+ tile_t *tile;
+
+ tile = &game->deck.tiles[game->current_tile];
+
+ printf ("Placing tile #%d\n", game->current_tile);
+
+ /* First, invalidate the region where the tile currently is. */
+ gtk_widget_queue_draw_area (widget, tile->x, tile->y, TILE_WIDTH, TILE_HEIGHT);
+
+ /* Then, move the tile */
+ tile->x = event->x;
+ tile->y = event->y;
+
+ /* Finally, invalidate the region where the tile is now. */
+ gtk_widget_queue_draw_area (widget, tile->x, tile->y, TILE_WIDTH, TILE_HEIGHT);
+
+ game->current_tile--;
+ if (game->current_tile < 0)
+ game->current_tile = game->deck.num_tiles - 1;