1/* makepng.c 2 * 3 * Copyright (c) 2013 John Cunningham Bowler 4 * 5 * Last changed in libpng 1.6.1 [March 28, 2013] 6 * 7 * This code is released under the libpng license. 8 * For conditions of distribution and use, see the disclaimer 9 * and license in png.h 10 * 11 * Make a test PNG image. The arguments are as follows: 12 * 13 * makepng [--sRGB|--linear|--1.8] [--color=<color>] color-type bit-depth \ 14 * [file-name] 15 * 16 * The color-type may be numeric (and must match the numbers used by the PNG 17 * specification) or one of the format names listed below. The bit-depth is the 18 * component bit depth, or the pixel bit-depth for a color-mapped image. 19 * 20 * Without any options no color-space information is written, with the options 21 * an sRGB or the appropriate gAMA chunk is written. "1.8" refers to the 22 * display system used on older Apple computers to correct for high ambient 23 * light levels in the viewing environment; it applies a transform of 24 * approximately value^(1/1.45) to the color values and so a gAMA chunk of 65909 25 * is written (1.45/2.2). 26 * 27 * The image data is generated internally. Unless --color is given the images 28 * used are as follows: 29 * 30 * 1 channel: a square image with a diamond, the least luminous colors are on 31 * the edge of the image, the most luminous in the center. 32 * 33 * 2 channels: the color channel increases in luminosity from top to bottom, the 34 * alpha channel increases in opacity from left to right. 35 * 36 * 3 channels: linear combinations of, from the top-left corner clockwise, 37 * black, green, white, red. 38 * 39 * 4 channels: linear combinations of, from the top-left corner clockwise, 40 * transparent, red, green, blue. 41 * 42 * For color-mapped images a four channel color-map is used and the PNG file has 43 * a tRNS chunk, as follows: 44 * 45 * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white 46 * 2-bit: entry 0: transparent-green 47 * entry 1: 40%-red 48 * entry 2: 80%-blue 49 * entry 3: opaque-white 50 * 4-bit: the 16 combinations of the 2-bit case 51 * 8-bit: the 256 combinations of the 4-bit case 52 * 53 * The palette always has 2^bit-depth entries and the tRNS chunk one fewer. The 54 * image is the 1-channel diamond, but using palette index, not luminosity. 55 * 56 * Image size is determined by the final pixel depth in bits, i.e. channels x 57 * bit-depth, as follows: 58 * 59 * 8 bits or less: 64x64 60 * 16 bits: 256x256 61 * More than 16 bits: 1024x1024 62 * 63 * Row filtering is turned off (the 'none' filter is used on every row) and the 64 * images are not interlaced. 65 * 66 * If --color is given then the whole image has that color, color-mapped images 67 * will have exactly one palette entry and all image files with be 16x16 in 68 * size. The color value is 1 to 4 decimal numbers as appropriate for the color 69 * type. 70 * 71 * If file-name is given then the PNG is written to that file, else it is 72 * written to stdout. Notice that stdout is not supported on systems where, by 73 * default, it assumes text output; this program makes no attempt to change the 74 * text mode of stdout! 75 */ 76#define _ISOC99_SOURCE /* for strtoull */ 77 78#include <stddef.h> /* for offsetof */ 79#include <stdlib.h> 80#include <stdio.h> 81#include <string.h> 82#include <ctype.h> 83#include <math.h> 84#include <errno.h> 85 86#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) 87# include <config.h> 88#endif 89 90/* Define the following to use this test against your installed libpng, rather 91 * than the one being built here: 92 */ 93#ifdef PNG_FREESTANDING_TESTS 94# include <png.h> 95#else 96# include "../../png.h" 97#endif 98 99/* This structure is used for inserting extra chunks (the --insert argument, not 100 * documented above.) 101 */ 102typedef struct chunk_insert 103{ 104 struct chunk_insert *next; 105 void (*insert)(png_structp, png_infop, int, png_charpp); 106 int nparams; 107 png_charp parameters[1]; 108} chunk_insert; 109 110static int 111channels_of_type(int color_type) 112{ 113 if (color_type & PNG_COLOR_MASK_PALETTE) 114 return 1; 115 116 else 117 { 118 int channels = 1; 119 120 if (color_type & PNG_COLOR_MASK_COLOR) 121 channels = 3; 122 123 if (color_type & PNG_COLOR_MASK_ALPHA) 124 return channels + 1; 125 126 else 127 return channels; 128 } 129} 130 131static int 132pixel_depth_of_type(int color_type, int bit_depth) 133{ 134 return channels_of_type(color_type) * bit_depth; 135} 136 137static unsigned int 138image_size_of_type(int color_type, int bit_depth, unsigned int *colors) 139{ 140 if (*colors) 141 return 16; 142 143 