Learn Haxe

Drawing Images Transparently in Kha

Posted on 2017-03-08

Tagged with: Kha

In Kha, you can draw images semi-transparently. This doesn't refer to drawing parts of the image transparently, but rather drawing the image as a partially-transparent "layer" (eg. 25% transparent).

Although you might expect to find an alpha or opacity field on the Image class. Kha keeps the opacity field on the Graphics class. For example, kha.graphics.Graphics2 has an opacity field. You can use it like so:

public function render(g:Graphics): Void
{
	g.begin(0); // black
	g.drawImage(mountains, 0, 0); // drawn fully opaque
	g.opacity = 0.25;
	g.drawImage(ball, 100, 50); // draws the ball at 25% transparency
	g.end();
}

Be careful to reset opacity back to 1.0 when you're done, so that anything drawn after the transparent image appears normal.