canvas.setAlpha

    canvas.setAlpha(value)

Set the transparency level with which subsequent draw operations should be performed. The default value for alpha is 255 (fully opaque).

Parameters

Parameter	Type	Description
value	number	An integer value from 0 (transparent) to 255 (opaque). Values outside this range will be clamped.

Example

    // Draw three colored bars with different opacities across the canvas on
    // an orange background
    function fillRGB(name) {
        var canvas = sb.getCanvas(name);
        var rw = canvas.width / 3;
        canvas.fill(0xff8000);
        canvas.setAlpha(50);
        canvas.fillRect(0, 0, rw, canvas.height, 0xff0000);
        canvas.setAlpha(150);
        canvas.fillRect(rw, 0, 2*rw, cavas.height, 0x00ff00);
        canvas.setAlpha(255);
        canvas.fillRect(2*rw, 0, 3*rw, canvas.height, 0x0000ff);
    }