src/png/pngget.c

   1
   2 /* pngget.c - retrieval of values from info struct
   3  *
   4  * Last changed in libpng 1.5.7 [December 15, 2011]
   5  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
   6  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
   7  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
   8  *
   9  * This code is released under the libpng license.
  10  * For conditions of distribution and use, see the disclaimer
  11  * and license in png.h
  12  *
  13  */
  14
  15 #include "pngpriv.h"
  16
  17 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
  18
  19 png_uint_32 PNGAPI
  20 png_get_valid(png_const_structp png_ptr, png_const_infop info_ptr,
  21     png_uint_32 flag)
  22 {
  23    if (png_ptr != NULL && info_ptr != NULL)
  24       return(info_ptr->valid & flag);
  25
  26    return(0);
  27 }
  28
  29 png_size_t PNGAPI
  30 png_get_rowbytes(png_const_structp png_ptr, png_const_infop info_ptr)
  31 {
  32    if (png_ptr != NULL && info_ptr != NULL)
  33       return(info_ptr->rowbytes);
  34
  35    return(0);
  36 }
  37
  38 #ifdef PNG_INFO_IMAGE_SUPPORTED
  39 png_bytepp PNGAPI
  40 png_get_rows(png_const_structp png_ptr, png_const_infop info_ptr)
  41 {
  42    if (png_ptr != NULL && info_ptr != NULL)
  43       return(info_ptr->row_pointers);
  44
  45    return(0);
  46 }
  47 #endif
  48
  49 #ifdef PNG_EASY_ACCESS_SUPPORTED
  50 /* Easy access to info, added in libpng-0.99 */
  51 png_uint_32 PNGAPI
  52 png_get_image_width(png_const_structp png_ptr, png_const_infop info_ptr)
  53 {
  54    if (png_ptr != NULL && info_ptr != NULL)
  55       return info_ptr->width;
  56
  57    return (0);
  58 }
  59
  60 png_uint_32 PNGAPI
  61 png_get_image_height(png_const_structp png_ptr, png_const_infop info_ptr)
  62 {
  63    if (png_ptr != NULL && info_ptr != NULL)
  64       return info_ptr->height;
  65
  66    return (0);
  67 }
  68
  69 png_byte PNGAPI
  70 png_get_bit_depth(png_const_structp png_ptr, png_const_infop info_ptr)
  71 {
  72    if (png_ptr != NULL && info_ptr != NULL)
  73       return info_ptr->bit_depth;
  74
  75    return (0);
  76 }
  77
  78 png_byte PNGAPI
  79 png_get_color_type(png_const_structp png_ptr, png_const_infop info_ptr)
  80 {
  81    if (png_ptr != NULL && info_ptr != NULL)
  82       return info_ptr->color_type;
  83
  84    return (0);
  85 }
  86
  87 png_byte PNGAPI
  88 png_get_filter_type(png_const_structp png_ptr, png_const_infop info_ptr)
  89 {
  90    if (png_ptr != NULL && info_ptr != NULL)
  91       return info_ptr->filter_type;
  92
  93    return (0);
  94 }
  95
  96 png_byte PNGAPI
  97 png_get_interlace_type(png_const_structp png_ptr, png_const_infop info_ptr)
  98 {
  99    if (png_ptr != NULL && info_ptr != NULL)
 100       return info_ptr->interlace_type;
 101
 102    return (0);
 103 }
 104
 105 png_byte PNGAPI
 106 png_get_compression_type(png_const_structp png_ptr, png_const_infop info_ptr)
 107 {
 108    if (png_ptr != NULL && info_ptr != NULL)
 109       return info_ptr->compression_type;
 110
 111    return (0);
 112 }
 113
 114 png_uint_32 PNGAPI
 115 png_get_x_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
 116 {
 117 #ifdef PNG_pHYs_SUPPORTED
 118    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
 119       {
 120          png_debug1(1, "in %s retrieval function",
 121              "png_get_x_pixels_per_meter");
 122
 123          if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
 124             return (info_ptr->x_pixels_per_unit);
 125       }
 126 #endif
 127
 128    return (0);
 129 }
 130
 131 png_uint_32 PNGAPI
 132 png_get_y_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
 133 {
 134 #ifdef PNG_pHYs_SUPPORTED
 135    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
 136    {
 137       png_debug1(1, "in %s retrieval function",
 138           "png_get_y_pixels_per_meter");
 139
 140       if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
 141          return (info_ptr->y_pixels_per_unit);
 142    }
 143 #endif
 144
 145    return (0);
 146 }
 147
 148 png_uint_32 PNGAPI
 149 png_get_pixels_per_meter(png_const_structp png_ptr, png_const_infop info_ptr)
 150 {
 151 #ifdef PNG_pHYs_SUPPORTED
 152    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
 153    {
 154       png_debug1(1, "in %s retrieval function", "png_get_pixels_per_meter");
 155
 156       if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER &&
 157           info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit)
 158          return (info_ptr->x_pixels_per_unit);
