Fixed bug #1026 Vittorio Giovara 2010-07-16 19:09:28 PDT i was reading SDL_renderer_gles and i noticed that every time we there is some gl call the gl state is modified with a couple of glEnableClientState()/glDisableClientState. While this is completely fine for desktops systems, this is a major performace kill on mobile devices, right where opengles is implemented. Normal practice in this case is to update the glstate once, keep it always the same and disable/enable other states only in very special occasions. On the web there's plenty of documentation (on the top of my head http://developer.apple.com/iphone/library/documentation/3DDrawing/Conceptual/OpenGLES_ProgrammingGuide/Performance/Performance.html#//apple_ref/doc/uid/TP40008793-CH105-SW5 ) and i personally tried this. I modified my code and got a 10 fps boost, then modified SDL_render_gles and shifted from 40 fps to 50 fps alone -- considering that i started from ~30fps i got an 80% performance increase with this technique. I have attached a dif of my changes, hope that it will be included in mainstream.

TestiPhoneOS.xcodeproj contains targets to compile many of the SDL test programs for iPhone OS.  Most of these test programs work fine, with the following exceptions:

testalpha:
	Program crashes.  Problem appears to effect Mac OS X as well.

testhread:
	SIGTERM kills the process immediately without executing the 'kill' function.  The posix standard says this shouldn't happen.  Apple seems intent on having iPhone apps exit promptly when the user requests it, so maybe that's why(?)

testlock:
	Locks appear to work, but there doesn't appear to be a simple way to send the process SIGINT.

testpalette:
	"SDL error: blitting boat: Blit combination not supported."  Happens on Mac OS X as well.

testsprite2: 
	SDL_CreateTextureFromSurface requests an ARGB pixel format, but iPhone's SDL video driver only supports ABGR.

testwin:
	Behaves as it does under Mac OS X ... not sure if that is correctly or not.

threadwin:
	Works if -threaded is not on.  Otherwise it doesn't work, but this is true under Mac OS X as well.