1/* makepng.c */ 2#define _ISOC99_SOURCE 3/* Copyright: */ 4#define COPYRIGHT "\251 2013,2015 John Cunningham Bowler" 5/* 6 * Last changed in libpng 1.6.20 [November 24, 2015] 7 * 8 * This code is released under the libpng license. 9 * For conditions of distribution and use, see the disclaimer 10 * and license in png.h 11 * 12 * Make a test PNG image. The arguments are as follows: 13 * 14 * makepng [--sRGB|--linear|--1.8] [--tRNS] [--nofilters] \ 15 * color-type bit-depth [file-name] 16 * 17 * The color-type may be numeric (and must match the numbers used by the PNG 18 * specification) or one of the format names listed below. The bit-depth is the 19 * component bit depth, or the pixel bit-depth for a color-mapped image. 20 * 21 * Without any options no color-space information is written, with the options 22 * an sRGB or the appropriate gAMA chunk is written. "1.8" refers to the 23 * display system used on older Apple computers to correct for high ambient 24 * light levels in the viewing environment; it applies a transform of 25 * approximately value^(1/1.45) to the color values and so a gAMA chunk of 65909 26 * is written (1.45/2.2). 27 * 28 * The image data is generated internally. Unless --color is given the images 29 * used are as follows: 30 * 31 * 1 channel: a square image with a diamond, the least luminous colors are on 32 * the edge of the image, the most luminous in the center. 33 * 34 * 2 channels: the color channel increases in luminosity from top to bottom, the 35 * alpha channel increases in opacity from left to right. 36 * 37 * 3 channels: linear combinations of, from the top-left corner clockwise, 38 * black, green, white, red. 39 * 40 * 4 channels: linear combinations of, from the top-left corner clockwise, 41 * transparent, red, green, blue. 42 * 43 * For color-mapped images a four channel color-map is used and if --tRNS is 44 * given the PNG file has a tRNS chunk, as follows: 45 * 46 * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white 47 * 2-bit: entry 0: transparent-green 48 * entry 1: 40%-red 49 * entry 2: 80%-blue 50 * entry 3: opaque-white 51 * 4-bit: the 16 combinations of the 2-bit case 52 * 8-bit: the 256 combinations of the 4-bit case 53 * 54 * The palette always has 2^bit-depth entries and the tRNS chunk one fewer. The 55 * image is the 1-channel diamond, but using palette index, not luminosity. 56 * 57 * For formats other than color-mapped ones if --tRNS is specified a tRNS chunk 58 * is generated with all channels equal to the low bits of 0x0101. 59 * 60 * Image size is determined by the final pixel depth in bits, i.e. channels x 61 * bit-depth, as follows: 62 * 63 * 8 bits or less: 64x64 64 * 16 bits: 256x256 65 * More than 16 bits: 1024x1024 66 * 67 * Row filtering is the libpng default but may be turned off (the 'none' filter 68 * is used on every row) with the --nofilters option. 69 * 70 * The images are not interlaced. 71 * 72 * If file-name is given then the PNG is written to that file, else it is 73 * written to stdout. Notice that stdout is not supported on systems where, by 74 * default, it assumes text output; this program makes no attempt to change the 75 * text mode of stdout! 76 * 77 * makepng --color=<color> ... 78 * 79 * If --color is given then the whole image has that color, color-mapped images 80 * will have exactly one palette entry and all image files with be 16x16 in 81 * size. The color value is 1 to 4 decimal numbers as appropriate for the color 82 * type. 83 * 84 * makepng --small ... 85 * 86 * If --small is given the images are no larger than required to include every 87 * possible pixel value for the format. 88 * 89 * For formats with pixels 8 bits or fewer in size the images consist of a 90 * single row with 2^pixel-depth pixels, one of every possible value. 91 * 92 * For formats with 16-bit pixels a 256x256 image is generated containing every 93 * possible pixel value. 94 * 95 * For larger pixel sizes a 256x256 image is generated where the first row 96 * consists of each pixel that has identical byte values throughout the pixel 97 * followed by rows where the byte values differ within the pixel. 98 * 99 * In all cases the pixel values are arranged in such a way that the SUB and UP 100 * filters give byte sequences for maximal zlib compression. By default (if 101 * --nofilters is not given) the SUB filter is used on the first row and the UP 102 * filter on all following rows. 103 * 104 * The --small option is meant to provide good test-case coverage, however the 105 * images are not easy to examine visually. Without the --small option the 106 * images contain identical color values; the pixel values are adjusted 107 * according to the gamma encoding with no gamma encoding being interpreted as 108 * sRGB. 109 * 110 * LICENSING 111 * ========= 112 * 113 * This code is copyright of the authors, see the COPYRIGHT define above. The 114 * code is licensed as above, using the libpng license. The code generates 115 * images which are solely the product of the code; the options choose which of 116 * the many possibilities to generate. The images that result (but not the code 117 * which generates them) are licensed as defined here: 118 * 119 * IMPORTANT: the COPYRIGHT #define must contain ISO-Latin-1 characters, the 120 * IMAGE_LICENSING #define must contain UTF-8 characters. The 'copyright' 121 * symbol 0xA9U (\251) in ISO-Latin-1 encoding and 0xC20xA9 (\302\251) in UTF-8. 122 */ 123#define IMAGE_LICENSING "Dedicated to the public domain per Creative Commons "\ 124 "license \"CC0 1.0\"; https://creativecommons.org/publicdomain/zero/1.0/" 125 126#include <stddef.h> /* for offsetof */ 127#include <stdlib.h> 128#include <stdio.h> 129#include <string.h> 130#include <ctype.h> 131#include <math.h> 132#include <errno.h> 133#include <assert.h> 134#include <stdint.h> 135 136#if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H) 137# include <config.h> 138#endif 139 140/* Define the following to use this test against your installed libpng, rather 141 * than the one being built here: 142 */ 143#ifdef PNG_FREESTANDING_TESTS 144# include <png.h> 145#else 146# include "../../png.h" 147#endif 148 149#include <zlib.h> 150 151/* Work round for GCC complaints about casting a (double) function result to 152 * an unsigned: 153 */ 154static unsigned int 155flooru(double d) 156{ 157 d = floor(d); 158 return (unsigned int)d; 159} 160 161static png_byte 162floorb(double d) 163{ 164 d = floor(d); 165 return (png_byte)d; 166} 167 168/* This structure is used for inserting extra chunks (the --insert argument, not 169 * documented above.) 