stereo viewing

stereo-viewing.clj

; This is a transliteration of the code listed here: http://wiki.processing.org/w/Stereo_viewing
; I stumbled on it in search of a means to get a handle to the GL context that 
; exposes the lower level OpenGL methods.

(ns stereo-viewing
  (:import [processing.core PConstants])
  (:use [quil.core] [quil.applet])
  )

(def rotation (atom 0))
(def gl (atom nil))

(defn setup []
  ; This is needed to stop the images being squashed
  (perspective (/ PConstants/PI 3.0) 1 0.1 1000)
  (no-stroke)
  ; current-applet returns the current PApplet object which contains
  ; the PGraphicsOpenGL object which itself contains the raw GL object,
  ; which is what I need to call the lower-level OpenGL goodies.
  (reset! gl (-> (current-applet) .g .gl))
  )

(defn draw-two-boxes []
  (push-matrix)
  (rotate-x @rotation)
  (rotate-y (/ @rotation 2.3))
  (box 30)
  (translate 0 0 30)
  (box 10)
  (pop-matrix)
  )

(defn draw []
  (swap! rotation + 0.01)
  (ambient-light 64 64 64)
  (point-light 128 128 128 0 20 -50)
  (background 0)
  (fill 255)

  ; Left Eye
  ; Using Camera gives us much more control over the eye position
  (camera -10 0 -100 0 0 0 0 -1 0)
  ; This means anything we draw will be limited to the left half of the screen
  (.glViewport @gl 50 50 200 200)
  (draw-two-boxes)

  ; Right Eye
  (camera 10 0 -100 0 0 0 0 -1 0)
  ; This means anything we draw will be limited to the _right_ half of the screen
  (.glViewport @gl 250 50 200 200)
  (draw-two-boxes)
  )

(defsketch main
  :title "stereo viewing"
  :setup setup
  :draw draw
  :size [500 300]
  :renderer :opengl
  )