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1
2 /* pngget.c - retrieval of values from info struct
3 *
4 * libpng 1.0.3 - January 14, 1999
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
7 * Copyright (c) 1996, 1997 Andreas Dilger
8 * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
9 */
10
11 #define PNG_INTERNAL
12 #include "png.h"
13
14 png_uint_32
15 png_get_valid(png_structp png_ptr, png_infop info_ptr, png_uint_32 flag)
16 {
17 if (png_ptr != NULL && info_ptr != NULL)
18 return(info_ptr->valid & flag);
19 else
20 return(0);
21 }
22
23 png_uint_32
24 png_get_rowbytes(png_structp png_ptr, png_infop info_ptr)
25 {
26 if (png_ptr != NULL && info_ptr != NULL)
27 return(info_ptr->rowbytes);
28 else
29 return(0);
30 }
31
32 #ifdef PNG_EASY_ACCESS_SUPPORTED
33 /* easy access to info, added in libpng-0.99 */
34 png_uint_32
35 png_get_image_width(png_structp png_ptr, png_infop info_ptr)
36 {
37 if (png_ptr != NULL && info_ptr != NULL)
38 {
39 return info_ptr->width;
40 }
41 return (0);
42 }
43
44 png_uint_32
45 png_get_image_height(png_structp png_ptr, png_infop info_ptr)
46 {
47 if (png_ptr != NULL && info_ptr != NULL)
48 {
49 return info_ptr->height;
50 }
51 return (0);
52 }
53
54 png_byte
55 png_get_bit_depth(png_structp png_ptr, png_infop info_ptr)
56 {
57 if (png_ptr != NULL && info_ptr != NULL)
58 {
59 return info_ptr->bit_depth;
60 }
61 return (0);
62 }
63
64 png_byte
65 png_get_color_type(png_structp png_ptr, png_infop info_ptr)
66 {
67 if (png_ptr != NULL && info_ptr != NULL)
68 {
69 return info_ptr->color_type;
70 }
71 return (0);
72 }
73
74 png_byte
75 png_get_filter_type(png_structp png_ptr, png_infop info_ptr)
76 {
77 if (png_ptr != NULL && info_ptr != NULL)
78 {
79 return info_ptr->filter_type;
80 }
81 return (0);
82 }
83
84 png_byte
85 png_get_interlace_type(png_structp png_ptr, png_infop info_ptr)
86 {
87 if (png_ptr != NULL && info_ptr != NULL)
88 {
89 return info_ptr->interlace_type;
90 }
91 return (0);
92 }
93
94 png_byte
95 png_get_compression_type(png_structp png_ptr, png_infop info_ptr)
96 {
97 if (png_ptr != NULL && info_ptr != NULL)
98 {
99 return info_ptr->compression_type;
100 }
101 return (0);
102 }
103
104 png_uint_32
105 png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
106 {
107 #if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
108 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
109 {
110 png_debug1(1, "in %s retrieval function\n", "png_get_x_pixels_per_meter");
111 if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
112 return (0);
113 else return (info_ptr->x_pixels_per_unit);
114 }
115 else
116 #endif
117 return (0);
118 }
119
120 png_uint_32
121 png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
122 {
123 #if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
124 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
125 {
126 png_debug1(1, "in %s retrieval function\n", "png_get_y_pixels_per_meter");
127 if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
128 return (0);
129 else return (info_ptr->y_pixels_per_unit);
130 }
131 else
132 #endif
133 return (0);
134 }
135
136 png_uint_32
137 png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
138 {
139 #if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
140 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
141 {
142 png_debug1(1, "in %s retrieval function\n", "png_get_pixels_per_meter");
143 if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER ||
144 info_ptr->x_pixels_per_unit != info_ptr->y_pixels_per_unit)
145 return (0);
146 else return (info_ptr->x_pixels_per_unit);
147 }
148 else
149 #endif
150 return (0);
151 }
152
153 float
154 png_get_pixel_aspect_ratio(png_structp png_ptr, png_infop info_ptr)
155 {
156 #if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
157 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
158 {
159 png_debug1(1, "in %s retrieval function\n", "png_get_aspect_ratio");
160 if (info_ptr->x_pixels_per_unit == 0)
161 return ((float)0.0);
162 else
163 return ((float)info_ptr->y_pixels_per_unit
164 /(float)info_ptr->x_pixels_per_unit);
165 }
166 else
167 #endif
168 return ((float)0.0);
169 }
170
171 png_uint_32
172 png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr)
173 {
174 #if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
175 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
176 {
