use accessor functions to access deprecated members of the png_structp
[imager.git] / PNG / impng.c
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1d7e3124 1#include "impng.h"
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2#include "png.h"
3
4/* Check to see if a file is a PNG file using png_sig_cmp(). png_sig_cmp()
5 * returns zero if the image is a PNG and nonzero if it isn't a PNG.
6 *
7 * The function check_if_png() shown here, but not used, returns nonzero (true)
8 * if the file can be opened and is a PNG, 0 (false) otherwise.
9 *
10 * If this call is successful, and you are going to keep the file open,
11 * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once
12 * you have created the png_ptr, so that libpng knows your application
13 * has read that many bytes from the start of the file. Make sure you
14 * don't call png_set_sig_bytes() with more than 8 bytes read or give it
15 * an incorrect number of bytes read, or you will either have read too
16 * many bytes (your fault), or you are telling libpng to read the wrong
17 * number of magic bytes (also your fault).
18 *
19 * Many applications already read the first 2 or 4 bytes from the start
20 * of the image to determine the file type, so it would be easiest just
21 * to pass the bytes to png_sig_cmp() or even skip that if you know
22 * you have a PNG file, and call png_set_sig_bytes().
23 */
24
25/* this is a way to get number of channels from color space
26 * Color code to channel number */
27
b33c08f8 28static int CC2C[PNG_COLOR_MASK_PALETTE|PNG_COLOR_MASK_COLOR|PNG_COLOR_MASK_ALPHA];
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29
30#define PNG_BYTES_TO_CHECK 4
31
32
33
02d1d628 34static void
790923a4 35wiol_read_data(png_structp png_ptr, png_bytep data, png_size_t length) {
f5b4354e 36 io_glue *ig = png_get_io_ptr(png_ptr);
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37 int rc = ig->readcb(ig, data, length);
38 if (rc != length) png_error(png_ptr, "Read overflow error on an iolayer source.");
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39}
40
02d1d628 41static void
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42wiol_write_data(png_structp png_ptr, png_bytep data, png_size_t length) {
43 int rc;
f5b4354e 44 io_glue *ig = png_get_io_ptr(png_ptr);
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45 rc = ig->writecb(ig, data, length);
46 if (rc != length) png_error(png_ptr, "Write error on an iolayer source.");
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47}
48
49static void
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50wiol_flush_data(png_structp png_ptr) {
51 /* XXX : This needs to be added to the io layer */
02d1d628 52}
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53
54
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55/* Check function demo
56
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57int
58check_if_png(char *file_name, FILE **fp) {
790923a4 59 char buf[PNG_BYTES_TO_CHECK];
790923a4 60 if ((*fp = fopen(file_name, "rb")) != NULL) return 0;
790923a4 61 if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK) return 0;
790923a4 62 return(!png_sig_cmp((png_bytep)buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
02d1d628 63}
15dc61b6 64*/
02d1d628 65
02d1d628 66undef_int
790923a4 67i_writepng_wiol(i_img *im, io_glue *ig) {
02d1d628 68 png_structp png_ptr;
a807aae6 69 png_infop info_ptr = NULL;
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70 int width,height,y;
71 volatile int cspace,channels;
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72 double xres, yres;
73 int aspect_only, have_res;
02d1d628 74
790923a4 75 mm_log((1,"i_writepng(im %p ,ig %p)\n", im, ig));
02d1d628 76
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77 height = im->ysize;
78 width = im->xsize;
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79
80 channels=im->channels;
81
790923a4 82 if (channels > 2) { cspace = PNG_COLOR_TYPE_RGB; channels-=3; }
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83 else { cspace=PNG_COLOR_TYPE_GRAY; channels--; }
84
85 if (channels) cspace|=PNG_COLOR_MASK_ALPHA;
86 mm_log((1,"cspace=%d\n",cspace));
87
790923a4 88 channels = im->channels;
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89
90 /* Create and initialize the png_struct with the desired error handler
91 * functions. If you want to use the default stderr and longjump method,
92 * you can supply NULL for the last three parameters. We also check that
93 * the library version is compatible with the one used at compile time,
94 * in case we are using dynamically linked libraries. REQUIRED.
