Dot product

README.md

not sure what this is, I think I was trying to figure out what a dot product is

dot.pde

PVector p1;
PVector p2;
PVector origin;

void setup() {
  size(500, 500);
  background(255);
  origin = new PVector(width * 0.5, height * 0.5);
  p1 = new PVector(0, height * -0.25);
  p2 = new PVector(width * 0.25, 0);
}

void draw() {
  background(255);

  translate(origin.x, origin.y);

  strokeWeight(4);
  stroke(255, 0, 0);
  line(0, 0, p1.x, p1.y);
  
  stroke(0, 255, 0);
  line(0, 0, p2.x, p2.y);

  float p3 = PVector.dot(p1, p2);
  fill(0);
  textAlign(CENTER);
  text(p3, 0, height * 0.25);
}

void mouseClicked() {
  p2.x = mouseX - origin.x;
  p2.y = mouseY - origin.y;
}

void mouseDragged() {
  p2.x = mouseX - origin.x;
  p2.y = mouseY - origin.y;  
}

a little math toy to illustrate the dot product between vectors. One vector is fixed while the other is affected by mouse control. Click and drag to move the second vector. The dot product of the two vectors is printed to the screen.