else 144 { 145 int pixel_depth = pixel_depth_of_type(color_type, bit_depth); 146 147 if (pixel_depth < 8) 148 return 64; 149 150 else if (pixel_depth > 16) 151 return 1024; 152 153 else 154 return 256; 155 } 156} 157 158static void 159set_color(png_colorp color, png_bytep trans, unsigned int red, 160 unsigned int green, unsigned int blue, unsigned int alpha, 161 png_const_bytep gamma_table) 162{ 163 color->red = gamma_table[red]; 164 color->green = gamma_table[green]; 165 color->blue = gamma_table[blue]; 166 *trans = (png_byte)alpha; 167} 168 169static int 170generate_palette(png_colorp palette, png_bytep trans, int bit_depth, 171 png_const_bytep gamma_table, unsigned int *colors) 172{ 173 /* 174 * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white 175 * 2-bit: entry 0: transparent-green 176 * entry 1: 40%-red 177 * entry 2: 80%-blue 178 * entry 3: opaque-white 179 * 4-bit: the 16 combinations of the 2-bit case 180 * 8-bit: the 256 combinations of the 4-bit case 181 */ 182 switch (colors[0]) 183 { 184 default: 185 fprintf(stderr, "makepng: --colors=...: invalid count %u\n", 186 colors[0]); 187 exit(1); 188 189 case 1: 190 set_color(palette+0, trans+0, colors[1], colors[1], colors[1], 255, 191 gamma_table); 192 return 1; 193 194 case 2: 195 set_color(palette+0, trans+0, colors[1], colors[1], colors[1], 196 colors[2], gamma_table); 197 return 1; 198 199 case 3: 200 set_color(palette+0, trans+0, colors[1], colors[2], colors[3], 255, 201 gamma_table); 202 return 1; 203 204 case 4: 205 set_color(palette+0, trans+0, colors[1], colors[2], colors[3], 206 colors[4], gamma_table); 207 return 1; 208 209 case 0: 210 if (bit_depth == 1) 211 { 212 set_color(palette+0, trans+0, 255, 0, 0, 0, gamma_table); 213 set_color(palette+1, trans+1, 255, 255, 255, 255, gamma_table); 214 return 2; 215 } 216 217 else 218 { 219 unsigned int size = 1U << (bit_depth/2); /* 2, 4 or 16 */ 220 unsigned int x, y, ip; 221 222 for (x=0; x<size; ++x) for (y=0; y<size; ++y) 223 { 224 ip = x + (size * y); 225 226 /* size is at most 16, so the scaled value below fits in 16 bits 227 */ 228# define interp(pos, c1, c2) ((pos * c1) + ((size-pos) * c2)) 229# define xyinterp(x, y, c1, c2, c3, c4) (((size * size / 2) +\ 230 (interp(x, c1, c2) * y + (size-y) * interp(x, c3, c4))) /\ 231 (size*size)) 232 233 set_color(palette+ip, trans+ip, 234 /* color: green, red,blue,white */ 235 xyinterp(x, y, 0, 255, 0, 255), 236 xyinterp(x, y, 255, 0, 0, 255), 237 xyinterp(x, y, 0, 0, 255, 255), 238 /* alpha: 0, 102, 204, 255) */ 239 xyinterp(x, y, 0, 102, 204, 255), 240 gamma_table); 241 } 242 243 return ip+1; 244 } 245 } 246} 247 248static void 249set_value(png_bytep row, size_t rowbytes, png_uint_32 x, unsigned int bit_depth, 250 png_uint_32 value, png_const_bytep gamma_table, double conv) 251{ 252 unsigned int mask = (1U << bit_depth)-1; 253 254 x *= bit_depth; /* Maximum x is 4*1024, maximum bit_depth is 16 */ 255 256 if (value <= mask) 257 { 258 png_uint_32 offset = x >> 3; 259 260 if (offset < rowbytes && (bit_depth < 16 || offset+1 < rowbytes)) 261 { 262 row += offset; 263 264 switch (bit_depth) 265 { 266 case 1: 267 case 2: 268 case 4: 269 /* Don't gamma correct - values get smashed */ 270 { 271 unsigned int shift = (8 - bit_depth) - (x & 0x7U); 272 273 mask <<= shift; 274 value = (value << shift) & mask; 275 *row = (png_byte)((*row & ~mask) | value); 276 } 277 return; 278 279 default: 280 fprintf(stderr, "makepng: bad bit depth (internal error)\n"); 281 exit(1); 282 283 case 16: 284 value = (unsigned int)floor(65535*pow(value/65535.,conv)+.5); 285 *row++ = (png_byte)(value >> 8); 286 *row = (png_byte)value; 287 return; 288 289 case 8: 290 *row = gamma_table[value]; 291 return; 292 } 293 } 294 295 else 296 { 297 fprintf(stderr, "makepng: row buffer overflow (internal error)\n"); 298 exit(1); 299 } 300 } 301 302 else 303 { 304 fprintf(stderr, "makepng: component overflow (internal error)\n"); 305 exit(1); 306 } 307} 308 309static void 310generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type, 311 int bit_depth, png_const_bytep gamma_table, double conv, 312 unsigned int *colors) 313{ 314 png_uint_32 size_max = image_size_of_type(color_type, bit_depth, colors)-1; 315 png_uint_32 depth_max = (1U << bit_depth)-1; /* up to 65536 */ 316 317 if (colors[0] == 0) switch (channels_of_type(color_type)) 318 { 319 /* 1 channel: a square image with a diamond, the least luminous colors are on 320 * the edge of the image, the most luminous in the center. 