[SDL] Improving SDL'c RLE handling

[David Olofson]

On Tuesday 18 April 2006 12:24, Gunnar von Boehn wrote:
> Dear Sam,
> 
> Sam Lantinga wrote:
> >>I have a small proposal for the way SDL handles RLE optimized
> >>surfaces. 
> >>The way SDL blittes RLE sprites that are partly clipped is not
> >>fully  
> >>optimized yet.
> [..]
> > Not a bad idea.  Would you like to submit a patch relative to
> > current CVS? 
> 
> Yes, I will.
> 
> 
> I have one question regarding the handling of RLE surfaces.
> I only had a brief look at the SDL source but so far my
> understanding 
> is that each surface can buffer for *one* RLE compressed image.
> 
> My (simple) approach on handling sprites was by having ONE surface 
> containing all the sprites of my application. (See attached
> example). 
> My app was blitting the appropriate sprite out of the big surface.
> While this works well with uncompressed sprites this is suboptimal
> for RLE compressed data IMHO.
> 
> What is the recommanded way of handling this?
> Is the only way of handling this creating
> one surfaces one for each single sprite frame?

As of now, yes.

With the change you're suggesting, one could tile sprites vertically 
without additional cost, but I'm not sure there's any point in normal 
applications. If you have very large numbers of small sprites, the 
lower memory overhead and reduced cache load might make it worth 
trying. Benchmark and see what happens with your particular 
application.


//David Olofson - Programmer, Composer, Open Source Advocate

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