view Alc/panning.c @ 33:3caceef436ea tip

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author Robert McIntyre <rlm@mit.edu>
date Sat, 11 Feb 2012 12:25:55 -0700
parents f9476ff7637e
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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 */
21 #include "config.h"
23 #include <math.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <ctype.h>
27 #include <assert.h>
29 #include "alMain.h"
30 #include "AL/al.h"
31 #include "AL/alc.h"
32 #include "alu.h"
34 static void SetSpeakerArrangement(const char *name, ALfloat SpeakerAngle[MAXCHANNELS],
35 enum Channel Speaker2Chan[MAXCHANNELS], ALint chans)
36 {
37 char layout_str[256];
38 char *confkey, *next;
39 char *sep, *end;
40 enum Channel val;
41 int i;
43 if(!ConfigValueExists(NULL, name))
44 name = "layout";
46 strncpy(layout_str, GetConfigValue(NULL, name, ""), sizeof(layout_str));
47 layout_str[sizeof(layout_str)-1] = 0;
49 if(!layout_str[0])
50 return;
52 next = confkey = layout_str;
53 while(next && *next)
54 {
55 confkey = next;
56 next = strchr(confkey, ',');
57 if(next)
58 {
59 *next = 0;
60 do {
61 next++;
62 } while(isspace(*next) || *next == ',');
63 }
65 sep = strchr(confkey, '=');
66 if(!sep || confkey == sep)
67 continue;
69 end = sep - 1;
70 while(isspace(*end) && end != confkey)
71 end--;
72 *(++end) = 0;
74 if(strcmp(confkey, "fl") == 0 || strcmp(confkey, "front-left") == 0)
75 val = FRONT_LEFT;
76 else if(strcmp(confkey, "fr") == 0 || strcmp(confkey, "front-right") == 0)
77 val = FRONT_RIGHT;
78 else if(strcmp(confkey, "fc") == 0 || strcmp(confkey, "front-center") == 0)
79 val = FRONT_CENTER;
80 else if(strcmp(confkey, "bl") == 0 || strcmp(confkey, "back-left") == 0)
81 val = BACK_LEFT;
82 else if(strcmp(confkey, "br") == 0 || strcmp(confkey, "back-right") == 0)
83 val = BACK_RIGHT;
84 else if(strcmp(confkey, "bc") == 0 || strcmp(confkey, "back-center") == 0)
85 val = BACK_CENTER;
86 else if(strcmp(confkey, "sl") == 0 || strcmp(confkey, "side-left") == 0)
87 val = SIDE_LEFT;
88 else if(strcmp(confkey, "sr") == 0 || strcmp(confkey, "side-right") == 0)
89 val = SIDE_RIGHT;
90 else
91 {
92 ERR("Unknown speaker for %s: \"%s\"\n", name, confkey);
93 continue;
94 }
96 *(sep++) = 0;
97 while(isspace(*sep))
98 sep++;
100 for(i = 0;i < chans;i++)
101 {
102 if(Speaker2Chan[i] == val)
103 {
104 long angle = strtol(sep, NULL, 10);
105 if(angle >= -180 && angle <= 180)
106 SpeakerAngle[i] = angle * M_PI/180.0f;
107 else
108 ERR("Invalid angle for speaker \"%s\": %ld\n", confkey, angle);
109 break;
110 }
111 }
112 }
114 for(i = 0;i < chans;i++)
115 {
116 int min = i;
117 int i2;
119 for(i2 = i+1;i2 < chans;i2++)
120 {
121 if(SpeakerAngle[i2] < SpeakerAngle[min])
122 min = i2;
123 }
125 if(min != i)
126 {
127 ALfloat tmpf;
128 enum Channel tmpc;
130 tmpf = SpeakerAngle[i];