321 */ 322 case 1: 323 { 324 png_uint_32 x; 325 png_uint_32 base = 2*size_max - abs(2*y-size_max); 326 327 for (x=0; x<=size_max; ++x) 328 { 329 png_uint_32 luma = base - abs(2*x-size_max); 330 331 /* 'luma' is now in the range 0..2*size_max, we need 332 * 0..depth_max 333 */ 334 luma = (luma*depth_max + size_max) / (2*size_max); 335 set_value(row, rowbytes, x, bit_depth, luma, gamma_table, conv); 336 } 337 } 338 break; 339 340 /* 2 channels: the color channel increases in luminosity from top to bottom, 341 * the alpha channel increases in opacity from left to right. 342 */ 343 case 2: 344 { 345 png_uint_32 alpha = (depth_max * y * 2 + size_max) / (2 * size_max); 346 png_uint_32 x; 347 348 for (x=0; x<=size_max; ++x) 349 { 350 set_value(row, rowbytes, 2*x, bit_depth, 351 (depth_max * x * 2 + size_max) / (2 * size_max), gamma_table, 352 conv); 353 set_value(row, rowbytes, 2*x+1, bit_depth, alpha, gamma_table, 354 conv); 355 } 356 } 357 break; 358 359 /* 3 channels: linear combinations of, from the top-left corner clockwise, 360 * black, green, white, red. 361 */ 362 case 3: 363 { 364 /* x0: the black->red scale (the value of the red component) at the 365 * start of the row (blue and green are 0). 366 * x1: the green->white scale (the value of the red and blue 367 * components at the end of the row; green is depth_max). 368 */ 369 png_uint_32 Y = (depth_max * y * 2 + size_max) / (2 * size_max); 370 png_uint_32 x; 371 372 /* Interpolate x/depth_max from start to end: 373 * 374 * start end difference 375 * red: Y Y 0 376 * green: 0 depth_max depth_max 377 * blue: 0 Y Y 378 */ 379 for (x=0; x<=size_max; ++x) 380 { 381 set_value(row, rowbytes, 3*x+0, bit_depth, /* red */ Y, 382 gamma_table, conv); 383 set_value(row, rowbytes, 3*x+1, bit_depth, /* green */ 384 (depth_max * x * 2 + size_max) / (2 * size_max), 385 gamma_table, conv); 386 set_value(row, rowbytes, 3*x+2, bit_depth, /* blue */ 387 (Y * x * 2 + size_max) / (2 * size_max), 388 gamma_table, conv); 389 } 390 } 391 break; 392 393 /* 4 channels: linear combinations of, from the top-left corner clockwise, 394 * transparent, red, green, blue. 395 */ 396 case 4: 397 { 398 /* x0: the transparent->blue scale (the value of the blue and alpha 399 * components) at the start of the row (red and green are 0). 400 * x1: the red->green scale (the value of the red and green 401 * components at the end of the row; blue is 0 and alpha is 402 * depth_max). 403 */ 404 png_uint_32 Y = (depth_max * y * 2 + size_max) / (2 * size_max); 405 png_uint_32 x; 406 407 /* Interpolate x/depth_max from start to end: 408 * 409 * start end difference 410 * red: 0 depth_max-Y depth_max-Y 411 * green: 0 Y Y 412 * blue: Y 0 -Y 413 * alpha: Y depth_max depth_max-Y 414 */ 415 for (x=0; x<=size_max; ++x) 416 { 417 set_value(row, rowbytes, 4*x+0, bit_depth, /* red */ 418 ((depth_max-Y) * x * 2 + size_max) / (2 * size_max), 419 gamma_table, conv); 420 set_value(row, rowbytes, 4*x+1, bit_depth, /* green */ 421 (Y * x * 2 + size_max) / (2 * size_max), 422 gamma_table, conv); 423 set_value(row, rowbytes, 4*x+2, bit_depth, /* blue */ 424 Y - (Y * x * 2 + size_max) / (2 * size_max), 425 gamma_table, conv); 426 set_value(row, rowbytes, 4*x+3, bit_depth, /* alpha */ 427 Y + ((depth_max-Y) * x * 2 + size_max) / (2 * size_max), 428 gamma_table, conv); 429 } 430 } 431 break; 432 433 default: 434 fprintf(stderr, "makepng: internal bad channel count\n"); 435 exit(2); 436 } 437 438 else if (color_type & PNG_COLOR_MASK_PALETTE) 439 { 440 /* Palette with fixed color: the image rows are all 0 and the image width 441 * is 16. 442 */ 443 memset(row, 0, rowbytes); 444 } 445 446 else if (colors[0] == channels_of_type(color_type)) 447 switch (channels_of_type(color_type)) 448 { 449 case 1: 450 { 451 const png_uint_32 luma = colors[1]; 452 png_uint_32 x; 453 454 for (x=0; x<=size_max; ++x) 455 set_value(row, rowbytes, x, bit_depth, luma, gamma_table, 456 conv); 457 } 458 break; 459 460 case 2: 461 { 462 const png_uint_32 luma = colors[1]; 463 const png_uint_32 alpha = colors[2]; 464 png_uint_32 x; 465 466 for (x=0; x<size_max; ++x) 467 { 468 set_value(row, rowbytes, 2*x, bit_depth, luma, gamma_table, 469 conv); 470 set_value(row, rowbytes, 2*x+1, bit_depth, alpha, gamma_table, 471 conv); 472 } 473 } 474 break; 475 476 case 3: 477 { 478 const png_uint_32 red = colors[1]; 479 const png_uint_32 green = colors[2]; 480 const png_uint_32 blue = colors[3]; 481 png_uint_32 x; 482 483 for (x=0; x<=size_max; ++x) 484 { 485 set_value(row, rowbytes, 3*x+0, bit_depth, red, gamma_table, 486 conv); 487 set_value(row, rowbytes, 3*x+1, bit_depth, green, gamma_table, 488 conv); 489 set_value(row, rowbytes, 3*x+2, bit_depth, blue, gamma_table, 490 conv); 491 } 492 } 493 break; 494 495 case 4: 496 { 497 const png_uint_32 red = colors[1]; 498 const png_uint_32 green = colors[2]; 499 const png_uint_32 blue = colors[3]; 500 const png_uint_32 alpha = colors[4]; 501 png_uint_32 x; 502 503 for (x=0; x<=size_max; ++x) 504 { 505 set_value(row, rowbytes, 4*x+0, bit_depth, red, gamma_table, 506 conv); 507 set_value(row, rowbytes, 4*x+1, bit_depth, green, gamma_table, 508 conv); 509 set_value(row, rowbytes, 4*x+2, bit_depth, blue, gamma_table, 510 conv); 511 set_value(row, rowbytes, 4*x+3, bit_depth, alpha, gamma_table, 512 conv); 513 } 514 } 515 break; 516 517 default: 518 fprintf(stderr, "makepng: internal bad channel count\n"); 519 exit(2); 520 } 521 522 else 523 { 524 fprintf(stderr, 525 "makepng: --color: count(%u) does not match channels(%u)\n", 526 colors[0], channels_of_type(color_type)); 527 exit(1); 528 } 529} 530 531 532static void PNGCBAPI 533makepng_warning(png_structp png_ptr, png_const_charp message) 534{ 535 const char **ep = png_get_error_ptr(png_ptr); 536 const char *name; 537 538 if (ep != NULL && *ep != NULL) 539 name = *ep; 540 541 else 542 name = "makepng"; 543 544 fprintf(stderr, "%s: warning: %s\n", name, message); 545} 546 547static void PNGCBAPI 548makepng_error(png_structp png_ptr, png_const_charp message) 549{ 550 makepng_warning(png_ptr, message); 551 png_longjmp(png_ptr, 1); 552} 553 554static int /* 0 on success, else an error code */ 555write_png(const char **name, FILE *fp, int color_type, int bit_depth, 556 volatile png_fixed_point gamma, chunk_insert * volatile insert, 557 unsigned int filters, unsigned int *colors) 558{ 559 png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, 560 name, makepng_error, makepng_warning); 561 volatile png_infop info_ptr = NULL; 562 volatile png_bytep row = NULL; 563 564 if (png_ptr == NULL) 565 { 566 fprintf(stderr, "makepng: OOM allocating write structure\n"); 567 return 1; 568 } 569 570 if (setjmp(png_jmpbuf(png_ptr))) 571 { 572 png_structp nv_ptr = png_ptr; 573 png_infop nv_info = info_ptr; 574 575 png_ptr = NULL; 576 info_ptr = NULL; 577 png_destroy_write_struct(&nv_ptr, &nv_info); 578 if (row != NULL) free(row); 579 return 1; 580 } 581 582 /* Allow benign errors so that we can write PNGs with errors */ 583 png_set_benign_errors(png_ptr, 1/*allowed*/); 584 png_init_io(png_ptr, fp); 585 586 info_ptr = png_create_info_struct(png_ptr); 587 if (info_ptr == NULL) 588 png_error(png_ptr, "OOM allocating info structure"); 589 590 { 591 unsigned int size = image_size_of_type(color_type, bit_depth, colors); 592 png_fixed_point real_gamma = 45455; /* For sRGB */ 593 png_byte gamma_table[256]; 594 double conv; 595 596 /* This function uses the libpng values used on read to carry extra 597 * information about the gamma: 598 */ 599 if (gamma == PNG_GAMMA_MAC_18) 600 gamma = 65909; 601 602 else if (gamma > 0 && gamma < 1000) 603 gamma = PNG_FP_1; 604 605 if (gamma > 0) 606 real_gamma = gamma; 607 608 { 609 unsigned int i; 610 611 if (real_gamma == 45455) for (i=0; i<256; ++i) 612 { 613 gamma_table[i] = (png_byte)i; 614 conv = 1.; 615 } 616 617 else 618 { 619 /* Convert 'i' from sRGB (45455) to real_gamma, this makes 620 * the images look the same regardless of the gAMA chunk. 621 */ 622 conv = real_gamma; 623 conv /= 45455; 624 625 gamma_table[0] = 0; 626 627 for (i=1; i<255; ++i) 628 gamma_table[i] = (png_byte)floor(pow(i/255.,conv) * 255 + .5); 629 630 gamma_table[255] = 255; 631 } 632 } 633 634 png_set_IHDR(png_ptr, info_ptr, size, size, bit_depth, color_type, 635 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); 636 637 if (color_type & PNG_COLOR_MASK_PALETTE) 638 { 639 int npalette; 640 png_color palette[256]; 641 png_byte trans[256]; 642 643 npalette = generate_palette(palette, trans, bit_depth, gamma_table, 644 colors); 645 png_set_PLTE(png_ptr, info_ptr, palette, npalette); 646 png_set_tRNS(png_ptr, info_ptr, trans, npalette-1, 647 NULL/*transparent color*/); 648 649 /* Reset gamma_table to prevent the image rows being changed */ 650 for (npalette=0; npalette<256; ++npalette) 651 gamma_table[npalette] = (png_byte)npalette; 652 } 653 654 if (gamma == PNG_DEFAULT_sRGB) 655 png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE); 656 657 else if (gamma > 0) /* Else don't set color space information */ 658 { 659 png_set_gAMA_fixed(png_ptr, info_ptr, real_gamma); 660 661 /* Just use the sRGB values here. */ 662 png_set_cHRM_fixed(png_ptr, info_ptr, 663 /* color x y */ 664 /* white */ 31270, 32900, 665 /* red */ 64000, 33000, 666 /* green */ 30000, 60000, 667 /* blue */ 15000, 6000 668 ); 669 } 670 671 /* Insert extra information. */ 