terom@0: #include "image.h"
terom@1: #include "cache.h"
terom@0: 
terom@1: #include <stdlib.h>
terom@1: #include <limits.h> // for _POSIX_PATH_MAX
terom@1: 
terom@1: #include <png.h>
terom@1: 
terom@1: static int pt_image_new (struct pt_image **img_ptr, struct pt_ctx *ctx, const char *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@1:     if ((img->path = strdup(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@2:     if ((fp = fopen(img->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@1:     // XXX: what to do with fp?
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@1:     png_destroy_read_struct(&png, &info, NULL);
terom@0: 
terom@0:     return 0;
terom@0: 
terom@0: error:
terom@0:     // clean up
terom@1:     png_destroy_read_struct(&png, &info, NULL);
terom@0: 
terom@0:     return -1;
terom@0: }
terom@0: 
terom@1: /**
terom@1:  * Build a filesystem path representing the appropriate path for this image's cache entry, and store it in the given
terom@1:  * buffer.
terom@1:  */
terom@1: static int pt_image_cache_path (struct pt_image *image, char *buf, size_t len)
terom@0: {
terom@2:     char *ext;
terom@2: 
terom@2:     // XXX: be more careful about buf len
terom@2:     
terom@2:     // copy filename
terom@2:     strncpy(buf, image->path, len);
terom@2: 
terom@2:     // find .ext
terom@2:     if ((ext = strrchr(buf, '.')) == NULL)
terom@2:         return -1;
terom@2: 
terom@2:     // change to .cache
terom@2:     strncpy(ext, ".cache", (buf + len) - ext);
terom@2: 
terom@2:     // hmmk
terom@2:     return 0;
terom@1: }
terom@0: 
terom@1: int pt_image_open (struct pt_image **image_ptr, struct pt_ctx *ctx, const char *path, int cache_mode)
terom@1: {
terom@1:     struct pt_image *image;
terom@1:     char cache_path[_POSIX_PATH_MAX];
terom@2:     int stale;
terom@1: 
terom@1:     // XXX: verify that the path exists and looks like a PNG file
terom@0: 
terom@0:     // alloc
terom@1:     if (pt_image_new(&image, ctx, path))
terom@0:         return -1;
terom@1:     
terom@1:     // compute cache file path
terom@1:     if (pt_image_cache_path(image, cache_path, sizeof(cache_path)))
terom@1:         goto error;
terom@0: 
terom@0:     // open the cache object for this image
terom@1:     if (pt_cache_open(&image->cache, cache_path, cache_mode))
terom@0:         goto error;
terom@0:     
terom@0:     // update if not fresh
terom@1:     // XXX: check cache_mode
terom@2:     if ((stale = pt_cache_stale(image->cache, image->path)) < 0)
terom@2:         goto error;
terom@2: 
terom@2:     if (stale)
terom@1:         pt_image_update_cache(image);
terom@0:     
terom@0:     // ok, ready for access
terom@1:     *image_ptr = image;
terom@0: 
terom@0:     return 0;
terom@0: 
terom@0: error:
terom@1:     pt_image_destroy(image);
terom@1: 
terom@1:     return -1;
terom@0: }
terom@1: 
terom@1: void pt_image_destroy (struct pt_image *image)
terom@1: {
terom@1:     free(image->path);
terom@1:     
terom@1:     if (image->cache)
terom@1:         pt_cache_destroy(image->cache);
terom@1: 
terom@1:     free(image);
terom@1: }