1 /**************************************************************************
3 * Copyright 2011 Jose Fonseca
4 * Copyright 2008-2010 VMware, Inc.
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 **************************************************************************/
43 static const int png_compression_level = Z_BEST_SPEED;
47 Image::writePNG(const char *filename) const {
52 fp = fopen(filename, "wb");
56 png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
60 info_ptr = png_create_info_struct(png_ptr);
62 png_destroy_write_struct(&png_ptr, NULL);
66 if (setjmp(png_jmpbuf(png_ptr))) {
67 png_destroy_write_struct(&png_ptr, &info_ptr);
71 png_init_io(png_ptr, fp);
76 color_type = PNG_COLOR_TYPE_RGB_ALPHA;
79 color_type = PNG_COLOR_TYPE_RGB;
82 color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
85 color_type = PNG_COLOR_TYPE_GRAY;
92 png_set_IHDR(png_ptr, info_ptr, width, height, 8, color_type,
93 PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
95 png_set_compression_level(png_ptr, png_compression_level);
97 png_write_info(png_ptr, info_ptr);
100 for (unsigned y = 0; y < height; ++y) {
101 png_bytep row = (png_bytep)(pixels + y*width*channels);
102 png_write_rows(png_ptr, &row, 1);
107 png_bytep row = (png_bytep)(pixels + y*width*channels);
108 png_write_rows(png_ptr, &row, 1);
112 png_write_end(png_ptr, info_ptr);
113 png_destroy_write_struct(&png_ptr, &info_ptr);
126 readPNG(const char *filename)
134 fp = fopen(filename, "rb");
138 png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
142 info_ptr = png_create_info_struct(png_ptr);
144 png_destroy_read_struct(&png_ptr, NULL, NULL);
148 end_info = png_create_info_struct(png_ptr);
150 png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
154 if (setjmp(png_jmpbuf(png_ptr))) {
155 png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
159 png_init_io(png_ptr, fp);
161 png_read_info(png_ptr, info_ptr);
163 png_uint_32 width, height;
164 int bit_depth, color_type, interlace_type, compression_type, filter_method;
166 png_get_IHDR(png_ptr, info_ptr,
168 &bit_depth, &color_type, &interlace_type,
169 &compression_type, &filter_method);
171 image = new Image(width, height);
175 /* Convert to RGBA8 */
176 if (color_type == PNG_COLOR_TYPE_PALETTE)
177 png_set_palette_to_rgb(png_ptr);
178 if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
179 png_set_expand_gray_1_2_4_to_8(png_ptr);
180 if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
181 png_set_tRNS_to_alpha(png_ptr);
183 png_set_strip_16(png_ptr);
185 for (unsigned y = 0; y < height; ++y) {
186 png_bytep row = (png_bytep)(image->pixels + y*width*4);
187 png_read_row(png_ptr, row, NULL);
190 png_read_end(png_ptr, info_ptr);
191 png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
196 png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
204 struct png_tmp_buffer
211 pngWriteCallback(png_structp png_ptr, png_bytep data, png_size_t length)
213 struct png_tmp_buffer *buf = (struct png_tmp_buffer*) png_get_io_ptr(png_ptr);
214 size_t nsize = buf->size + length;
216 /* allocate or grow buffer */
218 buf->buffer = (char*)realloc(buf->buffer, nsize);
220 buf->buffer = (char*)malloc(nsize);
223 png_error(png_ptr, "Buffer allocation error");
225 memcpy(buf->buffer + buf->size, data, length);
229 bool writePixelsToBuffer(unsigned char *pixels,
230 unsigned width, unsigned height, unsigned numChannels,
235 struct png_tmp_buffer png_mem;
240 png_mem.buffer = NULL;
243 switch (numChannels) {
245 type = PNG_COLOR_TYPE_RGB_ALPHA;
248 type = PNG_COLOR_TYPE_RGB;
251 type = PNG_COLOR_TYPE_GRAY_ALPHA;
254 type = PNG_COLOR_TYPE_GRAY;
260 png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
264 info_ptr = png_create_info_struct(png_ptr);
266 png_destroy_write_struct(&png_ptr, NULL);
270 if (setjmp(png_jmpbuf(png_ptr))) {
271 png_destroy_write_struct(&png_ptr, &info_ptr);
275 png_set_write_fn(png_ptr, &png_mem, pngWriteCallback, NULL);
277 png_set_IHDR(png_ptr, info_ptr, width, height, 8,
278 type, PNG_INTERLACE_NONE,
279 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
281 png_set_compression_level(png_ptr, png_compression_level);
283 png_write_info(png_ptr, info_ptr);
286 for (unsigned y = 0; y < height; ++y) {
287 png_bytep row = (png_bytep)(pixels + y*width*numChannels);
288 png_write_rows(png_ptr, &row, 1);
293 png_bytep row = (png_bytep)(pixels + y*width*numChannels);
294 png_write_rows(png_ptr, &row, 1);
298 png_write_end(png_ptr, info_ptr);
299 png_destroy_write_struct(&png_ptr, &info_ptr);
301 *buffer = png_mem.buffer;
302 *size = png_mem.size;
311 free(png_mem.buffer);
315 } /* namespace image */