Mercurial > sdl-ios-xcode
view src/thread/pthread/SDL_syssem.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 | f7b03b6838cb |
children | d547877e355e |
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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 <pthread.h> #include <semaphore.h> #include "SDL_thread.h" #include "SDL_timer.h" /* Wrapper around POSIX 1003.1b semaphores */ #if defined(__MACOSX__) || defined(__IPHONEOS__) /* Mac OS X doesn't support sem_getvalue() as of version 10.4 */ #include "../generic/SDL_syssem.c" #else struct SDL_semaphore { sem_t sem; }; /* Create a semaphore, initialized with value */ SDL_sem * SDL_CreateSemaphore(Uint32 initial_value) { SDL_sem *sem = (SDL_sem *) SDL_malloc(sizeof(SDL_sem)); if (sem) { if (sem_init(&sem->sem, 0, initial_value) < 0) { SDL_SetError("sem_init() failed"); SDL_free(sem); sem = NULL; } } else { SDL_OutOfMemory(); } return sem; } void SDL_DestroySemaphore(SDL_sem * sem) { if (sem) { sem_destroy(&sem->sem); SDL_free(sem); } } int SDL_SemTryWait(SDL_sem * sem) { int retval; if (!sem) { SDL_SetError("Passed a NULL semaphore"); return -1; } retval = SDL_MUTEX_TIMEDOUT; if (sem_trywait(&sem->sem) == 0) { retval = 0; } return retval; } int SDL_SemWait(SDL_sem * sem) { int retval; if (!sem) { SDL_SetError("Passed a NULL semaphore"); return -1; } retval = sem_wait(&sem->sem); if (retval < 0) { SDL_SetError("sem_wait() failed"); } return retval; } int SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout) { int retval; if (!sem) { SDL_SetError("Passed a NULL semaphore"); return -1; } /* Try the easy cases first */ if (timeout == 0) { return SDL_SemTryWait(sem); } if (timeout == SDL_MUTEX_MAXWAIT) { return SDL_SemWait(sem); } /* Ack! We have to busy wait... */ /* FIXME: Use sem_timedwait()? */ timeout += SDL_GetTicks(); do { retval = SDL_SemTryWait(sem); if (retval == 0) { break; } SDL_Delay(1); } while (SDL_GetTicks() < timeout); return retval; } Uint32 SDL_SemValue(SDL_sem * sem) { int ret = 0; if (sem) { sem_getvalue(&sem->sem, &ret); if (ret < 0) { ret = 0; } } return (Uint32) ret; } int SDL_SemPost(SDL_sem * sem) { int retval; if (!sem) { SDL_SetError("Passed a NULL semaphore"); return -1; } retval = sem_post(&sem->sem); if (retval < 0) { SDL_SetError("sem_post() failed"); } return retval; } #endif /* __MACOSX__ */ /* vi: set ts=4 sw=4 expandtab: */