672 while (insert != NULL) 673 { 674 insert->insert(png_ptr, info_ptr, insert->nparams, insert->parameters); 675 insert = insert->next; 676 } 677 678 /* Write the file header. */ 679 png_write_info(png_ptr, info_ptr); 680 681 /* Restrict the filters */ 682 png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, filters); 683 684 { 685 int passes = png_set_interlace_handling(png_ptr); 686 int pass; 687 png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr); 688 689 row = malloc(rowbytes); 690 691 if (row == NULL) 692 png_error(png_ptr, "OOM allocating row buffer"); 693 694 for (pass = 0; pass < passes; ++pass) 695 { 696 unsigned int y; 697 698 for (y=0; y<size; ++y) 699 { 700 generate_row(row, rowbytes, y, color_type, bit_depth, 701 gamma_table, conv, colors); 702 png_write_row(png_ptr, row); 703 } 704 } 705 } 706 } 707 708 /* Finish writing the file. */ 709 png_write_end(png_ptr, info_ptr); 710 711 { 712 png_structp nv_ptr = png_ptr; 713 png_infop nv_info = info_ptr; 714 715 png_ptr = NULL; 716 info_ptr = NULL; 717 png_destroy_write_struct(&nv_ptr, &nv_info); 718 } 719 free(row); 720 return 0; 721} 722 723 724static size_t 725load_file(png_const_charp name, png_bytepp result) 726{ 727 FILE *fp = tmpfile(); 728 729 if (fp != NULL) 730 { 731 FILE *ip = fopen(name, "rb"); 732 733 if (ip != NULL) 734 { 735 size_t total = 0; 736 int ch; 737 738 for (;;) 739 { 740 ch = getc(ip); 741 if (ch == EOF) break; 742 putc(ch, fp); 743 ++total; 744 } 745 746 if (ferror(ip)) 747 { 748 perror(name); 749 fprintf(stderr, "%s: read error\n", name); 750 (void)fclose(ip); 751 } 752 753 else 754 { 755 (void)fclose(ip); 756 757 if (ferror(fp)) 758 { 759 perror("temporary file"); 760 fprintf(stderr, "temporary file write error\n"); 761 } 762 763 else 764 { 765 rewind(fp); 766 767 if (total > 0) 768 { 769 /* Round up to a multiple of 4 here to allow an iCCP profile 770 * to be padded to a 4x boundary. 771 */ 772 png_bytep data = malloc((total+3)&~3); 773 774 if (data != NULL) 775 { 776 size_t new_size = 0; 777 778 for (;;) 779 { 780 ch = getc(fp); 781 if (ch == EOF) break; 782 data[new_size++] = (png_byte)ch; 783 } 784 785 if (ferror(fp) || new_size != total) 786 { 787 perror("temporary file"); 788 fprintf(stderr, "temporary file read error\n"); 789 free(data); 790 } 791 792 else 793 { 794 (void)fclose(fp); 795 *result = data; 796 return total; 797 } 798 } 799 800 else 801 fprintf(stderr, "%s: out of memory loading file\n", name); 802 } 803 804 else 805 fprintf(stderr, "%s: empty file\n", name); 806 } 807 } 808 } 809 810 else 811 { 812 perror(name); 813 fprintf(stderr, "%s: open failed\n", name); 814 } 815 816 fclose(fp); 817 } 818 819 else 820 fprintf(stderr, "makepng: %s: could not open temporary file\n", name); 821 822 exit(1); 823 return 0; 824} 825 826static png_size_t 827load_fake(png_charp param, png_bytepp profile) 828{ 829 char *endptr = NULL; 830 unsigned long long int size = strtoull(param, &endptr, 0/*base*/); 831 832 /* The 'fake' format is <number>*[string] */ 833 if (endptr != NULL && *endptr == '*') 834 { 835 size_t len = strlen(++endptr); 836 size_t result = (size_t)size; 837 838 if (len == 0) len = 1; /* capture the terminating '\0' */ 839 840 /* Now repeat that string to fill 'size' bytes. */ 841 if (result == size && (*profile = malloc(result)) != NULL) 842 { 843 png_bytep out = *profile; 844 845 if (len == 1) 846 memset(out, *endptr, result); 847 848 else 849 { 850 while (size >= len) 851 { 852 memcpy(out, endptr, len); 853 out += len; 854 size -= len; 855 } 856 memcpy(out, endptr, size); 857 } 858 859 return result; 860 } 861 862 else 863 { 864 fprintf(stderr, "%s: size exceeds system limits\n", param); 865 exit(1); 866 } 867 } 868 869 return 0; 870} 871 872static void 873check_param_count(int nparams, int expect) 874{ 875 if (nparams != expect) 876 { 877 fprintf(stderr, "bad parameter count (internal error)\n"); 878 exit(1); 879 } 880} 881 882static void 883insert_iCCP(png_structp png_ptr, png_infop info_ptr, int nparams, 884 png_charpp params) 885{ 886 png_bytep profile = NULL; 887 png_uint_32 proflen = 0; 888 int result; 889 890 check_param_count(nparams, 2); 891 892 switch (params[1][0]) 893 { 894 case '<': 895 { 896 png_size_t filelen = load_file(params[1]+1, &profile); 897 if (filelen > 0xfffffffc) /* Maximum profile length */ 898 { 899 fprintf(stderr, "%s: file too long (%lu) for an ICC profile\n", 900 params[1]+1, (unsigned long)filelen); 901 exit(1); 902 } 903 904 proflen = (png_uint_32)filelen; 905 } 906 break; 907 908 case '0': case '1': case '2': case '3': case '4': 909 case '5': case '6': case '7': case '8': case '9': 910 { 911 png_size_t fake_len = load_fake(params[1], &profile); 912 913 if (fake_len > 0) /* else a simple parameter */ 914 { 915 if (fake_len > 0xffffffff) /* Maximum profile length */ 916 { 917 fprintf(stderr, 918 "%s: fake data too long (%lu) for an ICC profile\n", 919 params[1], (unsigned long)fake_len); 920 exit(1); 921 } 922 proflen = (png_uint_32)(fake_len & ~3U); 923 /* Always fix up the profile length. */ 924 png_save_uint_32(profile, proflen); 925 break; 926 } 927 } 928 929 default: 930 fprintf(stderr, "--insert iCCP \"%s\": unrecognized\n", params[1]); 931 fprintf(stderr, " use '<' to read a file: \"<filename\"\n"); 932 exit(1); 933 } 934 935 result = 1; 936 937 if (proflen & 3) 938 { 939 fprintf(stderr, 940 "makepng: --insert iCCP %s: profile length made a multiple of 4\n", 941 params[1]); 942 943 /* load_file allocates extra space for this padding, the ICC spec requires 944 * padding with zero bytes. 945 */ 946 while (proflen & 3) 947 profile[proflen++] = 0; 948 } 949 950 if (profile != NULL && proflen > 3) 951 { 952 png_uint_32 prof_header = png_get_uint_32(profile); 953 954 if (prof_header != proflen) 955 { 956 fprintf(stderr, "--insert iCCP %s: profile length field wrong:\n", 957 params[1]); 958 fprintf(stderr, " actual %lu, recorded value %lu (corrected)\n", 959 (unsigned long)proflen, (unsigned long)prof_header); 960 png_save_uint_32(profile, proflen); 961 } 962 } 963 964 if (result && profile != NULL && proflen >=4) 965 png_set_iCCP(png_ptr, info_ptr, params[0], PNG_COMPRESSION_TYPE_BASE, 966 profile, proflen); 967 968 if (profile) 969 free(profile); 970 971 if (!result) 972 exit(1); 973} 974 975static void 976clear_text(png_text *text, png_charp keyword) 977{ 978 text->compression = -1; /* none */ 979 text->key = keyword; 980 text->text = NULL; 981 text->text_length = 0; /* libpng calculates this */ 982 text->itxt_length = 0; /* libpng calculates this */ 983 text->lang = NULL; 984 text->lang_key = NULL; 985} 986 987static void 988set_text(png_structp png_ptr, png_infop info_ptr, png_textp text, 989 png_charp param) 990{ 991 switch (param[0]) 992 { 993 case '<': 994 { 995 png_bytep file = NULL; 996 997 text->text_length = load_file(param+1, &file); 998 text->text = (png_charp)file; 999 } 1000 break; 1001 1002 case '0': case '1': case '2': case '3': case '4': 1003 case '5': case '6': case '7': case '8': case '9': 1004 { 1005 png_bytep data = NULL; 1006 png_size_t fake_len = load_fake(param, &data); 1007 1008 if (fake_len > 0) /* else a simple parameter */ 1009 { 1010 text->text_length = fake_len; 1011 text->text = (png_charp)data; 1012 break; 1013 } 1014 } 1015 1016 default: 1017 text->text = param; 1018 break; 1019 } 1020 1021 png_set_text(png_ptr, info_ptr, text, 1); 1022 1023 if (text->text != param) 1024 free(text->text); 1025} 1026 1027static void 1028insert_tEXt(png_structp png_ptr, png_infop info_ptr, int nparams, 1029 png_charpp params) 1030{ 1031 png_text text; 1032 1033 check_param_count(nparams, 2); 1034 clear_text(&text, params[0]); 1035 set_text(png_ptr, info_ptr, &text, params[1]); 1036} 1037 1038static void 1039insert_zTXt(png_structp png_ptr, png_infop info_ptr, int nparams, 1040 png_charpp params) 1041{ 1042 png_text text; 1043 1044 check_param_count(nparams, 2); 1045 clear_text(&text, params[0]); 1046 text.compression = 0; /* deflate */ 1047 set_text(png_ptr, info_ptr, &text, params[1]); 1048} 1049 1050static void 1051insert_iTXt(png_structp png_ptr, png_infop info_ptr, int nparams, 1052 png_charpp params) 1053{ 1054 png_text text; 1055 1056 check_param_count(nparams, 4); 1057 clear_text(&text, params[0]); 1058 text.compression = 2; /* iTXt + deflate */ 1059 text.lang = params[1];/* language tag */ 1060 text.lang_key = params[2]; /* translated keyword */ 1061 set_text(png_ptr, info_ptr, &text, params[3]); 1062} 1063 1064static void 1065insert_hIST(png_structp png_ptr, png_infop info_ptr, int nparams, png_charpp params) 1066{ 1067 int i; 1068 png_uint_16 freq[256]; 1069 1070 /* libpng takes the count from the PLTE count; we don't check it here but we 1071 * do set the array to 0 for unspecified entries. 1072 */ 1073 memset(freq, 0, sizeof freq); 1074 for (i=0; i<nparams; ++i) 1075 { 1076 char *endptr = NULL; 1077 unsigned long int l = strtoul(params[i], &endptr, 0/*base*/); 1078 1079 if (params[i][0] && *endptr == 0 && l <= 65535) 1080 freq[i] = (png_uint_16)l; 1081 1082 else 1083 { 1084 fprintf(stderr, "hIST[%d]: %s: invalid frequency\n", i, params[i]); 1085 exit(1); 1086 } 1087 } 1088 1089 png_set_hIST(png_ptr, info_ptr, freq); 1090} 1091 1092#if 0 1093static void 1094insert_sPLT(png_structp png_ptr, png_infop info_ptr, int nparams, png_charpp params) 1095{ 1096 fprintf(stderr, "insert sPLT: NYI\n"); 1097} 1098#endif 1099 1100static int 1101find_parameters(png_const_charp what, png_charp param, png_charp *list, 1102 int nparams) 1103{ 1104 /* Parameters are separated by '\n' or ':' characters, up to nparams are 1105 * accepted (more is an error) and the number found is returned. 