Mercurial > sdl-ios-xcode
view src/power/SDL_power.c @ 5053:b5b42be9333c
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.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 19 Jan 2011 23:56:16 -0800 |
parents | 42e1092225f9 |
children | b530ef003506 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2010 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" #include "SDL_power.h" /* * Returns SDL_TRUE if we have a definitive answer. * SDL_FALSE to try next implementation. */ typedef SDL_bool (*SDL_GetPowerInfo_Impl) (SDL_PowerState * state, int *seconds, int *percent); SDL_bool SDL_GetPowerInfo_Linux_proc_acpi(SDL_PowerState *, int *, int *); SDL_bool SDL_GetPowerInfo_Linux_proc_apm(SDL_PowerState *, int *, int *); SDL_bool SDL_GetPowerInfo_Windows(SDL_PowerState *, int *, int *); SDL_bool SDL_GetPowerInfo_MacOSX(SDL_PowerState *, int *, int *); SDL_bool SDL_GetPowerInfo_BeOS(SDL_PowerState *, int *, int *); SDL_bool SDL_GetPowerInfo_NintendoDS(SDL_PowerState *, int *, int *); SDL_bool SDL_GetPowerInfo_UIKit(SDL_PowerState *, int *, int *); #ifndef SDL_POWER_DISABLED #ifdef SDL_POWER_HARDWIRED /* This is for things that _never_ have a battery */ static SDL_bool SDL_GetPowerInfo_Hardwired(SDL_PowerState * state, int *seconds, int *percent) { *seconds = -1; *percent = -1; *state = SDL_POWERSTATE_NO_BATTERY; return SDL_TRUE; } #endif #endif static SDL_GetPowerInfo_Impl implementations[] = { #ifndef SDL_POWER_DISABLED #ifdef SDL_POWER_LINUX /* in order of preference. More than could work. */ SDL_GetPowerInfo_Linux_proc_acpi, SDL_GetPowerInfo_Linux_proc_apm, #endif #ifdef SDL_POWER_WINDOWS /* handles Win32, Win64, PocketPC. */ SDL_GetPowerInfo_Windows, #endif #ifdef SDL_POWER_UIKIT /* handles iPhone/iPad/etc */ SDL_GetPowerInfo_UIKit, #endif #ifdef SDL_POWER_MACOSX /* handles Mac OS X, Darwin. */ SDL_GetPowerInfo_MacOSX, #endif #ifdef SDL_POWER_NINTENDODS /* handles Nintendo DS. */ SDL_GetPowerInfo_NintendoDS, #endif #ifdef SDL_POWER_BEOS /* handles BeOS, Zeta, with euc.jp apm driver. */ SDL_GetPowerInfo_BeOS, #endif #ifdef SDL_POWER_HARDWIRED SDL_GetPowerInfo_Hardwired, #endif #endif }; SDL_PowerState SDL_GetPowerInfo(int *seconds, int *percent) { const int total = sizeof(implementations) / sizeof(implementations[0]); int _seconds, _percent; SDL_PowerState retval; int i; /* Make these never NULL for platform-specific implementations. */ if (seconds == NULL) { seconds = &_seconds; } if (percent == NULL) { percent = &_percent; } for (i = 0; i < total; i++) { if (implementations[i] (&retval, seconds, percent)) { return retval; } } /* nothing was definitive. */ *seconds = -1; *percent = -1; return SDL_POWERSTATE_UNKNOWN; } /* vi: set ts=4 sw=4 expandtab: */