Re: [pygame] Another blitting surface to itself crash

["René Dudfield" <renesd@xxxxxxxxx>]

nice work :)

By the sounds of it, that flag might be cleared by linux/glibc?  That
would make sense if it's working ok on linux.


On Wed, Aug 20, 2008 at 7:24 AM, Lenard Lindstrom <len-l@xxxxxxxxx> wrote:
> I believe I found the bug. And it was already fixed for SDL 1.3 (I cannot
> confirm it is also fixed for 1.2.13 in SVN since the site is down.) There
> should be a licensing requirement to do assembly level programming :-). The
> optimized reverse blit uses an i386 string move instruction. The direction
> of the copy is controlled by a register flag. A cleared flag causes a
> forward copy, the data pointers are incremented. A set flag causes a reverse
> copy, decrementing data pointers. The flag was set by the SDL copy code, but
> not cleared afterwards. And the flag doesn't reset itself apparently. So the
> set flag sat there like an armed bomb until the next string copy instruction
> was executed.
>
> Lenard
>
>
> Lenard Lindstrom wrote:
>>
>> That seems to be it. Try out the modified SDL.dll for Pythons 2.4. and
>> 2.5:
>>
>> http://www3.telus.net/len_l/pygame/SDL-self-blit.zip
>>
>> md5sum:
>> 59a283f9383d6b5512c236d98e39c97b *SDL-self-blit.zip
>>
>> Lenard
>>
>>
>> Lenard Lindstrom wrote:
>>>
>>> I will. But it will be hand-customized.
>>>
>>> Lenard
>>>
>>>
>>> Brian Fisher wrote:
>>>>
>>>> Hey Lenard,
>>>> Can you build SDL with mingw in a way that the inlined assembly won't be
>>>> used? (i.e. so that it uses the same source that VisualC does to build)
>>>>
>>>>
>>
>
>
> --
> Lenard Lindstrom
> <len-l@xxxxxxxxx>
>
>