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RealSound support

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@277
This commit is contained in:
Sjoerd van der Berg 2002-09-16 13:14:42 +00:00
parent 3edbb75c02
commit b93a294dfa
1 changed files with 41 additions and 22 deletions
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63
src/hardware/pcspeaker.cpp
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@ -16,16 +16,17 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <dosbox.h>
#include <mixer.h>
#include <math.h>
#include "dosbox.h"
#include "mixer.h"
#include "timer.h"
#ifndef PI
#define PI 3.14159265358979323846
#endif
#define SPKR_BUF 4096
#define SPKR_RATE 22050
#define SPKR_VOLUME 5000
@ -41,14 +42,26 @@ struct Speaker {
Bit16s volume;
MIXER_Channel * chan;
bool enabled;
bool realsound;
Bit16u buffer[SPKR_BUF];
Bitu buf_pos;
};
static Speaker spkr;
void PCSPEAKER_SetFreq(Bit32u freq) {
spkr.freq_add=(Bit32u)(FREQ_MAX/((float)SPKR_RATE/(float)freq));
void PCSPEAKER_SetCounter(Bitu cntr,Bitu mode) {
switch (mode) {
case 0:
if (cntr>72) cntr=72;
spkr.realsound=true;
spkr.buffer[spkr.buf_pos++]=(cntr-36)*600;
break;
case 3:
spkr.freq_add=(Bit32u)(FREQ_MAX/((float)SPKR_RATE/(PIT_TICK_RATE/(float)cntr)));
break;
}
}
void PCSPEAKER_Enable(bool enable) {
@ -57,25 +70,29 @@ void PCSPEAKER_Enable(bool enable) {
}
static void PCSPEAKER_CallBack(Bit8u * stream,Bit32u len) {
/* Generate the speaker wave, TODO Improve :) */
for (Bit32u c=0;c<len;c++) {
spkr.freq_pos+=spkr.freq_add;
if (spkr.freq_pos>=FREQ_MAX) spkr.freq_pos-=FREQ_MAX;
if (spkr.freq_pos>=FREQ_HALF) {
*(Bit16s*)(stream)=spkr.volume;
} else {
*(Bit16s*)(stream)=-spkr.volume;
if (spkr.realsound) {
/* Generate the "RealSound" */
Bitu buf_add=(spkr.buf_pos<<16)/len;
Bitu buf_pos=0;
spkr.buf_pos=0;spkr.realsound=0;
while (len-->0) {
*(Bit16s*)(stream)=spkr.buffer[buf_pos >> 16];
buf_pos+=buf_add;
stream+=2;
}
} else {
/* Generate a square wave */
while (len-->0) {
spkr.freq_pos+=spkr.freq_add;
if (spkr.freq_pos>=FREQ_MAX) spkr.freq_pos-=FREQ_MAX;
if (spkr.freq_pos>=FREQ_HALF) {
*(Bit16s*)(stream)=spkr.volume;
} else {
*(Bit16s*)(stream)=-spkr.volume;
}
stream+=2;
}
/*
if (spkr.freq_pos>=FREQ_HALF) {
spkr.freq_pos-=FREQ_HALF;
spkr.volume=-spkr.volume;
};
*(Bit16s*)(stream)=spkr.volume;
*/
stream+=2;
}
}
void PCSPEAKER_Init(void) {
@ -84,4 +101,6 @@ void PCSPEAKER_Init(void) {
MIXER_SetMode(spkr.chan,MIXER_16MONO);
spkr.volume=SPKR_VOLUME;
spkr.enabled=false;
spkr.realsound=false;
spkr.buf_pos=0;
}