/*  The Heart Beat                        */
float dir=-1;                          // direction of change
float tinto=255;                       // start out red

void setup( ){
  size(500, 500);                      // set canvas
  background(64);                      // pick gray for the app
  frameRate(15);                       // more fun to go slow
  noStroke();                          // show not lines
  fill(255,0,0);                       // start out pure red
}

void draw( ) {
  ellipse(200,250,100, 100);              //piece together 
  ellipse(300,250,100, 100);              //a heart shape
  triangle(153, 270, 348, 270, 250, 400); //from basic shapes
  rect(240, 250, 20, 20);                 //
  tinto=tinto+dir*5;                      //set a new color
  if (tinto < 180 ) {                     //is it too dark?
    dir=1;                                //yes, start to lighten
  }
  if (tinto > 255) {                      //is it full color  
    dir=-1;                               //start to darken
  }
  fill(tinto,0,0);                        //set the color
}