2009-05-02 23:03:37 +02:00
|
|
|
/*
|
|
|
|
|
* Copyright (C) 2002 The DOSBox Team
|
|
|
|
|
*
|
|
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
|
* it under the terms of the GNU General Public License as published by
|
|
|
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
|
|
|
* (at your option) any later version.
|
|
|
|
|
*
|
|
|
|
|
* This program is distributed in the hope that it will be useful,
|
|
|
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
|
|
* GNU Library General Public License for more details.
|
|
|
|
|
*
|
|
|
|
|
* You should have received a copy of the GNU General Public License
|
|
|
|
|
* along with this program; if not, write to the Free Software
|
|
|
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#include <dosbox.h>
|
|
|
|
|
#include <mixer.h>
|
|
|
|
|
#include <math.h>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#ifndef PI
|
|
|
|
|
#define PI 3.14159265358979323846
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#define SPKR_RATE 22050
|
|
|
|
|
#define SPKR_VOLUME 5000
|
|
|
|
|
|
|
|
|
|
#define FREQ_SHIFT 16
|
|
|
|
|
#define FREQ_MAX (2 << FREQ_SHIFT)
|
|
|
|
|
#define FREQ_HALF (FREQ_MAX >> 1)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
struct Speaker {
|
|
|
|
|
Bit32u freq_add;
|
|
|
|
|
Bit32u freq_pos;
|
|
|
|
|
Bit16s volume;
|
|
|
|
|
MIXER_Channel * chan;
|
|
|
|
|
bool enabled;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
static Speaker spkr;
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
void PCSPEAKER_SetFreq(Bit32u freq) {
|
|
|
|
|
spkr.freq_add=(Bit32u)(FREQ_MAX/((float)SPKR_RATE/(float)freq));
|
|
|
|
|
spkr.freq_pos=0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void PCSPEAKER_Enable(bool enable) {
|
|
|
|
|
spkr.enabled=enable;
|
|
|
|
|
MIXER_Enable(spkr.chan,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.freq_pos>=FREQ_HALF) {
|
|
|
|
|
spkr.freq_pos-=FREQ_HALF;
|
|
|
|
|
spkr.volume=-spkr.volume;
|
|
|
|
|
};
|
|
|
|
|
*(Bit16s*)(stream)=spkr.volume;
|
|
|
|
|
*/
|
|
|
|
|
stream+=2;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void PCSPEAKER_Init(void) {
|
|
|
|
|
spkr.chan=MIXER_AddChannel(&PCSPEAKER_CallBack,SPKR_RATE,"PC-SPEAKER");
|
|
|
|
|
MIXER_Enable(spkr.chan,false);
|
|
|
|
|
MIXER_SetMode(spkr.chan,MIXER_16MONO);
|
|
|
|
|
spkr.volume=SPKR_VOLUME;
|
|
|
|
|
spkr.enabled=false;
|
|
|
|
|
}
|
