I propose that instead of a predefined tile shape, the tiles should only be characterized by their horizontal dimentions and the vertical distance between floors.
Le Artiste will be able to choose a tile shape that he considers best (as you may know, I'm dying to try a view in which the "blue rectangle" of the tile is actually square).
Are you able the compile up to date versions? If you can get things to compile, there's a handful of constants that control all of that. I believe a "#define TILEHEIGHT 32" would get you that. Hmm. Maybe these should be init-able, too...
Another thing is freeing up the sprite size. The bottom edge of the blue rectangle should be the bottom edge of the sprite image, but it would be great if the artist was free to do a sprite as high and wide as he wants if he needs it. Of course, for clarity he'll want to stay above these red lines but even that should be up to him.
The tile height, from the POV of Stonesense should also only mean the vertical displacement of the next layer of floors. If a sprite would benefit from that few additional pixels in height- let the artist use them! That is of course as long as they don't stick out of the floor when viewing the level above (as it is now).
Hmm. Currently the system draws all tiles sorted by z, then x, then y. So if you stick too far out the wrong side, you will get "floored".
It would theoretically be possible to tile in a diagonal order, but it would be a pain in the neck.
It is possible via a workaround to get additional height on building sprites (width, too, but again "floored"), and this will probably be applicable to creature sprites eventually.
However, there is another reason for a predefined tile shape: it makes em fit on the objects.png file. But that can be ignored if you make sure to leave the sprites either side blank.
Hmm. The biggest problem I can see really is that tile order thing, so if we can think of a reasonable algorithm to get the x,y,z in the right order quickly, then it may all be doable.
Incidently, floors will probably have some thickness shortly, so sticking out the top will be less likely.