170 */ 171typedef struct chunk_insert 172{ 173 struct chunk_insert *next; 174 void (*insert)(png_structp, png_infop, int, png_charpp); 175 int nparams; 176 png_charp parameters[1]; 177} chunk_insert; 178 179static unsigned int 180channels_of_type(int color_type) 181{ 182 if (color_type & PNG_COLOR_MASK_PALETTE) 183 return 1; 184 185 else 186 { 187 int channels = 1; 188 189 if (color_type & PNG_COLOR_MASK_COLOR) 190 channels = 3; 191 192 if (color_type & PNG_COLOR_MASK_ALPHA) 193 return channels + 1; 194 195 else 196 return channels; 197 } 198} 199 200static unsigned int 201pixel_depth_of_type(int color_type, int bit_depth) 202{ 203 return channels_of_type(color_type) * bit_depth; 204} 205 206static unsigned int 207image_size_of_type(int color_type, int bit_depth, unsigned int *colors, 208 int small) 209{ 210 if (*colors) 211 return 16; 212 213 else 214 { 215 int pixel_depth = pixel_depth_of_type(color_type, bit_depth); 216 217 if (small) 218 { 219 if (pixel_depth <= 8) /* there will be one row */ 220 return 1 << pixel_depth; 221 222 else 223 return 256; 224 } 225 226 else if (pixel_depth < 8) 227 return 64; 228 229 else if (pixel_depth > 16) 230 return 1024; 231 232 else 233 return 256; 234 } 235} 236 237static void 238set_color(png_colorp color, png_bytep trans, unsigned int red, 239 unsigned int green, unsigned int blue, unsigned int alpha, 240 png_const_bytep gamma_table) 241{ 242 color->red = gamma_table[red]; 243 color->green = gamma_table[green]; 244 color->blue = gamma_table[blue]; 245 *trans = (png_byte)alpha; 246} 247 248static int 249generate_palette(png_colorp palette, png_bytep trans, int bit_depth, 250 png_const_bytep gamma_table, unsigned int *colors) 251{ 252 /* 253 * 1-bit: entry 0 is transparent-red, entry 1 is opaque-white 254 * 2-bit: entry 0: transparent-green 255 * entry 1: 40%-red 256 * entry 2: 80%-blue 257 * entry 3: opaque-white 258 * 4-bit: the 16 combinations of the 2-bit case 259 * 8-bit: the 256 combinations of the 4-bit case 260 */ 261 switch (colors[0]) 262 { 263 default: 264 fprintf(stderr, "makepng: --colors=...: invalid count %u\n", 265 colors[0]); 266 exit(1); 267 268 case 1: 269 set_color(palette+0, trans+0, colors[1], colors[1], colors[1], 255, 270 gamma_table); 271 return 1; 272 273 case 2: 274 set_color(palette+0, trans+0, colors[1], colors[1], colors[1], 275 colors[2], gamma_table); 276 return 1; 277 278 case 3: 279 set_color(palette+0, trans+0, colors[1], colors[2], colors[3], 255, 280 gamma_table); 281 return 1; 282 283 case 4: 284 set_color(palette+0, trans+0, colors[1], colors[2], colors[3], 285 colors[4], gamma_table); 286 return 1; 287 288 case 0: 289 if (bit_depth == 1) 290 { 291 set_color(palette+0, trans+0, 255, 0, 0, 0, gamma_table); 292 set_color(palette+1, trans+1, 255, 255, 255, 255, gamma_table); 293 return 2; 294 } 295 296 else 297 { 298 unsigned int size = 1U << (bit_depth/2); /* 2, 4 or 16 */ 299 unsigned int x, y; 300 volatile unsigned int ip = 0; 301 302 for (x=0; x<size; ++x) for (y=0; y<size; ++y) 303 { 304 ip = x + (size * y); 305 306 /* size is at most 16, so the scaled value below fits in 16 bits 307 */ 308# define interp(pos, c1, c2) ((pos * c1) + ((size-pos) * c2)) 309# define xyinterp(x, y, c1, c2, c3, c4) (((size * size / 2) +\ 310 (interp(x, c1, c2) * y + (size-y) * interp(x, c3, c4))) /\ 311 (size*size)) 312 313 set_color(palette+ip, trans+ip, 314 /* color: green, red,blue,white */ 315 xyinterp(x, y, 0, 255, 0, 255), 316 xyinterp(x, y, 255, 0, 0, 255), 317 xyinterp(x, y, 0, 0, 255, 255), 318 /* alpha: 0, 102, 204, 255) */ 319 xyinterp(x, y, 0, 102, 204, 255), 320 gamma_table); 321 } 322 323 return ip+1; 324 } 325 } 326} 327 328static void 329set_value(png_bytep row, size_t rowbytes, png_uint_32 x, unsigned int bit_depth, 330 png_uint_32 value, png_const_bytep gamma_table, double conv) 331{ 332 unsigned int mask = (1U << bit_depth)-1; 333 334 x *= bit_depth; /* Maximum x is 4*1024, maximum bit_depth is 16 */ 335 336 if (value <= mask) 337 { 338 png_uint_32 offset = x >> 3; 339 340 if (offset < rowbytes && (bit_depth < 16 || offset+1 < rowbytes)) 341 { 342 row += offset; 343 344 switch (bit_depth) 345 { 346 case 1: 347 case 2: 348 case 4: 349 /* Don't gamma correct - values get smashed */ 350 { 351 unsigned int shift = (8 - bit_depth) - (x & 0x7U); 352 353 mask <<= shift; 354 value = (value << shift) & mask; 355 *row = (png_byte)((*row & ~mask) | value); 356 } 357 return; 358 359 default: 360 fprintf(stderr, "makepng: bad bit depth (internal error)\n"); 361 exit(1); 362 363 case 16: 364 value = flooru(65535*pow(value/65535.,conv)+.5); 365 *row++ = (png_byte)(value >> 8); 366 *row = (png_byte)value; 367 return; 368 369 case 8: 370 *row = gamma_table[value]; 371 return; 372 } 373 } 374 375 else 376 { 377 fprintf(stderr, "makepng: row buffer overflow (internal error)\n"); 378 exit(1); 379 } 380 } 381 382 else 383 { 384 fprintf(stderr, "makepng: component overflow (internal error)\n"); 385 exit(1); 386 } 387} 388 389static int /* filter mask for row */ 390generate_row(png_bytep row, size_t rowbytes, unsigned int y, int color_type, 391 int bit_depth, png_const_bytep gamma_table, double conv, 392 unsigned int *colors, int small) 393{ 394 int filters = 0; /* file *MASK*, 0 means the default, not NONE */ 395 png_uint_32 size_max = 396 image_size_of_type(color_type, bit_depth, colors, small)-1; 397 png_uint_32 depth_max = (1U << bit_depth)-1; /* up to 65536 */ 398 399 if (colors[0] == 0) if (small) 400 { 401 unsigned int pixel_depth = pixel_depth_of_type(color_type, bit_depth); 402 403 /* For pixel depths less than 16 generate a single row containing all the 404 * possible pixel values. For 16 generate all 65536 byte pair 405 * combinations in a 256x256 pixel array. 