Stuff

////////////////////////////////////////////////////////////////////////////////
// Adds a rectangle into the dirty list. If it can't be added it is split in
// 4 parts which are then added recursively
void MAS::DRS::InvalidateRect(const Rect& r) {
	MAS::Rect *s = CanAdd(r);
	if (!s) {
		rectlist.push_back(r);
	}
	else {
		int x1 = r.x();
		int x2 = r.x2();
		int y1 = r.y();
		int y2 = r.y2();

		// Get the coordiantes of the rectangle that is in the way
		int wx1 = s->x();
		int wy1 = s->y();
		int wx2 = s->x2();
		int wy2 = s->y2();

		// Now check which corner points of the rect we're trying to add are
		// inside the rect that is on top and split the rect accordingly
		int inside = 0;

		inside |= (((MAS::Point(x1, y1) <= *s) ? 1 : 0)<<0);		// upper-left
		inside |= (((MAS::Point(x2, y1) <= *s) ? 1 : 0)<<1);		// upper-right
		inside |= (((MAS::Point(x1, y2) <= *s) ? 1 : 0)<<2);		// lower-left
		inside |= (((MAS::Point(x2, y2) <= *s) ? 1 : 0)<<3);		// lower right

		switch (inside) {
			// no corners are inside the window (the window is inside the rectangle) -->
			// --> split the rectangle in 3 or 4 pieces
			case 0x00:
				if (wy1 > y1)	InvalidateRect(MAS::Rect(x1, y1, r.w(), wy1-y1));
				if (wx1 > x1)	InvalidateRect(MAS::Rect(x1, MAX(y1, wy1), wx1-x1, MIN(y2, wy2) - MAX(y1, wy1)));
				if (wx2 < x2)	InvalidateRect(MAS::Rect(wx2, MAX(y1, wy1), x2-wx2, MIN(y2, wy2) - MAX(y1, wy1)));
				if (wy2 < y2)	InvalidateRect(MAS::Rect(x1, wy2, r.w(), y2-wy2));
				break;
			// only the top left is inside --> split in 2 rectangles
			case 0x01:
				InvalidateRect(MAS::Rect(wx2, y1, x2-wx2, wy2-y1));
				InvalidateRect(MAS::Rect(x1, wy2, r.w(), y2-wy2));
				break;
			// only the top right is inside --> 2 rectangles
			case 0x02:
				InvalidateRect(MAS::Rect(x1, y1, wx1-x1, wy2-y1));
				InvalidateRect(MAS::Rect(x1, wy2, r.w(), y2-wy2));
				break;
			// both top corners are inside --> add the bottom half
			case 0x03:
				InvalidateRect(MAS::Rect(x1, wy2, r.w(), y2-wy2));
				break;
			// only the lower left is inside --> 2 rectangles
			case 0x04:
				InvalidateRect(MAS::Rect(x1, y1, r.w(), wy1-y1));
				InvalidateRect(MAS::Rect(wx2, wy1, x2-wx2, y2-wy1));
				break;
			// both left corners are inside --> add the right half
			case 0x05:
				InvalidateRect(MAS::Rect(wx2, y1, x2-wx2, r.h()));
				break;
			// only the lower right is inside --> 2 rectangles
			case 0x08:
				InvalidateRect(MAS::Rect(x1, y1, r.w(), wy1-y1));
				InvalidateRect(MAS::Rect(x1, wy1, wx1-x1, y2-wy1));
				break;
			// both right corners are inside --> add the left half
			case 0x0A:
				InvalidateRect(MAS::Rect(x1, y1, wx1-x1, r.h()));
				break;
			// both lower corners are inside --> add the top half
			case 0x0C:
				InvalidateRect(MAS::Rect(x1, y1, r.w(), wy1-y1));
				break;
		};
	}
}