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Sinewave and disabling support, although sine is buggy.

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@551
This commit is contained in:
Sjoerd van der Berg 2002-11-30 11:54:54 +00:00
parent a49847e0e1
commit 96edd67bb7
1 changed files with 59 additions and 19 deletions
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78
src/hardware/pcspeaker.cpp
View file

@ -20,6 +20,7 @@
#include "dosbox.h"
#include "mixer.h"
#include "timer.h"
#include "setup.h"
#ifndef PI
@ -30,20 +31,25 @@
#define SPKR_RATE 22050
#define SPKR_VOLUME 5000
#define FREQ_SHIFT 16
#define FREQ_MAX (2 << FREQ_SHIFT)
#define SPKR_SHIFT 16
#define SIN_ENT 1024
#define SIN_MAX (SIN_ENT << SPKR_SHIFT)
#define FREQ_MAX (2 << SPKR_SHIFT)
#define FREQ_HALF (FREQ_MAX >> 1)
struct Speaker {
Bit32u freq_add;
Bit32u freq_pos;
Bitu freq_add;
Bitu freq_pos;
Bit16s volume;
MIXER_Channel * chan;
bool enabled;
bool realsound;
bool sinewave;
Bitu mode;
Bit16u buffer[SPKR_BUF];
Bit16s table[SIN_ENT];
Bitu buf_pos;
};
@ -52,6 +58,7 @@ static Speaker spkr;
void PCSPEAKER_SetCounter(Bitu cntr,Bitu mode) {
spkr.mode=mode;
switch (mode) {
case 0:
if (cntr>72) cntr=72;
@ -59,8 +66,14 @@ void PCSPEAKER_SetCounter(Bitu cntr,Bitu mode) {
if (spkr.buf_pos<SPKR_BUF) 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)));
if (spkr.sinewave) {
spkr.freq_add=(Bitu)(SIN_MAX/((float)SPKR_RATE/(PIT_TICK_RATE/(float)cntr)));
} else {
spkr.freq_add=(Bitu)(FREQ_MAX/((float)SPKR_RATE/(PIT_TICK_RATE/(float)cntr)));
}
break;
case 4:
spkr.freq_pos=(Bitu)(SPKR_RATE/(PIT_TICK_RATE/(float)cntr));
}
}
@ -70,19 +83,27 @@ void PCSPEAKER_Enable(bool enable) {
}
static void PCSPEAKER_CallBack(Bit8u * stream,Bit32u len) {
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;
switch (spkr.mode) {
case 0:
/* 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;
}
break;
}
} else {
/* Generate a square wave */
while (len-->0) {
case 3:
if (spkr.sinewave) while (len-->0) {
spkr.freq_pos+=spkr.freq_add;
spkr.freq_pos&=(SIN_MAX-1);
*(Bit16s*)(stream)=spkr.table[spkr.freq_pos>>SPKR_SHIFT];
stream+=2;
} else 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) {
@ -92,11 +113,26 @@ static void PCSPEAKER_CallBack(Bit8u * stream,Bit32u len) {
}
stream+=2;
}
break;
case 4:
while (len-->0) {
if (spkr.freq_pos) {
*(Bit16s*)(stream)=spkr.volume;
spkr.freq_pos--;
} else {
*(Bit16s*)(stream)=-spkr.volume;
}
stream+=2;
}
break;
}
}
void PCSPEAKER_Init(Section* sec) {
MSG_Add("SPEAKER_CONFIGFILE_HELP","pcspeaker related options.\n");
Section_prop * section=static_cast<Section_prop *>(sec);
if(!section->Get_bool("enabled")) return;
spkr.sinewave=section->Get_bool("sinewave");
spkr.chan=MIXER_AddChannel(&PCSPEAKER_CallBack,SPKR_RATE,"PC-SPEAKER");
MIXER_Enable(spkr.chan,false);
MIXER_SetMode(spkr.chan,MIXER_16MONO);
@ -104,4 +140,8 @@ void PCSPEAKER_Init(Section* sec) {
spkr.enabled=false;
spkr.realsound=false;
spkr.buf_pos=0;
/* Generate the sine wave */
for (Bitu i=0;i<SIN_ENT;i++) {
spkr.table[i]=(Bit16s)(sin(2*PI/SIN_ENT*i)*SPKR_VOLUME*1.5);
}
}