terom@0: #include "image.h"
terom@0: 
terom@0: static int pt_image_new (struct pt_image **img_ptr, struct pt_ctx *ctx, const char *png_path)
terom@0: {
terom@0:     struct pt_image *img;
terom@0: 
terom@0:     // alloc
terom@0:     if ((img = calloc(1, sizeof(*img))) == NULL)
terom@0:         return -1;
terom@0: 
terom@0:     if ((img->png_path = strdup(png_path)) == NULL)
terom@0:         goto error;
terom@0: 
terom@0:     // init
terom@0:     img->ctx = ctx;
terom@0:     
terom@0:     // ok
terom@0:     *img_ptr = img;
terom@0: 
terom@0:     return 0;
terom@0: 
terom@0: error:
terom@0:     pt_image_destroy(img);
terom@0: 
terom@0:     return -1;
terom@0: }
terom@0: 
terom@0: /**
terom@0:  * Open the image's FILE
terom@0:  */
terom@0: static int pt_image_open_file (struct pt_image *img, FILE **file_ptr)
terom@0: {
terom@0:     FILE *fp;
terom@0:     
terom@0:     // open
terom@0:     if (fopen(img->png_path, "rb") < 0)
terom@0:         return -1;
terom@0: 
terom@0:     // ok
terom@0:     *file_ptr = fp;
terom@0: 
terom@0:     return 0;
terom@0: }
terom@0: 
terom@0: /**
terom@0:  * Open the PNG image, setting up the I/O and returning the png_structp and png_infop
terom@0:  */
terom@0: static int pt_image_open_png (struct pt_image *img, png_structp *png_ptr, png_infop *info_ptr)
terom@0: {
terom@0:     FILE *fp = NULL;
terom@0:     png_structp png = NULL;
terom@0:     png_infop info = NULL;
terom@0:     
terom@0:     // open I/O
terom@0:     if (pt_image_open_file(img, &fp))
terom@0:         goto error;
terom@0: 
terom@0:     // create the struct
terom@0:     if ((png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL)) == NULL)
terom@0:         goto error;
terom@0: 
terom@0:     // create the info
terom@0:     if ((info = png_create_info_struct(png)) == NULL)
terom@0:         goto error;
terom@0: 
terom@0:     // setup error trap for the I/O
terom@0:     if (setjmp(png_jmpbuf(png)))
terom@0:         goto error;
terom@0:     
terom@0:     // setup I/O to FILE
terom@0:     png_init_io(png, fp);
terom@0: 
terom@0:     // ok
terom@0:     *png_ptr = png;
terom@0:     *info_ptr = info;
terom@0: 
terom@0:     return 0;
terom@0: 
terom@0: error:
terom@0:     // cleanup file
terom@0:     if (fp) fclose(fp);
terom@0: 
terom@0:     // cleanup PNG state
terom@0:     png_destroy_read_struct(&png, &info, NULL);
terom@0: 
terom@0:     return -1;
terom@0: }
terom@0: 
terom@0: /**
terom@0:  * Open the PNG image, and write out to the cache
terom@0:  */
terom@0: static int pt_image_update_cache (struct pt_image *img)
terom@0: {
terom@0:     png_structp png;
terom@0:     png_infop info;
terom@0: 
terom@0:     // open .png
terom@0:     if (pt_image_open_png(img, &png, &info))
terom@0:         return -1;
terom@0:     
terom@0:     // setup error trap
terom@0:     if (setjmp(png_jmpbuf(png)))
terom@0:         goto error;
terom@0: 
terom@0:     // read meta-info
terom@0:     png_read_info(png, info);
terom@0: 
terom@0:     // pass to cache object
terom@0:     if (pt_cache_update_png(img->cache, png, info))
terom@0:         goto error;
terom@0: 
terom@0:     // finish off, ignore trailing data
terom@0:     png_read_end(png, NULL);
terom@0: 
terom@0:     // clean up
terom@0:     png_destroy_read_struct(&png, &info);
terom@0: 
terom@0:     return 0;
terom@0: 
terom@0: error:
terom@0:     // clean up
terom@0:     png_destroy_read_struct(&png, &info);
terom@0: 
terom@0:     return -1;
terom@0: }
terom@0: 
terom@0: int pt_image_open (struct pt_image **img_ptr, struct pt_ctx *ctx, const char *png_path, int cache_mode)
terom@0: {
terom@0:     struct pt_image *img;
terom@0: 
terom@0:     // XXX: verify that the png_path exists and looks like a PNG file
terom@0: 
terom@0:     // alloc
terom@0:     if (pt_image_new(&img, ctx, png_path))
terom@0:         return -1;
terom@0: 
terom@0:     // open the cache object for this image
terom@0:     if (pt_cache_open(&img->cache, img, mode))
terom@0:         goto error;
terom@0:     
terom@0:     // update if not fresh
terom@0:     if (!pt_cache_fresh(img->cache))
terom@0:         pt_image_update_cache(img);
terom@0:     
terom@0:     // ok, ready for access
terom@0:     *img_ptr = img;
terom@0: 
terom@0:     return 0;
terom@0: 
terom@0: error:
terom@0:     pt_image_destroy(img);
terom@0: }