source: trunk/src/dsound/dsmixer.cpp@ 4540

Last change on this file since 4540 was 3925, checked in by bird, 25 years ago

Added the CVS keyword Id.
File size: 6.2 KB
Line 
1/* $Id: dsmixer.cpp,v 1.3 2000-08-02 15:48:27 bird Exp $ */
2/*
3 * DirectSound Software Mixer
4 *
5 * Copyright 2000 Michal Necasek
6 * Copyright 2000 Ondrej Necasek
7 *
8 * Project Odin Software License can be found in LICENSE.TXT
9 *
10 */
11
12
13/*@Header***********************************************************************
14* Header Files *
15*******************************************************************************/
16#define INCL_DOSMISC
17#include <os2win.h>
18
19#include <stdlib.h>
20#include <string.h>
21
22#define INITGUID
23#include <dsound.h>
24
25#include "os2dsound.h"
26#include "os2sndbuffer.h"
27#include "os2notify.h"
28#include <misc.h>
29
30signed long mixbuf[2300*2]; /* enough for 50 ms at 44100Hz stereo */
31
32void MixCallback(ULONG cbMix) {
33 // Check for priority level here; for DSSCL_WRITEPRIMARY just play directly
34 // from the primary buffer; for all others mix the secondary buffers
35 if (OS2IDirectSoundBuffer::primary->parentDS->GetCoopLevel() != DSSCL_WRITEPRIMARY)
36 MixFunc(OS2IDirectSoundBuffer::dsbroot, OS2IDirectSoundBuffer::primary, cbMix);
37 else {
38 }
39}
40
41void MixOneBuffer(OS2IDirectSoundBuffer *inBuf, int tomix, int outrate)
42{
43 unsigned char *data8b;
44 signed short *data16b;
45 int inpos, spd, i, j, sample, len, bytespersample, vol1, vol2;
46 int oldpos;
47
48 bytespersample = inBuf->lpfxFormat->wBitsPerSample *
49 inBuf->lpfxFormat->nChannels / 8;
50 inpos = inBuf->playpos / bytespersample * 1024 + inBuf->frac;
51 spd = 1024 * inBuf->frequency / outrate;
52 if (inBuf->pan <= 0)
53 vol1 = inBuf->volume;
54 else
55 vol1 = inBuf->volume * (256 - inBuf->pan) / 256;
56 if (inBuf->pan >= 0)
57 vol2 = inBuf->volume;
58 else
59 vol2 = inBuf->volume * (256 + inBuf->pan) / 256;
60
61 len = inBuf->bufferdesc.dwBufferBytes / bytespersample * 1024;
62 if ((inBuf->lpfxFormat->nChannels == 2) && (inBuf->lpfxFormat->wBitsPerSample == 16)) {
63 data16b = (signed short *) inBuf->lpBuffer;
64 for (i = 0; i < tomix; i++) {
65 j = inpos / 1024 * 2;
66 mixbuf[i*2] += data16b[j] * vol1 / 256;
67 mixbuf[i*2+1] += data16b[j+1] * vol2 / 256;
68 inpos += spd;
69 if (inpos >= len) {
70 if (inBuf->fLoop) inpos -= len;
71 else {
72 inBuf->fPlaying = FALSE;
73 if (inBuf->notify != NULL)
74 inBuf->notify->CheckStop();
75 break;
76 }
77 }
78 }
79 }
80 if ((inBuf->lpfxFormat->nChannels == 1) && (inBuf->lpfxFormat->wBitsPerSample == 16)) {
81 data16b = (signed short *) inBuf->lpBuffer;
82 for (i = 0; i < tomix; i++) {
83 j = inpos / 1024;
84 sample = data16b[j];
85 mixbuf[i*2] += sample * vol1 / 256;
86 mixbuf[i*2+1] += sample * vol2 / 256;
87 inpos += spd;
88 if (inpos >= len) {
89 if (inBuf->fLoop) inpos -= len;
90 else {
91 inBuf->fPlaying = FALSE;
92 if (inBuf->notify != NULL)
93 inBuf->notify->CheckStop();
94 break;
95 }
96 }
97 }
98 }