131 SpeakerAngle[i] = SpeakerAngle[min];
132 SpeakerAngle[min] = tmpf;
134 tmpc = Speaker2Chan[i];
135 Speaker2Chan[i] = Speaker2Chan[min];
136 Speaker2Chan[min] = tmpc;
137 }
138 }
139 }
141 static ALfloat aluLUTpos2Angle(ALint pos)
142 {
143 if(pos < QUADRANT_NUM)
144 return aluAtan((ALfloat)pos / (ALfloat)(QUADRANT_NUM - pos));
145 if(pos < 2 * QUADRANT_NUM)
146 return M_PI_2 + aluAtan((ALfloat)(pos - QUADRANT_NUM) / (ALfloat)(2 * QUADRANT_NUM - pos));
147 if(pos < 3 * QUADRANT_NUM)
148 return aluAtan((ALfloat)(pos - 2 * QUADRANT_NUM) / (ALfloat)(3 * QUADRANT_NUM - pos)) - M_PI;
149 return aluAtan((ALfloat)(pos - 3 * QUADRANT_NUM) / (ALfloat)(4 * QUADRANT_NUM - pos)) - M_PI_2;
150 }
152 ALint aluCart2LUTpos(ALfloat re, ALfloat im)
153 {
154 ALint pos = 0;
155 ALfloat denom = aluFabs(re) + aluFabs(im);
156 if(denom > 0.0f)
157 pos = (ALint)(QUADRANT_NUM*aluFabs(im) / denom + 0.5);
159 if(re < 0.0)
160 pos = 2 * QUADRANT_NUM - pos;
161 if(im < 0.0)
162 pos = LUT_NUM - pos;
163 return pos%LUT_NUM;
164 }
166 ALvoid aluInitPanning(ALCdevice *Device)
167 {
168 ALfloat SpeakerAngle[MAXCHANNELS];
169 enum Channel *Speaker2Chan;
170 ALfloat Alpha, Theta;
171 ALint pos;
172 ALuint s;
174 Speaker2Chan = Device->Speaker2Chan;
175 switch(Device->FmtChans)
176 {
177 case DevFmtMono:
178 Device->NumChan = 1;
179 Speaker2Chan[0] = FRONT_CENTER;
180 SpeakerAngle[0] = 0.0f * M_PI/180.0f;
181 break;
183 case DevFmtStereo:
184 Device->NumChan = 2;
185 Speaker2Chan[0] = FRONT_LEFT;
186 Speaker2Chan[1] = FRONT_RIGHT;
187 SpeakerAngle[0] = -90.0f * M_PI/180.0f;
188 SpeakerAngle[1] = 90.0f * M_PI/180.0f;
189 SetSpeakerArrangement("layout_STEREO", SpeakerAngle, Speaker2Chan, Device->NumChan);
190 break;
192 case DevFmtQuad:
193 Device->NumChan = 4;
194 Speaker2Chan[0] = BACK_LEFT;
195 Speaker2Chan[1] = FRONT_LEFT;
196 Speaker2Chan[2] = FRONT_RIGHT;
197 Speaker2Chan[3] = BACK_RIGHT;
198 SpeakerAngle[0] = -135.0f * M_PI/180.0f;
199 SpeakerAngle[1] = -45.0f * M_PI/180.0f;
200 SpeakerAngle[2] = 45.0f * M_PI/180.0f;
201 SpeakerAngle[3] = 135.0f * M_PI/180.0f;
202 SetSpeakerArrangement("layout_QUAD", SpeakerAngle, Speaker2Chan, Device->NumChan);
203 break;
205 case DevFmtX51:
206 Device->NumChan = 5;
207 Speaker2Chan[0] = BACK_LEFT;
208 Speaker2Chan[1] = FRONT_LEFT;
209 Speaker2Chan[2] = FRONT_CENTER;
210 Speaker2Chan[3] = FRONT_RIGHT;
211 Speaker2Chan[4] = BACK_RIGHT;
212 SpeakerAngle[0] = -110.0f * M_PI/180.0f;
213 SpeakerAngle[1] = -30.0f * M_PI/180.0f;
214 SpeakerAngle[2] = 0.0f * M_PI/180.0f;
215 SpeakerAngle[3] = 30.0f * M_PI/180.0f;
216 SpeakerAngle[4] = 110.0f * M_PI/180.0f;
217 SetSpeakerArrangement("layout_51CHN", SpeakerAngle, Speaker2Chan, Device->NumChan);
218 break;
220 case DevFmtX51Side:
221 Device->NumChan = 5;
222 Speaker2Chan[0] = SIDE_LEFT;
223 Speaker2Chan[1] = FRONT_LEFT;