177 png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
178 if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
179 return (0);
180 else return (info_ptr->x_offset);
181 }
182 else
183 #endif
184 return (0);
185 }
186
187 png_uint_32
188 png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr)
189 {
190 #if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
191 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
192 {
193 png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
194 if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
195 return (0);
196 else return (info_ptr->y_offset);
197 }
198 else
199 #endif
200 return (0);
201 }
202
203 png_uint_32
204 png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr)
205 {
206 #if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
207 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
208 {
209 png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
210 if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
211 return (0);
212 else return (info_ptr->x_offset);
213 }
214 else
215 #endif
216 return (0);
217 }
218
219 png_uint_32
220 png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr)
221 {
222 #if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
223 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
224 {
225 png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
226 if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
227 return (0);
228 else return (info_ptr->y_offset);
229 }
230 else
231 #endif
232 return (0);
233 }
234
235 #ifdef PNG_INCH_CONVERSIONS
236 png_uint_32
237 png_get_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
238 {
239 return ((png_uint_32)((float)png_get_pixels_per_meter(png_ptr, info_ptr)
240 *.03937 +.5)
241 }
242
243 png_uint_32
244 png_get_x_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
245 {
246 return ((png_uint_32)((float)png_get_x_pixels_per_meter(png_ptr, info_ptr)
247 *.03937 +.5)
248 }
249
250 png_uint_32
251 png_get_y_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
252 {
253 return ((png_uint_32)((float)png_get_y_pixels_per_meter(png_ptr, info_ptr)
254 *.03937 +.5)
255 }
256
257 float
258 png_get_x_offset_inches(png_structp png_ptr, png_infop info_ptr)
259 {
260 return ((float)png_get_x_offset_microns(png_ptr, info_ptr)
261 *.03937/1000000. +.5)
262 }
263
264 float
265 png_get_y_offset_inches(png_structp png_ptr, png_infop info_ptr)
266 {
267 return ((float)png_get_y_offset_microns(png_ptr, info_ptr)
268 *.03937/1000000. +.5)
269 }
270
271 #if defined(PNG_READ_pHYs_SUPPORTED)
272 png_uint_32
273 png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr,
274 png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
275 {
276 png_uint_32 retval = 0;
277
278 if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
279 {
280 png_debug1(1, "in %s retrieval function\n", "pHYs");
281 if (res_x != NULL)
282 {
283 *res_x = info_ptr->x_pixels_per_unit;
284 retval |= PNG_INFO_pHYs;
285 }
286 if (res_y != NULL)
287 {
288 *res_y = info_ptr->y_pixels_per_unit;
289 retval |= PNG_INFO_pHYs;
290 }
291 if (unit_type != NULL)
292 {
293 *unit_type = (int)info_ptr->phys_unit_type;
294 retval |= PNG_INFO_pHYs;
295 if(unit_type == 1)
296 {
297 if (res_x != NULL) *res_x = (png_uint_32)(*res_x * 39.37 + .50);
298 if (res_y != NULL) *res_y = (png_uint_32)(*res_y * 39.37 + .50);
299 }
300 }
301 }
302 return (retval);
303 }
304 #endif /* PNG_READ_pHYs_SUPPORTED */
305 #endif /* PNG_INCH_CONVERSIONS */
306
307 /* png_get_channels really belongs in here, too, but it's been around longer */
308
309 #endif /* PNG_EASY_ACCESS_SUPPORTED */
310
311 png_byte
312 png_get_channels(png_structp png_ptr, png_infop info_ptr)
313 {
314 if (png_ptr != NULL && info_ptr != NULL)
315 return(info_ptr->channels);
316 else
317 return (0);
318 }
319
320 png_bytep
321 png_get_signature(png_structp png_ptr, png_infop info_ptr)
322 {
323 if (png_ptr != NULL && info_ptr != NULL)
324 return(info_ptr->signature);
325 else
326 return (NULL);
327 }
328
329 #if defined(PNG_READ_bKGD_SUPPORTED)
330 png_uint_32
331 png_get_bKGD(png_structp png_ptr, png_infop info_ptr,
332 png_color_16p *background)
333 {
334 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD)
335 && background != NULL)
336 {
337 png_debug1(1, "in %s retrieval function\n", "bKGD");
338 *background = &(info_ptr->background);
339 return (PNG_INFO_bKGD);
