67 lines
1.2 KiB
C++
67 lines
1.2 KiB
C++
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// Game_Music_Emu $vers. http://www.slack.net/~ant/
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#include "Pwm_Emu.h"
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#include "pwm.h"
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Pwm_Emu::Pwm_Emu() { chip = 0; }
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Pwm_Emu::~Pwm_Emu()
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{
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if ( chip ) device_stop_pwm( chip );
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}
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int Pwm_Emu::set_rate( int clock )
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{
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if ( chip )
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{
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device_stop_pwm( chip );
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chip = 0;
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}
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chip = device_start_pwm( clock );
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if ( !chip )
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return 1;
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reset();
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return 0;
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}
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void Pwm_Emu::reset()
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{
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device_reset_pwm( chip );
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}
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void Pwm_Emu::write( int channel, int data )
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{
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pwm_chn_w( chip, channel, data );
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}
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void Pwm_Emu::run( int pair_count, sample_t* out )
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{
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stream_sample_t bufL[ 1024 ];
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stream_sample_t bufR[ 1024 ];
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stream_sample_t * buffers[2] = { bufL, bufR };
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while (pair_count > 0)
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{
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int todo = pair_count;
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if (todo > 1024) todo = 1024;
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pwm_update( chip, buffers, todo );
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for (int i = 0; i < todo; i++)
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{
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int output_l = bufL [i];
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int output_r = bufR [i];
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output_l += out [0];
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output_r += out [1];
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if ( (short)output_l != output_l ) output_l = 0x7FFF ^ ( output_l >> 31 );
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if ( (short)output_r != output_r ) output_r = 0x7FFF ^ ( output_r >> 31 );
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out [0] = output_l;
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out [1] = output_r;
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out += 2;
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}
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pair_count -= todo;
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}
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}
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