95 */
96
97 png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,NULL,NULL,NULL);
98
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99 if (png_ptr == NULL) return 0;
100
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101
102 /* Allocate/initialize the image information data. REQUIRED */
103 info_ptr = png_create_info_struct(png_ptr);
104
105 if (info_ptr == NULL) {
a807aae6 106 png_destroy_write_struct(&png_ptr, &info_ptr);
790923a4 107 return 0;
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108 }
109
110 /* Set error handling. REQUIRED if you aren't supplying your own
111 * error hadnling functions in the png_create_write_struct() call.
112 */
f5b4354e 113 if (setjmp(png_jmpbuf(png_ptr))) {
a807aae6 114 png_destroy_write_struct(&png_ptr, &info_ptr);
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115 return(0);
116 }
117
790923a4 118 png_set_write_fn(png_ptr, (png_voidp) (ig), wiol_write_data, wiol_flush_data);
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119
120 /* Set the image information here. Width and height are up to 2^31,
121 * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
122 * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
123 * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB,
124 * or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or
125 * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST
126 * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
127 */
128
129 png_set_IHDR(png_ptr, info_ptr, width, height, 8, cspace,
130 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
131
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132 have_res = 1;
133 if (i_tags_get_float(&im->tags, "i_xres", 0, &xres)) {
134 if (i_tags_get_float(&im->tags, "i_yres", 0, &yres))
135 ; /* nothing to do */
136 else
137 yres = xres;
138 }
139 else {
140 if (i_tags_get_float(&im->tags, "i_yres", 0, &yres))
141 xres = yres;
142 else
143 have_res = 0;
144 }
145 if (have_res) {
146 aspect_only = 0;
147 i_tags_get_int(&im->tags, "i_aspect_only", 0, &aspect_only);
148 xres /= 0.0254;
149 yres /= 0.0254;
150 png_set_pHYs(png_ptr, info_ptr, xres + 0.5, yres + 0.5,
151 aspect_only ? PNG_RESOLUTION_UNKNOWN : PNG_RESOLUTION_METER);
152 }
153
02d1d628 154 png_write_info(png_ptr, info_ptr);
790923a4 155
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156 if (!im->virtual && im->type == i_direct_type && im->bits == i_8_bits) {
157 for (y = 0; y < height; y++)
158 png_write_row(png_ptr, (png_bytep) &(im->idata[channels*width*y]));
159 }
160 else {
161 unsigned char *data = mymalloc(im->xsize * im->channels);
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162 for (y = 0; y < height; y++) {
163 i_gsamp(im, 0, im->xsize, y, data, NULL, im->channels);
164 png_write_row(png_ptr, (png_bytep)data);
faa9b3e7 165 }
435e4a7d 166 myfree(data);
faa9b3e7 167 }
790923a4 168
02d1d628 169 png_write_end(png_ptr, info_ptr);
790923a4 170
a807aae6 171 png_destroy_write_struct(&png_ptr, &info_ptr);
02d1d628 172
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173 ig->closecb(ig);
174
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175 return(1);
176}
177
178
179
faa9b3e7 180static void get_png_tags(i_img *im, png_structp png_ptr, png_infop info_ptr);
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181
182i_img*
1d7e3124 183i_readpng_wiol(io_glue *ig) {
02576e8d 184 i_img *im = NULL;
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185 png_structp png_ptr;
186 png_infop info_ptr;
790923a4 187 png_uint_32 width, height;
02d1d628 188 int bit_depth, color_type, interlace_type;
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189 int number_passes,y;
190 int channels,pass;
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191 unsigned int sig_read;
192
790923a4 193 sig_read = 0;
02d1d628 194
1d7e3124 195 mm_log((1,"i_readpng_wiol(ig %p)\n", ig));
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196
197 png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,NULL,NULL,NULL);
790923a4 198 png_set_read_fn(png_ptr, (png_voidp) (ig), wiol_read_data);
