sketch.js

var fixed_rect, moving_rect;


function setup() {
  createCanvas(800,400);
  fixed_rect = createSprite(400, 200, 50, 100);
  fixed_rect.shapeColor = "green";
  fixed_rect.debug = true;

  moving_rect = createSprite(300, 200, 50, 100);
  moving_rect.shapeColor = "green";
  moving_rect.debug = true;
}

function draw() {
  background(255,255,255);
  moving_rect.x = mouseX;
  moving_rect.y = mouseY;

  if(moving_rect.x - fixed_rect.x < fixed_rect.width/2 + moving_rect.width/2 && 
    fixed_rect.x - moving_rect.x < fixed_rect.width/2 + moving_rect.width/2 &&
    moving_rect.y - fixed_rect.y < fixed_rect.width/2 + moving_rect.width/2 && 
    fixed_rect.y - moving_rect.y < fixed_rect.width/2 + moving_rect.width/2){
    moving_rect.shapeColor = "red";
    fixed_rect.shapeColor = "red";
  }else{
    moving_rect.shapeColor = "green";
    fixed_rect.shapeColor = "green";
  }


  drawSprites();
}