Support for openfl.filters.BevelFilter

[scanline]

At the moment the BevelFilter is completely missing - not even a stub. A quick example like this:

package;

import openfl.display.Shape;
import openfl.display.Sprite;
import openfl.filters.BevelFilter;
import openfl.text.TextField;
import openfl.text.TextFormat;

class Main extends Sprite
{

	public function new()
	{
		super();
		var button:Sprite = createButton(10, 10);
		addChild(button);

		button = createButton(310, 10);
		button.filters = [new BevelFilter(14, 45, 0xFFFFFF, 0.5, 0x000000, 0.5, 4, 4, 1, 1, "inner", false)];
		addChild(button);

		button = createButton(10, 120);
		button.filters = [new BevelFilter(14, 45, 0xFFFFFF, 0.5, 0x000000, 0.5, 4, 4, 1, 1, "inner", true)];
		addChild(button);

		button = createButton(310, 120);
		button.filters = [new BevelFilter(14, 45, 0xFFFFFF, 0.5, 0x000000, 0.5, 4, 4, 1, 1, "outer", false)];
		addChild(button);

		button = createButton(10, 230);
		button.filters = [new BevelFilter(14, 45, 0xFFFFFF, 0.5, 0x000000, 0.5, 4, 4, 1, 1, "full", false)];
		addChild(button);
	}

	private function createButton(x:Float, y:Float):Sprite
	{
		var sprite:Sprite = new Sprite();

		var shape = new Shape();
		shape.graphics.beginFill(0xd3d3d3, 1);
		shape.graphics.drawRoundRect(0, 0, 280, 96, 20, 20);
		shape.graphics.endFill();
		sprite.addChild(shape);

		var format:TextFormat = new TextFormat();
		format.size = 48;
		format.font = "_sans";
		format.align = "center";

		var tField:TextField = new TextField();
		tField.autoSize = "left";
		tField.defaultTextFormat = format;
		tField.text = "Button";
		tField.y = 48 - tField.height / 2;
		tField.x = 140 - tField.width / 2;
		sprite.addChild(tField);
		sprite.x = x;
		sprite.y = y;
		return sprite;
	}
}

which the Flashplayer displays like this:

just throws Type not found : openfl.filters.BevelFilter when targeting e.g. html5.

With this pull request OpenFL now supports the complete features of the BevelFilter and things will look like this:

BitmapFilterType.INNER with knockout set to true and false work flawlessly while BitmapFilterType.OUTER and BitmapFilterType.FULL suffer from the same fate as any other of OpenFL's OpenGL-based filters (GlowFilter and the like):
OpenFL does not allow dynamic resizing of textures to make room for the filter's effect.

[joshtynjala]

I switched the base branch to 9.4.0-Dev since the 9.3.0 release is happening soon, and this should have more time for testing once merged.

[scanline]

As it turns out I was wrong. After digging through openfl.display.DisplayObjectRenderer.hx

openfl/src/openfl/display/DisplayObjectRenderer.hx

Line 371 in bc334e2

displayObject.__getFilterBounds(rect, displayObject.__cacheBitmapMatrix);

I realized that OpenFL does take care of the extra area caused by a filter now. We just need to tell it the new size.
Well, with the latest commit the outcome of this filter will now look close to the Flashplayer even for BitmapFilterType.FULL and BitmapFilterType.OUTER.

[joshtynjala]

This works correctly in Chrome and Safari. However, in Firefox, there's an exception thrown. If you can fix it, I'll be happy to merge!

[openfl.display.Shader] ERROR: Unable to initialize the shader program
Uniform uBevelType is not linkable between attached shaders.