Vector Math
/**
* Vector
* by Daniel Shiffman.
*
* Demonstration of some basic vector math: subtraction,
* normalization, scaling. Normalizing a vector sets
* its length to 1.
*/
void setup() {
size(640, 360);
}
void draw() {
background(0);
// A vector that points to the mouse location
PVector mouse(mouseX, mouseY);
// A vector that points to the center of the window
PVector center(width/2, height/2);
// Subtract center from mouse which results in a
// vector that points from center to mouse
mouse.sub(center);
// Normalize the vector
mouse.normalize();
// Multiply its length by 150 (Scaling its length)
mouse.mult(150);
translate(width/2, height/2);
// Draw the resulting vector
stroke(255);
strokeWeight(4);
line(0, 0, mouse.x, mouse.y);
}