function setup() {
createCanvas(400, 400);
}

function draw() {
background(220);
line(20, 20, 380, 380);
}
function setup() {
createCanvas(400, 400);
}

function draw() {
var points = [ [30, 20],
[85, 75],
[150, 40],
[200, 100],
[250, 20]
];

for (var i = 0; i < points.length - 1; i++) {
line(points[i][0], points[i][1], points[i + 1][0], points[i + 1][1]);
}
}function setup() {
createCanvas(400, 400);
background(220);

// 設定 (0,0) 原點座標在視窗中心點
translate(width / 2, height / 2);

// 繪製一個正方形
rect(0, 0, 50, 50);
}