void setup ()
{
  // Set sketch to use P3D library for 3D images
  size(300, 300, P3D);
  background(50);
}

void draw ()
{
  background(50);
  if (mouseX > 50 && mouseX < 200)
  {
    fill(100, 175, 175);
  }
  else
  {
    fill(175, 100, 175);
  }
  // Draw rectangle w/ top left corner at (75, 75)
  // and width = height = 150 pixels
  translate(150, 150, -25); // Shift origin 150 px right and down, and 25 px back (into screen)
  rectMode(CENTER);
  rotateX(radians(mouseY)); // Rotate 45 degrees clockwise
  rotateY(radians(mouseX)); // Rotate left/right based on mouse position
  rect(0, 0, 20, 20); // Center rectangle over origin
  rect(-50, 0, 20, 20);
  rect(50, 0, 20, 20);
}