This example is for Processing 3+. If you have a previous version, use the examples included with your software. If you see any errors or have suggestions, please let us know.

**Rotate.**

Rotating a square around the Z axis. To get the results you expect, send the rotate function angle parameters that are values between 0 and PI*2 (TWO_PI which is roughly 6.28). If you prefer to think about angles as degrees (0-360), you can use the radians() method to convert your values. For example: scale(radians(90)) is identical to the statement scale(PI/2).

float angle; float jitter; void setup() { size(640, 360); noStroke(); fill(255); rectMode(CENTER); } void draw() { background(51); // during even-numbered seconds (0, 2, 4, 6...) if (second() % 2 == 0) { jitter = random(-0.1, 0.1); } angle = angle + jitter; float c = cos(angle); translate(width/2, height/2); rotate(c); rect(0, 0, 180, 180); }