Processing Evolved

    function setup() {
        let canvas = createCanvas(600, 600, WEBGL);
        canvas.parent('animation-holder');
    resizeAnimation();
    resizeAnimation();
    resizeAnimation();
    resizeAnimation();
    }

    let angle = 0;
    let oscillation = 0;

    function draw() {
        background(0);
        rotateX(angle);
        rotateY(angle * 0.5);
        rotateZ(angle * 0.25);
        noFill();
        let c1 = color(255, 0, 0);
        let c2 = color(255, 128, 0);
        setGradient(0, 0, 200, 200, c1, c2, "X");
        box(200);

        // Legs
        push();
        translate(0, 100 + sin(oscillation) * 50, 0);
        rotateX(PI / 2);
        setGradient(0, 0, 50, 200, c1, c2, "Y");
        box(50, 200, 50);
        pop();

        push();
        translate(0, -100 - sin(oscillation) * 50, 0);
        rotateX(-PI / 2);
        setGradient(0, 0, 50, 200, c1, c2, "Y");
        box(50, 200, 50);
        pop();

        angle += 0.01;
        oscillation += 0.03;
    }

    function setGradient(x, y, w, h, c1, c2, axis) {
        noFill();

        if (axis === "Y") {
            for (let i = y; i <= y + h; i++) {
                let inter = map(i, y, y + h, 0, 1);
                let c = lerpColor(c1, c2, inter);
                stroke(c);
                line(x, i, x + w, i);
            }
        } else if (axis === "X") {
            for (let i = x; i <= x + w; i++) {
                let inter = map(i, x, x + w, 0, 1);
                let c = lerpColor(c1, c2, inter);
                stroke(c);
                line(i, y, i, y + h);
            }
        }
    }