addtiledef2() works like addtiledef(), but instead you use small image chunks and also pass the coordinates (where you want to place the chunks) as arguments, in pixels. Example:
PHP Code:
addtiledef2("block.png", "level_", 512, 320);
Will add block.png to the currently active tileset, overwriting the four tiles at 512, 320 (blocking tiles in the type 1 tileset). Paint will do the trick if you need to find the pixel coordinates for this stuff. Just leave your mouse over the desired topleft-most pixel of the tile and use the coordinates in Paint's status bar.