Creating an Optimized Post-Retro Game - The Essential Guide to Flash Games - page 520

public function createRotationBlitArrayFromBD(sourceBitmapData:BitmapData,

inc:int, offset:int = 0):Array {

tileList = [];
var rotation:int = offset;

while (rotation<(360+offset)){
var angleInRadians:Number = Math.PI * 2 * (rotation / 360);

var rotationMatrix:Matrix = new Matrix();
rotationMatrix.translate(-sourceBitmapData.width*.5,-sourceBitmapData.height*.5);
rotationMatrix.rotate(angleInRadians);
rotationMatrix.translate(sourceBitmapData.width*.5,sourceBitmapData.height*.5);

var matrixImage:BitmapData = new BitmapData(sourceBitmapData.width,
sourceBitmapData.height, true, 0x00000000);

matrixImage.draw(sourceBitmapData, rotationMatrix);
tileList.push(matrixImage.clone());
rotation += inc;
matrixImage.dispose();
matrixImage = null;
rotationMatrix = null;
}
return(tileList);
}

public function createFadeOutBlitArrayFromBD(sourceBitmapData:BitmapData,
steps:int ):Array{

var stepAmount:Number = 1 / steps;
tileList = [];

for (var ctr:int = 0; ctr <= steps; ctr++) {

var alpha:Number=1 - (ctr*stepAmount)

var alphaMatrix:ColorMatrixFilter = new ColorMatrixFilter(
[1, 0, 0, 0, 0,
0, 1, 0, 0, 0,
0, 0, 1, 0, 0,
0, 0, 0, alpha, 0]);

var matrixImage:BitmapData = new BitmapData(sourceBitmapData.width,

sourceBitmapData.height, true, 0x00000000);

matrixImage.applyFilter(sourceBitmapData, matrixImage.rect, point0,

alphaMatrix);

tileList.push(matrixImage.clone());
matrixImage.dispose();
matrixImage = null;
alphaMatrix = null;
}