[SDL] Weird surface behavior

Ti Leggett leggett at eecs.tulane.edu
Wed Aug 22 06:21:01 PDT 2001


On 2001.08.22 04:07 =?ISO-8859-1?Q?Mattias Engdeg=E5rd?= wrote:
> Ti Leggett <leggett at eecs.tulane.edu> wrote:
> >color_map->pixels should remain constant since all I do is load the image
> once
> >and copy from it. surface->pixels should change only once (the first pass
> >through). After that it should remain the same since color_map shouldn't
> >change.
> 
> >> Also in the main loop don't you need to lock a surface even to get read
> >> access to it (I am not sure)?
> 
> No.
> 
> 1. surface->pixels may return a different value each time the surface is
>    locked, so don't keep a pointer to pixels after unlocking
> 2. you must lock surfaces for any pixel access, reading or writing
> 

Alrighty. Then that brings up another question. How big of performance hit is
locking and unlocking theses surfaces repeatedly?

-- 
Ti Leggett
leggett at eecs.tulane.edu




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