cog/Frameworks/GME/gme/Ymf262_Emu.cpp

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2013-09-28 03:24:46 +00:00
// Game_Music_Emu $vers. http://www.slack.net/~ant/
#include "Ymf262_Emu.h"
#include <math.h>
#include "dbopl.h"
Ymf262_Emu::Ymf262_Emu() { opl = 0; }
Ymf262_Emu::~Ymf262_Emu()
{
delete opl;
}
int Ymf262_Emu::set_rate( int sample_rate, int clock_rate )
{
delete opl;
opl = 0;
opl = new DBOPL::Chip;
if ( !opl )
return 1;
this->sample_rate = sample_rate;
this->clock_rate = clock_rate;
reset();
return 0;
}
void Ymf262_Emu::reset()
{
opl->Setup( clock_rate, sample_rate );
}
void Ymf262_Emu::write0( int addr, int data )
{
opl->WriteReg( addr, data );
}
void Ymf262_Emu::write1( int addr, int data )
{
opl->WriteReg( 0x100 + addr, data );
}
void Ymf262_Emu::run( int pair_count, sample_t* out )
{
Bit32s buf[ 2048 ];
while (pair_count > 0)
{
int todo = pair_count;
if (todo > 1024) todo = 1024;
if ( opl->opl3Active )
{
opl->GenerateBlock3( todo, buf );
for (int i = 0; i < todo; i++)
{
int output_l, output_r;
output_l = buf [i * 2];
output_r = buf [i * 2 + 1];
output_l += out [0];
output_r += out [1];
if ( (short)output_l != output_l ) output_l = 0x7FFF ^ ( output_l >> 31 );
if ( (short)output_r != output_r ) output_r = 0x7FFF ^ ( output_r >> 31 );
out [0] = output_l;
out [1] = output_r;
out += 2;
}
}
else
{
opl->GenerateBlock2( todo, buf );
for (int i = 0; i < todo; i++)
{
int output_l, output_r;
int output = buf [i];
output_l = output + out [0];
output_r = output + out [1];
if ( (short)output_l != output_l ) output_l = 0x7FFF ^ ( output_l >> 31 );
if ( (short)output_r != output_r ) output_r = 0x7FFF ^ ( output_r >> 31 );
out [0] = output_l;
out [1] = output_r;
out += 2;
}
}
pair_count -= todo;
}
}