require "opengl" require "glut" display = proc { GL.Clear(GL::COLOR_BUFFER_BIT) GL.Begin(GL::TRIANGLES) GL.Color3f(1.0, 0.0, 0.0) # red GL.Vertex3f(0.0, 0.0, 0.0) # center GL.Color3f(0.0, 1.0, 0.0) # green GL.Vertex3f(1.0, 0.0, 0.0) # right GL.Color3f(0.0, 0.0, 1.0) # blue GL.Vertex3f(0.0, 1.0, 0.0) # up GL.End(); GLUT.SwapBuffers() } GLUT.Init() GLUT.CreateWindow("ruby-opengl test") GLUT.DisplayF