# Move the mouse left and right to see the detail change

settings <- function() {
    size(100, 100, P3D)
}

setup <- function() {
    frameRate(30)
}

draw <- function() {
    background(204)
    
    x = mouseX
    y = mouseY
    z = -100
    
    # Draw 'X' at z = -100
    stroke(255)
    line(x - 10, y - 10, z, x + 10, y + 10, z)
    line(x + 10, y - 10, z, x - 10, y + 10, z)
    
    # Draw gray line at z = 0 and same y value. Notice the parallax
    stroke(102)
    line(0, y, 0, width, y, 0)
    
    # Draw black line at z = 0 to match the y value element drawn at z
    # = -100
    stroke(0)
    theY = screenY(x, y, z)
    line(0, theY, 0, width, theY, 0)
}