English Amiga Board - View Single Post - Blitter fill, writing clearing instead of setting?

a/b · 16 December 2019, 17:21

Well, that's a different picture than the one in the first post.

In any case, you wouldn't have do draw that line if you were using the FCI bit. When you are doing filled poly clipping, you normally draw a vertical line on the right-hand border when a line-segment is >= width, because blitter works right to left, and skip the left-hand border entirely (don't draw anything when < 0). So you just either change your poly-clipper to optionally skip those lines, or make two routines if performance is an issue.
Or is there another 'hidden' constraint?

16 December 2019, 17:21	#9
a/b Registered User Join Date: Jun 2016 Location: europe Posts: 1,039	Well, that's a different picture than the one in the first post. In any case, you wouldn't have do draw that line if you were using the FCI bit. When you are doing filled poly clipping, you normally draw a vertical line on the right-hand border when a line-segment is >= width, because blitter works right to left, and skip the left-hand border entirely (don't draw anything when < 0). So you just either change your poly-clipper to optionally skip those lines, or make two routines if performance is an issue. Or is there another 'hidden' constraint?