406 */ 407 switch (pixel_depth) 408 { 409 case 1: 410 assert(y == 0 && rowbytes == 1 && size_max == 1); 411 row[0] = 0x6CU; /* binary: 01101100, only top 2 bits used */ 412 filters = PNG_FILTER_NONE; 413 break; 414 415 case 2: 416 assert(y == 0 && rowbytes == 1 && size_max == 3); 417 row[0] = 0x1BU; /* binary 00011011, all bits used */ 418 filters = PNG_FILTER_NONE; 419 break; 420 421 case 4: 422 assert(y == 0 && rowbytes == 8 && size_max == 15); 423 row[0] = 0x01U; 424 row[1] = 0x23U; /* SUB gives 0x22U for all following bytes */ 425 row[2] = 0x45U; 426 row[3] = 0x67U; 427 row[4] = 0x89U; 428 row[5] = 0xABU; 429 row[6] = 0xCDU; 430 row[7] = 0xEFU; 431 filters = PNG_FILTER_SUB; 432 break; 433 434 case 8: 435 /* The row will have all the pixel values in order starting with 436 * '1', the SUB filter will change every byte into '1' (including 437 * the last, which generates pixel value '0'). Since the SUB filter 438 * has value 1 this should result in maximum compression. 439 */ 440 assert(y == 0 && rowbytes == 256 && size_max == 255); 441 for (;;) 442 { 443 row[size_max] = 0xFFU & (size_max+1); 444 if (size_max == 0) 445 break; 446 --size_max; 447 } 448 filters = PNG_FILTER_SUB; 449 break; 450 451 case 16: 452 /* Rows are generated such that each row has a constant difference 453 * between the first and second byte of each pixel and so that the 454 * difference increases by 1 at each row. The rows start with the 455 * first byte value of 0 and the value increases to 255 across the 456 * row. 457 * 458 * The difference starts at 1, so the first row is: 459 * 460 * 0 1 1 2 2 3 3 4 ... 254 255 255 0 461 * 462 * This means that running the SUB filter on the first row produces: 463 * 464 * [SUB==1] 0 1 0 1 0 1... 465 * 466 * Then the difference is 2 on the next row, giving: 467 * 468 * 0 2 1 3 2 4 3 5 ... 254 0 255 1 469 * 470 * When the UP filter is run on this libpng produces: 471 * 472 * [UP ==2] 0 1 0 1 0 1... 473 * 474 * And so on for all the remain rows to the final two * rows: 475 * 476 * row 254: 0 255 1 0 2 1 3 2 4 3 ... 254 253 255 254 477 * row 255: 0 0 1 1 2 2 3 3 4 4 ... 254 254 255 255 478 */ 479 assert(rowbytes == 512 && size_max == 255); 480 for (;;) 481 { 482 row[2*size_max ] = 0xFFU & size_max; 483 row[2*size_max+1] = 0xFFU & (size_max+y+1); 484 if (size_max == 0) 485 break; 486 --size_max; 487 } 488 /* The first row must include PNG_FILTER_UP so that libpng knows we 489 * need to keep it for the following row: 490 */ 491 filters = (y == 0 ? PNG_FILTER_SUB+PNG_FILTER_UP : PNG_FILTER_UP); 492 break; 493 494 case 24: 495 case 32: 496 case 48: 497 case 64: 498 /* The rows are filled by an alogorithm similar to the above, in the 499 * first row pixel bytes are all equal, increasing from 0 by 1 for 500 * each pixel. In the second row the bytes within a pixel are 501 * incremented 1,3,5,7,... from the previous row byte. Using an odd 502 * number ensures all the possible byte values are used. 503 */ 504 assert(size_max == 255 && rowbytes == 256*(pixel_depth>>3)); 505 pixel_depth >>= 3; /* now in bytes */ 506 while (rowbytes > 0) 507 { 508 const size_t pixel_index = --rowbytes/pixel_depth; 509 510 if (y == 0) 511 row[rowbytes] = 0xFFU & pixel_index; 512 513 else 514 { 515 const size_t byte_offset = 516 rowbytes - pixel_index * pixel_depth; 517 518 row[rowbytes] = 519 0xFFU & (pixel_index + (byte_offset * 2*y) + 1); 520 } 521 } 522 filters = (y == 0 ? PNG_FILTER_SUB+PNG_FILTER_UP : PNG_FILTER_UP); 523 break; 524 525 default: 526 assert(0/*NOT REACHED*/); 527 } 528 } 529 530 else switch (channels_of_type(color_type)) 531 { 532 /* 1 channel: a square image with a diamond, the least luminous colors are on 533 * the edge of the image, the most luminous in the center. 534 */ 535 case 1: 536 { 537 png_uint_32 x; 538 png_uint_32 base = 2*size_max - abs(2*y-size_max); 539 540 for (x=0; x<=size_max; ++x) 541 { 542 png_uint_32 luma = base - abs(2*x-size_max); 543 544 /* 'luma' is now in the range 0..2*size_max, we need 545 * 0..depth_max 546 */ 547 luma = (luma*depth_max + size_max) / (2*size_max); 548 set_value(row, rowbytes, x, bit_depth, luma, gamma_table, conv); 549 } 550 } 551 break; 552 553 /* 2 channels: the color channel increases in luminosity from top to bottom, 554 * the alpha channel increases in opacity from left to right. 555 */ 556 case 2: 557 { 558 png_uint_32 alpha = (depth_max * y * 2 + size_max) / (2 * size_max); 559 png_uint_32 x; 560 561 for (x=0; x<=size_max; ++x) 562 { 563 set_value(row, rowbytes, 2*x, bit_depth, 564 (depth_max * x * 2 + size_max) / (2 * size_max), gamma_table, 565 conv); 566 set_value(row, rowbytes, 2*x+1, bit_depth, alpha, gamma_table, 567 conv); 568 } 569 } 570 break; 571 572 /* 3 channels: linear combinations of, from the top-left corner clockwise, 573 * black, green, white, red. 574 */ 575 case 3: 576 { 577 /* x0: the black->red scale (the value of the red component) at the 578 * start of the row (blue and green are 0). 579 * x1: the green->white scale (the value of the red and blue 580 * components at the end of the row; green is depth_max). 581 */ 582 png_uint_32 Y = (depth_max * y * 2 + size_max) / (2 * size_max); 583 png_uint_32 x; 584 585 /* Interpolate x/depth_max from start to end: 586 * 587 * start end difference 588 * red: Y Y 0 589 * green: 0 depth_max depth_max 590 * blue: 0 Y Y 591 */ 592 for (x=0; x<=size_max; ++x) 593 { 594 set_value(row, rowbytes, 3*x+0, bit_depth, /* red */ Y, 595 gamma_table, conv); 596 set_value(row, rowbytes, 3*x+1, bit_depth, /* green */ 597 (depth_max * x * 2 + size_max) / (2 * size_max), 598 gamma_table, conv); 599 set_value(row, rowbytes, 3*x+2, bit_depth, /* blue */ 600 (Y * x * 2 + size_max) / (2 * size_max), 601 gamma_table, conv); 602 } 603 } 604 break; 605 606 /* 4 channels: linear combinations of, from the top-left corner clockwise, 607 * transparent, red, green, blue. 608 */ 609 case 4: 610 { 611 /* x0: the transparent->blue scale (the value of the blue and alpha 612 * components) at the start of the row (red and green are 0). 613 * x1: the red->green scale (the value of the red and green 614 * components at the end of the row; blue is 0 and alpha is 615 * depth_max). 