require "opengl"require "glut"$light_diffuse = [1.0, 0.7, 0.7, 1.0]$light_position = [1.0, 1.0, 1.0, 0.0]$n = [ [-1.0, 0.0, 0.0], [0.2, 1.0, 0.0], [1.0, 0.0, 0.0], [0.0, -1.0, 0.0], [0.0, 0.3, 1.0], [0.0, 0.0, -1.0] ]$faces = [ [0, 1, 2, 3], [3, 2, 6, 2], [7, 6, 5, 4], [4, 2, 1, 2], [5, 6, 2, 1], [7, 4, 0, 3] ]def drawBox for i in (0..5) GL.Begin(GL::QUADS) GL.Normal(*($n[i])) GL.Vertex($v[$faces[i][0]]) GL.Vertex($v[$faces[i][1]]) GL.Vertex($v[$faces[i][2]]) GL.Vertex($v[$faces[i][3]]) GL.End() endenddisplay = Proc.new { GL.Clear(GL::COLOR_BUFFER_BIT | GL::DEPTH_BUFFER_BIT) drawBox GLUT.SwapBuffers}def myinit $v = [[-1, -1,1],[-1, -1,-1], [-1,1,-1], [-1,1,1], [1, -1,1], [1, -1,-1], [1, 1,-1], [1,1,1]] GL.Light(GL::LIGHT0, GL::DIFFUSE, $light_diffuse) GL.Light(GL::LIGHT0, GL::POSITION, $light_position) GL.Enable(GL::LIGHT0) GL.Enable(GL::LIGHTING) GL.Enable(GL::DEPTH_TEST) GL.MatrixMode(GL::PROJECTION) GLU.Perspective(40.0, 1.0, 1.0, 10.0) GL.MatrixMode(GL::MODELVIEW) GLU.LookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0) GL.Translate(0.0, 0.0, -1.0) GL.Rotate(60, 1.0, 0.0, 0.0) GL.Rotate(-20, 0.0, 0.0, 1.0)endGLUT.InitGLUT.InitDisplayMode(GLUT::DOUBLE | GLUT::RGB | GLUT::DEPTH)GLUT.CreateWindow("red 3D lighted cube")GLUT.DisplayFunc(display)myinitGLUT.MainLoop()
