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First CVS upload.

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@80
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Sjoerd van der Berg 2002-07-27 13:08:48 +00:00
parent 7d1ca9bdd4
commit 42e5d0b779
158 changed files with 42940 additions and 0 deletions
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src/hardware/pcspeaker.cpp Normal file
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/*
* 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;
}