffer + pm->buffer_position, cb); st -= cb; pb += cb; pm->buffer_position += cb; } }
/* Separate the callback into the actual implementation (which is passed the * png_modifier explicitly) and the callback, which gets the modifier from the * png_struct. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2397-L2599
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
modifier_read
static void modifier_read(png_structp ppIn, png_bytep pb, png_size_t st) { png_const_structp pp = ppIn; png_modifier *pm = voidcast(png_modifier*, png_get_io_ptr(pp)); if (pm == NULL || pm->this.pread != pp) png_error(pp, "bad modifier_read call"); modifier_read_imp(pm, pb, st); }
/* The callback: */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2602-L2612
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
modifier_progressive_read
static void modifier_progressive_read(png_modifier *pm, png_structp pp, png_infop pi) { if (pm->this.pread != pp || pm->this.current == NULL || pm->this.next == NULL) png_error(pp, "store state damaged (progressive)"); /* This is another Horowitz and Hill random noise generator. In this case * the aim is to stress the progressive reader with truly horrible variable * buffer sizes in the range 1..500, so a sequence of 9 bit random numbers * is generated. We could probably just count from 1 to 32767 and get as * good a result. */ for (;;) { static png_uint_32 noise = 1; png_size_t cb, cbAvail; png_byte buffer[512]; /* Generate 15 more bits of stuff: */ noise = (noise << 9) | ((noise ^ (noise >> (9-5))) & 0x1ff); cb = noise & 0x1ff; /* Check that this number of bytes are available (in the current buffer.) * (This doesn't quite work - the modifier might delete a chunk; unlikely * but possible, it doesn't happen at present because the modifier only * adds chunks to standard images.) */ cbAvail = store_read_buffer_avail(&pm->this); if (pm->buffer_count > pm->buffer_position) cbAvail += pm->buffer_count - pm->buffer_position; if (cb > cbAvail) { /* Check for EOF: */ if (cbAvail == 0) break; cb = cbAvail; } modifier_read_imp(pm, buffer, cb); png_process_data(pp, pi, buffer, cb); } /* Check the invariants at the end (if this fails it's a problem in this * file!) */ if (pm->buffer_count > pm->buffer_position || pm->this.next != &pm->this.current->data || pm->this.readpos < pm->this.current->datacount) png_error(pp, "progressive read implementation error"); }
/* Like store_progressive_read but the data is getting changed as we go so we * need a local buffer. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2617-L2669
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
set_modifier_for_read
static png_structp set_modifier_for_read(png_modifier *pm, png_infopp ppi, png_uint_32 id, PNG_CONST char *name) { /* Do this first so that the modifier fields are cleared even if an error * happens allocating the png_struct. No allocation is done here so no * cleanup is required. */ pm->state = modifier_start; pm->bit_depth = 0; pm->colour_type = 255; pm->pending_len = 0; pm->pending_chunk = 0; pm->flush = 0; pm->buffer_count = 0; pm->buffer_position = 0; return set_store_for_read(&pm->this, ppi, id, name); }
/* Set up a modifier. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L2672-L2691
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
standard_width
static png_uint_32 standard_width(png_const_structp pp, png_uint_32 id) { png_uint_32 width = WIDTH_FROM_ID(id); UNUSED(pp) if (width == 0) width = transform_width(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)); return width; }
/* The following can only be defined here, now we have the definitions * of the transform image sizes. */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L3175-L3185
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
standard_row
static void standard_row(png_const_structp pp, png_byte std[STANDARD_ROWMAX], png_uint_32 id, png_uint_32 y) { if (WIDTH_FROM_ID(id) == 0) transform_row(pp, std, COL_FROM_ID(id), DEPTH_FROM_ID(id), y); else size_row(std, WIDTH_FROM_ID(id) * bit_size(pp, COL_FROM_ID(id), DEPTH_FROM_ID(id)), y); }
/* Return a row based on image id and 'y' for checking: */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L3783-L3792
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