 159    }
 160 #endif
 161
 162    return (0);
 163 }
 164
 165 #ifdef PNG_FLOATING_POINT_SUPPORTED
 166 float PNGAPI
 167 png_get_pixel_aspect_ratio(png_const_structp png_ptr, png_const_infop info_ptr)
 168 {
 169 #ifdef PNG_READ_pHYs_SUPPORTED
 170    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
 171    {
 172       png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio");
 173
 174       if (info_ptr->x_pixels_per_unit != 0)
 175          return ((float)((float)info_ptr->y_pixels_per_unit
 176              /(float)info_ptr->x_pixels_per_unit));
 177    }
 178 #endif
 179
 180    return ((float)0.0);
 181 }
 182 #endif
 183
 184 #ifdef PNG_FIXED_POINT_SUPPORTED
 185 png_fixed_point PNGAPI
 186 png_get_pixel_aspect_ratio_fixed(png_const_structp png_ptr,
 187     png_const_infop info_ptr)
 188 {
 189 #ifdef PNG_READ_pHYs_SUPPORTED
 190    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)
 191        && info_ptr->x_pixels_per_unit > 0 && info_ptr->y_pixels_per_unit > 0
 192        && info_ptr->x_pixels_per_unit <= PNG_UINT_31_MAX
 193        && info_ptr->y_pixels_per_unit <= PNG_UINT_31_MAX)
 194    {
 195       png_fixed_point res;
 196
 197       png_debug1(1, "in %s retrieval function", "png_get_aspect_ratio_fixed");
 198
 199       /* The following casts work because a PNG 4 byte integer only has a valid
 200        * range of 0..2^31-1; otherwise the cast might overflow.
 201        */
 202       if (png_muldiv(&res, (png_int_32)info_ptr->y_pixels_per_unit, PNG_FP_1,
 203           (png_int_32)info_ptr->x_pixels_per_unit))
 204          return res;
 205    }
 206 #endif
 207
 208    return 0;
 209 }
 210 #endif
 211
 212 png_int_32 PNGAPI
 213 png_get_x_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr)
 214 {
 215 #ifdef PNG_oFFs_SUPPORTED
 216    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
 217    {
 218       png_debug1(1, "in %s retrieval function", "png_get_x_offset_microns");
 219
 220       if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
 221          return (info_ptr->x_offset);
 222    }
 223 #endif
 224
 225    return (0);
 226 }
 227
 228 png_int_32 PNGAPI
 229 png_get_y_offset_microns(png_const_structp png_ptr, png_const_infop info_ptr)
 230 {
 231 #ifdef PNG_oFFs_SUPPORTED
 232    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
 233    {
 234       png_debug1(1, "in %s retrieval function", "png_get_y_offset_microns");
 235
 236       if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
 237          return (info_ptr->y_offset);
 238    }
 239 #endif
 240
 241    return (0);
 242 }
 243
 244 png_int_32 PNGAPI
 245 png_get_x_offset_pixels(png_const_structp png_ptr, png_const_infop info_ptr)
 246 {
 247 #ifdef PNG_oFFs_SUPPORTED
 248    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
 249    {
 250       png_debug1(1, "in %s retrieval function", "png_get_x_offset_pixels");
 251
 252       if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
 253          return (info_ptr->x_offset);
 254    }
 255 #endif
 256
 257    return (0);
 258 }
 259
 260 png_int_32 PNGAPI
 261 png_get_y_offset_pixels(png_const_structp png_ptr, png_const_infop info_ptr)
 262 {
 263 #ifdef PNG_oFFs_SUPPORTED
 264    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
 265    {
 266       png_debug1(1, "in %s retrieval function", "png_get_y_offset_pixels");
 267
 268       if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
 269          return (info_ptr->y_offset);
 270    }
 271 #endif
 272
 273    return (0);
 274 }
 275
 276 #ifdef PNG_INCH_CONVERSIONS_SUPPORTED
 277 static png_uint_32
 278 ppi_from_ppm(png_uint_32 ppm)
 279 {
 280 #if 0
 281    /* The conversion is *(2.54/100), in binary (32 digits):
 282     * .00000110100000001001110101001001
 283     */
 284    png_uint_32 t1001, t1101;
 285    ppm >>= 1;                  /* .1 */
 286    t1001 = ppm + (ppm >> 3);   /* .1001 */
 287    t1101 = t1001 + (ppm >> 1); /* .1101 */
 288    ppm >>= 20;                 /* .000000000000000000001 */
 289    t1101 += t1101 >> 15;       /* .1101000000000001101 */
 290    t1001 >>= 11;               /* .000000000001001 */
 291    t1001 += t1001 >> 12;       /* .000000000001001000000001001 */
 292    ppm += t1001;               /* .000000000001001000001001001 */
 293    ppm += t1101;               /* .110100000001001110101001001 */
 294    return (ppm + 16) >> 5;/* .00000110100000001001110101001001 */
 295 #else
 296    /* The argument is a PNG unsigned integer, so it is not permitted
 297     * to be bigger than 2^31.
