Alc/panning.c

   1 /**
   2  * OpenAL cross platform audio library
   3  * Copyright (C) 1999-2010 by authors.
   4  * This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Library General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  *  License along with this library; if not, write to the
  16  *  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  *  Boston, MA  02111-1307, USA.
  18  * Or go to http://www.gnu.org/copyleft/lgpl.html
  19  */
  20
  21 #include "config.h"
  22
  23 #include <math.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include <assert.h>
  28
  29 #include "alMain.h"
  30 #include "AL/al.h"
  31 #include "AL/alc.h"
  32 #include "alu.h"
  33
  34 static void SetSpeakerArrangement(const char *name, ALfloat SpeakerAngle[MAXCHANNELS],
  35                                   enum Channel Speaker2Chan[MAXCHANNELS], ALint chans)
  36 {
  37     char *confkey, *next;
  38     char *layout_str;
  39     char *sep, *end;
  40     enum Channel val;
  41     const char *str;
  42     int i;
  43
  44     if(!ConfigValueStr(NULL, name, &str) && !ConfigValueStr(NULL, "layout", &str))
  45         return;
  46
  47     layout_str = strdup(str);
  48     next = confkey = layout_str;
  49     while(next && *next)
  50     {
  51         confkey = next;
  52         next = strchr(confkey, ',');
  53         if(next)
  54         {
  55             *next = 0;
  56             do {
  57                 next++;
  58             } while(isspace(*next) || *next == ',');
  59         }
  60
  61         sep = strchr(confkey, '=');
  62         if(!sep || confkey == sep)
  63         {
  64             ERR("Malformed speaker key: %s\n", confkey);
  65             continue;
  66         }
  67
  68         end = sep - 1;
  69         while(isspace(*end) && end != confkey)
  70             end--;
  71         *(++end) = 0;
  72
  73         if(strcmp(confkey, "fl") == 0 || strcmp(confkey, "front-left") == 0)
  74             val = FRONT_LEFT;
  75         else if(strcmp(confkey, "fr") == 0 || strcmp(confkey, "front-right") == 0)
  76             val = FRONT_RIGHT;
  77         else if(strcmp(confkey, "fc") == 0 || strcmp(confkey, "front-center") == 0)
  78             val = FRONT_CENTER;
  79         else if(strcmp(confkey, "bl") == 0 || strcmp(confkey, "back-left") == 0)
  80             val = BACK_LEFT;
  81         else if(strcmp(confkey, "br") == 0 || strcmp(confkey, "back-right") == 0)
  82             val = BACK_RIGHT;
  83         else if(strcmp(confkey, "bc") == 0 || strcmp(confkey, "back-center") == 0)
  84             val = BACK_CENTER;
  85         else if(strcmp(confkey, "sl") == 0 || strcmp(confkey, "side-left") == 0)
  86             val = SIDE_LEFT;
  87         else if(strcmp(confkey, "sr") == 0 || strcmp(confkey, "side-right") == 0)
  88             val = SIDE_RIGHT;
  89         else
  90         {
  91             ERR("Unknown speaker for %s: \"%s\"\n", name, confkey);
  92             continue;
  93         }
  94
  95         *(sep++) = 0;
  96         while(isspace(*sep))
  97             sep++;
  98
  99         for(i = 0;i < chans;i++)
 100         {
 101             if(Speaker2Chan[i] == val)
 102             {
 103                 long angle = strtol(sep, NULL, 10);
 104                 if(angle >= -180 && angle <= 180)
 105                     SpeakerAngle[i] = angle * F_PI/180.0f;
 106                 else
 107                     ERR("Invalid angle for speaker \"%s\": %ld\n", confkey, angle);
 108                 break;
 109             }
 110         }
 111     }
 112     free(layout_str);
 113     layout_str = NULL;
 114
 115     for(i = 0;i < chans;i++)
 116     {
 117         int min = i;
 118         int i2;
 119
 120         for(i2 = i+1;i2 < chans;i2++)
 121         {
 122             if(SpeakerAngle[i2] < SpeakerAngle[min])