99 if ((inBuf->lpfxFormat->nChannels == 2) && (inBuf->lpfxFormat->wBitsPerSample == 8)) {
100 data8b = (unsigned char *) inBuf->lpBuffer;
101 for (i = 0; i < tomix; i++) {
102 j = inpos / 1024 * 2;
103 sample = ((int) data8b[j] - 128) * vol1;
104 mixbuf[i*2] += sample;
105 sample = ((int) data8b[j+1] - 128) * vol2;
106 mixbuf[i*2+1] += sample;
107 inpos += spd;
108 if (inpos >= len) {
109 if (inBuf->fLoop) inpos -= len;
110 else {
111 inBuf->fPlaying = FALSE;
112 if (inBuf->notify != NULL)
113 inBuf->notify->CheckStop();
114 break;
115 }
116 }
117 }
118 }
119 if ((inBuf->lpfxFormat->nChannels == 1) && (inBuf->lpfxFormat->wBitsPerSample == 8)) {
120 data8b = (unsigned char *) inBuf->lpBuffer;
121 for (i = 0; i < tomix; i++) {
122 j = inpos / 1024;
123 sample = (int) data8b[j] - 128;
124 mixbuf[i*2] += sample * vol1;
125 mixbuf[i*2+1] += sample * vol2;
126 inpos += spd;
127 if (inpos >= len) {
128 if (inBuf->fLoop) inpos -= len;
129 else {
130 inBuf->fPlaying = FALSE;
131 if (inBuf->notify != NULL)
132 inBuf->notify->CheckStop();
133 break;
134 }
135 }
136 }
137 }
138 oldpos = inBuf->playpos;
139 inBuf->playpos = inpos / 1024 * bytespersample;
140 inBuf->frac = inpos % 1024;
141
142 // Check if any notifications are to be signaled
143 if (inBuf->notify != NULL)
144 inBuf->notify->CheckPos(oldpos, inBuf->playpos);
145
146 // keep the write cursor about 15ms ahead of the play cursor
147 inBuf->writepos = inBuf->playpos + inBuf->frequency * bytespersample / 67;
148 inBuf->writepos %= inBuf->bufferdesc.dwBufferBytes;
149}
150
151void MixFunc (OS2IDirectSoundBuffer *firstBuf, OS2IDirectSoundBuffer *outBuf,
152 ULONG cbMix) {
153 OS2IDirectSoundBuffer *inBuf = firstBuf;
154 int i, outbits, outrate, outnch, tomix, outpos, outlen;
155 unsigned char *data8b;
156 signed short *data16b;
157
158 outbits = outBuf->lpfxFormat->wBitsPerSample;
159 outrate = outBuf->lpfxFormat->nSamplesPerSec;
160 outnch = outBuf->lpfxFormat->nChannels;
161 tomix = cbMix * 8 / outbits / outnch;
162
163 memset(&mixbuf, 0, tomix * 2 * sizeof(mixbuf[0]));
164
165 while (inBuf != NULL) {
166 if (inBuf->fPlaying) {
167 MixOneBuffer(inBuf, tomix, outrate);
168 }
169 inBuf = inBuf->next;
170 }
171
172 outpos = outBuf->playpos * 8 / outbits;
173 outlen = outBuf->bufferdesc.dwBufferBytes * 8 / outbits;
174 if (outbits == 16) {
175 data16b = (signed short *) outBuf->lpBuffer;
176 for (i = 0; i < tomix * outnch; i++) {
177 if (mixbuf[i] <= -32768) data16b[outpos] = -32768;
178 else if (mixbuf[i] >= 32767) data16b[outpos] = 32767;
179 else data16b[outpos] = mixbuf[i];
180 outpos++;
181 if (outpos >= outlen) outpos = 0;
182 }
183 } else {
184 data8b = (unsigned char *) outBuf->lpBuffer;
185 for (i = 0; i < tomix * outnch; i++) {
186 if (mixbuf[i] <= -32768) data8b[outpos] = 0;
187 else if (mixbuf[i] >= 32767) data8b[outpos] = 255;
188 else data8b[outpos] = mixbuf[i] / 256 + 128;
189 outpos++;
190 if (outpos >= outlen) outpos = 0;
191 }
192 }
193 outBuf->playpos = outpos * outbits / 8;
194}
195
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