share/png/contrib/libtests/makepng.c

   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  */
 102 typedef 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
 110 static int
 111 channels_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
 131 static int
 132 pixel_depth_of_type(int color_type, int bit_depth)
 133 {
 134    return channels_of_type(color_type) * bit_depth;
 135 }
 136
 137 static unsigned int
 138 image_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
 158 static void
 159 set_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
 169 static int
 170 generate_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
 248 static void
 249 set_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
 309 static void
 310 generate_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
 532 static void PNGCBAPI
 533 makepng_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
 547 static void PNGCBAPI
 548 makepng_error(png_structp png_ptr, png_const_charp message)
 549 {
 550    makepng_warning(png_ptr, message);
 551    png_longjmp(png_ptr, 1);
 552 }
 553
 554 static int /* 0 on success, else an error code */
 555 write_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
 724 static size_t
 725 load_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
 826 static png_size_t
 827 load_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
 872 static void
 873 check_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
 882 static void
 883 insert_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
 975 static void
 976 clear_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
 987 static void
 988 set_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
1027 static void
1028 insert_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
1038 static void
1039 insert_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
1050 static void
1051 insert_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
1064 static void
1065 insert_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
1093 static void
1094 insert_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
1100 static int
1101 find_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
1128 static void
1129 bad_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
1135 static chunk_insert *
1136 make_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
1162 static chunk_insert *
1163 find_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  */
1238 static void
1239 parse_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
1276 int
1277 main(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 }