Changing brightness for my color picker (with easy-to-run code)

programming flash
1

I have a color picker, and I need to be able to change the movieclips brightness. I don’t know how, but here is an idea of what I’m going for - using the alpha property instead:


function drawGradientBox(size:uint, col:Array, alph:Array, rat:Array, matRot:Number) {
	var sp:Sprite = new Sprite();
	var mat:Matrix = new Matrix();
	var fill:String = GradientType.LINEAR;
	mat.createGradientBox(size, size, matRot, 0, 0);
	sp.graphics.beginGradientFill(fill, col, alph, rat, mat);
	sp.graphics.drawRect(0, 0, size, size);
	return sp;
}

function deg2rad(deg:Number):Number {
	return deg * (Math.PI/180);
}

function onHover(evt:MouseEvent):void {
	if (spectrum.hitTestPoint(mouseX, mouseY, true)) {
		col = bmd.getPixel(spectrum.mouseX, spectrum.mouseY);
		//code.text = prependZeros(col);
	}
}

function onAlphaHover(evt:MouseEvent){
	colorPicker.alpha = evt.localY/100;
}

function prependZeros(hex:uint):String {
	var hexString = hex.toString(16).toUpperCase();
	var cnt:int = 6 - hexString.length;
	var zeros:String = "";
	for (var i:int = 0; i < cnt; i++) {
		zeros += "0";
	}
	return "#" + zeros + hexString;
}

var underlay:Sprite = new Sprite();
underlay.graphics.beginFill(0);
underlay.graphics.drawRect(0, 0, 100, 100);
underlay.x = underlay.y = 10;
//addChild(underlay);

var colorPicker:Sprite = new Sprite();
colorPicker.cacheAsBitmap = true;
var colors:Array = [0xFF0000, 0xFFFF00, 0x00FF00, 0x00FFFF, 0x0000FF, 0xFF00FF, 0xFF0000];
var alphas:Array = [1, 1, 1, 1, 1, 1, 1];
var ratios:Array = [0, 42, 84, 126, 168, 210, 255];
var spectrum:Sprite = drawGradientBox(100, colors, alphas, ratios, 0);
colorPicker.addChild(spectrum);
colors = [0x000000, 0x000000];
alphas = [1, 0];
ratios = [0, 255];
var overlay:Sprite = drawGradientBox(100, colors, alphas, ratios, deg2rad(-90));
colorPicker.addChild(overlay);
colorPicker.x = 10;
colorPicker.y = 10;
this.addChild(colorPicker);
var col:uint;
var bmd:BitmapData = new BitmapData(colorPicker.width, colorPicker.
height, false, 0xFFFFFFFF);
bmd.draw(colorPicker);
colorPicker.addEventListener(MouseEvent.MOUSE_MOVE, onHover, false, 0, true);


var darknessPicker:Sprite = new Sprite();
darknessPicker.cacheAsBitmap = true;
colors = [0x000000, 0xFFFFFF];
alphas = [1, 1];
ratios = [0, 255];
var spectrum2:Sprite = drawGradientBox(100, colors, alphas, ratios, deg2rad(-90));
darknessPicker.addChild(spectrum2);
darknessPicker.width = 10;
darknessPicker.y = 10;
darknessPicker.x = 120;
this.addChild(darknessPicker);

darknessPicker.addEventListener(MouseEvent.MOUSE_MOVE, onAlphaHover, false, 0, true);

Any idea how I can change brightness? I want to take this little color picker and hook it in to some javascript - I think it will run a lot smoother than the pure JS ones out there.