616 */ 617 png_uint_32 Y = (depth_max * y * 2 + size_max) / (2 * size_max); 618 png_uint_32 x; 619 620 /* Interpolate x/depth_max from start to end: 621 * 622 * start end difference 623 * red: 0 depth_max-Y depth_max-Y 624 * green: 0 Y Y 625 * blue: Y 0 -Y 626 * alpha: Y depth_max depth_max-Y 627 */ 628 for (x=0; x<=size_max; ++x) 629 { 630 set_value(row, rowbytes, 4*x+0, bit_depth, /* red */ 631 ((depth_max-Y) * x * 2 + size_max) / (2 * size_max), 632 gamma_table, conv); 633 set_value(row, rowbytes, 4*x+1, bit_depth, /* green */ 634 (Y * x * 2 + size_max) / (2 * size_max), 635 gamma_table, conv); 636 set_value(row, rowbytes, 4*x+2, bit_depth, /* blue */ 637 Y - (Y * x * 2 + size_max) / (2 * size_max), 638 gamma_table, conv); 639 set_value(row, rowbytes, 4*x+3, bit_depth, /* alpha */ 640 Y + ((depth_max-Y) * x * 2 + size_max) / (2 * size_max), 641 gamma_table, conv); 642 } 643 } 644 break; 645 646 default: 647 fprintf(stderr, "makepng: internal bad channel count\n"); 648 exit(2); 649 } 650 651 else if (color_type & PNG_COLOR_MASK_PALETTE) 652 { 653 /* Palette with fixed color: the image rows are all 0 and the image width 654 * is 16. 655 */ 656 memset(row, 0, rowbytes); 657 } 658 659 else if (colors[0] == channels_of_type(color_type)) 660 switch (channels_of_type(color_type)) 661 { 662 case 1: 663 { 664 const png_uint_32 luma = colors[1]; 665 png_uint_32 x; 666 667 for (x=0; x<=size_max; ++x) 668 set_value(row, rowbytes, x, bit_depth, luma, gamma_table, 669 conv); 670 } 671 break; 672 673 case 2: 674 { 675 const png_uint_32 luma = colors[1]; 676 const png_uint_32 alpha = colors[2]; 677 png_uint_32 x; 678 679 for (x=0; x<size_max; ++x) 680 { 681 set_value(row, rowbytes, 2*x, bit_depth, luma, gamma_table, 682 conv); 683 set_value(row, rowbytes, 2*x+1, bit_depth, alpha, gamma_table, 684 conv); 685 } 686 } 687 break; 688 689 case 3: 690 { 691 const png_uint_32 red = colors[1]; 692 const png_uint_32 green = colors[2]; 693 const png_uint_32 blue = colors[3]; 694 png_uint_32 x; 695 696 for (x=0; x<=size_max; ++x) 697 { 698 set_value(row, rowbytes, 3*x+0, bit_depth, red, gamma_table, 699 conv); 700 set_value(row, rowbytes, 3*x+1, bit_depth, green, gamma_table, 701 conv); 702 set_value(row, rowbytes, 3*x+2, bit_depth, blue, gamma_table, 703 conv); 704 } 705 } 706 break; 707 708 case 4: 709 { 710 const png_uint_32 red = colors[1]; 711 const png_uint_32 green = colors[2]; 712 const png_uint_32 blue = colors[3]; 713 const png_uint_32 alpha = colors[4]; 714 png_uint_32 x; 715 716 for (x=0; x<=size_max; ++x) 717 { 718 set_value(row, rowbytes, 4*x+0, bit_depth, red, gamma_table, 719 conv); 720 set_value(row, rowbytes, 4*x+1, bit_depth, green, gamma_table, 721 conv); 722 set_value(row, rowbytes, 4*x+2, bit_depth, blue, gamma_table, 723 conv); 724 set_value(row, rowbytes, 4*x+3, bit_depth, alpha, gamma_table, 725 conv); 726 } 727 } 728 break; 729 730 default: 731 fprintf(stderr, "makepng: internal bad channel count\n"); 732 exit(2); 733 } 734 735 else 736 { 737 fprintf(stderr, 738 "makepng: --color: count(%u) does not match channels(%u)\n", 739 colors[0], channels_of_type(color_type)); 740 exit(1); 741 } 742 743 return filters; 744} 745 746 747static void PNGCBAPI 748makepng_warning(png_structp png_ptr, png_const_charp message) 749{ 750 const char **ep = png_get_error_ptr(png_ptr); 751 const char *name; 752 753 if (ep != NULL && *ep != NULL) 754 name = *ep; 755 756 else 757 name = "makepng"; 758 759 fprintf(stderr, "%s: warning: %s\n", name, message); 760} 761 762static void PNGCBAPI 763makepng_error(png_structp png_ptr, png_const_charp message) 764{ 765 makepng_warning(png_ptr, message); 766 png_longjmp(png_ptr, 1); 767} 768 769static int /* 0 on success, else an error code */ 770write_png(const char **name, FILE *fp, int color_type, int bit_depth, 771 volatile png_fixed_point gamma, chunk_insert * volatile insert, 772 unsigned int filters, unsigned int *colors, int small, int tRNS) 773{ 774 png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, 775 name, makepng_error, makepng_warning); 776 volatile png_infop info_ptr = NULL; 777 volatile png_bytep row = NULL; 778 779 if (png_ptr == NULL) 780 { 781 fprintf(stderr, "makepng: OOM allocating write structure\n"); 782 return 1; 783 } 784 785 if (setjmp(png_jmpbuf(png_ptr))) 786 { 787 png_structp nv_ptr = png_ptr; 788 png_infop nv_info = info_ptr; 789 790 png_ptr = NULL; 791 info_ptr = NULL; 792 png_destroy_write_struct(&nv_ptr, &nv_info); 793 if (row != NULL) free(row); 794 return 1; 795 } 796 797 /* Allow benign errors so that we can write PNGs with errors */ 798 png_set_benign_errors(png_ptr, 1/*allowed*/); 799 800 /* Max out the text compression level in an attempt to make the license 801 * small. If --small then do the same for the IDAT. 802 */ 803 if (small) 804 png_set_compression_level(png_ptr, Z_BEST_COMPRESSION); 805 806 png_set_text_compression_level(png_ptr, Z_BEST_COMPRESSION); 807 808 png_init_io(png_ptr, fp); 809 810 info_ptr = png_create_info_struct(png_ptr); 811 if (info_ptr == NULL) 812 png_error(png_ptr, "OOM allocating info structure"); 813 814 { 815 const unsigned int size = 816 image_size_of_type(color_type, bit_depth, colors, small); 817 unsigned int ysize; 818 png_fixed_point real_gamma = 45455; /* For sRGB */ 819 png_byte gamma_table[256]; 820 double conv; 821 822 /* Normally images are square, but with 'small' we want to simply generate 823 * all the pixel values, or all that we reasonably can: 824 */ 825 if (small) 826 { 827 const unsigned int pixel_depth = 828 pixel_depth_of_type(color_type, bit_depth); 829 830 if (pixel_depth <= 8U) 831 { 832 assert(size == (1U<<pixel_depth)); 833 ysize = 1U; 834 } 835 836 else 837 { 838 assert(size == 256U); 839 ysize = 256U; 840 } 841 } 842 843 else 844 ysize = size; 845 846 /* This function uses the libpng values used on read to carry extra 847 * information about the gamma: 848 */ 849 if (gamma == PNG_GAMMA_MAC_18) 850 gamma = 65909; 851 852 else if (gamma > 0 && gamma < 1000) 853 gamma = PNG_FP_1; 854 855 if (gamma > 0) 856 real_gamma = gamma; 857 858 { 859 unsigned int i; 860 861 if (real_gamma == 45455) for (i=0; i<256; ++i) 862 { 863 gamma_table[i] = (png_byte)i; 864 conv = 1.; 865 } 866 867 else 868 { 869 /* Convert 'i' from sRGB (45455) to real_gamma, this makes 870 * the images look the same regardless of the gAMA chunk. 