simpledisplay: Sprite.takeScreenshot() returns a completely black MemoryImage

[TheZipCreator]

Sprite's takeScreenshot() function returns an entirely black TrueColorImage. It should just return an image containing what was on the sprite.
This works correctly on Linux, but not on Windows

example code:

import arsd.simpledisplay, arsd.png;

void main() {
	auto win = new SimpleWindow(500, 500, "Test");
	auto img = Image.fromMemoryImage(readPng("./smiley.png")); // replace "./smiley.png" with a path to an image on your computer
	auto sprite = new Sprite(win, img);
	auto sprite2 = Sprite.fromMemoryImage(win, sprite.takeScreenshot(), true); // *should* just copy the data in the other sprite
	scope(exit) {
		sprite.dispose();
		sprite2.dispose();
	}
	win.eventLoop(10, delegate() {
		auto sp = win.draw;
		// this should be two copies of the same image, but on Windows it doesn't work
		sprite.drawAt(sp, Point(0, 0));
		sprite2.drawAt(sp, Point(100, 0));
	});
}

[adamdruppe]

I might have only implemented it on windows themselves, will need to check if it does win32 bitmap copy too (which is an easy operation but ... maybe i missed a spot)