Mercurial > sdl-ios-xcode
view src/timer/nds/SDL_systimer.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 | 481dabb098ef |
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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" #ifdef SDL_TIMER_NDS #include <nds.h> #include <nds/timers.h> #include "SDL_timer.h" #include "../SDL_timer_c.h" #include "../SDL_systimer.h" /* Data to handle a single periodic alarm */ static int timer_alive = 0; static Uint32 timer_ticks; void SDL_StartTicks(void) { if (!timer_alive) { SDL_SYS_TimerInit(); SDL_SYS_StartTimer(); } timer_ticks = 0; } Uint32 SDL_GetTicks(void) { return timer_ticks; } void SDL_Delay(Uint32 ms) { Uint32 start = SDL_GetTicks(); while (timer_alive) { if ((SDL_GetTicks() - start) >= ms) break; } } static int RunTimer(void *unused) { while (timer_alive) { if (SDL_timer_running) { } SDL_Delay(1); } return (0); } void NDS_TimerInterrupt(void) { timer_ticks++; } /* This is only called if the event thread is not running */ int SDL_SYS_TimerInit(void) { timer_alive = 1; timer_ticks = 0; TIMER_CR(3) = TIMER_DIV_1024 | TIMER_IRQ_REQ; TIMER_DATA(3) = TIMER_FREQ_1024(1000); irqSet(IRQ_TIMER3, NDS_TimerInterrupt); irqEnable(IRQ_TIMER3); return 0; } void SDL_SYS_TimerQuit(void) { if (timer_alive) { TIMER_CR(3) = 0; } timer_alive = 0; irqDisable(IRQ_TIMER3); } int SDL_SYS_StartTimer(void) { TIMER_CR(3) |= TIMER_ENABLE; return 0; } void SDL_SYS_StopTimer(void) { TIMER_CR(3) &= ~TIMER_ENABLE; return; } #endif /* SDL_TIMER_NDS */ /* vi: set ts=4 sw=4 expandtab: */