 298     */
 299    png_fixed_point result;
 300    if (ppm <= PNG_UINT_31_MAX && png_muldiv(&result, (png_int_32)ppm, 127,
 301        5000))
 302       return result;
 303
 304    /* Overflow. */
 305    return 0;
 306 #endif
 307 }
 308
 309 png_uint_32 PNGAPI
 310 png_get_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr)
 311 {
 312    return ppi_from_ppm(png_get_pixels_per_meter(png_ptr, info_ptr));
 313 }
 314
 315 png_uint_32 PNGAPI
 316 png_get_x_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr)
 317 {
 318    return ppi_from_ppm(png_get_x_pixels_per_meter(png_ptr, info_ptr));
 319 }
 320
 321 png_uint_32 PNGAPI
 322 png_get_y_pixels_per_inch(png_const_structp png_ptr, png_const_infop info_ptr)
 323 {
 324    return ppi_from_ppm(png_get_y_pixels_per_meter(png_ptr, info_ptr));
 325 }
 326
 327 #ifdef PNG_FIXED_POINT_SUPPORTED
 328 static png_fixed_point
 329 png_fixed_inches_from_microns(png_structp png_ptr, png_int_32 microns)
 330 {
 331    /* Convert from metres * 1,000,000 to inches * 100,000, meters to
 332     * inches is simply *(100/2.54), so we want *(10/2.54) == 500/127.
 333     * Notice that this can overflow - a warning is output and 0 is
 334     * returned.
 335     */
 336    return png_muldiv_warn(png_ptr, microns, 500, 127);
 337 }
 338
 339 png_fixed_point PNGAPI
 340 png_get_x_offset_inches_fixed(png_structp png_ptr,
 341     png_const_infop info_ptr)
 342 {
 343    return png_fixed_inches_from_microns(png_ptr,
 344        png_get_x_offset_microns(png_ptr, info_ptr));
 345 }
 346 #endif
 347
 348 #ifdef PNG_FIXED_POINT_SUPPORTED
 349 png_fixed_point PNGAPI
 350 png_get_y_offset_inches_fixed(png_structp png_ptr,
 351     png_const_infop info_ptr)
 352 {
 353    return png_fixed_inches_from_microns(png_ptr,
 354        png_get_y_offset_microns(png_ptr, info_ptr));
 355 }
 356 #endif
 357
 358 #ifdef PNG_FLOATING_POINT_SUPPORTED
 359 float PNGAPI
 360 png_get_x_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr)
 361 {
 362    /* To avoid the overflow do the conversion directly in floating
 363     * point.
 364     */
 365    return (float)(png_get_x_offset_microns(png_ptr, info_ptr) * .00003937);
 366 }
 367 #endif
 368
 369 #ifdef PNG_FLOATING_POINT_SUPPORTED
 370 float PNGAPI
 371 png_get_y_offset_inches(png_const_structp png_ptr, png_const_infop info_ptr)
 372 {
 373    /* To avoid the overflow do the conversion directly in floating
 374     * point.
 375     */
 376    return (float)(png_get_y_offset_microns(png_ptr, info_ptr) * .00003937);
 377 }
 378 #endif
 379
 380 #ifdef PNG_pHYs_SUPPORTED
 381 png_uint_32 PNGAPI
 382 png_get_pHYs_dpi(png_const_structp png_ptr, png_const_infop info_ptr,
 383     png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
 384 {
 385    png_uint_32 retval = 0;
 386
 387    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
 388    {
 389       png_debug1(1, "in %s retrieval function", "pHYs");
 390
 391       if (res_x != NULL)
 392       {
 393          *res_x = info_ptr->x_pixels_per_unit;
 394          retval |= PNG_INFO_pHYs;
 395       }
 396
 397       if (res_y != NULL)
 398       {
 399          *res_y = info_ptr->y_pixels_per_unit;
 400          retval |= PNG_INFO_pHYs;
 401       }
 402
 403       if (unit_type != NULL)
 404       {
 405          *unit_type = (int)info_ptr->phys_unit_type;
 406          retval |= PNG_INFO_pHYs;
 407
 408          if (*unit_type == 1)
 409          {
 410             if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
 411             if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
 412          }
 413       }
 414    }
 415
 416    return (retval);
 417 }
 418 #endif /* PNG_pHYs_SUPPORTED */
 419 #endif  /* PNG_INCH_CONVERSIONS_SUPPORTED */
 420
 421 /* png_get_channels really belongs in here, too, but it's been around longer */
 422
 423 #endif  /* PNG_EASY_ACCESS_SUPPORTED */
 424
 425 png_byte PNGAPI
 426 png_get_channels(png_const_structp png_ptr, png_const_infop info_ptr)
 427 {
 428    if (png_ptr != NULL && info_ptr != NULL)
 429       return(info_ptr->channels);
 430
 431    return (0);
 432 }
 433
 434 png_const_bytep PNGAPI
 435 png_get_signature(png_const_structp png_ptr, png_infop info_ptr)
 436 {
 437    if (png_ptr != NULL && info_ptr != NULL)
 438       return(info_ptr->signature);
 439
 440    return (NULL);
 441 }
 442
 443 #ifdef PNG_bKGD_SUPPORTED
 444 png_uint_32 PNGAPI
