achim@forst.informatik.rwth-aachen.de (Achim Schmidt) (06/20/91)
I've written a routine which does line drawing with the blitter. But I found out, that there are some mistakes ... I wonder, if its my code or the blitter ? 1. The lines are normally a few pixels to the left or right from the endpoint. That depends on the line, if its going to the right or to the left. Am I using the wrong algorithm to calculate the blitter-reg values or is it a calculation error in the Blitter ? 2. When (x2-x1) > 2* (y2-y1) then the point in the last line (=y2) is missing. That has some strange effects, when filling a polygon... I fixed it by simply adding 1 to the Blitterline length register. Is that correct ? 3. How does Move()/Draw() work ?? Do they use the blitter? Thanks for your help... achim@forst.informatik.rwth-aachen.de