 123                 min = i2;
 124         }
 125
 126         if(min != i)
 127         {
 128             ALfloat tmpf;
 129             enum Channel tmpc;
 130
 131             tmpf = SpeakerAngle[i];
 132             SpeakerAngle[i] = SpeakerAngle[min];
 133             SpeakerAngle[min] = tmpf;
 134
 135             tmpc = Speaker2Chan[i];
 136             Speaker2Chan[i] = Speaker2Chan[min];
 137             Speaker2Chan[min] = tmpc;
 138         }
 139     }
 140 }
 141
 142 static ALfloat aluLUTpos2Angle(ALint pos)
 143 {
 144     if(pos < QUADRANT_NUM)
 145         return aluAtan((ALfloat)pos / (ALfloat)(QUADRANT_NUM - pos));
 146     if(pos < 2 * QUADRANT_NUM)
 147         return F_PI_2 + aluAtan((ALfloat)(pos - QUADRANT_NUM) / (ALfloat)(2 * QUADRANT_NUM - pos));
 148     if(pos < 3 * QUADRANT_NUM)
 149         return aluAtan((ALfloat)(pos - 2 * QUADRANT_NUM) / (ALfloat)(3 * QUADRANT_NUM - pos)) - F_PI;
 150     return aluAtan((ALfloat)(pos - 3 * QUADRANT_NUM) / (ALfloat)(4 * QUADRANT_NUM - pos)) - F_PI_2;
 151 }
 152
 153 ALint aluCart2LUTpos(ALfloat re, ALfloat im)
 154 {
 155     ALint pos = 0;
 156     ALfloat denom = aluFabs(re) + aluFabs(im);
 157     if(denom > 0.0f)
 158         pos = (ALint)(QUADRANT_NUM*aluFabs(im) / denom + 0.5);
 159
 160     if(re < 0.0f)
 161         pos = 2 * QUADRANT_NUM - pos;
 162     if(im < 0.0f)
 163         pos = LUT_NUM - pos;
 164     return pos%LUT_NUM;
 165 }
 166
 167 ALvoid aluInitPanning(ALCdevice *Device)
 168 {
 169     ALfloat SpeakerAngle[MAXCHANNELS];
 170     const char *layoutname = NULL;
 171     enum Channel *Speaker2Chan;
 172     ALfloat Alpha, Theta;
 173     ALint pos;
 174     ALuint s;
 175
 176     Speaker2Chan = Device->Speaker2Chan;
 177     switch(Device->FmtChans)
 178     {
 179         case DevFmtMono:
 180             Device->NumChan = 1;
 181             Speaker2Chan[0] = FRONT_CENTER;
 182             SpeakerAngle[0] = F_PI/180.0f * 0.0f;
 183             layoutname = NULL;
 184             break;
 185
 186         case DevFmtStereo:
 187             Device->NumChan = 2;
 188             Speaker2Chan[0] = FRONT_LEFT;
 189             Speaker2Chan[1] = FRONT_RIGHT;
 190             SpeakerAngle[0] = F_PI/180.0f * -30.0f;
 191             SpeakerAngle[1] = F_PI/180.0f *  30.0f;
 192             layoutname = "layout_stereo";
 193             break;
 194
 195         case DevFmtQuad:
 196             Device->NumChan = 4;
 197             Speaker2Chan[0] = BACK_LEFT;
 198             Speaker2Chan[1] = FRONT_LEFT;
 199             Speaker2Chan[2] = FRONT_RIGHT;
 200             Speaker2Chan[3] = BACK_RIGHT;
 201             SpeakerAngle[0] = F_PI/180.0f * -135.0f;
 202             SpeakerAngle[1] = F_PI/180.0f *  -45.0f;
 203             SpeakerAngle[2] = F_PI/180.0f *   45.0f;
 204             SpeakerAngle[3] = F_PI/180.0f *  135.0f;
 205             layoutname = "layout_quad";
 206             break;
 207
 208         case DevFmtX51:
 209             Device->NumChan = 5;
 210             Speaker2Chan[0] = BACK_LEFT;
 211             Speaker2Chan[1] = FRONT_LEFT;
 212             Speaker2Chan[2] = FRONT_CENTER;
 213             Speaker2Chan[3] = FRONT_RIGHT;
 214             Speaker2Chan[4] = BACK_RIGHT;
 215             SpeakerAngle[0] = F_PI/180.0f * -110.0f;
 216             SpeakerAngle[1] = F_PI/180.0f *  -30.0f;
 217             SpeakerAngle[2] = F_PI/180.0f *    0.0f;
 218             SpeakerAngle[3] = F_PI/180.0f *   30.0f;
 219             SpeakerAngle[4] = F_PI/180.0f *  110.0f;
 220             layoutname = "layout_surround51";
 221             break;
 222
 223         case DevFmtX51Side:
 224             Device->NumChan = 5;
 225             Speaker2Chan[0] = SIDE_LEFT;
 226             Speaker2Chan[1] = FRONT_LEFT;
 227             Speaker2Chan[2] = FRONT_CENTER;
