I’m working on a game that required me to convert screen -> isometric space, and it took me some time to come up with these equations, and theagentd suggested I post my findings: https://gist.github.com/4009942
in case it gets deleted
Screen -> Isometric space equations
iX = (((ScreenX) / tileWidth) - ((ScreenY) / tileHeight));
iY = (((ScreenX) / tileWidth) + ((ScreenY) / tileHeight));
Isometric -> Screen space equations
ScreenX = (iX + iY) * tileWidth / 2;
ScreenY = (iY - iX) * tileHeight / 2;
Assuming the isometric coordinating system goes as this: http://i.imgur.com/aUM4g.png