image_transform_png_set_palette_to_rgb_set
static void image_transform_png_set_palette_to_rgb_set(PNG_CONST image_transform *this, transform_display *that, png_structp pp, png_infop pi) { png_set_palette_to_rgb(pp); this->next->set(this->next, that, pp, pi); }
/* png_set_palette_to_rgb */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L6040-L6046
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
image_transform_png_set_tRNS_to_alpha_set
static void image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this, transform_display *that, png_structp pp, png_infop pi) { png_set_tRNS_to_alpha(pp); this->next->set(this->next, that, pp, pi); }
/* png_set_tRNS_to_alpha */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L6078-L6084
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
image_transform_png_set_gray_to_rgb_set
static void image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this, transform_display *that, png_structp pp, png_infop pi) { png_set_gray_to_rgb(pp); this->next->set(this->next, that, pp, pi); }
/* png_set_gray_to_rgb */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L6136-L6142
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
image_transform_png_set_expand_set
static void image_transform_png_set_expand_set(PNG_CONST image_transform *this, transform_display *that, png_structp pp, png_infop pi) { png_set_expand(pp); this->next->set(this->next, that, pp, pi); }
/* png_set_expand */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L6195-L6201
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
image_transform_png_set_expand_gray_1_2_4_to_8_set
static void image_transform_png_set_expand_gray_1_2_4_to_8_set( PNG_CONST image_transform *this, transform_display *that, png_structp pp, png_infop pi) { png_set_expand_gray_1_2_4_to_8(pp); this->next->set(this->next, that, pp, pi); }
/* png_set_expand_gray_1_2_4_to_8 * LIBPNG BUG: this just does an 'expand' */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L6244-L6251
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
image_transform_png_set_expand_16_set
static void image_transform_png_set_expand_16_set(PNG_CONST image_transform *this, transform_display *that, png_structp pp, png_infop pi) { png_set_expand_16(pp); this->next->set(this->next, that, pp, pi); }
/* png_set_expand_16 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L6276-L6282
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
image_transform_png_set_scale_16_set
static void image_transform_png_set_scale_16_set(PNG_CONST image_transform *this, transform_display *that, png_structp pp, png_infop pi) { png_set_scale_16(pp); this->next->set(this->next, that, pp, pi); }
/* API added in 1.5.4 */ /* png_set_scale_16 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L6324-L6330
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
image_transform_png_set_strip_16_set
static void image_transform_png_set_strip_16_set(PNG_CONST image_transform *this, transform_display *that, png_structp pp, png_infop pi) { png_set_strip_16(pp); this->next->set(this->next, that, pp, pi); }
/* the default before 1.5.4 */ /* png_set_strip_16 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L6368-L6374
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
image_transform_png_set_strip_alpha_set
static void image_transform_png_set_strip_alpha_set(PNG_CONST image_transform *this, transform_display *that, png_structp pp, png_infop pi) { png_set_strip_alpha(pp); this->next->set(this->next, that, pp, pi); }
/* png_set_strip_alpha */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L6435-L6441
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gamma_component_compose
