My Sketch demo

function setup() {

  createCanvas(500, 500); //畫布

  background('#ffffff')

}

​

function draw() {

  background(100,20);

  fill(255,200,frameCount);

  stroke(255,0,0);//border顏色

  if (mouseIsPressed){ //滑鼠按下之後

    fill(255,mouseX, mouseY);

    rect(mouseX, mouseY, mouseX, 20);// mouseX,mouseY滑鼠x軸y軸位置

  }else{

    fill(0,mouseY,mouseX); //物件填色

    ellipse(mouseX, mouseY, 50, 50);

  }

  //strokeWeight(10);//畫筆寬度

  //print(frameCount)// 目前畫面已累積的禎數

​

}