871 */ 872 conv = real_gamma; 873 conv /= 45455; 874 875 gamma_table[0] = 0; 876 877 for (i=1; i<255; ++i) 878 gamma_table[i] = floorb(pow(i/255.,conv) * 255 + .5); 879 880 gamma_table[255] = 255; 881 } 882 } 883 884 png_set_IHDR(png_ptr, info_ptr, size, ysize, bit_depth, color_type, 885 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); 886 887 if (color_type & PNG_COLOR_MASK_PALETTE) 888 { 889 int npalette; 890 png_color palette[256]; 891 png_byte trans[256]; 892 893 npalette = generate_palette(palette, trans, bit_depth, gamma_table, 894 colors); 895 png_set_PLTE(png_ptr, info_ptr, palette, npalette); 896 897 if (tRNS) 898 png_set_tRNS(png_ptr, info_ptr, trans, npalette-1, 899 NULL/*transparent color*/); 900 901 /* Reset gamma_table to prevent the image rows being changed */ 902 for (npalette=0; npalette<256; ++npalette) 903 gamma_table[npalette] = (png_byte)npalette; 904 } 905 906 else if (tRNS) 907 { 908 png_color_16 col; 909 910 col.red = col.green = col.blue = col.gray = 911 0x0101U & ((1U<<bit_depth)-1U); 912 col.index = 0U; 913 png_set_tRNS(png_ptr, info_ptr, NULL/*trans*/, 1U, &col); 914 } 915 916 if (gamma == PNG_DEFAULT_sRGB) 917 png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_ABSOLUTE); 918 919 else if (gamma > 0) /* Else don't set color space information */ 920 { 921 png_set_gAMA_fixed(png_ptr, info_ptr, real_gamma); 922 923 /* Just use the sRGB values here. */ 924 png_set_cHRM_fixed(png_ptr, info_ptr, 925 /* color x y */ 926 /* white */ 31270, 32900, 927 /* red */ 64000, 33000, 928 /* green */ 30000, 60000, 929 /* blue */ 15000, 6000 930 ); 931 } 932 933 /* Insert extra information. */ 934 while (insert != NULL) 935 { 936 insert->insert(png_ptr, info_ptr, insert->nparams, insert->parameters); 937 insert = insert->next; 938 } 939 940 /* Write the file header. */ 941 png_write_info(png_ptr, info_ptr); 942 943 /* Restrict the filters */ 944 png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, filters); 945 946 { 947# ifdef PNG_WRITE_INTERLACING_SUPPORTED 948 int passes = png_set_interlace_handling(png_ptr); 949# else /* !WRITE_INTERLACING */ 950 int passes = 1; 951# endif /* !WRITE_INTERLACING */ 952 int pass; 953 png_size_t rowbytes = png_get_rowbytes(png_ptr, info_ptr); 954 955 row = malloc(rowbytes); 956 957 if (row == NULL) 958 png_error(png_ptr, "OOM allocating row buffer"); 959 960 for (pass = 0; pass < passes; ++pass) 961 { 962 unsigned int y; 963 964 for (y=0; y<ysize; ++y) 965 { 966 unsigned int row_filters = 967 generate_row(row, rowbytes, y, color_type, bit_depth, 968 gamma_table, conv, colors, small); 969 970 if (row_filters != 0 && filters == PNG_ALL_FILTERS) 971 png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, row_filters); 972 973 png_write_row(png_ptr, row); 974 } 975 } 976 } 977 } 978 979 /* Finish writing the file. */ 980 png_write_end(png_ptr, info_ptr); 981 982 { 983 png_structp nv_ptr = png_ptr; 984 png_infop nv_info = info_ptr; 985 986 png_ptr = NULL; 987 info_ptr = NULL; 988 png_destroy_write_struct(&nv_ptr, &nv_info); 989 } 990 free(row); 991 return 0; 992} 993 994 995static size_t 996load_file(png_const_charp name, png_bytepp result) 997{ 998 FILE *fp = tmpfile(); 999 1000 if (fp != NULL) 1001 { 1002 FILE *ip = fopen(name, "rb"); 1003 1004 if (ip != NULL) 1005 { 1006 size_t total = 0; 1007 int ch; 1008 1009 for (;;) 1010 { 1011 ch = getc(ip); 1012 if (ch == EOF) break; 1013 putc(ch, fp); 1014 ++total; 1015 } 1016 1017 if (ferror(ip)) 1018 { 1019 perror(name); 1020 fprintf(stderr, "%s: read error\n", name); 1021 (void)fclose(ip); 1022 } 1023 1024 else 1025 { 1026 (void)fclose(ip); 1027 1028 if (ferror(fp)) 1029 { 1030 perror("temporary file"); 1031 fprintf(stderr, "temporary file write error\n"); 1032 } 1033 1034 else 1035 { 1036 rewind(fp); 1037 1038 if (total > 0) 1039 { 1040 /* Round up to a multiple of 4 here to allow an iCCP profile 1041 * to be padded to a 4x boundary. 1042 */ 1043 png_bytep data = malloc((total+3)&~3); 1044 1045 if (data != NULL) 1046 { 1047 size_t new_size = 0; 1048 1049 for (;;) 1050 { 1051 ch = getc(fp); 1052 if (ch == EOF) break; 1053 data[new_size++] = (png_byte)ch; 1054 } 1055 1056 if (ferror(fp) || new_size != total) 1057 { 1058 perror("temporary file"); 1059 fprintf(stderr, "temporary file read error\n"); 1060 free(data); 1061 } 1062 1063 else 1064 { 1065 (void)fclose(fp); 1066 *result = data; 1067 return total; 1068 } 1069 } 1070 1071 else 1072 fprintf(stderr, "%s: out of memory loading file\n", name); 1073 } 1074 1075 else 1076 fprintf(stderr, "%s: empty file\n", name); 1077 } 1078 } 1079 } 1080 1081 else 1082 { 1083 perror(name); 1084 fprintf(stderr, "%s: open failed\n", name); 1085 } 1086 1087 fclose(fp); 1088 } 1089 1090 else 1091 fprintf(stderr, "makepng: %s: could not open temporary file\n", name); 1092 1093 exit(1); 1094 return 0; 1095} 1096 1097static png_size_t 1098load_fake(png_charp param, png_bytepp profile) 1099{ 1100 char *endptr = NULL; 1101 uint64_t size = strtoull(param, &endptr, 0/*base*/); 1102 1103 /* The 'fake' format is <number>*[string] */ 1104 if (endptr != NULL && *endptr == '*') 1105 { 1106 size_t len = strlen(++endptr); 1107 size_t result = (size_t)size; 1108 1109 if (len == 0) len = 1; /* capture the terminating '\0' */ 1110 1111 /* Now repeat that string to fill 'size' bytes. */ 1112 if (result == size && (*profile = malloc(result)) != NULL) 1113 { 1114 png_bytep out = *profile; 1115 1116 if (len == 1) 1117 memset(out, *endptr, result); 1118 1119 else 1120 { 1121 while (size >= len) 1122 { 1123 memcpy(out, endptr, len); 1124 out += len; 1125 size -= len; 1126 } 1127 memcpy(out, endptr, size); 1128 } 1129 1130 return result; 1131 } 1132 1133 else 1134 { 1135 fprintf(stderr, "%s: size exceeds system limits\n", param); 1136 exit(1); 1137 } 1138 } 1139 1140 return 0; 1141} 1142 1143static void 1144check_param_count(int nparams, int expect) 1145{ 1146 if (nparams != expect) 1147 { 1148 fprintf(stderr, "bad parameter count (internal error)\n"); 1149 exit(1); 1150 } 1151} 1152 1153static void 1154insert_iCCP(png_structp png_ptr, png_infop info_ptr, int nparams, 1155 png_charpp params) 1156{ 1157 png_bytep profile = NULL; 1158 png_uint_32 proflen = 0; 1159 int result; 1160 1161 check_param_count(nparams, 2); 1162 1163 switch (params[1][0]) 1164 { 1165 case '<': 1166 { 1167 png_size_t filelen = load_file(params[1]+1, &profile); 1168 if (filelen > 0xfffffffc) /* Maximum profile length */ 1169 { 1170 fprintf(stderr, "%s: file too long (%lu) for an ICC profile\n", 1171 params[1]+1, (unsigned long)filelen); 1172 exit(1); 1173 } 1174 1175 