224 Speaker2Chan[2] = FRONT_CENTER;
225 Speaker2Chan[3] = FRONT_RIGHT;
226 Speaker2Chan[4] = SIDE_RIGHT;
227 SpeakerAngle[0] = -90.0f * M_PI/180.0f;
228 SpeakerAngle[1] = -30.0f * M_PI/180.0f;
229 SpeakerAngle[2] = 0.0f * M_PI/180.0f;
230 SpeakerAngle[3] = 30.0f * M_PI/180.0f;
231 SpeakerAngle[4] = 90.0f * M_PI/180.0f;
232 SetSpeakerArrangement("layout_51SIDECHN", SpeakerAngle, Speaker2Chan, Device->NumChan);
233 break;
235 case DevFmtX61:
236 Device->NumChan = 6;
237 Speaker2Chan[0] = SIDE_LEFT;
238 Speaker2Chan[1] = FRONT_LEFT;
239 Speaker2Chan[2] = FRONT_CENTER;
240 Speaker2Chan[3] = FRONT_RIGHT;
241 Speaker2Chan[4] = SIDE_RIGHT;
242 Speaker2Chan[5] = BACK_CENTER;
243 SpeakerAngle[0] = -90.0f * M_PI/180.0f;
244 SpeakerAngle[1] = -30.0f * M_PI/180.0f;
245 SpeakerAngle[2] = 0.0f * M_PI/180.0f;
246 SpeakerAngle[3] = 30.0f * M_PI/180.0f;
247 SpeakerAngle[4] = 90.0f * M_PI/180.0f;
248 SpeakerAngle[5] = 180.0f * M_PI/180.0f;
249 SetSpeakerArrangement("layout_61CHN", SpeakerAngle, Speaker2Chan, Device->NumChan);
250 break;
252 case DevFmtX71:
253 Device->NumChan = 7;
254 Speaker2Chan[0] = BACK_LEFT;
255 Speaker2Chan[1] = SIDE_LEFT;
256 Speaker2Chan[2] = FRONT_LEFT;
257 Speaker2Chan[3] = FRONT_CENTER;
258 Speaker2Chan[4] = FRONT_RIGHT;
259 Speaker2Chan[5] = SIDE_RIGHT;
260 Speaker2Chan[6] = BACK_RIGHT;
261 SpeakerAngle[0] = -150.0f * M_PI/180.0f;
262 SpeakerAngle[1] = -90.0f * M_PI/180.0f;
263 SpeakerAngle[2] = -30.0f * M_PI/180.0f;
264 SpeakerAngle[3] = 0.0f * M_PI/180.0f;
265 SpeakerAngle[4] = 30.0f * M_PI/180.0f;
266 SpeakerAngle[5] = 90.0f * M_PI/180.0f;
267 SpeakerAngle[6] = 150.0f * M_PI/180.0f;
268 SetSpeakerArrangement("layout_71CHN", SpeakerAngle, Speaker2Chan, Device->NumChan);
269 break;
270 }
272 for(pos = 0; pos < LUT_NUM; pos++)
273 {
274 ALfloat *PanningLUT = Device->PanningLUT[pos];
276 /* clear all values */
277 for(s = 0; s < MAXCHANNELS; s++)
278 PanningLUT[s] = 0.0f;
280 if(Device->NumChan == 1)
281 {
282 PanningLUT[Speaker2Chan[0]] = 1.0f;
283 continue;
284 }
286 /* source angle */
287 Theta = aluLUTpos2Angle(pos);
289 /* set panning values */
290 for(s = 0; s < Device->NumChan - 1; s++)
291 {
292 if(Theta >= SpeakerAngle[s] && Theta < SpeakerAngle[s+1])
293 {
294 /* source between speaker s and speaker s+1 */
295 Alpha = M_PI_2 * (Theta-SpeakerAngle[s]) /
296 (SpeakerAngle[s+1]-SpeakerAngle[s]);
297 PanningLUT[Speaker2Chan[s]] = cos(Alpha);
298 PanningLUT[Speaker2Chan[s+1]] = sin(Alpha);
299 break;
300 }
301 }
302 if(s == Device->NumChan - 1)
303 {
304 /* source between last and first speaker */
305 if(Theta < SpeakerAngle[0])
306 Theta += 2.0f * M_PI;
307 Alpha = M_PI_2 * (Theta-SpeakerAngle[s]) /
308 (2.0f * M_PI + SpeakerAngle[0]-SpeakerAngle[s]);
309 PanningLUT[Speaker2Chan[s]] = cos(Alpha);
310 PanningLUT[Speaker2Chan[0]] = sin(Alpha);
311 }
312 }
313 }