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Re: [pygame] Segmentation Fault in PolyPlay 1.3 Walker demo
maybe SDL_gfx has gotten a fix for something like that at some point?
http://www.ferzkopp.net/joomla/content/view/19/14/
isn't aaline source cribbed from SDL_gfx?
On Mon, Apr 7, 2008 at 1:54 PM, Marcus von Appen <mva@xxxxxxxxxxxx> wrote:
> On, Mon Apr 07, 2008, Lenard Lindstrom wrote:
>
> > Forget that last observation. The traceback doesn't show the arguments
> > correctly. I have traced the problem to clipaaline. When pts[0] is 0 and
> > pts[2] is 1 or pts[1] is 0 and pts[3] is 1 it copies pts[2] and pts[3] to
> > pts[0] and pts[1]. This causes a divided by 0.0 later in drawaaline which
> > leads to a memory access problem. It doesn't matter if the surface is 24 or
> > 32 bit.
>
> [...]
> That's the same I figured out half an hour ago :-). It's the
> Cohen-Sutherland clipping line implementation with slight adaptions and
> works well for normal pixel lines. I'm currently looking into the aaline
> clipping implementation and try to find a matching fix that takes the AA
> into account _and_ still provides a more or less reasonable result for
> those cases.
>
> Regards
> Marcus
>