proflen = (png_uint_32)filelen; 1176 } 1177 break; 1178 1179 case '0': case '1': case '2': case '3': case '4': 1180 case '5': case '6': case '7': case '8': case '9': 1181 { 1182 png_size_t fake_len = load_fake(params[1], &profile); 1183 1184 if (fake_len > 0) /* else a simple parameter */ 1185 { 1186 if (fake_len > 0xffffffff) /* Maximum profile length */ 1187 { 1188 fprintf(stderr, 1189 "%s: fake data too long (%lu) for an ICC profile\n", 1190 params[1], (unsigned long)fake_len); 1191 exit(1); 1192 } 1193 proflen = (png_uint_32)(fake_len & ~3U); 1194 /* Always fix up the profile length. */ 1195 png_save_uint_32(profile, proflen); 1196 break; 1197 } 1198 } 1199 1200 default: 1201 fprintf(stderr, "--insert iCCP \"%s\": unrecognized\n", params[1]); 1202 fprintf(stderr, " use '<' to read a file: \"<filename\"\n"); 1203 exit(1); 1204 } 1205 1206 result = 1; 1207 1208 if (proflen & 3) 1209 { 1210 fprintf(stderr, 1211 "makepng: --insert iCCP %s: profile length made a multiple of 4\n", 1212 params[1]); 1213 1214 /* load_file allocates extra space for this padding, the ICC spec requires 1215 * padding with zero bytes. 1216 */ 1217 while (proflen & 3) 1218 profile[proflen++] = 0; 1219 } 1220 1221 if (profile != NULL && proflen > 3) 1222 { 1223 png_uint_32 prof_header = png_get_uint_32(profile); 1224 1225 if (prof_header != proflen) 1226 { 1227 fprintf(stderr, "--insert iCCP %s: profile length field wrong:\n", 1228 params[1]); 1229 fprintf(stderr, " actual %lu, recorded value %lu (corrected)\n", 1230 (unsigned long)proflen, (unsigned long)prof_header); 1231 png_save_uint_32(profile, proflen); 1232 } 1233 } 1234 1235 if (result && profile != NULL && proflen >=4) 1236 png_set_iCCP(png_ptr, info_ptr, params[0], PNG_COMPRESSION_TYPE_BASE, 1237 profile, proflen); 1238 1239 if (profile) 1240 free(profile); 1241 1242 if (!result) 1243 exit(1); 1244} 1245 1246static void 1247clear_text(png_text *text, png_charp keyword) 1248{ 1249 text->compression = -1; /* none */ 1250 text->key = keyword; 1251 text->text = NULL; 1252 text->text_length = 0; /* libpng calculates this */ 1253 text->itxt_length = 0; /* libpng calculates this */ 1254 text->lang = NULL; 1255 text->lang_key = NULL; 1256} 1257 1258static void 1259set_text(png_structp png_ptr, png_infop info_ptr, png_textp text, 1260 png_charp param) 1261{ 1262 switch (param[0]) 1263 { 1264 case '<': 1265 { 1266 png_bytep file = NULL; 1267 1268 text->text_length = load_file(param+1, &file); 1269 text->text = (png_charp)file; 1270 } 1271 break; 1272 1273 case '0': case '1': case '2': case '3': case '4': 1274 case '5': case '6': case '7': case '8': case '9': 1275 { 1276 png_bytep data = NULL; 1277 png_size_t fake_len = load_fake(param, &data); 1278 1279 if (fake_len > 0) /* else a simple parameter */ 1280 { 1281 text->text_length = fake_len; 1282 text->text = (png_charp)data; 1283 break; 1284 } 1285 } 1286 1287 default: 1288 text->text = param; 1289 break; 1290 } 1291 1292 png_set_text(png_ptr, info_ptr, text, 1); 1293 1294 if (text->text != param) 1295 free(text->text); 1296} 1297 1298static void 1299insert_tEXt(png_structp png_ptr, png_infop info_ptr, int nparams, 1300 png_charpp params) 1301{ 1302 png_text text; 1303 1304 check_param_count(nparams, 2); 1305 clear_text(&text, params[0]); 1306 set_text(png_ptr, info_ptr, &text, params[1]); 1307} 1308 1309static void 1310insert_zTXt(png_structp png_ptr, png_infop info_ptr, int nparams, 1311 png_charpp params) 1312{ 1313 png_text text; 1314 1315 check_param_count(nparams, 2); 1316 clear_text(&text, params[0]); 1317 text.compression = 0; /* deflate */ 1318 set_text(png_ptr, info_ptr, &text, params[1]); 1319} 1320 1321static void 1322insert_iTXt(png_structp png_ptr, png_infop info_ptr, int nparams, 1323 png_charpp params) 1324{ 1325 png_text text; 1326 1327 check_param_count(nparams, 4); 1328 clear_text(&text, params[0]); 1329 text.compression = 2; /* iTXt + deflate */ 1330 text.lang = params[1];/* language tag */ 1331 text.lang_key = params[2]; /* translated keyword */ 1332 set_text(png_ptr, info_ptr, &text, params[3]); 1333} 1334 1335static void 1336insert_hIST(png_structp png_ptr, png_infop info_ptr, int nparams, 1337 png_charpp params) 1338{ 1339 int i; 1340 png_uint_16 freq[256]; 1341 1342 /* libpng takes the count from the PLTE count; we don't check it here but we 1343 * do set the array to 0 for unspecified entries. 1344 */ 1345 memset(freq, 0, sizeof freq); 1346 for (i=0; i<nparams; ++i) 1347 { 1348 char *endptr = NULL; 1349 unsigned long int l = strtoul(params[i], &endptr, 0/*base*/); 1350 1351 if (params[i][0] && *endptr == 0 && l <= 65535) 1352 freq[i] = (png_uint_16)l; 1353 1354 else 1355 { 1356 fprintf(stderr, "hIST[%d]: %s: invalid frequency\n", i, params[i]); 1357 exit(1); 1358 } 1359 } 1360 1361 png_set_hIST(png_ptr, info_ptr, freq); 1362} 1363 1364static png_byte 1365bval(png_const_structrp png_ptr, png_charp param, unsigned int maxval) 1366{ 1367 char *endptr = NULL; 1368 unsigned long int l = strtoul(param, &endptr, 0/*base*/); 1369 1370 if (param[0] && *endptr == 0 && l <= maxval) 1371 return (png_byte)l; 1372 1373 else 1374 png_error(png_ptr, "sBIT: invalid sBIT value"); 1375} 1376 1377static void 1378insert_sBIT(png_structp png_ptr, png_infop info_ptr, int nparams, 1379 png_charpp params) 1380{ 1381 const int ct = png_get_color_type(png_ptr, info_ptr); 1382 const int c = (ct & PNG_COLOR_MASK_COLOR ? 3 : 1) + 1383 (ct & PNG_COLOR_MASK_ALPHA ? 1 : 0); 1384 const unsigned int maxval = 1385 ct & PNG_COLOR_MASK_PALETTE ? 8U : png_get_bit_depth(png_ptr, info_ptr); 1386 png_color_8 sBIT; 1387 1388 if (nparams != c) 1389 png_error(png_ptr, "sBIT: incorrect parameter count"); 1390 1391 if (ct & PNG_COLOR_MASK_COLOR) 1392 { 1393 sBIT.red = bval(png_ptr, params[0], maxval); 1394 sBIT.green = bval(png_ptr, params[1], maxval); 1395 sBIT.blue = bval(png_ptr, params[2], maxval); 1396 sBIT.gray = 42; 1397 } 1398 1399 else 1400 { 1401 sBIT.red = sBIT.green = sBIT.blue = 42; 1402 sBIT.gray = bval(png_ptr, params[0], maxval); 1403 } 1404 1405 if (ct & PNG_COLOR_MASK_ALPHA) 1406 sBIT.alpha = bval(png_ptr, params[nparams-1], maxval); 1407 1408 else 1409 sBIT.alpha = 42; 1410 1411 png_set_sBIT(png_ptr, info_ptr, &sBIT); 1412} 1413 1414#if 0 1415static void 1416insert_sPLT(png_structp png_ptr, png_infop info_ptr, int nparams, png_charpp params) 1417{ 1418 fprintf(stderr, "insert sPLT: NYI\n"); 1419} 1420#endif 1421 1422static int 1423find_parameters(png_const_charp what, png_charp param, png_charp *list, 1424 int nparams) 1425{ 1426 /* Parameters are separated by '\n' or ':' characters, up to nparams are 1427 * accepted (more is an error) and the number found is returned. 