1106 */ 1107 int i; 1108 for (i=0; *param && i<nparams; ++i) 1109 { 1110 list[i] = param; 1111 while (*++param) if (*param == '\n' || *param == ':') 1112 { 1113 *param++ = 0; /* Terminate last parameter */ 1114 break; /* And start a new one. */ 1115 } 1116 } 1117 1118 if (*param) 1119 { 1120 fprintf(stderr, "--insert %s: too many parameters (%s)\n", what, param); 1121 exit(1); 1122 } 1123 1124 list[i] = NULL; /* terminates list */ 1125 return i; /* number of parameters filled in */ 1126} 1127 1128static void 1129bad_parameter_count(png_const_charp what, int nparams) 1130{ 1131 fprintf(stderr, "--insert %s: bad parameter count %d\n", what, nparams); 1132 exit(1); 1133} 1134 1135static chunk_insert * 1136make_insert(png_const_charp what, 1137 void (*insert)(png_structp, png_infop, int, png_charpp), 1138 int nparams, png_charpp list) 1139{ 1140 int i; 1141 chunk_insert *cip; 1142 1143 cip = malloc(offsetof(chunk_insert,parameters) + 1144 nparams * sizeof (png_charp)); 1145 1146 if (cip == NULL) 1147 { 1148 fprintf(stderr, "--insert %s: out of memory allocating %d parameters\n", 1149 what, nparams); 1150 exit(1); 1151 } 1152 1153 cip->next = NULL; 1154 cip->insert = insert; 1155 cip->nparams = nparams; 1156 for (i=0; i<nparams; ++i) 1157 cip->parameters[i] = list[i]; 1158 1159 return cip; 1160} 1161 1162static chunk_insert * 1163find_insert(png_const_charp what, png_charp param) 1164{ 1165 png_uint_32 chunk = 0; 1166 png_charp parameter_list[1024]; 1167 int i, nparams; 1168 1169 /* Assemble the chunk name */ 1170 for (i=0; i<4; ++i) 1171 { 1172 char ch = what[i]; 1173 1174 if ((ch >= 65 && ch <= 90) || (ch >= 97 && ch <= 122)) 1175 chunk = (chunk << 8) + what[i]; 1176 1177 else 1178 break; 1179 } 1180 1181 if (i < 4 || what[4] != 0) 1182 { 1183 fprintf(stderr, "makepng --insert \"%s\": invalid chunk name\n", what); 1184 exit(1); 1185 } 1186 1187 /* Assemble the parameter list. */ 1188 nparams = find_parameters(what, param, parameter_list, 1024); 1189 1190# define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) 1191 1192 switch (chunk) 1193 { 1194 case CHUNK(105,67,67,80): /* iCCP */ 1195 if (nparams == 2) 1196 return make_insert(what, insert_iCCP, nparams, parameter_list); 1197 break; 1198 1199 case CHUNK(116,69,88,116): /* tEXt */ 1200 if (nparams == 2) 1201 return make_insert(what, insert_tEXt, nparams, parameter_list); 1202 break; 1203 1204 case CHUNK(122,84,88,116): /* zTXt */ 1205 if (nparams == 2) 1206 return make_insert(what, insert_zTXt, nparams, parameter_list); 1207 break; 1208 1209 case CHUNK(105,84,88,116): /* iTXt */ 1210 if (nparams == 4) 1211 return make_insert(what, insert_iTXt, nparams, parameter_list); 1212 break; 1213 1214 case CHUNK(104,73,83,84): /* hIST */ 1215 if (nparams <= 256) 1216 return make_insert(what, insert_hIST, nparams, parameter_list); 1217 break; 1218 1219#if 0 1220 case CHUNK(115,80,76,84): /* sPLT */ 1221 return make_insert(what, insert_sPLT, nparams, parameter_list); 1222#endif 1223 1224 default: 1225 fprintf(stderr, "makepng --insert \"%s\": unrecognized chunk name\n", 1226 what); 1227 exit(1); 1228 } 1229 1230 bad_parameter_count(what, nparams); 1231 return NULL; 1232} 1233 1234/* This is a not-very-good parser for a sequence of numbers (including 0). It 1235 * doesn't accept some apparently valid things, but it accepts all the sensible 1236 * combinations. 1237 */ 1238static void 1239parse_color(char *arg, unsigned int *colors) 1240{ 1241 unsigned int ncolors = 0; 1242 1243 while (*arg && ncolors < 4) 1244 { 1245 char *ep = arg; 1246 1247 unsigned long ul = strtoul(arg, &ep, 0); 1248 1249 if (ul > 65535) 1250 { 1251 fprintf(stderr, "makepng --color=...'%s': too big\n", arg); 1252 exit(1); 1253 } 1254 1255 if (ep == arg) 1256 { 1257 fprintf(stderr, "makepng --color=...'%s': not a valid color\n", arg); 1258 exit(1); 1259 } 1260 1261 if (*ep) ++ep; /* skip a separator */ 1262 arg = ep; 1263 1264 colors[++ncolors] = (unsigned int)ul; /* checked above */ 1265 } 1266 1267 if (*arg) 1268 { 1269 fprintf(stderr, "makepng --color=...'