Learning Processing: Chapter 3: Example 3-2: mouseX and mouseY

Example

// Learning Processing
// Daniel Shiffman
// http://www.learningprocessing.com

// Example 3-2: mouseX and mouseY

void setup() {
  size(200,200);
}

void draw() {
  // Try moving background() to setup() and see the difference!
  background(255);

  // Body
  stroke(0);
  fill(175);
  rectMode(CENTER);
  
  // mouseX is a keyword that the sketch replaces with the horizontal position of the mouse.
  // mouseY is a keyword that the sketch replaces with the vertical position of the mouse.
  rect(mouseX,mouseY,50,50);   
}

Comments (5)

Moisa

I like that!
Indu

Is there a way to set the size of the window equal to the size of the screen/interface on which the applet is displayed?
Thanks!
shiffman

Processing 1.5.1:

size(screen.width,screen.height)

Processing 2.0 alpha:

size(screenWidth,screenHeight);
Rey

Why does rectMode(CENTER); has to be repeated within the draw() cycle? Can it be defined once, right after “size(200, 200,);” in the setup() section?
shiffman

Yes, it absolutely could. However, I find that it’s often good practice to specify the mode at the moment you draw the shape as you often draw many shapes with varying modes throughout your code.