I'm getting into 3D graphics and so what I'm trying to make is a simple Minecraft clone. In Minecraft, some block types have different textures on each face. However, that seems to greatly reduce my framerate when I render these multi-textured objects. I've implemented a few measures to control which objects are rendered, but the problem is still happening, as demonstrated in this short video: http://www.pyraetos.net/lag.avi
I know that Minecraft has just one texture file, and the "individual" textures are produced with texture coordinates. Could this have something to do with it? Thank you in advance.
EDIT: If you watch the video, the FPS counter is part of the window title.