[maemo-developers] Tips to optimize SDL aplication

[From: Eero Tamminen]

Hi,

ext Tapani Pälli wrote:
> ext Michael Stepanov wrote:
>> I ported existing SDL application to maemo platform. It works fine on
>> N800 but on Nokia770 ii crashes very often. And I suppose it happens
>> because the application takes a lot of recourses - memory or CPU. Can
>> somebody give me a right point to optimize that application - some
>> docs, hack, tips.
>>
> One thing to note is that make sure you are clipping properly all the
> drawing you do. However it sounds like there are some other bugs in the
> application. Try to run it in desktop environment using valgrind
> (http://valgrind.org/). Also from the optimization point of view, make
> sure you are converting all your surfaces to same format as screen has
> (using SDL_ConvertSurface for example).

The latter point is important because because image data is usually
where SDL apps memory goes and having them as 16-bit instead of 32-bits
can both almost halve the memory needs and (if the program was badly
programmed to start with) almost double the performance.  The
conversions can slow down the startup slightly though.

CPU usage cannot get application crashing, so I wouldn't worry about
clipping and screen updates yet, but Valgrind should be definitely
used.  For instructions, see:
	http://maemo.org/development/tools/doc/valgrind


	- Eero