AS3 cacheAsBitmap confusion - actionscript-3

Question

My goal was to have low resolution circles (very pixelated). I know there are other ways to do this, but I'm trying to understand how cacheAsBitmap works. When I use a sprite sheet that I have drawn very very small, and then scale the bitmap up, it looks great (very blocky, pixelated, smoothing turned off). Fine. But when I draw a circle programatically very small (say radius of 4), and then cache it, and then scale it up, it is pixelated, but very much a full, round circle. I take it that somehow the player isn't actually caching it as a bitmap until it is rendered on the screen. Even when I don't do the scale up until the swf is fully loaded and running, I still just get big circles that are perfectly round (but pixelated). Is there a way to cache something programatically that will then scale up the way my imported bitmaps do?
the code I tried looks basically like this:
for (var i: int = 0; i < 200; i++) {
var size: Number = 8;
var item: RunnerMassObj = new RunnerMassObj();
item.graphics.lineStyle(0,0x0,0,true);
item.graphics.beginFill(0xFF8844 + i * 10);
if (i < 10) {
item.graphics.drawCircle(0, 0,size);
} else {
item.graphics.drawRect(0, 0, size, size);
}
item.graphics.endFill();
addChild(item);
item.x = Math.random() * 1000 + 50;
item.y = Math.random() * 1000;
item._bottom.y = size;
// here I cache it as a bitmap.
item.cacheAsBitmap = true;
allMassObj.push(item);
}
and then in my engineTick code I have this:
for(var i:int = 0; i < allMassObj.length; i++)
{
// and here I scale it up, expecting the pixels to stay pixelated.
// has the circle somehow maintained its vector shape?
allMassObj[i].scaleX = 10;
allMassObj[i].scaleY = 10;
}
and instead of the big pixels on the left, I get the tiny "true to screen" pixels on the right:
Any insights will be much appreciated!

Answer 1

If you convert your item into a BitmapData then you could disable smooth:
item = new BitmapData(instance.width * scale, instance.height * scale, true, 0x0);
item.draw(instance, m, null, null, null, false); // final false disables smoothing
(Do not tryied but I think it's worth to have a look)
Best.
Edit: additionally: try to investigate something near color depth of your bitmap. As you know, if you can convert your bitmap to 1 or 2 bit colors, then resizing it, probably you will get a hard pixelated image as you wish.

Answer 2

But when I draw a circle programatically very small (say radius of 4), and then cache it, and then scale it up, it is pixelated, but very much a full, round circle.
The thing is that it's just cached as a bitmap. It doesn't behave like one. The documentation is pretty clear on this one:
After you set the cacheAsBitmap property to true, the rendering does not change
The point of cacheAsBitmap is to improve rendering performance for complex vector data that doesn't change:
If set to true, Flash runtimes cache an internal bitmap representation of the display object. This caching can increase performance for display objects that contain complex vector content.
It basically "bakes" the vector geometry into pixels behind the scenes, so that it doesn't have to do the calculations to display it again and again.
When the DisplayObject is transformed, the cache is updated. That's why you never see a pixelated version of your circle.