I like to keep my tileset graphics simple so that I can compose them together during tilemap creation. So instead of having, say, three tiles for grass, building, and building + grass, I keep them separately as a building and grass tile, and if I need building + grass, I lay one above the other on separate layers like in the picture below.
This gives me more freedom and flexibility. In the example picture below, all three layers are in the background and should behave as one unit. Is it possible then to render this into one just layer, instead of three, to save on draw calls? I know 2DTK's tilemap has a
SetTile function. Is it possible to call it without erasing the previous contents, so that I can effectively combine tiles together?
Picture example of what I'm trying to achieve: