-/**************************************************************************
- *
- * Copyright 2011 Jose Fonseca
- * Copyright 2008-2010 VMware, Inc.
- * All Rights Reserved.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- *
- **************************************************************************/
-
-
-#include <zlib.h>
-#include <png.h>
-
-#include <assert.h>
-#include <stdint.h>
-#include <stdlib.h>
-
-#include <fstream>
-
-#include "image.hpp"
-
-
-namespace image {
-
-
-static const int png_compression_level = Z_BEST_SPEED;
-
-
-static void
-pngWriteCallback(png_structp png_ptr, png_bytep data, png_size_t length)
-{
- std::ostream *os = (std::ostream *) png_get_io_ptr(png_ptr);
- os->write((const char *)data, length);
-}
-
-bool
-Image::writePNG(std::ostream &os) const
-{
- png_structp png_ptr;
- png_infop info_ptr;
- int color_type;
-
- switch (channels) {
- case 4:
- color_type = PNG_COLOR_TYPE_RGB_ALPHA;
- break;
- case 3:
- color_type = PNG_COLOR_TYPE_RGB;
- break;
- case 2:
- color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
- break;
- case 1:
- color_type = PNG_COLOR_TYPE_GRAY;
- break;
- default:
- assert(0);
- goto no_png;
- }
-
- png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
- if (!png_ptr)
- goto no_png;
-
- info_ptr = png_create_info_struct(png_ptr);
- if (!info_ptr) {
- png_destroy_write_struct(&png_ptr, NULL);
- goto no_png;
- }
-
- if (setjmp(png_jmpbuf(png_ptr))) {
- png_destroy_write_struct(&png_ptr, &info_ptr);
- goto no_png;
- }
-
- png_set_write_fn(png_ptr, &os, pngWriteCallback, NULL);
-
- png_set_IHDR(png_ptr, info_ptr, width, height, 8,
- color_type, PNG_INTERLACE_NONE,
- PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
-
- png_set_compression_level(png_ptr, png_compression_level);
-
- png_write_info(png_ptr, info_ptr);
-
- if (!flipped) {
- for (unsigned y = 0; y < height; ++y) {
- png_bytep row = (png_bytep)(pixels + y*width*channels);
- png_write_rows(png_ptr, &row, 1);
- }
- } else {
- unsigned y = height;
- while (y--) {
- png_bytep row = (png_bytep)(pixels + y*width*channels);
- png_write_rows(png_ptr, &row, 1);
- }
- }
-
- png_write_end(png_ptr, info_ptr);
- png_destroy_write_struct(&png_ptr, &info_ptr);
-
- return true;
-
-no_png:
- return false;
-}
-
-
-Image *
-readPNG(const char *filename)
-{
- FILE *fp;
- png_structp png_ptr;
- png_infop info_ptr;
- png_infop end_info;
- Image *image;
-
- fp = fopen(filename, "rb");
- if (!fp)
- goto no_fp;
-
- png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
- if (!png_ptr)
- goto no_png;
-
- info_ptr = png_create_info_struct(png_ptr);
- if (!info_ptr) {
- png_destroy_read_struct(&png_ptr, NULL, NULL);
- goto no_png;
- }
-
- end_info = png_create_info_struct(png_ptr);
- if (!end_info) {
- png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
- goto no_png;
- }
-
- if (setjmp(png_jmpbuf(png_ptr))) {
- png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
- goto no_png;
- }
-
- png_init_io(png_ptr, fp);
-
- png_read_info(png_ptr, info_ptr);
-
- png_uint_32 width, height;
- int bit_depth, color_type, interlace_type, compression_type, filter_method;
-
- png_get_IHDR(png_ptr, info_ptr,
- &width, &height,
- &bit_depth, &color_type, &interlace_type,
- &compression_type, &filter_method);
-
- image = new Image(width, height);
- if (!image)
- goto no_image;
-
- /* Convert to RGBA8 */
- if (color_type == PNG_COLOR_TYPE_PALETTE)
- png_set_palette_to_rgb(png_ptr);
- if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
- png_set_expand_gray_1_2_4_to_8(png_ptr);
- if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
- png_set_tRNS_to_alpha(png_ptr);
- if (bit_depth == 16)
- png_set_strip_16(png_ptr);
-
- for (unsigned y = 0; y < height; ++y) {
- png_bytep row = (png_bytep)(image->pixels + y*width*4);
- png_read_row(png_ptr, row, NULL);
- }
-
- png_read_end(png_ptr, info_ptr);
- png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
- fclose(fp);
- return image;
-
-no_image:
- png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
-no_png:
- fclose(fp);
-no_fp:
- return NULL;
-}
-
-
-
-} /* namespace image */