 445 png_get_bKGD(png_const_structp png_ptr, png_infop info_ptr,
 446    png_color_16p *background)
 447 {
 448    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
 449        && background != NULL)
 450    {
 451       png_debug1(1, "in %s retrieval function", "bKGD");
 452
 453       *background = &(info_ptr->background);
 454       return (PNG_INFO_bKGD);
 455    }
 456
 457    return (0);
 458 }
 459 #endif
 460
 461 #ifdef PNG_cHRM_SUPPORTED
 462 /* The XYZ APIs were added in 1.5.5 to take advantage of the code added at the
 463  * same time to correct the rgb grayscale coefficient defaults obtained from the
 464  * cHRM chunk in 1.5.4
 465  */
 466 png_uint_32 PNGFAPI
 467 png_get_cHRM_XYZ_fixed(png_structp png_ptr, png_const_infop info_ptr,
 468     png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
 469     png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
 470     png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
 471     png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
 472     png_fixed_point *int_blue_Z)
 473 {
 474    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
 475    {
 476       png_xy xy;
 477       png_XYZ XYZ;
 478
 479       png_debug1(1, "in %s retrieval function", "cHRM_XYZ");
 480
 481       xy.whitex = info_ptr->x_white;
 482       xy.whitey = info_ptr->y_white;
 483       xy.redx = info_ptr->x_red;
 484       xy.redy = info_ptr->y_red;
 485       xy.greenx = info_ptr->x_green;
 486       xy.greeny = info_ptr->y_green;
 487       xy.bluex = info_ptr->x_blue;
 488       xy.bluey = info_ptr->y_blue;
 489
 490       /* The *_checked function handles error reporting, so just return 0 if
 491        * there is a failure here.
 492        */
 493       if (png_XYZ_from_xy_checked(png_ptr, &XYZ, xy))
 494       {
 495          if (int_red_X != NULL)
 496             *int_red_X = XYZ.redX;
 497          if (int_red_Y != NULL)
 498             *int_red_Y = XYZ.redY;
 499          if (int_red_Z != NULL)
 500             *int_red_Z = XYZ.redZ;
 501          if (int_green_X != NULL)
 502             *int_green_X = XYZ.greenX;
 503          if (int_green_Y != NULL)
 504             *int_green_Y = XYZ.greenY;
 505          if (int_green_Z != NULL)
 506             *int_green_Z = XYZ.greenZ;
 507          if (int_blue_X != NULL)
 508             *int_blue_X = XYZ.blueX;
 509          if (int_blue_Y != NULL)
 510             *int_blue_Y = XYZ.blueY;
 511          if (int_blue_Z != NULL)
 512             *int_blue_Z = XYZ.blueZ;
 513
 514          return (PNG_INFO_cHRM);
 515       }
 516    }
 517
 518    return (0);
 519 }
 520
 521 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 522 png_uint_32 PNGAPI
 523 png_get_cHRM(png_const_structp png_ptr, png_const_infop info_ptr,
 524     double *white_x, double *white_y, double *red_x, double *red_y,
 525     double *green_x, double *green_y, double *blue_x, double *blue_y)
 526 {
 527    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
 528    {
 529       png_debug1(1, "in %s retrieval function", "cHRM");
 530
 531       if (white_x != NULL)
 532          *white_x = png_float(png_ptr, info_ptr->x_white, "cHRM white X");
 533       if (white_y != NULL)
 534          *white_y = png_float(png_ptr, info_ptr->y_white, "cHRM white Y");
 535       if (red_x != NULL)
 536          *red_x = png_float(png_ptr, info_ptr->x_red, "cHRM red X");
 537       if (red_y != NULL)
 538          *red_y = png_float(png_ptr, info_ptr->y_red, "cHRM red Y");
 539       if (green_x != NULL)
 540          *green_x = png_float(png_ptr, info_ptr->x_green, "cHRM green X");
 541       if (green_y != NULL)
 542          *green_y = png_float(png_ptr, info_ptr->y_green, "cHRM green Y");
 543       if (blue_x != NULL)
 544          *blue_x = png_float(png_ptr, info_ptr->x_blue, "cHRM blue X");
 545       if (blue_y != NULL)
 546          *blue_y = png_float(png_ptr, info_ptr->y_blue, "cHRM blue Y");
 547       return (PNG_INFO_cHRM);
 548    }
 549
 550    return (0);
 551 }
 552
 553 png_uint_32 PNGAPI
 554 png_get_cHRM_XYZ(png_structp png_ptr, png_const_infop info_ptr,
 555    double *red_X, double *red_Y, double *red_Z, double *green_X,
 556    double *green_Y, double *green_Z, double *blue_X, double *blue_Y,
 557    double *blue_Z)
 558 {
 559    png_XYZ XYZ;
 560
 561    if (png_get_cHRM_XYZ_fixed(png_ptr, info_ptr,
 562       &XYZ.redX, &XYZ.redY, &XYZ.redZ, &XYZ.greenX, &XYZ.greenY, &XYZ.greenZ,
