imagefile.c.svn-base

psp播放器PPA源码,在MSYS/CYGWIN环境下编译（GNU-C）

#include <stdlib.h>
#include <malloc.h>
#include <string.h>
#include <png.h>
#include "mem64.h"
#include "imagefile.h"

void user_warning_fn(png_structp png_ptr, png_const_charp warning_msg){
}

Image* loadPNGImage(const char* filename){
	png_structp png_ptr;
	png_infop info_ptr;
	unsigned int sig_read = 0;
	png_uint_32 width, height;
	int bit_depth, color_type, interlace_type, x, y;
	u32* line;
	FILE *fp;
	
	if ((fp = fopen(filename, "rb")) == NULL) return NULL;
	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
	if (png_ptr == NULL) {
		fclose(fp);
		return NULL;;
	}
	png_set_error_fn(png_ptr, (png_voidp) NULL, (png_error_ptr) NULL, user_warning_fn);
	info_ptr = png_create_info_struct(png_ptr);
	if (info_ptr == NULL) {
		fclose(fp);
		png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
		return NULL;
	}
	if (setjmp(png_jmpbuf(png_ptr))) {
		fclose(fp);
		png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
		return NULL;
	}

	png_init_io(png_ptr, fp);
	png_set_sig_bytes(png_ptr, sig_read);
	png_read_info(png_ptr, info_ptr);
	png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, int_p_NULL, int_p_NULL);
	
	png_set_strip_16(png_ptr);
	png_set_packing(png_ptr);
	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_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);
	png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
	
	Image *image = createImage(width, height);
	if ( image == NULL ) {
		fclose(fp);
		png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
		return NULL;
	}
	
	line = (u32*) malloc_64(width * 4);
	if (!line) {
		freeImage(image);
		fclose(fp);
		png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
		return NULL;
	}
	for (y = 0; y < height; y++) {
		png_read_row(png_ptr, (u8*) line, png_bytep_NULL);
		for (x = 0; x < width; x++) {
			u32 color = line[x];
			image->data[x + y * image->textureWidth] =  color;
		}
	}
	free(line);
	png_read_end(png_ptr, info_ptr);
	png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
	fclose(fp);
	return image;
}