How to apply transform to graphics in OpenFL - graphics

Question

I'm converting a JavaScript library to Haxe. In this library, there is an animated effect constructed with many of shapes. So I used the OpenFL library to render shapes.
But now I have a technical problem with transformation.
Some of the shapes has the child shapes so it's transform should be applied to the child shapes too.
For example, please imagine shapeC is attached on shapeB and, shapeB and shapeD are also attached on shapeA. In this case, shapeB, shapeD should be transformed by both of transformA and their own transform and, shapeC also should by transformA, transformB and transformC.
To achieve this, is it a good solution to render the same level shapes in one graphic and apply the parent's transform to that graphic? (on above example, render shapeB and shapeD to one graphic and a apply transformA to that graphic)
I think it's not a good optimized solution to calculate the final transform from all parents transforms and apply that to all vertexes of that shape. Please tech me the best optimized solution for rendering.
Any suggestion will be welcome.
And if there is any confused things on this question, please pardon me and let me check.

Answer 1

You can use the Sprite class:
var parentShape = new Sprite ();
parentShape.graphics.beginFill (0xFF0000);
parentShape.graphics.drawRect (0, 0, 100, 100);
var childShape = new Sprite ();
childShape.graphics.beginFill (0x00FF00);
childShape.graphics.drawCircle (0, 0, 50);
childShape.x = 200;
childShape.y = 200;
parentShape.addChild (childShape);
addChild (parentShape);
Each shape will use its own canvas element, so if you create a lot of shapes, you may decide to flatten it into a single image when you are ready. This is possible using cacheAsBitmap or bitmapData.draw
parentShape.cacheAsBitmap = true;
...or
removeChild (parentShape);
var bitmapData = new BitmapData (Math.ceil (parentShape.width), Math.ceil (parentShape.height), true, 0);
bitmapData.draw (parentShape);
var bitmap = new Bitmap (bitmapData);
addChild (bitmap);