static double gamma_component_compose(int do_background, double input_sample, double alpha, double background, int *compose) { switch (do_background) { #ifdef PNG_READ_BACKGROUND_SUPPORTED case PNG_BACKGROUND_GAMMA_SCREEN: case PNG_BACKGROUND_GAMMA_FILE: case PNG_BACKGROUND_GAMMA_UNIQUE: /* Standard PNG background processing. */ if (alpha < 1) { if (alpha > 0) { input_sample = input_sample * alpha + background * (1-alpha); if (compose != NULL) *compose = 1; } else input_sample = background; } break; #endif #ifdef PNG_READ_ALPHA_MODE_SUPPORTED case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: /* The components are premultiplied in either case and the output is * gamma encoded (to get standard Porter-Duff we expect the output * gamma to be set to 1.0!) */ case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: /* The optimization is that the partial-alpha entries are linear * while the opaque pixels are gamma encoded, but this only affects the * output encoding. */ if (alpha < 1) { if (alpha > 0) { input_sample *= alpha; if (compose != NULL) *compose = 1; } else input_sample = 0; } break; #endif default: /* Standard cases where no compositing is done (so the component * value is already correct.) */ UNUSED(alpha) UNUSED(background) UNUSED(compose) break; } return input_sample; }
/* This function handles composition of a single non-alpha component. The * argument is the input sample value, in the range 0..1, and the alpha value. * The result is the composed, linear, input sample. If alpha is less than zero * this is the alpha component and the function should not be called! */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L7709-L7773
4389085c8ce35cff887a4cc18fc47d1133d89ffb
BigWorld-Engine-14.4.1
github_2023
v2v3v4
c
gamma_component_validate
static double gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi, PNG_CONST unsigned int id, PNG_CONST unsigned int od, PNG_CONST double alpha /* <0 for the alpha channel itself */, PNG_CONST double background /* component background value */) { PNG_CONST unsigned int isbit = id >> vi->isbit_shift; PNG_CONST unsigned int sbit_max = vi->sbit_max; PNG_CONST unsigned int outmax = vi->outmax; PNG_CONST int do_background = vi->do_background; double i; /* First check on the 'perfect' result obtained from the digitized input * value, id, and compare this against the actual digitized result, 'od'. * 'i' is the input result in the range 0..1: */ i = isbit; i /= sbit_max; /* Check for the fast route: if we don't do any background composition or if * this is the alpha channel ('alpha' < 0) or if the pixel is opaque then * just use the gamma_correction field to correct to the final output gamma. */ if (alpha == 1 /* opaque pixel component */ || !do_background #ifdef PNG_READ_ALPHA_MODE_SUPPORTED || do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_PNG #endif || (alpha < 0 /* alpha channel */ #ifdef PNG_READ_ALPHA_MODE_SUPPORTED && do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN #endif )) { /* Then get the gamma corrected version of 'i' and compare to 'od', any * error less than .5 is insignificant - just quantization of the output * value to the nearest digital value (nevertheless the error is still * recorded - it's interesting ;-) */ double encoded_sample = i; double encoded_error; /* alpha less than 0 indicates the alpha channel, which is always linear */ if (alpha >= 0 && vi->gamma_correction > 0) encoded_sample = pow(encoded_sample, vi->gamma_correction); encoded_sample *= outmax; encoded_error = fabs(od-encoded_sample); if (encoded_error > vi->dp->maxerrout) vi->dp->maxerrout = encoded_error; if (encoded_error < vi->maxout_total && encoded_error < vi->outlog) return i; } /* The slow route - attempt to do linear calculations. */ /* There may be an error, or background processing is required, so calculate * the actual sample values - unencoded light intensity values. Note that in * practice these are not completely unencoded because they include a * 'viewing correction' to decrease or (normally) increase the perceptual * contrast of the image. There's nothing we can do about this - we don't * know what it is - so assume the unencoded value is perceptually linear. */ { double input_sample = i; /* In range 0..1 */ double output, error, encoded_sample, encoded_error; double es_lo, es_hi; int compose = 0; /* Set to one if composition done */ int output_is_encoded; /* Set if encoded to screen gamma */ int log_max_error = 1; /* Check maximum error values */ png_const_charp pass = 0; /* Reason test passes (or 0 for fail) */ /* Convert to linear light (with the above caveat.) The alpha channel is * already linear. */ if (alpha >= 0) { int tcompose; if (vi->file_inverse > 0) input_sample = pow(input_sample, vi->file_inverse); /* Handle the compose processing: */ tcompose = 0; input_sample = gamma_component_compose(do_background, input_sample, alpha, background, &tcompose); if (tcompose) compose = 1; } /* And similarly for the output value, but we need to check the background * handling to linearize it correctly. */ output = od; output /= outmax; output_is_encoded = vi->screen_gamma > 0; if (alpha < 0) /* The alpha channel */ { #ifdef PNG_READ_ALPHA_MODE_SUPPORTED if (do_background != ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN) #endif { /* In all other cases the output alpha channel is linear already, * don't log errors here, they are much larger in linear data. */ output_is_encoded = 0; log_max_error = 0; } } #ifdef PNG_READ_ALPHA_MODE_SUPPORTED else /* A component */ { if (do_background == ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED && alpha < 1) /* the optimized case - linear output */ { if (alpha > 0) log_max_error = 0; output_is_encoded = 0; } } #endif if (output_is_encoded) output = pow(output, vi->screen_gamma); /* Calculate (or recalculate) the encoded_sample value and repeat the * check above (unnecessary if we took the fast route, but harmless.) */ encoded_sample = input_sample; if (output_is_encoded) encoded_sample = pow(encoded_sample, vi->screen_inverse); encoded_sample *= outmax; encoded_error = fabs(od-encoded_sample); /* Don't log errors in the alpha channel, or the 'optimized' case, * neither are significant to the overall perception. */ if (log_max_error && encoded_error > vi->dp->maxerrout) vi->dp->maxerrout = encoded_error; if (encoded_error < vi->maxout_total) { if (encoded_error < vi->outlog) return i; /* Test passed but error is bigger than the log limit, record why the * test passed: */ pass = "less than maxout:\n"; } /* i: the original input value in the range 0..1 * * pngvalid calculations: * input_sample: linear result; i linearized and composed, range 0..1 * encoded_sample: encoded result; input_sample scaled to ouput bit depth * * libpng calculations: * output: linear result; od scaled to 0..1 and linearized * od: encoded result from libpng */ /* Now we have the numbers for real errors, both absolute values as as a * percentage of the correct value (output): */ error = fabs(input_sample-output); if (log_max_error && error > vi->dp->maxerrabs) vi->dp->maxerrabs = error; /* The following is an attempt to ignore the tendency of quantization to * dominate the percentage errors for lower result values: */ if (log_max_error && input_sample > .5) { double percentage_error = error/input_sample; if (percentage_error > vi->dp->maxerrpc) vi->dp->maxerrpc = percentage_error; } /* Now calculate the digitization limits for 'encoded_sample' using the * 'max' values. Note that maxout is in the encoded space but maxpc and * maxabs are in linear light space. * * First find the maximum error in linear light space, range 0..1: */ { double tmp = input_sample * vi->maxpc; if (tmp < vi->maxabs) tmp = vi->maxabs; /* If 'compose' is true the composition was done in linear space using * integer arithmetic. This introduces an extra error of +/- 0.5 (at * least) in the integer space used. 'maxcalc' records this, taking * into account the possibility that even for 16 bit output 8 bit space * may have been used. */ if (compose && tmp < vi->maxcalc) tmp = vi->maxcalc; /* The 'maxout' value refers to the encoded result, to compare with * this encode input_sample adjusted by the maximum error (tmp) above. */ es_lo = encoded_sample - vi->maxout; if (es_lo > 0 && input_sample-tmp > 0) { double low_value = input_sample-tmp; if (output_is_encoded) low_value = pow(low_value, vi->screen_inverse); low_value *= outmax; if (low_value < es_lo) es_lo = low_value; /* Quantize this appropriately: */ es_lo = ceil(es_lo / vi->outquant - .5) * vi->outquant; } else es_lo = 0; es_hi = encoded_sample + vi->maxout; if (es_hi < outmax && input_sample+tmp < 1) { double high_value = input_sample+tmp; if (output_is_encoded) high_value = pow(high_value, vi->screen_inverse); high_value *= outmax; if (high_value > es_hi) es_hi = high_value; es_hi = floor(es_hi / vi->outquant + .5) * vi->outquant; } else es_hi = outmax; } /* The primary test is that the final encoded value returned by the * library should be between the two limits (inclusive) that were * calculated above. */ if (od >= es_lo && od <= es_hi) { /* The value passes, but we may need to log the information anyway. */ if (encoded_error < vi->outlog) return i; if (pass == 0) pass = "within digitization limits:\n"; } { /* There has been an error in processing, or we need to log this * value. */ double is_lo, is_hi; /* pass is set at this point if either of the tests above would have * passed. Don't do these additional tests here - just log the * original [es_lo..es_hi] values. */ if (pass == 0 && vi->use_input_precision) { /* Ok, something is wrong - this actually happens in current libpng * 16-to-8 processing. Assume that the input value (id, adjusted * for sbit) can be anywhere between value-.5 and value+.5 - quite a * large range if sbit is low. */ double tmp = (isbit - .5)/sbit_max; if (tmp <= 0) tmp = 0; else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) tmp = pow(tmp, vi->file_inverse); tmp = gamma_component_compose(do_background, tmp, alpha, background, NULL); if (output_is_encoded && tmp > 0 && tmp < 1) tmp = pow(tmp, vi->screen_inverse); is_lo = ceil(outmax * tmp - vi->maxout_total); if (is_lo < 0) is_lo = 0; tmp = (isbit + .5)/sbit_max; if (tmp <= 0) tmp = 0; else if (alpha >= 0 && vi->file_inverse > 0 && tmp < 1) tmp = pow(tmp, vi->file_inverse); tmp = gamma_component_compose(do_background, tmp, alpha, background, NULL); if (output_is_encoded && tmp > 0 && tmp < 1) tmp = pow(tmp, vi->screen_inverse); is_hi = floor(outmax * tmp + vi->maxout_total); if (is_hi > outmax) is_hi = outmax; if (!(od < is_lo || od > is_hi)) { if (encoded_error < vi->outlog) return i; pass = "within input precision limits:\n"; } /* One last chance. If this is an alpha channel and the 16to8 * option has been used and 'inaccurate' scaling is used then the * bit reduction is obtained by simply using the top 8 bits of the * value. * * This is only done for older libpng versions when the 'inaccurate' * (chop) method of scaling was used. */ # ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED # if PNG_LIBPNG_VER < 10504 /* This may be required for other components in the future, * but at present the presence of gamma correction effectively * prevents the errors in the component scaling (I don't quite * understand why, but since it's better this way I care not * to ask, JB 20110419.) */ if (pass == 0 && alpha < 0 && vi->scale16 && vi->sbit > 8 && vi->sbit + vi->isbit_shift == 16) { tmp = ((id >> 8) - .5)/255; if (tmp > 0) { is_lo = ceil(outmax * tmp - vi->maxout_total); if (is_lo < 0) is_lo = 0; } else is_lo = 0; tmp = ((id >> 8) + .5)/255; if (tmp < 1) { is_hi = floor(outmax * tmp + vi->maxout_total); if (is_hi > outmax) is_hi = outmax; } else is_hi = outmax; if (!(od < is_lo || od > is_hi)) { if (encoded_error < vi->outlog) return i; pass = "within 8 bit limits:\n"; } } # endif # endif } else /* !use_input_precision */ is_lo = es_lo, is_hi = es_hi; /* Attempt to output a meaningful error/warning message: the message * output depends on the background/composite operation being performed * because this changes what parameters were actually used above. */ { size_t pos = 0; /* Need either 1/255 or 1/65535 precision here; 3 or 6 decimal * places. Just use outmax to work out which. */ int precision = (outmax >= 1000 ? 6 : 3); int use_input=1, use_background=0, do_compose=0; char msg[256]; if (pass != 0) pos = safecat(msg, sizeof msg, pos, "\n\t"); /* Set up the various flags, the output_is_encoded flag above * is also used below. do_compose is just a double check. */ switch (do_background) { # ifdef PNG_READ_BACKGROUND_SUPPORTED case PNG_BACKGROUND_GAMMA_SCREEN: case PNG_BACKGROUND_GAMMA_FILE: case PNG_BACKGROUND_GAMMA_UNIQUE: use_background = (alpha >= 0 && alpha < 1); /*FALL THROUGH*/ # endif # ifdef PNG_READ_ALPHA_MODE_SUPPORTED case ALPHA_MODE_OFFSET + PNG_ALPHA_STANDARD: case ALPHA_MODE_OFFSET + PNG_ALPHA_BROKEN: case ALPHA_MODE_OFFSET + PNG_ALPHA_OPTIMIZED: # endif /* ALPHA_MODE_SUPPORTED */ do_compose = (alpha > 0 && alpha < 1); use_input = (alpha != 0); break; default: break; } /* Check the 'compose' flag */ if (compose != do_compose) png_error(vi->pp, "internal error (compose)"); /* 'name' is the component name */ pos = safecat(msg, sizeof msg, pos, name); pos = safecat(msg, sizeof msg, pos, "("); pos = safecatn(msg, sizeof