Ruby-opengl

teapot.rb

require 'opengl'
require 'glu'
require 'glut'

$x = 0
$y = 0

def onMove(x,y)
  $x = x
  $y = y    
end

def onRender
  glClear GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT

  glMatrixMode GL_PROJECTION
  glLoadIdentity
  gluPerspective 40, 480/320, -10,10
  gluLookAt $x, $y, $y, 1, 1, 1, 0, 1, 0

  glMatrixMode GL_MODELVIEW
  glLoadIdentity

  glMaterialfv GL_FRONT, GL_SPECULAR, [1, 1, 1, 1]
  glMaterialfv GL_FRONT, GL_SHININESS, [20]

  glutSolidTeapot 10

  glutSwapBuffers
end

begin
  # initialize glut library
  glutInit

  # initialize glut window
  glutInitWindowPosition 100,100
  glutInitWindowSize 480,320
  glutInitDisplayMode GLUT_DEPTH | GLUT_RGBA | GLUT_DOUBLE

  # create glut window
  glutCreateWindow "ruby-gl"

  # regist callback methods
  glutDisplayFunc :onRender
  glutIdleFunc :onRender
  glutMotionFunc :onMove

  # set up environments
  glEnable GL_DEPTH_TEST
  glEnable GL_LIGHTING
  glEnable GL_LIGHT0

  glLightfv GL_LIGHT0, GL_POSITION, [10, 10, 10, 0]
  glLightfv GL_LIGHT0, GL_AMBIENT, [1, 0, 1, 1]
  glLightfv GL_LIGHT0, GL_DIFFUSE, [0, 1, 1, 1]
  glLightfv GL_LIGHT0, GL_SPECULAR, [1, 1, 1, 1]

  # start program
  glutMainLoop

rescue
  p "Error : #{$!}"  
end