 563       &XYZ.blueX, &XYZ.blueY, &XYZ.blueZ) & PNG_INFO_cHRM)
 564    {
 565       if (red_X != NULL)
 566          *red_X = png_float(png_ptr, XYZ.redX, "cHRM red X");
 567       if (red_Y != NULL)
 568          *red_Y = png_float(png_ptr, XYZ.redY, "cHRM red Y");
 569       if (red_Z != NULL)
 570          *red_Z = png_float(png_ptr, XYZ.redZ, "cHRM red Z");
 571       if (green_X != NULL)
 572          *green_X = png_float(png_ptr, XYZ.greenX, "cHRM green X");
 573       if (green_Y != NULL)
 574          *green_Y = png_float(png_ptr, XYZ.greenY, "cHRM green Y");
 575       if (green_Z != NULL)
 576          *green_Z = png_float(png_ptr, XYZ.greenZ, "cHRM green Z");
 577       if (blue_X != NULL)
 578          *blue_X = png_float(png_ptr, XYZ.blueX, "cHRM blue X");
 579       if (blue_Y != NULL)
 580          *blue_Y = png_float(png_ptr, XYZ.blueY, "cHRM blue Y");
 581       if (blue_Z != NULL)
 582          *blue_Z = png_float(png_ptr, XYZ.blueZ, "cHRM blue Z");
 583       return (PNG_INFO_cHRM);
 584    }
 585
 586    return (0);
 587 }
 588 #  endif
 589
 590 #  ifdef PNG_FIXED_POINT_SUPPORTED
 591 png_uint_32 PNGAPI
 592 png_get_cHRM_fixed(png_const_structp png_ptr, png_const_infop info_ptr,
 593     png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
 594     png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
 595     png_fixed_point *blue_x, png_fixed_point *blue_y)
 596 {
 597    png_debug1(1, "in %s retrieval function", "cHRM");
 598
 599    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
 600    {
 601       if (white_x != NULL)
 602          *white_x = info_ptr->x_white;
 603       if (white_y != NULL)
 604          *white_y = info_ptr->y_white;
 605       if (red_x != NULL)
 606          *red_x = info_ptr->x_red;
 607       if (red_y != NULL)
 608          *red_y = info_ptr->y_red;
 609       if (green_x != NULL)
 610          *green_x = info_ptr->x_green;
 611       if (green_y != NULL)
 612          *green_y = info_ptr->y_green;
 613       if (blue_x != NULL)
 614          *blue_x = info_ptr->x_blue;
 615       if (blue_y != NULL)
 616          *blue_y = info_ptr->y_blue;
 617       return (PNG_INFO_cHRM);
 618    }
 619
 620    return (0);
 621 }
 622 #  endif
 623 #endif
 624
 625 #ifdef PNG_gAMA_SUPPORTED
 626 png_uint_32 PNGFAPI
 627 png_get_gAMA_fixed(png_const_structp png_ptr, png_const_infop info_ptr,
 628     png_fixed_point *file_gamma)
 629 {
 630    png_debug1(1, "in %s retrieval function", "gAMA");
 631
 632    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
 633        && file_gamma != NULL)
 634    {
 635       *file_gamma = info_ptr->gamma;
 636       return (PNG_INFO_gAMA);
 637    }
 638
 639    return (0);
 640 }
 641 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 642 png_uint_32 PNGAPI
 643 png_get_gAMA(png_const_structp png_ptr, png_const_infop info_ptr,
 644     double *file_gamma)
 645 {
 646    png_fixed_point igamma;
 647    png_uint_32 ok = png_get_gAMA_fixed(png_ptr, info_ptr, &igamma);
 648
 649    if (ok)
 650       *file_gamma = png_float(png_ptr, igamma, "png_get_gAMA");
 651
 652    return ok;
 653 }
 654
 655 #  endif
 656 #endif
 657
 658 #ifdef PNG_sRGB_SUPPORTED
 659 png_uint_32 PNGAPI
 660 png_get_sRGB(png_const_structp png_ptr, png_const_infop info_ptr,
 661     int *file_srgb_intent)
 662 {
 663    png_debug1(1, "in %s retrieval function", "sRGB");
 664
 665    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
 666        && file_srgb_intent != NULL)
 667    {
 668       *file_srgb_intent = (int)info_ptr->srgb_intent;
 669       return (PNG_INFO_sRGB);
 670    }
 671
 672    return (0);
 673 }
 674 #endif
 675
 676 #ifdef PNG_iCCP_SUPPORTED
 677 png_uint_32 PNGAPI
 678 png_get_iCCP(png_const_structp png_ptr, png_const_infop info_ptr,
 679     png_charpp name, int *compression_type,
 680     png_bytepp profile, png_uint_32 *proflen)
 681 {
 682    png_debug1(1, "in %s retrieval function", "iCCP");
 683
 684    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
 685        && name != NULL && compression_type != NULL && profile != NULL &&
 686                  proflen != NULL)
 687    {
 688       *name = info_ptr->iccp_name;
 689       *profile = info_ptr->iccp_profile;
 690       /* Compression_type is a dummy so the API won't have to change
 691        * if we introduce multiple compression types later.
