static bool read_tile(openslide_t *osr,
cairo_t *cr,
struct _openslide_level *level,
int64_t tile_col, int64_t tile_row,
void *arg,
GError **err) {
struct level *l = (struct level *) level;
struct _openslide_tiff_level *tiffl = &l->tiffl;
TIFF *tiff = arg;
// tile size
int64_t tw = tiffl->tile_w;
int64_t th = tiffl->tile_h;
// cache
struct _openslide_cache_entry *cache_entry;
uint32_t *tiledata = _openslide_cache_get(osr->cache,
level, tile_col, tile_row,
&cache_entry);
if (!tiledata) {
tiledata = g_slice_alloc(tw * th * 4);
if (!_openslide_tiff_read_tile(tiffl, tiff,
tiledata, tile_col, tile_row,
err)) {
g_slice_free1(tw * th * 4, tiledata);
return false;
}
// clip, if necessary
if (!_openslide_tiff_clip_tile(tiffl, tiledata,
tile_col, tile_row,
err)) {
g_slice_free1(tw * th * 4, tiledata);
return false;
}
// put it in the cache
_openslide_cache_put(osr->cache, level, tile_col, tile_row,
tiledata, tw * th * 4,
&cache_entry);
}
// draw it
cairo_surface_t *surface = cairo_image_surface_create_for_data((unsigned char *) tiledata,
CAIRO_FORMAT_ARGB32,
tw, th,
tw * 4);
cairo_set_source_surface(cr, surface, 0, 0);
cairo_surface_destroy(surface);
cairo_paint(cr);
// done with the cache entry, release it
_openslide_cache_entry_unref(cache_entry);
return true;
}
static void hash_destroy_value(gpointer data) {
struct _openslide_cache_value *value = data;
// remove the item from the list
g_queue_delete_link(value->cache->list, value->link);
// decrement the total size
value->cache->total_size -= value->entry->size;
g_assert(value->cache->total_size >= 0);
// unref the entry
_openslide_cache_entry_unref(value->entry);
// free the value
g_slice_free(struct _openslide_cache_value, value);
}
