Penumbra is not under active development. However, it’s still a fun way to play around with OpenGL and Clojure. Bugs will be fixed, time permitting, but new features are unlikely.

Penumbra is an idiomatic wrapper for OpenGL in Clojure, by way of LWJGL.

This Java/C code

glEnable(GL_LIGHT0);
glPushMatrix();
glTranslated(0, 0, -10);
glBegin(GL_QUADS);
glVertex3d(0, 0, 0);
glVertex3d(0, 1, 0);
glVertex3d(1, 1, 0);
glVertex3d(1, 0, 0);
glEnd();
glPopMatrix();

becomes

(enable :light0)
(push-matrix
  (translate 0 0 -10)
  (draw-quads
    (vertex 0 0 0)
    (vertex 0 1 0)
    (vertex 1 1 0)
    (vertex 1 0 0)))

Numerous sample programs can be found in /src/example. They include clean, functional implementations of Tetris and Asteroids, and a GPU-driven Mandelbrot viewer.

A long term goal for Penumbra is to simplify GPU programming as much as possible, allowing for both advanced graphical effects and general computation. This is a work in progress, but this n-body simulation is a good example of what’s possible.

Using Penumbra

Directions for installation and use in other projects can be found here.

If you have any questions, please visit the mailing list.