libmodplay/mixer.c

   1 /*
   2 Copyright (c) 2002,2003, Christian Nowak <chnowak@web.de>
   3 All rights reserved.
   4
   5 Modified by Francisco Mu�oz 'Hermes' MAY 2008
   6
   7 Redistribution and use in source and binary forms, with or without modification, are
   8 permitted provided that the following conditions are met:
   9
  10 - Redistributions of source code must retain the above copyright notice, this list of
  11   conditions and the following disclaimer.
  12 - Redistributions in binary form must reproduce the above copyright notice, this list
  13   of conditions and the following disclaimer in the documentation and/or other
  14   materials provided with the distribution.
  15 - The names of the contributors may not be used to endorse or promote products derived
  16   from this software without specific prior written permission.
  17
  18 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
  19 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  20 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
  21 THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  23 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  24 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  25 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
  26 THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27 */
  28
  29 /* mixer.c */
  30
  31 #include "defines.h"
  32 #include "modplay.h"
  33
  34 #if defined(DREAMCAST)
  35 #define PREFILL_WORD 0
  36 #elif defined(MINGW)
  37 #define PREFILL_WORD 32768
  38 #elif defined(ALLEGRO)
  39 #define PREFILL_WORD 32768
  40 #elif defined(GP32)
  41 #define PREFILL_WORD 32768
  42 #elif defined(GEKKO)
  43 #define PREFILL_WORD 0
  44 #else
  45 #define PREFILL_WORD 32768
  46 #endif
  47
  48
  49 #define MIX_SAMPLES \
  50                                 accum = (s32)b[i] + (s32)((((s32)data[playpos.aword.high]*volume)>>6) << shiftval); \
  51                                 if(accum<-32768) accum = -32768; if(accum>32767) accum = 32767; \
  52                 b[i] = accum; \
  53                 playpos.adword+=incval; \
  54                 if ( playpos.adword>=loop_end ) \
  55                   { \
  56                     if (mod->instrument[mod->instnum[voice]].looped) \
  57                       playpos.adword -= mod->instrument[mod->instnum[voice]].loop_length<<16; \
  58                     else \
  59                       { \
  60                         playpos.adword = (mod->instrument[mod->instnum[voice]].loop_end-1)<<16; \
  61                         mod->channel_active[voice] = FALSE; \
  62                         break; \
  63                       } \
  64                   }
  65
  66 s32 mix_mono_16bit ( MOD * mod, s16 * buf, s32 numSamples )
  67   {
  68     s32 accum;
  69     s32 voice, i, j;
  70     s16 * b = buf;
  71     s32 shiftval = mod->shiftval;
  72     s32 numIterations;
  73     s32 numIterationsRest;
  74
  75     numIterations = numSamples>>4;
  76     numIterationsRest = numSamples&((1<<4)-1);
  77
  78
  79     for (i=j=0;j<numIterations;j++)
  80       {
  81         buf[i] = PREFILL_WORD;i++;
  82         buf[i] = PREFILL_WORD;i++;
  83         buf[i] = PREFILL_WORD;i++;
  84         buf[i] = PREFILL_WORD;i++;
  85         buf[i] = PREFILL_WORD;i++;
  86         buf[i] = PREFILL_WORD;i++;
  87         buf[i] = PREFILL_WORD;i++;
  88         buf[i] = PREFILL_WORD;i++;
  89         buf[i] = PREFILL_WORD;i++;
  90         buf[i] = PREFILL_WORD;i++;
  91         buf[i] = PREFILL_WORD;i++;
  92         buf[i] = PREFILL_WORD;i++;
  93         buf[i] = PREFILL_WORD;i++;
  94         buf[i] = PREFILL_WORD;i++;
  95         buf[i] = PREFILL_WORD;i++;
  96         buf[i] = PREFILL_WORD;i++;
  97       }
  98     for (j=0;j<numIterationsRest;j++,i++)
  99       buf[i] = PREFILL_WORD;
 100
 101
 102     for (voice=0;voice<mod->num_channels;++voice)
 103       {
 104         if (mod->instrument[mod->instnum[voice]].data != NULL && mod->channel_active[voice])
 105           {
 106             u32 incval,noteidx;
 107
 108                         noteidx = (mod->chanfreq[voice] - mod->chanfreq[voice]*2*(mod->instrument[mod->instnum[voice]].finetune-8)/256);