1428 */ 1429 int i; 1430 for (i=0; *param && i<nparams; ++i) 1431 { 1432 list[i] = param; 1433 while (*++param) if (*param == '\n' || *param == ':') 1434 { 1435 *param++ = 0; /* Terminate last parameter */ 1436 break; /* And start a new one. */ 1437 } 1438 } 1439 1440 if (*param) 1441 { 1442 fprintf(stderr, "--insert %s: too many parameters (%s)\n", what, param); 1443 exit(1); 1444 } 1445 1446 list[i] = NULL; /* terminates list */ 1447 return i; /* number of parameters filled in */ 1448} 1449 1450static void 1451bad_parameter_count(png_const_charp what, int nparams) 1452{ 1453 fprintf(stderr, "--insert %s: bad parameter count %d\n", what, nparams); 1454 exit(1); 1455} 1456 1457static chunk_insert * 1458make_insert(png_const_charp what, 1459 void (*insert)(png_structp, png_infop, int, png_charpp), 1460 int nparams, png_charpp list) 1461{ 1462 int i; 1463 chunk_insert *cip; 1464 1465 cip = malloc(offsetof(chunk_insert,parameters) + 1466 nparams * sizeof (png_charp)); 1467 1468 if (cip == NULL) 1469 { 1470 fprintf(stderr, "--insert %s: out of memory allocating %d parameters\n", 1471 what, nparams); 1472 exit(1); 1473 } 1474 1475 cip->next = NULL; 1476 cip->insert = insert; 1477 cip->nparams = nparams; 1478 for (i=0; i<nparams; ++i) 1479 cip->parameters[i] = list[i]; 1480 1481 return cip; 1482} 1483 1484static chunk_insert * 1485find_insert(png_const_charp what, png_charp param) 1486{ 1487 png_uint_32 chunk = 0; 1488 png_charp parameter_list[1024]; 1489 int i, nparams; 1490 1491 /* Assemble the chunk name */ 1492 for (i=0; i<4; ++i) 1493 { 1494 char ch = what[i]; 1495 1496 if ((ch >= 65 && ch <= 90) || (ch >= 97 && ch <= 122)) 1497 chunk = (chunk << 8) + what[i]; 1498 1499 else 1500 break; 1501 } 1502 1503 if (i < 4 || what[4] != 0) 1504 { 1505 fprintf(stderr, "makepng --insert \"%s\": invalid chunk name\n", what); 1506 exit(1); 1507 } 1508 1509 /* Assemble the parameter list. */ 1510 nparams = find_parameters(what, param, parameter_list, 1024); 1511 1512# define CHUNK(a,b,c,d) (((a)<<24)+((b)<<16)+((c)<<8)+(d)) 1513 1514 switch (chunk) 1515 { 1516 case CHUNK(105,67,67,80): /* iCCP */ 1517 if (nparams == 2) 1518 return make_insert(what, insert_iCCP, nparams, parameter_list); 1519 break; 1520 1521 case CHUNK(116,69,88,116): /* tEXt */ 1522 if (nparams == 2) 1523 return make_insert(what, insert_tEXt, nparams, parameter_list); 1524 break; 1525 1526 case CHUNK(122,84,88,116): /* zTXt */ 1527 if (nparams == 2) 1528 return make_insert(what, insert_zTXt, nparams, parameter_list); 1529 break; 1530 1531 case CHUNK(105,84,88,116): /* iTXt */ 1532 if (nparams == 4) 1533 return make_insert(what, insert_iTXt, nparams, parameter_list); 1534 break; 1535 1536 case CHUNK(104,73,83,84): /* hIST */ 1537 if (nparams <= 256) 1538 return make_insert(what, insert_hIST, nparams, parameter_list); 1539 break; 1540 1541 case CHUNK(115,66,73,84): /* sBIT */ 1542 if (nparams <= 4) 1543 return make_insert(what, insert_sBIT, nparams, parameter_list); 1544 break; 1545 1546#if 0 1547 case CHUNK(115,80,76,84): /* sPLT */ 1548 return make_insert(what, insert_sPLT, nparams, parameter_list); 1549#endif 1550 1551 default: 1552 fprintf(stderr, "makepng --insert \"%s\": unrecognized chunk name\n", 1553 what); 1554 exit(1); 1555 } 1556 1557 bad_parameter_count(what, nparams); 1558 return NULL; 1559} 1560 1561/* This is necessary because libpng expects writeable strings for things like 1562 * text chunks (maybe this should be fixed...) 1563 */ 1564static png_charp 1565strstash(png_const_charp foo) 1566{ 1567 /* The program indicates a memory allocation error by crashing, this is by 1568 * design. 1569 */ 1570 if (foo != NULL) 1571 { 1572 png_charp bar = malloc(strlen(foo)+1); 1573 return strcpy(bar, foo); 1574 } 1575 1576 return NULL; 1577} 1578 1579static png_charp 1580strstash_list(const png_const_charp *text) 1581{ 1582 size_t foo = 0; 1583 png_charp result, bar; 1584 const png_const_charp *line = text; 1585 1586 while (*line != NULL) 1587 foo += strlen(*line++); 1588 1589 result = bar = malloc(foo+1); 1590 1591 line = text; 1592 while (*line != NULL) 1593 { 1594 foo = strlen(*line); 1595 memcpy(bar, *line++, foo); 1596 bar += foo; 1597 } 1598 1599 *bar = 0; 1600 return result; 1601} 1602 1603/* These are used to insert Copyright and Licence fields, they allow the text to 1604 * have \n unlike the --insert option. 1605 */ 1606static chunk_insert * 1607add_tEXt(const char *key, const png_const_charp *text) 1608{ 1609 static char what[5] = { 116, 69, 88, 116, 0 }; 1610 png_charp parameter_list[3]; 1611 1612 parameter_list[0] = strstash(key); 1613 parameter_list[1] = strstash_list(text); 1614 parameter_list[2] = NULL; 1615 1616 return make_insert(what, insert_tEXt, 2, parameter_list); 1617} 1618 1619static chunk_insert * 1620add_iTXt(const char *key, const char *language, const char *language_key, 1621 const png_const_charp *text) 1622{ 1623 static char what[5] = { 105, 84, 88, 116, 0 }; 1624 png_charp parameter_list[5]; 1625 1626 parameter_list[0] = strstash(key); 1627 parameter_list[1] = strstash(language); 1628 parameter_list[2] = strstash(language_key); 1629 parameter_list[3] = strstash_list(text); 1630 parameter_list[4] = NULL; 1631 1632 return make_insert(what, insert_iTXt, 4, parameter_list); 1633} 1634 1635/* This is a not-very-good parser for a sequence of numbers (including 0). It 1636 * doesn't accept some apparently valid things, but it accepts all the sensible 1637 * combinations. 1638 */ 1639static void 1640parse_color(char *arg, unsigned int *colors) 1641{ 1642 unsigned int ncolors = 0; 1643 1644 while (*arg && ncolors < 4) 1645 { 1646 char *ep = arg; 1647 1648 unsigned long ul = strtoul(arg, &ep, 0); 1649 1650 if (ul > 65535) 1651 { 1652 fprintf(stderr, "makepng --color=...'%s': too big\n", arg); 1653 exit(1); 1654 } 1655 1656 if (ep == arg) 1657 { 1658 fprintf(stderr, "makepng --color=...'%s': not a valid color\n", arg); 1659 exit(1); 1660 } 1661 1662 if (*ep) ++ep; /* skip a separator */ 1663 arg = ep; 1664 1665 colors[++ncolors] = (unsigned int)ul; /* checked above */ 1666 } 1667 1668 if (*arg) 1669 { 1670 fprintf(stderr, "makepng --color=...'%s': too many values\n", arg); 1671 exit(1); 1672 } 1673 1674 *colors = ncolors; 1675} 1676 1677int 1678main(int argc, char **argv) 1679{ 1680 FILE *fp = stdout; 1681 const char *file_name = NULL; 1682 int color_type = 8; /* invalid */ 1683 int bit_depth = 32; /* invalid */ 1684 int small = 0; /* make full size images */ 1685 int tRNS = 0; /* don't output a tRNS chunk */ 1686 unsigned int colors[5]; 1687 unsigned int filters = PNG_ALL_FILTERS; 1688 png_fixed_point gamma = 0; /* not set */ 1689 chunk_insert *head_insert = NULL; 1690 chunk_insert **insert_ptr = &head_insert; 1691 1692 memset(colors, 0, sizeof colors); 1693 1694 while (--argc > 0) 1695 { 1696 char *arg = *++argv; 1697 1698 if (strcmp(arg, "--small") == 0) 1699 { 1700 small = 1; 1701 continue; 1702 } 1703 1704 if (strcmp(arg, "--tRNS") == 0) 1705 { 1706 tRNS = 1; 1707 continue; 1708 } 1709 1710 if (strcmp(arg, "--sRGB") == 0) 1711 { 1712 gamma = PNG_DEFAULT_sRGB; 1713 continue; 1714 } 1715 1716 if (strcmp(arg, "--linear") == 0) 1717 { 1718 gamma = PNG_FP_1; 1719 continue; 1720 } 1721 1722 if (strcmp(arg, "--1.8") == 0) 1723 { 1724 gamma = PNG_GAMMA_MAC_18; 1725 continue; 1726 } 1727 1728 if (strcmp(arg, "--nofilters") == 0) 1729 { 1730 filters = PNG_FILTER_NONE; 1731 continue; 1732 } 1733 1734 if (strncmp(arg, "--color=", 8) == 0) 1735 { 1736 parse_color(arg+8, colors); 1737 continue; 1738 } 1739 1740 if (argc >= 3 && strcmp(arg, "--insert") == 0) 1741 { 1742 png_const_charp what = *++argv; 1743 png_charp param = *++argv; 1744 chunk_insert *new_insert; 1745 1746 argc -= 2; 1747 1748 new_insert = find_insert(what, param); 1749 1750 if (new_insert != NULL) 1751 { 1752 *insert_ptr = new_insert; 1753 insert_ptr = &new_insert->next; 1754 } 1755 1756 continue; 1757 } 1758 1759 if (arg[0] == '-') 1760 { 1761 fprintf(stderr, "makepng: %s: invalid option\n", arg); 1762 exit(1); 1763 } 1764 1765 if (strcmp(arg, "palette") == 0) 1766 { 1767 color_type = PNG_COLOR_TYPE_PALETTE; 1768 continue; 1769 } 1770 1771 if (strncmp(arg, "gray", 4) == 0) 1772 { 1773 if (arg[4] == 0) 1774 { 1775 color_type = PNG_COLOR_TYPE_GRAY; 1776 continue; 1777 } 1778 1779 else if (strcmp(arg+4, "a") == 0 || 1780 strcmp(arg+4, "alpha") == 0 || 1781 strcmp(arg+4, "-alpha") == 0) 1782 { 1783 color_type = PNG_COLOR_TYPE_GRAY_ALPHA; 1784 continue; 1785 } 1786 } 1787 1788 if (strncmp(arg, "rgb", 3) == 0) 1789 { 1790 if (arg[3] == 0) 1791 { 1792 color_type = PNG_COLOR_TYPE_RGB; 1793 continue; 1794 } 1795 1796 else if (strcmp(arg+3, "a") == 0 || 1797 strcmp(arg+3, "alpha") == 0 || 1798 strcmp(arg+3, "-alpha") == 0) 1799 { 1800 color_type = PNG_COLOR_TYPE_RGB_ALPHA; 1801 continue; 1802 } 1803 } 1804 1805 if (color_type == 8 && isdigit(arg[0])) 1806 { 1807 color_type = atoi(arg); 1808 if (color_type < 0 || color_type > 6 || color_type == 1 || 1809 color_type == 5) 1810 { 1811 fprintf(stderr, "makepng: %s: not a valid color type\n", arg); 1812 exit(1); 1813 } 1814 1815 continue; 1816 } 1817 1818 if (bit_depth == 32 && isdigit(arg[0])) 1819 { 1820 bit_depth = atoi(arg); 1821 if (bit_depth <= 0 || bit_depth > 16 || 1822 (bit_depth & -bit_depth) != bit_depth) 1823 { 1824 fprintf(stderr, "makepng: %s: not a valid bit depth\n", arg); 1825 exit(1); 1826 } 1827 1828 continue; 1829 } 1830 1831 if (argc == 1) /* It's the file name */ 1832 { 1833 fp = fopen(arg, "wb"); 1834 if (fp == NULL) 1835 { 1836 fprintf(stderr, "%s: %s: could not open\n", arg, strerror(errno)); 1837 exit(1); 1838 } 1839 1840 file_name = arg; 1841 continue; 1842 } 1843 1844 fprintf(stderr, "makepng: %s: unknown argument\n", arg); 1845 exit(1); 1846 } /* argument while loop */ 1847 1848 if (color_type == 8 || bit_depth == 32) 1849 { 1850 fprintf(stderr, "usage: makepng [--small] [--sRGB|--linear|--1.8] " 1851 "[--color=...] color-type bit-depth [file-name]\n" 1852 " Make a test PNG file, by default writes to stdout.\n" 1853 " Other options are available, UTSL.\n"); 1854 exit(1); 1855 } 1856 1857 /* Check the colors */ 1858 { 1859 const unsigned int lim = (color_type == PNG_COLOR_TYPE_PALETTE ? 255U : 1860 (1U<<bit_depth)-1); 1861 unsigned int i; 1862 1863 for (i=1; i<=colors[0]; ++i) 1864 if (colors[i] > lim) 1865 { 1866 fprintf(stderr, "makepng: --color=...: %u out of range [0..%u]\n", 1867 colors[i], lim); 1868 exit(1); 1869 } 1870 } 1871 1872 /* small and colors are incomparible (will probably crash if both are used at 1873 * the same time!) 1874 */ 1875 if (small && colors[0] != 0) 1876 { 1877 fprintf(stderr, "makepng: --color --small: only one at a time!\n"); 1878 exit(1); 1879 } 1880 1881 /* Restrict the filters for more speed to those we know are used for the 1882 * generated images. 1883 */ 1884 if (filters == PNG_ALL_FILTERS && !small/*small provides defaults*/) 1885 { 1886 if ((color_type & PNG_COLOR_MASK_PALETTE) != 0 || bit_depth < 8) 1887 filters = PNG_FILTER_NONE; 1888 1889 else if (color_type & PNG_COLOR_MASK_COLOR) /* rgb */ 1890 { 1891 if (bit_depth == 8) 1892 filters &= ~(PNG_FILTER_NONE | PNG_FILTER_AVG); 1893 1894 else 1895 filters = PNG_FILTER_SUB | PNG_FILTER_PAETH; 1896 } 1897 1898 else /* gray 8 or 16-bit */ 1899 filters &= ~PNG_FILTER_NONE; 1900 } 1901 1902 /* Insert standard copyright and licence text. */ 1903 { 1904 static png_const_charp copyright[] = 1905 { 1906 COPYRIGHT, /* ISO-Latin-1 */ 1907 NULL 1908 }; 1909 static png_const_charp licensing[] = 1910 { 1911 IMAGE_LICENSING, /* UTF-8 */ 1912 NULL 1913 }; 1914 1915 chunk_insert *new_insert; 1916 1917 new_insert = add_tEXt("Copyright", copyright); 1918 if (new_insert != NULL) 1919 { 1920 *insert_ptr = new_insert; 1921 insert_ptr = &new_insert->next; 1922 } 1923 1924 new_insert = add_iTXt("Licensing", "en", NULL, licensing); 1925 if (new_insert != NULL) 1926 { 1927 *insert_ptr = new_insert; 1928 insert_ptr = &new_insert->next; 1929 } 1930 } 1931 1932 { 1933 int ret = write_png(&file_name, fp, color_type, bit_depth, gamma, 1934 head_insert, filters, colors, small, tRNS); 1935 1936 if (ret != 0 && file_name != NULL) 1937 remove(file_name); 1938 1939 return ret; 1940 } 1941} 1942