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ctruLua/libs/sfillib/libsfil/source/sfil_png.c
2015-08-17 21:10:54 +02:00

139 lines
3.4 KiB
C

#include "sfil.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <png.h>
#define PNG_SIGSIZE (8)
static void _sfil_read_png_file_fn(png_structp png_ptr, png_bytep data, png_size_t length)
{
FILE *fp = (FILE *)png_get_io_ptr(png_ptr);
fread(data, 1, length, fp);
}
static void _sfil_read_png_buffer_fn(png_structp png_ptr, png_bytep data, png_size_t length)
{
unsigned int *address = png_get_io_ptr(png_ptr);
memcpy(data, (void *)*address, length);
*address += length;
}
static sf2d_texture *_sfil_load_PNG_generic(const void *io_ptr, png_rw_ptr read_data_fn, sf2d_place place)
{
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (png_ptr == NULL) {
goto exit_error;
}
png_infop info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
goto exit_destroy_read;
}
png_bytep *row_ptrs = NULL;
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)0);
if (row_ptrs != NULL)
free(row_ptrs);
goto exit_error;
}
png_set_read_fn(png_ptr, (png_voidp)io_ptr, read_data_fn);
png_set_sig_bytes(png_ptr, PNG_SIGSIZE);
png_read_info(png_ptr, info_ptr);
unsigned int width, height;
int bit_depth, color_type;
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth,
&color_type, NULL, NULL, NULL);
if ((color_type == PNG_COLOR_TYPE_PALETTE && bit_depth <= 8)
|| (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
|| png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)
|| (bit_depth == 16)) {
png_set_expand(png_ptr);
}
if (bit_depth == 8 && color_type == PNG_COLOR_TYPE_RGB)
png_set_filler(png_ptr, 0xFF, PNG_FILLER_AFTER);
if (color_type == PNG_COLOR_TYPE_PALETTE) {
png_set_palette_to_rgb(png_ptr);
png_set_filler(png_ptr, 0xFF, PNG_FILLER_AFTER);
}
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 < 8)
png_set_packing(png_ptr);
png_read_update_info(png_ptr, info_ptr);
row_ptrs = (png_bytep *)malloc(sizeof(png_bytep) * height);
sf2d_texture *texture = sf2d_create_texture(width, height, GPU_RGBA8, place);
int stride = texture->pow2_w * 4;
int i;
for (i = 0; i < height; i++) {
row_ptrs[i] = (png_bytep)(texture->data + i*stride);
}
png_read_image(png_ptr, row_ptrs);
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)0);
free(row_ptrs);
sf2d_texture_tile32(texture);
return texture;
exit_destroy_read:
png_destroy_read_struct(&png_ptr, (png_infopp)0, (png_infopp)0);
exit_error:
return NULL;
}
sf2d_texture *sfil_load_PNG_file(const char *filename, sf2d_place place)
{
png_byte pngsig[PNG_SIGSIZE];
FILE *fp;
if ((fp = fopen(filename, "rb")) == NULL) {
goto exit_error;
}
if (fread(pngsig, 1, PNG_SIGSIZE, fp) != PNG_SIGSIZE) {
goto exit_close;
}
if (png_sig_cmp(pngsig, 0, PNG_SIGSIZE) != 0) {
goto exit_close;
}
sf2d_texture *texture = _sfil_load_PNG_generic((void *)fp, _sfil_read_png_file_fn, place);
fclose(fp);
return texture;
exit_close:
fclose(fp);
exit_error:
return NULL;
}
sf2d_texture *sfil_load_PNG_buffer(const void *buffer, sf2d_place place)
{
if (png_sig_cmp((png_byte *) buffer, 0, PNG_SIGSIZE) != 0) {
return NULL;
}
unsigned int buffer_address = (unsigned int)buffer + PNG_SIGSIZE;
return _sfil_load_PNG_generic((void *)&buffer_address, _sfil_read_png_buffer_fn, place);
}