 109                         incval = mod->inctab[noteidx];
 110
 111             s8 * data = mod->instrument[mod->instnum[voice]].data;
 112             union_dword playpos;
 113             u32 loop_end = mod->instrument[mod->instnum[voice]].loop_end<<16;
 114             s32 volume = mod->volume[voice];
 115             playpos.adword = mod->playpos[voice];
 116
 117             if ( voice<mod->num_voices )
 118               volume = (volume*(s32)mod->musicvolume)>>6;
 119             else
 120               volume = (volume*(s32)mod->sfxvolume)>>6;
 121
 122             if (mod->freq==32000 || mod->freq==48000)
 123               incval >>= 2;
 124
 125             for (j=i=0;j<numIterations;j++)
 126               {
 127                 MIX_SAMPLES;i++;
 128                 MIX_SAMPLES;i++;
 129                 MIX_SAMPLES;i++;
 130                 MIX_SAMPLES;i++;
 131                 MIX_SAMPLES;i++;
 132                 MIX_SAMPLES;i++;
 133                 MIX_SAMPLES;i++;
 134                 MIX_SAMPLES;i++;
 135                 MIX_SAMPLES;i++;
 136                 MIX_SAMPLES;i++;
 137                 MIX_SAMPLES;i++;
 138                 MIX_SAMPLES;i++;
 139                 MIX_SAMPLES;i++;
 140                 MIX_SAMPLES;i++;
 141                 MIX_SAMPLES;i++;
 142                 MIX_SAMPLES;i++;
 143               }
 144             for (j=0;j<numIterationsRest;j++,i++)
 145               {
 146                 MIX_SAMPLES;
 147               }
 148             mod->playpos[voice] = playpos.adword;
 149           }
 150       }
 151     return numSamples;
 152   }
 153
 154 s32 mix_stereo_16bit ( MOD * mod, s16 * buf, s32 numSamples )
 155   {
 156     s32 accum;
 157     s32 voice, i, j;
 158     s16 * b = buf;
 159     s32 shiftval = mod->shiftval+1;
 160     s32 numIterations, numIterationsRest;
 161
 162     numIterations = (numSamples)>>2;
 163     numIterationsRest = (numSamples)&((1<<2)-1);
 164
 165     for (i=j=0;j<numIterations;j++)
 166       {
 167         buf[i] = buf[i+1] = PREFILL_WORD;i+=2;
 168         buf[i] = buf[i+1] = PREFILL_WORD;i+=2;
 169         buf[i] = buf[i+1] = PREFILL_WORD;i+=2;
 170         buf[i] = buf[i+1] = PREFILL_WORD;i+=2;
 171       }
 172     for (j=0;j<numIterationsRest;j++,i+=2)
 173         buf[i] = buf[i+1] = PREFILL_WORD;
 174
 175 /*    for (j=0;j<numSamples*2;j+=2)
 176       buf[j] = buf[j+1] = PREFILL_WORD;*/
 177
 178     for (voice=0;voice<mod->num_channels;++voice)
 179       {
 180         s32 lrofs = (((voice-1)>>1)&1)^1;
 181         if (mod->instrument[mod->instnum[voice]].data != NULL && mod->channel_active[voice])
 182           {
 183             u32 incval,noteidx;
 184
 185                         noteidx = (mod->chanfreq[voice] - mod->chanfreq[voice]*2*(mod->instrument[mod->instnum[voice]].finetune-8)/256);
 186                         incval = mod->inctab[noteidx];
 187
 188             s8 * data = mod->instrument[mod->instnum[voice]].data;
 189             union_dword playpos;
 190             u32 loop_end = mod->instrument[mod->instnum[voice]].loop_end<<16;
 191             s32 volume = mod->volume[voice];
 192
 193             if ( voice<mod->num_voices )
 194               volume = (volume*(s32)mod->musicvolume)>>6;
 195             else
 196               volume = (volume*(s32)mod->sfxvolume)>>6;
 197
 198             playpos.adword = mod->playpos[voice];
 199             if (mod->freq==32000 || mod->freq==48000)
 200               incval >>= 2;
 201
 202             i = lrofs;
 203             for (j=0;j<numIterations;j++)
 204               {
 205                 MIX_SAMPLES;i+=2;
 206                 MIX_SAMPLES;i+=2;
 207                 MIX_SAMPLES;i+=2;
 208                 MIX_SAMPLES;i+=2;
 209               }
 210             for (j=0;j<numIterationsRest;j++)
 211               {
 212                 MIX_SAMPLES;i+=2;
 213               }
 214 /*            for (i=0;i<numSamples*2;i+=2)
 215               {
 216                 MIX_SAMPLES;
 217               }*/
 218             mod->playpos[voice] = playpos.adword;
 219           }
 220       }
 221
 222     return numSamples;
 223   }