 692        */
 693       *proflen = info_ptr->iccp_proflen;
 694       *compression_type = info_ptr->iccp_compression;
 695       return (PNG_INFO_iCCP);
 696    }
 697
 698    return (0);
 699 }
 700 #endif
 701
 702 #ifdef PNG_sPLT_SUPPORTED
 703 png_uint_32 PNGAPI
 704 png_get_sPLT(png_const_structp png_ptr, png_const_infop info_ptr,
 705     png_sPLT_tpp spalettes)
 706 {
 707    if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
 708    {
 709       *spalettes = info_ptr->splt_palettes;
 710       return ((png_uint_32)info_ptr->splt_palettes_num);
 711    }
 712
 713    return (0);
 714 }
 715 #endif
 716
 717 #ifdef PNG_hIST_SUPPORTED
 718 png_uint_32 PNGAPI
 719 png_get_hIST(png_const_structp png_ptr, png_const_infop info_ptr,
 720     png_uint_16p *hist)
 721 {
 722    png_debug1(1, "in %s retrieval function", "hIST");
 723
 724    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)
 725        && hist != NULL)
 726    {
 727       *hist = info_ptr->hist;
 728       return (PNG_INFO_hIST);
 729    }
 730
 731    return (0);
 732 }
 733 #endif
 734
 735 png_uint_32 PNGAPI
 736 png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
 737     png_uint_32 *width, png_uint_32 *height, int *bit_depth,
 738     int *color_type, int *interlace_type, int *compression_type,
 739     int *filter_type)
 740
 741 {
 742    png_debug1(1, "in %s retrieval function", "IHDR");
 743
 744    if (png_ptr == NULL || info_ptr == NULL || width == NULL ||
 745        height == NULL || bit_depth == NULL || color_type == NULL)
 746       return (0);
 747
 748    *width = info_ptr->width;
 749    *height = info_ptr->height;
 750    *bit_depth = info_ptr->bit_depth;
 751    *color_type = info_ptr->color_type;
 752
 753    if (compression_type != NULL)
 754       *compression_type = info_ptr->compression_type;
 755
 756    if (filter_type != NULL)
 757       *filter_type = info_ptr->filter_type;
 758
 759    if (interlace_type != NULL)
 760       *interlace_type = info_ptr->interlace_type;
 761
 762    /* This is redundant if we can be sure that the info_ptr values were all
 763     * assigned in png_set_IHDR().  We do the check anyhow in case an
 764     * application has ignored our advice not to mess with the members
 765     * of info_ptr directly.
 766     */
 767    png_check_IHDR (png_ptr, info_ptr->width, info_ptr->height,
 768        info_ptr->bit_depth, info_ptr->color_type, info_ptr->interlace_type,
 769        info_ptr->compression_type, info_ptr->filter_type);
 770
 771    return (1);
 772 }
 773
 774 #ifdef PNG_oFFs_SUPPORTED
 775 png_uint_32 PNGAPI
 776 png_get_oFFs(png_const_structp png_ptr, png_const_infop info_ptr,
 777     png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
 778 {
 779    png_debug1(1, "in %s retrieval function", "oFFs");
 780
 781    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
 782        && offset_x != NULL && offset_y != NULL && unit_type != NULL)
 783    {
 784       *offset_x = info_ptr->x_offset;
 785       *offset_y = info_ptr->y_offset;
 786       *unit_type = (int)info_ptr->offset_unit_type;
 787       return (PNG_INFO_oFFs);
 788    }
 789
 790    return (0);
 791 }
 792 #endif
 793
 794 #ifdef PNG_pCAL_SUPPORTED
 795 png_uint_32 PNGAPI
 796 png_get_pCAL(png_const_structp png_ptr, png_const_infop info_ptr,
 797     png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
 798     png_charp *units, png_charpp *params)
 799 {
 800    png_debug1(1, "in %s retrieval function", "pCAL");
 801
 802    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)
 803        && purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
 804        nparams != NULL && units != NULL && params != NULL)
 805    {
 806       *purpose = info_ptr->pcal_purpose;
 807       *X0 = info_ptr->pcal_X0;
 808       *X1 = info_ptr->pcal_X1;
 809       *type = (int)info_ptr->pcal_type;
 810       *nparams = (int)info_ptr->pcal_nparams;
 811       *units = info_ptr->pcal_units;
 812       *params = info_ptr->pcal_params;
 813       return (PNG_INFO_pCAL);
 814    }
 815
 816    return (0);
 817 }
 818 #endif
 819
 820 #ifdef PNG_sCAL_SUPPORTED
 821 #  ifdef PNG_FIXED_POINT_SUPPORTED
 822 #    ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
 823 png_uint_32 PNGAPI
 824 png_get_sCAL_fixed(png_structp png_ptr, png_const_infop info_ptr,