%s': too many values\n", arg); 1270 exit(1); 1271 } 1272 1273 *colors = ncolors; 1274} 1275 1276int 1277main(int argc, char **argv) 1278{ 1279 FILE *fp = stdout; 1280 const char *file_name = NULL; 1281 int color_type = 8; /* invalid */ 1282 int bit_depth = 32; /* invalid */ 1283 unsigned int colors[5]; 1284 unsigned int filters = PNG_ALL_FILTERS; 1285 png_fixed_point gamma = 0; /* not set */ 1286 chunk_insert *head_insert = NULL; 1287 chunk_insert **insert_ptr = &head_insert; 1288 1289 memset(colors, 0, sizeof colors); 1290 1291 while (--argc > 0) 1292 { 1293 char *arg = *++argv; 1294 1295 if (strcmp(arg, "--sRGB") == 0) 1296 { 1297 gamma = PNG_DEFAULT_sRGB; 1298 continue; 1299 } 1300 1301 if (strcmp(arg, "--linear") == 0) 1302 { 1303 gamma = PNG_FP_1; 1304 continue; 1305 } 1306 1307 if (strcmp(arg, "--1.8") == 0) 1308 { 1309 gamma = PNG_GAMMA_MAC_18; 1310 continue; 1311 } 1312 1313 if (strcmp(arg, "--nofilters") == 0) 1314 { 1315 filters = PNG_FILTER_NONE; 1316 continue; 1317 } 1318 1319 if (strncmp(arg, "--color=", 8) == 0) 1320 { 1321 parse_color(arg+8, colors); 1322 continue; 1323 } 1324 1325 if (argc >= 3 && strcmp(arg, "--insert") == 0) 1326 { 1327 png_const_charp what = *++argv; 1328 png_charp param = *++argv; 1329 chunk_insert *new_insert; 1330 1331 argc -= 2; 1332 1333 new_insert = find_insert(what, param); 1334 1335 if (new_insert != NULL) 1336 { 1337 *insert_ptr = new_insert; 1338 insert_ptr = &new_insert->next; 1339 } 1340 1341 continue; 1342 } 1343 1344 if (arg[0] == '-') 1345 { 1346 fprintf(stderr, "makepng: %s: invalid option\n", arg); 1347 exit(1); 1348 } 1349 1350 if (strcmp(arg, "palette") == 0) 1351 { 1352 color_type = PNG_COLOR_TYPE_PALETTE; 1353 continue; 1354 } 1355 1356 if (strncmp(arg, "gray", 4) == 0) 1357 { 1358 if (arg[4] == 0) 1359 { 1360 color_type = PNG_COLOR_TYPE_GRAY; 1361 continue; 1362 } 1363 1364 else if (strcmp(arg+4, "a") == 0 || 1365 strcmp(arg+4, "alpha") == 0 || 1366 strcmp(arg+4, "-alpha") == 0) 1367 { 1368 color_type = PNG_COLOR_TYPE_GRAY_ALPHA; 1369 continue; 1370 } 1371 } 1372 1373 if (strncmp(arg, "rgb", 3) == 0) 1374 { 1375 if (arg[3] == 0) 1376 { 1377 color_type = PNG_COLOR_TYPE_RGB; 1378 continue; 1379 } 1380 1381 else if (strcmp(arg+3, "a") == 0 || 1382 strcmp(arg+3, "alpha") == 0 || 1383 strcmp(arg+3, "-alpha") == 0) 1384 { 1385 color_type = PNG_COLOR_TYPE_RGB_ALPHA; 1386 continue; 1387 } 1388 } 1389 1390 if (color_type == 8 && isdigit(arg[0])) 1391 { 1392 color_type = atoi(arg); 1393 if (color_type < 0 || color_type > 6 || color_type == 1 || 1394 color_type == 5) 1395 { 1396 fprintf(stderr, "makepng: %s: not a valid color type\n", arg); 1397 exit(1); 1398 } 1399 1400 continue; 1401 } 1402 1403 if (bit_depth == 32 && isdigit(arg[0])) 1404 { 1405 bit_depth = atoi(arg); 1406 if (bit_depth <= 0 || bit_depth > 16 || 1407 (bit_depth & -bit_depth) != bit_depth) 1408 { 1409 fprintf(stderr, "makepng: %s: not a valid bit depth\n", arg); 1410 exit(1); 1411 } 1412 1413 continue; 1414 } 1415 1416 if (argc == 1) /* It's the file name */ 1417 { 1418 fp = fopen(arg, "wb"); 1419 if (fp == NULL) 1420 { 1421 fprintf(stderr, "%s: %s: could not open\n", arg, strerror(errno)); 1422 exit(1); 1423 } 1424 1425 file_name = arg; 1426 continue; 1427 } 1428 1429 fprintf(stderr, "makepng: %s: unknown argument\n", arg); 1430 exit(1); 1431 } /* argument while loop */ 1432 1433 if (color_type == 8 || bit_depth == 32) 1434 { 1435 fprintf(stderr, "usage: makepng [--sRGB|--linear|--1.8] " 1436 "[--color=...] color-type bit-depth [file-name]\n" 1437 " Make a test PNG file, by default writes to stdout.\n"); 1438 exit(1); 1439 } 1440 1441 /* Check the colors */ 1442 { 1443 const unsigned int lim = (color_type == PNG_COLOR_TYPE_PALETTE ? 255U : 1444 (1U<<bit_depth)-1); 1445 unsigned int i; 1446 1447 for (i=1; i<=colors[0]; ++i) 1448 if (colors[i] > lim) 1449 { 1450 fprintf(stderr, "makepng: --color=...: %u out of range [0..%u]\n", 1451 colors[i], lim); 1452 exit(1); 1453 } 1454 } 1455 1456 /* Restrict the filters for more speed to those we know are used for the 1457 * generated images. 1458 */ 1459 if (filters == PNG_ALL_FILTERS) 1460 { 1461 if ((color_type & PNG_COLOR_MASK_PALETTE) != 0 || bit_depth < 8) 1462 filters = PNG_FILTER_NONE; 1463 1464 else if (color_type & PNG_COLOR_MASK_COLOR) /* rgb */ 1465 { 1466 if (bit_depth == 8) 1467 filters &= ~(PNG_FILTER_NONE | PNG_FILTER_AVG); 1468 1469 else 1470 filters = PNG_FILTER_SUB | PNG_FILTER_PAETH; 1471 } 1472 1473 else /* gray 8 or 16-bit */ 1474 filters &= ~PNG_FILTER_NONE; 1475 } 1476 1477 { 1478 int ret = write_png(&file_name, fp, color_type, bit_depth, gamma, 1479 head_insert, filters, colors); 1480 1481 if (ret != 0 && file_name != NULL) 1482 remove(file_name); 1483 1484 return ret; 1485 } 1486} 1487