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#include "image.h"
#include "common.h"
unsigned decode32(uint32_t** out, unsigned* w, unsigned* h,
unsigned char* in, size_t insize)
{
#if defined(USE_LIBPNG)
unsigned retval = 1;
FILE* fp = fmemopen(in, insize, "rb");;
png_bytep* row_pointers = NULL;
if (insize < 8 || png_sig_cmp(in, 0, 8)) abort();
png_structp png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
png_infop info = png_create_info_struct(png);
if(setjmp(png_jmpbuf(png))) goto cleanup;
png_init_io(png, fp);
png_read_info(png, info);
if(png_get_bit_depth(png, info) == 16) png_set_strip_16(png);
*w = png_get_image_width(png, info);
*h = png_get_image_height(png, info);
png_byte color_type = png_get_color_type(png, info);
if(color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png);
if(png_get_valid(png, info, PNG_INFO_tRNS))
png_set_tRNS_to_alpha(png);
row_pointers = local_malloc(sizeof(png_bytep) * *h);
*out = local_malloc(sizeof(**out) * (*w * *h));
for(int y = 0; y < *h; y++)
{
row_pointers[y] = (png_byte*)(*out+((*w)*y));
}
png_read_image(png, row_pointers);
retval = 0;
cleanup:
png_destroy_read_struct(&png, &info, NULL);
if (fp) fclose(fp);
if (row_pointers) free(row_pointers);
return retval;
#elif defined(USE_LODEPNG)
return lodepng_decode32((unsigned char**)out, w, h, in, insize);
#else
#error "No decode implementation"
#endif
}
unsigned encode32_file(const char* filename, const uint32_t* image, unsigned w, unsigned h)
{
#if defined(USE_LIBPNG)
/* create file */
FILE *fp = fopen(filename, "wb");
png_bytep* row_pointers = NULL;
/* initialize stuff */
png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
png_infop info_ptr = png_create_info_struct(png);
if(setjmp(png_jmpbuf(png))) goto cleanup;
png_init_io(png, fp);
png_set_IHDR(png, info_ptr, w, h,
8, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_write_info(png, info_ptr);
row_pointers = local_malloc(sizeof(png_bytep) * h);
for(int y = 0; y < h; y++)
{
row_pointers[y] = (png_byte*)(image+(w*y));
}
png_write_image(png, row_pointers);
png_write_end(png, NULL);
cleanup:
free(row_pointers);
fclose(fp);
#elif defined(USE_LODEPNG)
return lodepng_encode32_file(filename, image, w, h);
#else
#error "No encode implementation"
#endif
}
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