diff options
Diffstat (limited to 'loadpng.c')
| -rw-r--r-- | loadpng.c | 275 |
1 files changed, 0 insertions, 275 deletions
diff --git a/loadpng.c b/loadpng.c deleted file mode 100644 index 218ae20..0000000 --- a/loadpng.c +++ /dev/null @@ -1,275 +0,0 @@ -#include <stdio.h> -#include <stdlib.h> - -#include <png.h> - -#if 0 -#define LOG(x...) fprintf(stderr,"error: " x) -#else -#define LOG(x...) do {} while (0) -#endif - -void *loadpng(const char *fn, unsigned *_width, unsigned *_height) -{ - FILE *fp = 0; - unsigned char header[8]; - unsigned char *data = 0; - unsigned char **rowptrs = 0; - png_structp p = 0; - png_infop pi = 0; - - png_uint_32 width, height; - int bitdepth, colortype, imethod, cmethod, fmethod, i; - - p = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0); - if(p == 0) { - LOG("%s: failed to allocate png read struct\n", fn); - return 0; - } - - pi = png_create_info_struct(p); - if(pi == 0) { - LOG("%s: failed to allocate png info struct\n", fn); - goto oops; - } - - fp = fopen(fn, "rb"); - if(fp == 0) { - LOG("%s: failed to open file\n", fn); - return 0; - } - - if(fread(header, 8, 1, fp) != 1) { - LOG("%s: failed to read header\n", fn); - goto oops; - } - - if(png_sig_cmp(header, 0, 8)) { - LOG("%s: header is not a PNG header\n", fn); - goto oops; - } - - if(setjmp(png_jmpbuf(p))) { - LOG("%s: png library error\n", fn); - oops: - png_destroy_read_struct(&p, &pi, 0); - if(fp != 0) fclose(fp); - if(data != 0) free(data); - if(rowptrs != 0) free(rowptrs); - return 0; - } - - png_init_io(p, fp); - png_set_sig_bytes(p, 8); - - png_read_info(p, pi); - - png_get_IHDR(p, pi, &width, &height, &bitdepth, &colortype, - &imethod, &cmethod, &fmethod); -// printf("PNG: %d x %d (d=%d, c=%d)\n", -// width, height, bitdepth, colortype); - - switch(colortype){ - case PNG_COLOR_TYPE_PALETTE: - png_set_palette_to_rgb(p); - break; - - case PNG_COLOR_TYPE_RGB: - if(png_get_valid(p, pi, PNG_INFO_tRNS)) { - png_set_tRNS_to_alpha(p); - } else { - png_set_filler(p, 0xff, PNG_FILLER_AFTER); - } - break; - - case PNG_COLOR_TYPE_RGB_ALPHA: - break; - - case PNG_COLOR_TYPE_GRAY: - if(bitdepth < 8) { - png_set_gray_1_2_4_to_8(p); - } - - default: - LOG("%s: unsupported (grayscale?) color type\n"); - goto oops; - } - - if(bitdepth == 16) { - png_set_strip_16(p); - } - - data = (unsigned char*) malloc((width * 4) * height); - rowptrs = (unsigned char **) malloc(sizeof(unsigned char*) * height); - - if((data == 0) || (rowptrs == 0)){ - LOG("could not allocate data buffer\n"); - goto oops; - } - - for(i = 0; i < height; i++) { - rowptrs[i] = data + ((width * 4) * i); - } - - png_read_image(p, rowptrs); - - png_destroy_read_struct(&p, &pi, 0); - fclose(fp); - if(rowptrs != 0) free(rowptrs); - - *_width = width; - *_height = height; - - return (void*) data; -} - - -typedef struct -{ - const unsigned char* base; - const unsigned char* end; - const unsigned char* cursor; - -} PngReader; - -static void -png_reader_read_data( png_structp png_ptr, - png_bytep data, - png_size_t length ) -{ - PngReader* reader = png_get_io_ptr(png_ptr); - png_size_t avail = (png_size_t)(reader->end - reader->cursor); - - if (avail > length) - avail = length; - - memcpy( data, reader->cursor, avail ); - reader->cursor += avail; -} - - -void *readpng(const unsigned char *base, size_t size, unsigned *_width, unsigned *_height) -{ - PngReader reader; - unsigned char *data = 0; - unsigned char **rowptrs = 0; - png_structp p = 0; - png_infop pi = 0; - - png_uint_32 width, height; - int bitdepth, colortype, imethod, cmethod, fmethod, i; - - p = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0); - if(p == 0) { - LOG("%s: failed to allocate png read struct\n", fn); - return 0; - } - - pi = png_create_info_struct(p); - if(pi == 0) { - LOG("%s: failed to allocate png info struct\n", fn); - goto oops; - } - - reader.base = base; - reader.end = base + size; - reader.cursor = base; - - if(size < 8 || png_sig_cmp((unsigned char*)base, 0, 8)) { - LOG("%s: header is not a PNG header\n", fn); - goto oops; - } - - reader.cursor += 8; - - if(setjmp(png_jmpbuf(p))) { - LOG("%s: png library error\n", fn); - oops: - png_destroy_read_struct(&p, &pi, 0); - if(data != 0) free(data); - if(rowptrs != 0) free(rowptrs); - return 0; - } - - png_set_read_fn (p, &reader, png_reader_read_data); - png_set_sig_bytes(p, 8); - - png_read_info(p, pi); - - png_get_IHDR(p, pi, &width, &height, &bitdepth, &colortype, - &imethod, &cmethod, &fmethod); -// printf("PNG: %d x %d (d=%d, c=%d)\n", -// width, height, bitdepth, colortype); - - switch(colortype){ - case PNG_COLOR_TYPE_PALETTE: - png_set_palette_to_rgb(p); - break; - - case PNG_COLOR_TYPE_RGB: - if(png_get_valid(p, pi, PNG_INFO_tRNS)) { - png_set_tRNS_to_alpha(p); - } else { - png_set_filler(p, 0xff, PNG_FILLER_AFTER); - } - break; - - case PNG_COLOR_TYPE_RGB_ALPHA: - break; - - case PNG_COLOR_TYPE_GRAY: - if(bitdepth < 8) { - png_set_gray_1_2_4_to_8(p); - } - - default: - LOG("%s: unsupported (grayscale?) color type\n"); - goto oops; - } - - if(bitdepth == 16) { - png_set_strip_16(p); - } - - data = (unsigned char*) malloc((width * 4) * height); - rowptrs = (unsigned char **) malloc(sizeof(unsigned char*) * height); - - if((data == 0) || (rowptrs == 0)){ - LOG("could not allocate data buffer\n"); - goto oops; - } - - for(i = 0; i < height; i++) { - rowptrs[i] = data + ((width * 4) * i); - } - - png_read_image(p, rowptrs); - - png_destroy_read_struct(&p, &pi, 0); - if(rowptrs != 0) free(rowptrs); - - *_width = width; - *_height = height; - - return (void*) data; -} - - -#if 0 -int main(int argc, char **argv) -{ - unsigned w,h; - unsigned char *data; - - if(argc < 2) return 0; - - - data = loadpng(argv[1], &w, &h); - - if(data != 0) { - printf("w: %d h: %d\n", w, h); - } - - return 0; -} -#endif |