const sketch = p => { p.setup = () => { //キャンバスを作成 const canvas = p.createCanvas(600,425); canvas.id = '__P5sc__'; //背景色 p.background('#eee'); p.stroke('#aaa'); } p.draw = () => { if (p.mouseIsPressed) { p.fill(0,0,0,10); } else { p.fill('#fff'); } 　　　　p.triangle(p.mouseX, p.mouseY, p.mouseX+15, p.mouseY+30, p.mouseX+-15, p.mouseY+30); } } new p5(sketch, 'editor');