340 }
341 return (0);
342 }
343 #endif
344
345 #if defined(PNG_READ_cHRM_SUPPORTED)
346 png_uint_32
347 png_get_cHRM(png_structp png_ptr, png_infop info_ptr,
348 double *white_x, double *white_y, double *red_x, double *red_y,
349 double *green_x, double *green_y, double *blue_x, double *blue_y)
350 {
351 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
352 {
353 png_debug1(1, "in %s retrieval function\n", "cHRM");
354 if (white_x != NULL)
355 *white_x = (double)info_ptr->x_white;
356 if (white_y != NULL)
357 *white_y = (double)info_ptr->y_white;
358 if (red_x != NULL)
359 *red_x = (double)info_ptr->x_red;
360 if (red_y != NULL)
361 *red_y = (double)info_ptr->y_red;
362 if (green_x != NULL)
363 *green_x = (double)info_ptr->x_green;
364 if (green_y != NULL)
365 *green_y = (double)info_ptr->y_green;
366 if (blue_x != NULL)
367 *blue_x = (double)info_ptr->x_blue;
368 if (blue_y != NULL)
369 *blue_y = (double)info_ptr->y_blue;
370 return (PNG_INFO_cHRM);
371 }
372 return (0);
373 }
374 #endif
375
376 #if defined(PNG_READ_gAMA_SUPPORTED)
377 png_uint_32
378 png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma)
379 {
380 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
381 && file_gamma != NULL)
382 {
383 png_debug1(1, "in %s retrieval function\n", "gAMA");
384 *file_gamma = (double)info_ptr->gamma;
385 return (PNG_INFO_gAMA);
386 }
387 return (0);
388 }
389 #endif
390
391 #if defined(PNG_READ_sRGB_SUPPORTED)
392 png_uint_32
393 png_get_sRGB(png_structp png_ptr, png_infop info_ptr, int *file_srgb_intent)
394 {
395 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
396 && file_srgb_intent != NULL)
397 {
398 png_debug1(1, "in %s retrieval function\n", "sRGB");
399 *file_srgb_intent = (int)info_ptr->srgb_intent;
400 return (PNG_INFO_sRGB);
401 }
402 return (0);
403 }
404 #endif
405
406 #if defined(PNG_READ_hIST_SUPPORTED)
407 png_uint_32
408 png_get_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p *hist)
409 {
410 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)
411 && hist != NULL)
412 {
413 png_debug1(1, "in %s retrieval function\n", "hIST");
414 *hist = info_ptr->hist;
415 return (PNG_INFO_hIST);
416 }
417 return (0);
418 }
419 #endif
420
421 png_uint_32
422 png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
423 png_uint_32 *width, png_uint_32 *height, int *bit_depth,
424 int *color_type, int *interlace_type, int *compression_type,
425 int *filter_type)
426
427 {
428 if (png_ptr != NULL && info_ptr != NULL && width != NULL && height != NULL &&
429 bit_depth != NULL && color_type != NULL)
430 {
431 int pixel_depth, channels;
432 png_uint_32 rowbytes_per_pixel;
433
434 png_debug1(1, "in %s retrieval function\n", "IHDR");
435 *width = info_ptr->width;
436 *height = info_ptr->height;
437 *bit_depth = info_ptr->bit_depth;
438 *color_type = info_ptr->color_type;
439 if (compression_type != NULL)
440 *compression_type = info_ptr->compression_type;
441 if (filter_type != NULL)
442 *filter_type = info_ptr->filter_type;
443 if (interlace_type != NULL)
444 *interlace_type = info_ptr->interlace_type;
445
446 /* check for potential overflow of rowbytes */
447 if (*color_type == PNG_COLOR_TYPE_PALETTE)
448 channels = 1;
449 else if (*color_type & PNG_COLOR_MASK_COLOR)
450 channels = 3;
451 else
452 channels = 1;
453 if (*color_type & PNG_COLOR_MASK_ALPHA)
454 channels++;
455 pixel_depth = *bit_depth * channels;
456 rowbytes_per_pixel = (pixel_depth + 7) >> 3;
457 if ((*width > (png_uint_32)2147483647L/rowbytes_per_pixel))
458 {
459 png_warning(png_ptr,
460 "Width too large for libpng to process image data.");
461 }
462 return (1);
463 }
464 return (0);
465 }
466
467 #if defined(PNG_READ_oFFs_SUPPORTED)
468 png_uint_32
469 png_get_oFFs(png_structp png_ptr, png_infop info_ptr,
470 png_uint_32 *offset_x, png_uint_32 *offset_y, int *unit_type)
471 {
472 if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
473 && offset_x != NULL && offset_y != NULL && unit_type != NULL)
474 {
475 png_debug1(1, "in %s retrieval function\n", "oFFs");
476 *offset_x = info_ptr->x_offset;
477 *offset_y = info_ptr->y_offset;
478 *unit_type = (int)info_ptr->offset_unit_type;
479 return (PNG_INFO_oFFs);
480 }
481 return (0);
482 }
483 #endif
484
485 #if defined(PNG_READ_pCAL_SUPPORTED)
486 png_uint_32
487 png_get_pCAL(png_structp png_ptr, png_infop info_ptr,
