scummvm/backends/dc/audio.cpp
Marcus Comstedt 3be01c0560 Sound buffer adjustment.
svn-id: r13269
2004-03-14 13:14:03 +00:00

98 lines
2.4 KiB
C++

/* ScummVM - Scumm Interpreter
* Dreamcast port
* Copyright (C) 2002-2004 Marcus Comstedt
*
* 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 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.
*
* $Header$
*
*/
#include <common/stdafx.h>
#include <common/scummsys.h>
#include "base/engine.h"
#include "dc.h"
EXTERN_C void *memcpy4s(void *s1, const void *s2, unsigned int n);
void initSound()
{
stop_sound();
do_sound_command(CMD_SET_FREQ_EXP(FREQ_22050_EXP));
do_sound_command(CMD_SET_STEREO(1));
do_sound_command(CMD_SET_BUFFER(SOUND_BUFFER_SHIFT));
}
bool OSystem_Dreamcast::setSoundCallback(SoundProc proc, void *param)
{
assert(SAMPLE_MODE == 0);
_sound_proc_param = param;
_sound_proc = proc;
return true;
}
void OSystem_Dreamcast::clearSoundCallback()
{
_sound_proc = NULL;
_sound_proc_param = NULL;
}
void OSystem_Dreamcast::checkSound()
{
int n;
int curr_ring_buffer_samples;
if(!_sound_proc)
return;
if(read_sound_int(&SOUNDSTATUS->mode) != MODE_PLAY)
start_sound();
curr_ring_buffer_samples = read_sound_int(&SOUNDSTATUS->ring_length);
n = read_sound_int(&SOUNDSTATUS->samplepos);
if((n-=fillpos)<0)
n += curr_ring_buffer_samples;
n = ADJUST_BUFFER_SIZE(n-10);
if(n<100)
return;
_sound_proc(_sound_proc_param, (byte*)temp_sound_buffer,
2*SAMPLES_TO_BYTES(n));
if(fillpos+n > curr_ring_buffer_samples) {
int r = curr_ring_buffer_samples - fillpos;
memcpy4s(RING_BUF+fillpos, temp_sound_buffer, SAMPLES_TO_BYTES(r));
fillpos = 0;
n -= r;
memcpy4s(RING_BUF, temp_sound_buffer+r, SAMPLES_TO_BYTES(n));
} else {
memcpy4s(RING_BUF+fillpos, temp_sound_buffer, SAMPLES_TO_BYTES(n));
}
if((fillpos += n) >= curr_ring_buffer_samples)
fillpos = 0;
}
int OSystem_Dreamcast::getOutputSampleRate() const
{
return read_sound_int(&SOUNDSTATUS->freq);
}