msg, pos, id); if (use_input || pass != 0/*logging*/) { if (isbit != id) { /* sBIT has reduced the precision of the input: */ pos = safecat(msg, sizeof msg, pos, ", sbit("); pos = safecatn(msg, sizeof msg, pos, vi->sbit); pos = safecat(msg, sizeof msg, pos, "): "); pos = safecatn(msg, sizeof msg, pos, isbit); } pos = safecat(msg, sizeof msg, pos, "/"); /* The output is either "id/max" or "id sbit(sbit): isbit/max" */ pos = safecatn(msg, sizeof msg, pos, vi->sbit_max); } pos = safecat(msg, sizeof msg, pos, ")"); /* A component may have been multiplied (in linear space) by the * alpha value, 'compose' says whether this is relevant. */ if (compose || pass != 0) { /* If any form of composition is being done report our * calculated linear value here (the code above doesn't record * the input value before composition is performed, so what * gets reported is the value after composition.) */ if (use_input || pass != 0) { if (vi->file_inverse > 0) { pos = safecat(msg, sizeof msg, pos, "^"); pos = safecatd(msg, sizeof msg, pos, vi->file_inverse, 2); } else pos = safecat(msg, sizeof msg, pos, "[linear]"); pos = safecat(msg, sizeof msg, pos, "*(alpha)"); pos = safecatd(msg, sizeof msg, pos, alpha, precision); } /* Now record the *linear* background value if it was used * (this function is not passed the original, non-linear, * value but it is contained in the test name.) */ if (use_background) { pos = safecat(msg, sizeof msg, pos, use_input ? "+" : " "); pos = safecat(msg, sizeof msg, pos, "(background)"); pos = safecatd(msg, sizeof msg, pos, background, precision); pos = safecat(msg, sizeof msg, pos, "*"); pos = safecatd(msg, sizeof msg, pos, 1-alpha, precision); } } /* Report the calculated value (input_sample) and the linearized * libpng value (output) unless this is just a component gamma * correction. */ if (compose || alpha < 0 || pass != 0) { pos = safecat(msg, sizeof msg, pos, pass != 0 ? " =\n\t" : " = "); pos = safecatd(msg, sizeof msg, pos, input_sample, precision); pos = safecat(msg, sizeof msg, pos, " (libpng: "); pos = safecatd(msg, sizeof msg, pos, output, precision); pos = safecat(msg, sizeof msg, pos, ")"); /* Finally report the output gamma encoding, if any. */ if (output_is_encoded) { pos = safecat(msg, sizeof msg, pos, " ^"); pos = safecatd(msg, sizeof msg, pos, vi->screen_inverse, 2); pos = safecat(msg, sizeof msg, pos, "(to screen) ="); } else pos = safecat(msg, sizeof msg, pos, " [screen is linear] ="); } if ((!compose && alpha >= 0) || pass != 0) { if (pass != 0) /* logging */ pos = safecat(msg, sizeof msg, pos, "\n\t[overall:"); /* This is the non-composition case, the internal linear * values are irrelevant (though the log below will reveal * them.) Output a much shorter warning/error message and report * the overall gamma correction. */ if (vi->gamma_correction > 0) { pos = safecat(msg, sizeof msg, pos, " ^"); pos = safecatd(msg, sizeof msg, pos, vi->gamma_correction, 2); pos = safecat(msg, sizeof msg, pos, "(gamma correction) ="); } else pos = safecat(msg, sizeof msg, pos, " [no gamma correction] ="); if (pass != 0) pos = safecat(msg, sizeof msg, pos, "]"); } /* This is our calculated encoded_sample which should (but does * not) match od: */ pos = safecat(msg, sizeof msg, pos, pass != 0 ? "\n\t" : " "); pos = safecatd(msg, sizeof msg, pos, is_lo, 1); pos = safecat(msg, sizeof msg, pos, " < "); pos = safecatd(msg, sizeof msg, pos, encoded_sample, 1); pos = safecat(msg, sizeof msg, pos, " (libpng: "); pos = safecatn(msg, sizeof msg, pos, od); pos = safecat(msg, sizeof msg, pos, ")"); pos = safecat(msg, sizeof msg, pos, "/"); pos = safecatn(msg, sizeof msg, pos, outmax); pos = safecat(msg, sizeof msg, pos, " < "); pos = safecatd(msg, sizeof msg, pos, is_hi, 1); if (pass == 0) /* The error condition */ { # ifdef PNG_WARNINGS_SUPPORTED png_warning(vi->pp, msg); # else store_warning(vi->pp, msg); # endif } else /* logging this value */ store_verbose(&vi->dp->pm->this, vi->pp, pass, msg); } } } return i; }
/* This API returns the encoded *input* component, in the range 0..1 */
https://github.com/v2v3v4/BigWorld-Engine-14.4.1/blob/4389085c8ce35cff887a4cc18fc47d1133d89ffb/programming/bigworld/third_party/png/contrib/libtests/pngvalid.c#L7776-L8332
4389085c8ce35cff887a4cc18fc47d1133d89ffb