488 png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
489 png_charp *units, png_charpp *params)
490 {
491 if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL &&
492 purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
493 nparams != NULL && units != NULL && params != NULL)
494 {
495 png_debug1(1, "in %s retrieval function\n", "pCAL");
496 *purpose = info_ptr->pcal_purpose;
497 *X0 = info_ptr->pcal_X0;
498 *X1 = info_ptr->pcal_X1;
499 *type = (int)info_ptr->pcal_type;
500 *nparams = (int)info_ptr->pcal_nparams;
501 *units = info_ptr->pcal_units;
502 *params = info_ptr->pcal_params;
503 return (PNG_INFO_pCAL);
504 }
505 return (0);
506 }
507 #endif
508
509 #if defined(PNG_READ_pHYs_SUPPORTED)
510 png_uint_32
511 png_get_pHYs(png_structp png_ptr, png_infop info_ptr,
512 png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
513 {
514 png_uint_32 retval = 0;
515
516 if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
517 {
518 png_debug1(1, "in %s retrieval function\n", "pHYs");
519 if (res_x != NULL)
520 {
521 *res_x = info_ptr->x_pixels_per_unit;
522 retval |= PNG_INFO_pHYs;
523 }
524 if (res_y != NULL)
525 {
526 *res_y = info_ptr->y_pixels_per_unit;
527 retval |= PNG_INFO_pHYs;
528 }
529 if (unit_type != NULL)
530 {
531 *unit_type = (int)info_ptr->phys_unit_type;
532 retval |= PNG_INFO_pHYs;
533 }
534 }
535 return (retval);
536 }
537 #endif
538
539 png_uint_32
540 png_get_PLTE(png_structp png_ptr, png_infop info_ptr, png_colorp *palette,
541 int *num_palette)
542 {
543 if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_PLTE &&
544 palette != NULL)
545 {
546 png_debug1(1, "in %s retrieval function\n", "PLTE");
547 *palette = info_ptr->palette;
548 *num_palette = info_ptr->num_palette;
549 png_debug1(3, "num_palette = %d\n", *num_palette);
550 return (PNG_INFO_PLTE);
551 }
552 return (0);
553 }
554
555 #if defined(PNG_READ_sBIT_SUPPORTED)
556 png_uint_32
557 png_get_sBIT(png_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit)
558 {
559 if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT &&
560 sig_bit != NULL)
561 {
562 png_debug1(1, "in %s retrieval function\n", "sBIT");
563 *sig_bit = &(info_ptr->sig_bit);
564 return (PNG_INFO_sBIT);
565 }
566 return (0);
567 }
568 #endif
569
570 #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
571 png_uint_32
572 png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr,
573 int *num_text)
574 {
575 if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0)
576 {
577 png_debug1(1, "in %s retrieval function\n",
578 (png_ptr->chunk_name[0] == '\0' ? "text"
579 : (png_const_charp)png_ptr->chunk_name));
580 if (text_ptr != NULL)
581 *text_ptr = info_ptr->text;
582 if (num_text != NULL)
583 *num_text = info_ptr->num_text;
584 return ((png_uint_32)info_ptr->num_text);
585 }
586 return(0);
587 }
588 #endif
589
590 #if defined(PNG_READ_tIME_SUPPORTED)
591 png_uint_32
592 png_get_tIME(png_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
593 {
594 if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME &&
595 mod_time != NULL)
596 {
597 png_debug1(1, "in %s retrieval function\n", "tIME");
598 *mod_time = &(info_ptr->mod_time);
599 return (PNG_INFO_tIME);
600 }
601 return (0);
602 }
603 #endif
604
605 #if defined(PNG_READ_tRNS_SUPPORTED)
606 png_uint_32
607 png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
608 png_bytep *trans, int *num_trans, png_color_16p *trans_values)
609 {
610 png_uint_32 retval = 0;
611 if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
612 {
613 png_debug1(1, "in %s retrieval function\n", "tRNS");
614 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
615 {
616 if (trans != NULL)
617 {
618 *trans = info_ptr->trans;
619 retval |= PNG_INFO_tRNS;
620 }
621 if (trans_values != NULL)
622 *trans_values = &(info_ptr->trans_values);
623 }
624 else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */
625 {
626 if (trans_values != NULL)
627 {
628 *trans_values = &(info_ptr->trans_values);
629 retval |= PNG_INFO_tRNS;
630 }
631 if(trans != NULL)
632 *trans = NULL;
633 }
634 if(num_trans != NULL)
635 {
636 *num_trans = info_ptr->num_trans;
637 retval |= PNG_INFO_tRNS;
638 }
639 }
640 return (retval);
641 }
642 #endif
643
644 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
645 png_byte
646 png_get_rgb_to_gray_status (png_structp png_ptr)
647 {
648 return png_ptr->rgb_to_gray_status;
649 }
650 #endif