Converting points array to `BPolygon` has significant cost, including
heap allocation, when drawing a lot of polygons.
Change-Id: I81e6b4031bac4beadcc79412c58eedddffc00a82
Reviewed-on: https://review.haiku-os.org/c/haiku/+/10337
Reviewed-by: waddlesplash <[email protected]>