 825     int *unit, png_fixed_point *width, png_fixed_point *height)
 826 {
 827    if (png_ptr != NULL && info_ptr != NULL &&
 828        (info_ptr->valid & PNG_INFO_sCAL))
 829    {
 830       *unit = info_ptr->scal_unit;
 831       /*TODO: make this work without FP support */
 832       *width = png_fixed(png_ptr, atof(info_ptr->scal_s_width), "sCAL width");
 833       *height = png_fixed(png_ptr, atof(info_ptr->scal_s_height),
 834          "sCAL height");
 835       return (PNG_INFO_sCAL);
 836    }
 837
 838    return(0);
 839 }
 840 #    endif /* FLOATING_ARITHMETIC */
 841 #  endif /* FIXED_POINT */
 842 #  ifdef PNG_FLOATING_POINT_SUPPORTED
 843 png_uint_32 PNGAPI
 844 png_get_sCAL(png_const_structp png_ptr, png_const_infop info_ptr,
 845     int *unit, double *width, double *height)
 846 {
 847    if (png_ptr != NULL && info_ptr != NULL &&
 848        (info_ptr->valid & PNG_INFO_sCAL))
 849    {
 850       *unit = info_ptr->scal_unit;
 851       *width = atof(info_ptr->scal_s_width);
 852       *height = atof(info_ptr->scal_s_height);
 853       return (PNG_INFO_sCAL);
 854    }
 855
 856    return(0);
 857 }
 858 #  endif /* FLOATING POINT */
 859 png_uint_32 PNGAPI
 860 png_get_sCAL_s(png_const_structp png_ptr, png_const_infop info_ptr,
 861     int *unit, png_charpp width, png_charpp height)
 862 {
 863    if (png_ptr != NULL && info_ptr != NULL &&
 864        (info_ptr->valid & PNG_INFO_sCAL))
 865    {
 866       *unit = info_ptr->scal_unit;
 867       *width = info_ptr->scal_s_width;
 868       *height = info_ptr->scal_s_height;
 869       return (PNG_INFO_sCAL);
 870    }
 871
 872    return(0);
 873 }
 874 #endif /* sCAL */
 875
 876 #ifdef PNG_pHYs_SUPPORTED
 877 png_uint_32 PNGAPI
 878 png_get_pHYs(png_const_structp png_ptr, png_const_infop info_ptr,
 879     png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
 880 {
 881    png_uint_32 retval = 0;
 882
 883    png_debug1(1, "in %s retrieval function", "pHYs");
 884
 885    if (png_ptr != NULL && info_ptr != NULL &&
 886        (info_ptr->valid & PNG_INFO_pHYs))
 887    {
 888       if (res_x != NULL)
 889       {
 890          *res_x = info_ptr->x_pixels_per_unit;
 891          retval |= PNG_INFO_pHYs;
 892       }
 893
 894       if (res_y != NULL)
 895       {
 896          *res_y = info_ptr->y_pixels_per_unit;
 897          retval |= PNG_INFO_pHYs;
 898       }
 899
 900       if (unit_type != NULL)
 901       {
 902          *unit_type = (int)info_ptr->phys_unit_type;
 903          retval |= PNG_INFO_pHYs;
 904       }
 905    }
 906
 907    return (retval);
 908 }
 909 #endif /* pHYs */
 910
 911 png_uint_32 PNGAPI
 912 png_get_PLTE(png_const_structp png_ptr, png_const_infop info_ptr,
 913     png_colorp *palette, int *num_palette)
 914 {
 915    png_debug1(1, "in %s retrieval function", "PLTE");
 916
 917    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE)
 918        && palette != NULL)
 919    {
 920       *palette = info_ptr->palette;
 921       *num_palette = info_ptr->num_palette;
 922       png_debug1(3, "num_palette = %d", *num_palette);
 923       return (PNG_INFO_PLTE);
 924    }
 925
 926    return (0);
 927 }
 928
 929 #ifdef PNG_sBIT_SUPPORTED
 930 png_uint_32 PNGAPI
 931 png_get_sBIT(png_const_structp png_ptr, png_infop info_ptr,
 932     png_color_8p *sig_bit)
 933 {
 934    png_debug1(1, "in %s retrieval function", "sBIT");
 935
 936    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)
 937        && sig_bit != NULL)
 938    {
 939       *sig_bit = &(info_ptr->sig_bit);
 940       return (PNG_INFO_sBIT);
 941    }
 942
 943    return (0);
 944 }
 945 #endif
 946
 947 #ifdef PNG_TEXT_SUPPORTED
 948 png_uint_32 PNGAPI
 949 png_get_text(png_const_structp png_ptr, png_const_infop info_ptr,
 950     png_textp *text_ptr, int *num_text)
 951 {
 952    if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
 953    {
 954       png_debug1(1, "in 0x%lx retrieval function",
 955          (unsigned long)png_ptr->chunk_name);
 956
 957       if (text_ptr != NULL)
 958          *text_ptr = info_ptr->text;
 959
 960       if (num_text != NULL)
 961          *num_text = info_ptr->num_text;
 962
 963       return ((png_uint_32)info_ptr->num_text);
 964    }
 965
 966    if (num_text != NULL)
 967       *num_text = 0;
 968
 969    return(0);
 970 }
 971 #endif
 972
 973 #ifdef PNG_tIME_SUPPORTED
 974 png_uint_32 PNGAPI