 228             Speaker2Chan[3] = FRONT_RIGHT;
 229             Speaker2Chan[4] = SIDE_RIGHT;
 230             SpeakerAngle[0] = F_PI/180.0f * -90.0f;
 231             SpeakerAngle[1] = F_PI/180.0f * -30.0f;
 232             SpeakerAngle[2] = F_PI/180.0f *   0.0f;
 233             SpeakerAngle[3] = F_PI/180.0f *  30.0f;
 234             SpeakerAngle[4] = F_PI/180.0f *  90.0f;
 235             layoutname = "layout_side51";
 236             break;
 237
 238         case DevFmtX61:
 239             Device->NumChan = 6;
 240             Speaker2Chan[0] = SIDE_LEFT;
 241             Speaker2Chan[1] = FRONT_LEFT;
 242             Speaker2Chan[2] = FRONT_CENTER;
 243             Speaker2Chan[3] = FRONT_RIGHT;
 244             Speaker2Chan[4] = SIDE_RIGHT;
 245             Speaker2Chan[5] = BACK_CENTER;
 246             SpeakerAngle[0] = F_PI/180.0f * -90.0f;
 247             SpeakerAngle[1] = F_PI/180.0f * -30.0f;
 248             SpeakerAngle[2] = F_PI/180.0f *   0.0f;
 249             SpeakerAngle[3] = F_PI/180.0f *  30.0f;
 250             SpeakerAngle[4] = F_PI/180.0f *  90.0f;
 251             SpeakerAngle[5] = F_PI/180.0f * 180.0f;
 252             layoutname = "layout_surround61";
 253             break;
 254
 255         case DevFmtX71:
 256             Device->NumChan = 7;
 257             Speaker2Chan[0] = BACK_LEFT;
 258             Speaker2Chan[1] = SIDE_LEFT;
 259             Speaker2Chan[2] = FRONT_LEFT;
 260             Speaker2Chan[3] = FRONT_CENTER;
 261             Speaker2Chan[4] = FRONT_RIGHT;
 262             Speaker2Chan[5] = SIDE_RIGHT;
 263             Speaker2Chan[6] = BACK_RIGHT;
 264             SpeakerAngle[0] = F_PI/180.0f * -150.0f;
 265             SpeakerAngle[1] = F_PI/180.0f *  -90.0f;
 266             SpeakerAngle[2] = F_PI/180.0f *  -30.0f;
 267             SpeakerAngle[3] = F_PI/180.0f *    0.0f;
 268             SpeakerAngle[4] = F_PI/180.0f *   30.0f;
 269             SpeakerAngle[5] = F_PI/180.0f *   90.0f;
 270             SpeakerAngle[6] = F_PI/180.0f *  150.0f;
 271             layoutname = "layout_surround71";
 272             break;
 273     }
 274     if(layoutname && Device->Type != Loopback)
 275         SetSpeakerArrangement(layoutname, SpeakerAngle, Speaker2Chan, Device->NumChan);
 276
 277     for(pos = 0; pos < LUT_NUM; pos++)
 278     {
 279         ALfloat *PanningLUT = Device->PanningLUT[pos];
 280
 281         /* clear all values */
 282         for(s = 0; s < MAXCHANNELS; s++)
 283             PanningLUT[s] = 0.0f;
 284
 285         if(Device->NumChan == 1)
 286         {
 287             PanningLUT[Speaker2Chan[0]] = 1.0f;
 288             continue;
 289         }
 290
 291         /* source angle */
 292         Theta = aluLUTpos2Angle(pos);
 293
 294         /* set panning values */
 295         for(s = 0; s < Device->NumChan - 1; s++)
 296         {
 297             if(Theta >= SpeakerAngle[s] && Theta < SpeakerAngle[s+1])
 298             {
 299                 /* source between speaker s and speaker s+1 */
 300                 Alpha = (Theta-SpeakerAngle[s]) /
 301                         (SpeakerAngle[s+1]-SpeakerAngle[s]);
 302                 PanningLUT[Speaker2Chan[s]]   = aluSqrt(1.0f-Alpha);
 303                 PanningLUT[Speaker2Chan[s+1]] = aluSqrt(     Alpha);
 304                 break;
 305             }
 306         }
 307         if(s == Device->NumChan - 1)
 308         {
 309             /* source between last and first speaker */
 310             if(Theta < SpeakerAngle[0])
 311                 Theta += F_PI*2.0f;
 312             Alpha = (Theta-SpeakerAngle[s]) /
 313                     (F_PI*2.0f + SpeakerAngle[0]-SpeakerAngle[s]);
 314             PanningLUT[Speaker2Chan[s]] = aluSqrt(1.0f-Alpha);
 315             PanningLUT[Speaker2Chan[0]] = aluSqrt(     Alpha);
 316         }
 317     }
 318 }