Animate

Remember that using the background() function clears the screen each frame, turning a drawing program into an animation.

void setup () { size(640,480); background(255); stroke(0); fill(0); } void draw() { background(255); ellipse(mouseX,mouseY,6,6); }
// rubber band void setup () { size(640,480); background(255); stroke(0); fill(0); } void draw() { background(255); line(mouseX,mouseY,0,0); line(mouseX,mouseY,640,0); line(mouseX,mouseY,640,480); line(mouseX,mouseY,0,480); }
// crosshairs void setup () { size(640,480); background(0); stroke(255,0,0); noFill(); } void draw() { background(0); line(0,mouseY,640,mouseY); line(mouseX,0,mouseX,480); ellipse(mouseX,mouseY,50,50); }