Mercurial > sdl-ios-xcode
view src/audio/SDL_mixer_m68k.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 | 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" /* m68k assembly mix routines Patrice Mandin */ #if defined(__M68000__) && !defined(__mcoldfire__) && defined(__GNUC__) void SDL_MixAudio_m68k_U8(char *dst, char *src, long len, long volume, char *mix8) { __asm__ __volatile__("tstl %2\n" " beqs stoploop_u8\n" "mixloop_u8:\n" /* Mix a sample */ " moveq #0,%%d0\n" " moveq #0,%%d1\n" " moveb %1@+,%%d0\n" /* d0 = *src++ */ " sub #128,%%d0\n" /* d0 -= 128 */ " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " moveb %0@,%%d1\n" /* d1 = *dst */ " asr #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " add #128,%%d0\n" /* d0 += 128 */ " add %%d1,%%d0\n" " moveb %4@(%%d0:w),%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_u8\n" "stoploop_u8:\n": /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume), "a"(mix8): /* clobbered registers */ "d0", "d1", "cc", "memory"); } void SDL_MixAudio_m68k_S8(char *dst, char *src, long len, long volume) { __asm__ __volatile__("tstl %2\n" " beqs stoploop_s8\n" " moveq #-128,%%d2\n" " moveq #127,%%d3\n" "mixloop_s8:\n" /* Mix a sample */ " moveq #0,%%d0\n" " moveq #0,%%d1\n" " moveb %1@+,%%d0\n" /* d0 = *src++ */ " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " moveb %0@,%%d1\n" /* d1 = *dst */ " asr #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " add %%d1,%%d0\n" " cmp %%d2,%%d0\n" " bges lower_limit_s8\n" " move %%d2,%%d0\n" "lower_limit_s8:\n" " cmp %%d3,%%d0\n" " bles upper_limit_s8\n" " move %%d3,%%d0\n" "upper_limit_s8:\n" " moveb %%d0,%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_s8\n" "stoploop_s8:\n": /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume): /* clobbered registers */ "d0", "d1", "d2", "d3", "cc", "memory"); } void SDL_MixAudio_m68k_S16MSB(short *dst, short *src, long len, long volume) { __asm__ __volatile__("tstl %2\n" " beqs stoploop_s16msb\n" " movel #-32768,%%d2\n" " movel #32767,%%d3\n" " lsrl #1,%2\n" "mixloop_s16msb:\n" /* Mix a sample */ " move %1@+,%%d0\n" /* d0 = *src++ */ " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " move %0@,%%d1\n" /* d1 = *dst */ " extl %%d1\n" /* extend d1 to 32 bits */ " asrl #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " addl %%d1,%%d0\n" " cmpl %%d2,%%d0\n" " bges lower_limit_s16msb\n" " move %%d2,%%d0\n" "lower_limit_s16msb:\n" " cmpl %%d3,%%d0\n" " bles upper_limit_s16msb\n" " move %%d3,%%d0\n" "upper_limit_s16msb:\n" " move %%d0,%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_s16msb\n" "stoploop_s16msb:\n": /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume): /* clobbered registers */ "d0", "d1", "d2", "d3", "cc", "memory"); } void SDL_MixAudio_m68k_S16LSB(short *dst, short *src, long len, long volume) { __asm__ __volatile__("tstl %2\n" " beqs stoploop_s16lsb\n" " movel #-32768,%%d2\n" " movel #32767,%%d3\n" " lsrl #1,%2\n" "mixloop_s16lsb:\n" /* Mix a sample */ " move %1@+,%%d0\n" /* d0 = *src++ */ " rorw #8,%%d0\n" " muls %3,%%d0\n" /* d0 *= volume (0<=volume<=128) */ " move %0@,%%d1\n" /* d1 = *dst */ " rorw #8,%%d1\n" " extl %%d1\n" /* extend d1 to 32 bits */ " asrl #7,%%d0\n" /* d0 /= 128 (SDL_MIX_MAXVOLUME) */ " addl %%d1,%%d0\n" " cmpl %%d2,%%d0\n" " bges lower_limit_s16lsb\n" " move %%d2,%%d0\n" "lower_limit_s16lsb:\n" " cmpl %%d3,%%d0\n" " bles upper_limit_s16lsb\n" " move %%d3,%%d0\n" "upper_limit_s16lsb:\n" " rorw #8,%%d0\n" " move %%d0,%0@+\n" /* Loop till done */ " subql #1,%2\n" " bhis mixloop_s16lsb\n" "stoploop_s16lsb:\n": /* no return value */ : /* input */ "a"(dst), "a"(src), "d"(len), "d"(volume): /* clobbered registers */ "d0", "d1", "d2", "d3", "cc", "memory"); } #endif /* vi: set ts=4 sw=4 expandtab: */