Archives week 15 of 2009

As mentioned many times already, OpenGL 3.1 is eliminating the matrix manipulation code from the OpenGL API.  OpenGLContext/PyVRML97 already had a matrix-calculation mechanism, but it wasn't used for rendering anything, it was just used for certain bookkeeping operations.

To make it practical to use the matrices for rendering they need to be cached.  I'm eventually ...

Set up a little spike test that overrides the matrix setup for the projection and model-view matrices to be identity values.  The test then uses visitor.find() to construct paths to all Rendering node-types in a scenegraph and sets up the matrices with a call to glLoadMatrix on my calculated matrices and then renders the Rendering ...

Spent rather more time this afternoon than I'd intended working on fixing font rendering.  It was just a little spike test using Pygame to create a TextureAtlas and then rendering the atlas texture onto a quad to be sure it showed up.  Except that it didn't.

Which brings me to the point of this post: ...

I'm guessing that everyone who's ever taken "intro to not particularly slow computer graphics" has written their own texture atlas implementation, so hey, I should too :) .  Texture atlases are collections of large numbers of small textures which are packed into a single, larger texture with some book-keeping metadata to allow the GL to ...