 975 png_get_tIME(png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
 976 {
 977    png_debug1(1, "in %s retrieval function", "tIME");
 978
 979    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)
 980        && mod_time != NULL)
 981    {
 982       *mod_time = &(info_ptr->mod_time);
 983       return (PNG_INFO_tIME);
 984    }
 985
 986    return (0);
 987 }
 988 #endif
 989
 990 #ifdef PNG_tRNS_SUPPORTED
 991 png_uint_32 PNGAPI
 992 png_get_tRNS(png_const_structp png_ptr, png_infop info_ptr,
 993     png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
 994 {
 995    png_uint_32 retval = 0;
 996    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
 997    {
 998       png_debug1(1, "in %s retrieval function", "tRNS");
 999
1000       if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
1001       {
1002          if (trans_alpha != NULL)
1003          {
1004             *trans_alpha = info_ptr->trans_alpha;
1005             retval |= PNG_INFO_tRNS;
1006          }
1007
1008          if (trans_color != NULL)
1009             *trans_color = &(info_ptr->trans_color);
1010       }
1011
1012       else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
1013       {
1014          if (trans_color != NULL)
1015          {
1016             *trans_color = &(info_ptr->trans_color);
1017             retval |= PNG_INFO_tRNS;
1018          }
1019
1020          if (trans_alpha != NULL)
1021             *trans_alpha = NULL;
1022       }
1023
1024       if (num_trans != NULL)
1025       {
1026          *num_trans = info_ptr->num_trans;
1027          retval |= PNG_INFO_tRNS;
1028       }
1029    }
1030
1031    return (retval);
1032 }
1033 #endif
1034
1035 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1036 int PNGAPI
1037 png_get_unknown_chunks(png_const_structp png_ptr, png_const_infop info_ptr,
1038     png_unknown_chunkpp unknowns)
1039 {
1040    if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
1041    {
1042       *unknowns = info_ptr->unknown_chunks;
1043       return info_ptr->unknown_chunks_num;
1044    }
1045
1046    return (0);
1047 }
1048 #endif
1049
1050 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1051 png_byte PNGAPI
1052 png_get_rgb_to_gray_status (png_const_structp png_ptr)
1053 {
1054    return (png_byte)(png_ptr ? png_ptr->rgb_to_gray_status : 0);
1055 }
1056 #endif
1057
1058 #ifdef PNG_USER_CHUNKS_SUPPORTED
1059 png_voidp PNGAPI
1060 png_get_user_chunk_ptr(png_const_structp png_ptr)
1061 {
1062    return (png_ptr ? png_ptr->user_chunk_ptr : NULL);
1063 }
1064 #endif
1065
1066 png_size_t PNGAPI
1067 png_get_compression_buffer_size(png_const_structp png_ptr)
1068 {
1069    return (png_ptr ? png_ptr->zbuf_size : 0);
1070 }
1071
1072 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
1073 /* These functions were added to libpng 1.2.6 and were enabled
1074  * by default in libpng-1.4.0 */
1075 png_uint_32 PNGAPI
1076 png_get_user_width_max (png_const_structp png_ptr)
1077 {
1078    return (png_ptr ? png_ptr->user_width_max : 0);
1079 }
1080
1081 png_uint_32 PNGAPI
1082 png_get_user_height_max (png_const_structp png_ptr)
1083 {
1084    return (png_ptr ? png_ptr->user_height_max : 0);
1085 }
1086
1087 /* This function was added to libpng 1.4.0 */
1088 png_uint_32 PNGAPI
1089 png_get_chunk_cache_max (png_const_structp png_ptr)
1090 {
1091    return (png_ptr ? png_ptr->user_chunk_cache_max : 0);
1092 }
1093
1094 /* This function was added to libpng 1.4.1 */
1095 png_alloc_size_t PNGAPI
1096 png_get_chunk_malloc_max (png_const_structp png_ptr)
1097 {
1098    return (png_ptr ? png_ptr->user_chunk_malloc_max : 0);
1099 }
1100 #endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
1101
1102 /* These functions were added to libpng 1.4.0 */
1103 #ifdef PNG_IO_STATE_SUPPORTED
1104 png_uint_32 PNGAPI
1105 png_get_io_state (png_structp png_ptr)
1106 {
1107    return png_ptr->io_state;
1108 }
1109
1110 png_uint_32 PNGAPI
1111 png_get_io_chunk_type (png_const_structp png_ptr)
1112 {
1113    return png_ptr->chunk_name;
1114 }
1115
1116 png_const_bytep PNGAPI
1117 png_get_io_chunk_name (png_structp png_ptr)
1118 {
1119    PNG_CSTRING_FROM_CHUNK(png_ptr->io_chunk_string, png_ptr->chunk_name);
1120    return png_ptr->io_chunk_string;
1121 }
1122 #endif /* ?PNG_IO_STATE_SUPPORTED */
1123
1124 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */