PGraphics pg;

void setup() { 
  size(400, 400);
  pg = createGraphics(400,400,P3D); 
  pg.colorMode(RGB, 1); 
} 

void draw3quads(float r1, float r2, float g1, float g2, float bin) {
  float r = 0;
  float g = 0;
  float b = 0;
  // rgb
  r = r1;  g = g1;  b = bin;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
  r = r2;  g = g1;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
  r = r2;  g = g2;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
  r = r1;  g = g2;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
  // brg
  r = bin;  g = r1;  b = g1;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
            g = r2;  b = g1;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
            g = r2;  b = g2;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
            g = r1;  b = g2;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
  // gbr
  r = g1; g = bin;  b = r1;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
  r = g1;           b = r2;
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
  r = g2;           b = r2;  
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
  r = g2;           b = r1;  
  pg.fill(255*r, 255*g, 255*b); pg.vertex(r*2-1, g*2-1, b*2-1);
}

float xmag = 0;
float ymag = 0;
boolean first = true;
boolean blend = false;

void draw() { 
  pg.beginDraw();
  pg.noStroke(); 
  if (blend) {
    if (first) {
      pg.background(0);
      first = false;
    }
    pg.filter(BLUR, 3);
  }
  else {
    pg.background(0,0,0,8);
  }
  
  pg.pushMatrix(); 
 
  pg.translate(width/2, height/2, -30); 
  
  float newXmag = mouseX/float(width) * TWO_PI;
  float newYmag = mouseY/float(height) * TWO_PI;
  
  float diff = xmag-newXmag;
  if (abs(diff) >  0.01) { 
    xmag -= diff/4.0; 
  }
  
  diff = ymag-newYmag;
  if (abs(diff) >  0.01) { 
    ymag -= diff/4.0; 
  }
  
  pg.rotateX(-ymag); 
  pg.rotateY(-xmag); 
  
  pg.scale(90);
  pg.beginShape(QUADS);

  float t = 1./3.;
  float s = 2./3.;

  // z==1
  draw3quads(0, t, 1, s, 1);
  draw3quads(t, s, 1, s, 1);
  draw3quads(s, 1, 1, s, 1);
  draw3quads(0, t, s, t, 1);
  //
  draw3quads(s, 1, s, t, 1);
  draw3quads(0, t, t, 0, 1);
  draw3quads(t, s, t, 0, 1);
  draw3quads(s, 1, t, 0, 1);
  
  // z = t
  //
  draw3quads(t, s, 0, t, s);
  //
  draw3quads(0, t, t, s, s);
  //
  draw3quads(s, 1, t, s, s);
  //
  draw3quads(t, s, s, 1, s);
  //
  
  // z = -t
  //
  draw3quads(t, s, 1, s, t);
  //
  draw3quads(0, t, s, t, t);
  //
  draw3quads(s, 1, s, t, t);
  //
  draw3quads(t, s, t, 0, t);
  //
  
  // z = -1
  draw3quads(0, t, s, 1, 0);
  draw3quads(t, s, s, 1, 0);
  draw3quads(s, 1, s, 1, 0);
  draw3quads(0, t, t, s, 0);
  //
  draw3quads(s, 1, t, s, 0);
  draw3quads(0, t, 0, t, 0);
  draw3quads(t, s, 0, t, 0);
  draw3quads(s, 1, 0, t, 0);

  pg.endShape();
  
  pg.popMatrix(); 
  
  pg.endDraw();
  image(pg, 0, 0);
}

void keyPressed() {
  if (key == ' ') {
    first = true;
  }
  else if (key == 'b') {
    blend = !blend;
  }
}