mathkit

This is a purely math-related utility kit, providing functions which can be useful for games, 3D, and GL in general. Right now this includes additional matrix functionality by @3b on top of sb-cga.

• ortho-matrix LEFT RIGHT BOTTOM TOP NEAR FAR: Construct an orthographic matrix like glOrtho from OpenGL 2.1.
• frustum LEFT RIGHT BOTTOM TOP NEAR FAR: Construct a perspective matrix from the given parameters, like glFrustum from OpenGL 2.1.
• perspective-matrix FOVY-DEGREES ASPECT Z-NEAR Z-FAR: Construct a perspective matrix from the given parameters, like gluPerspective from OpenGL 2.1.
• look-at EYE TARGET UP: Where EYE, TARGET, and UP are vectors, construct a viewing matrix much like gluLookAt from OpenGL 2.1.

Note: These merely create native Lisp matrices; they do not multiply them like the similar GL functions or in any way set them as GL state like the old fixed-function pipeline.

Additionally:

• copy-matrix M: Create a copy of M.
• deg-to-rad D: Convert D degrees to radians.