/**
a 3d stereo viewing demo by 
<a href="http://www.local-guru.net/blog">Guru</a>
*/

PGraphics pg1, pg2;

void setup() {
  size( 600,300);
  pg1 = createGraphics( 300,300,P3D);
  pg2 = createGraphics( 300,300,P3D);
  frameRate(25);
  smooth();
}

float ang = 0;

void draw() {
  pg1.beginDraw();
  cam(pg1, 10 );
  drawCube(pg1);
  pg1.endDraw();
  
  pg2.beginDraw();
  cam(pg2, -10 );
  drawCube(pg2);
  pg2.endDraw();
  
  image(pg1, 0, 0);
  image(pg2, width/2, 0);
  
  ang += 0.05;  

}

void cam( PGraphics pg, float offset ) {
  pg.camera(pg.width/2 + offset, pg.height/2, (pg.height/2)/tan(PI*60/360), pg.width/2, pg.height/2, 0, 0, 1, 0 );
}

void drawCube(PGraphics pg) {
  pg.lights();
  pg.background(0);
  pg.pushMatrix();
  pg.translate( pg.width/2, pg.height/2, map(mouseX,0,300,40,-200) );
  pg.rotateX(ang);
  pg.rotateY(ang/4);
  pg.strokeWeight(2);
  pg.stroke(0,255,0);
  pg.noFill();
  pg.box(100);
  pg.popMatrix();
}