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199
200 info_ptr = png_create_info_struct(png_ptr);
201 if (info_ptr == NULL) {
202 png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
203 return NULL;
204 }
205
f5b4354e 206 if (setjmp(png_jmpbuf(png_ptr))) {
02576e8d 207 if (im) i_img_destroy(im);
790923a4 208 mm_log((1,"i_readpng_wiol: error.\n"));
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209 png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
210 return NULL;
211 }
790923a4 212
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213 png_set_sig_bytes(png_ptr, sig_read);
214 png_read_info(png_ptr, info_ptr);
215 png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, NULL, NULL);
216
217 mm_log((1,
790923a4 218 "png_get_IHDR results: width %d, height %d, bit_depth %d, color_type %d, interlace_type %d\n",
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219 width,height,bit_depth,color_type,interlace_type));
220
221 CC2C[PNG_COLOR_TYPE_GRAY]=1;
222 CC2C[PNG_COLOR_TYPE_PALETTE]=3;
223 CC2C[PNG_COLOR_TYPE_RGB]=3;
224 CC2C[PNG_COLOR_TYPE_RGB_ALPHA]=4;
225 CC2C[PNG_COLOR_TYPE_GRAY_ALPHA]=2;
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226 channels = CC2C[color_type];
227
228 mm_log((1,"i_readpng_wiol: channels %d\n",channels));
229
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230 if (!i_int_check_image_file_limits(width, height, channels, sizeof(i_sample_t))) {
231 mm_log((1, "i_readpnm: image size exceeds limits\n"));
232 png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
233 return NULL;
234 }
235
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236 png_set_strip_16(png_ptr);
237 png_set_packing(png_ptr);
238 if (color_type == PNG_COLOR_TYPE_PALETTE) png_set_expand(png_ptr);
239 if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) png_set_expand(png_ptr);
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240
241 if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
242 channels++;
243 mm_log((1, "image has transparency, adding alpha: channels = %d\n", channels));
244 png_set_expand(png_ptr);
245 }
790923a4 246
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247 number_passes = png_set_interlace_handling(png_ptr);
248 mm_log((1,"number of passes=%d\n",number_passes));
249 png_read_update_info(png_ptr, info_ptr);
790923a4 250
1d7e3124 251 im = i_img_8_new(width,height,channels);
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252 if (!im) {
253 png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
254 return NULL;
255 }
790923a4 256
02d1d628 257 for (pass = 0; pass < number_passes; pass++)
faa9b3e7 258 for (y = 0; y < height; y++) { png_read_row(png_ptr,(png_bytep) &(im->idata[channels*width*y]), NULL); }
02d1d628 259
790923a4 260 png_read_end(png_ptr, info_ptr);
02d1d628 261
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262 get_png_tags(im, png_ptr, info_ptr);
263
790923a4 264 png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
02d1d628 265
790923a4 266 mm_log((1,"(0x%08X) <- i_readpng_scalar\n", im));
02d1d628 267
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268 return im;
269}
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270
271static void get_png_tags(i_img *im, png_structp png_ptr, png_infop info_ptr) {
272 png_uint_32 xres, yres;
273 int unit_type;
352c64ed 274
1d7e3124 275 i_tags_set(&im->tags, "i_format", "png", -1);
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276 if (png_get_pHYs(png_ptr, info_ptr, &xres, &yres, &unit_type)) {
277 mm_log((1,"pHYs (%d, %d) %d\n", xres, yres, unit_type));
278 if (unit_type == PNG_RESOLUTION_METER) {
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279 i_tags_set_float2(&im->tags, "i_xres", 0, xres * 0.0254, 5);
280 i_tags_set_float2(&im->tags, "i_yres", 0, yres * 0.0254, 5);
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281 }
282 else {
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283 i_tags_setn(&im->tags, "i_xres", xres);
284 i_tags_setn(&im->tags, "i_yres", yres);
285 i_tags_setn(&im->tags, "i_aspect_only", 1);
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286 }
287 }
288}