diff options
Diffstat (limited to 'plugins/gme/game-music-emu-0.6pre/gme/Sms_Fm_Apu.cpp')
| -rw-r--r-- | plugins/gme/game-music-emu-0.6pre/gme/Sms_Fm_Apu.cpp | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6pre/gme/Sms_Fm_Apu.cpp b/plugins/gme/game-music-emu-0.6pre/gme/Sms_Fm_Apu.cpp new file mode 100644 index 00000000..55ad8beb --- /dev/null +++ b/plugins/gme/game-music-emu-0.6pre/gme/Sms_Fm_Apu.cpp @@ -0,0 +1,80 @@ +#include "Sms_Fm_Apu.h"
+
+#include "blargg_source.h"
+
+Sms_Fm_Apu::Sms_Fm_Apu()
+{ }
+
+Sms_Fm_Apu::~Sms_Fm_Apu()
+{ }
+
+blargg_err_t Sms_Fm_Apu::init( double clock_rate, double sample_rate )
+{
+ period_ = clock_rate / sample_rate + 0.5;
+ CHECK_ALLOC( !apu.set_rate( sample_rate, clock_rate ) );
+
+ set_output( 0 );
+ volume( 1.0 );
+ reset();
+ return blargg_ok;
+}
+
+void Sms_Fm_Apu::reset()
+{
+ addr = 0;
+ next_time = 0;
+ last_amp = 0;
+
+ apu.reset();
+}
+
+void Sms_Fm_Apu::write_data( blip_time_t time, int data )
+{
+ if ( time > next_time )
+ run_until( time );
+
+ apu.write( addr, data );
+}
+
+void Sms_Fm_Apu::run_until( blip_time_t end_time )
+{
+ assert( end_time > next_time );
+
+ Blip_Buffer* const output = this->output_;
+ if ( !output )
+ {
+ next_time = end_time;
+ return;
+ }
+
+ blip_time_t time = next_time;
+ do
+ {
+ Ym2413_Emu::sample_t samples [2];
+ apu.run( 1, samples );
+ int amp = (samples [0] + samples [1]) >> 1;
+
+ int delta = amp - last_amp;
+ if ( delta )
+ {
+ last_amp = amp;
+ synth.offset_inline( time, delta, output );
+ }
+ time += period_;
+ }
+ while ( time < end_time );
+
+ next_time = time;
+}
+
+void Sms_Fm_Apu::end_frame( blip_time_t time )
+{
+ if ( time > next_time )
+ run_until( time );
+
+ next_time -= time;
+ assert( next_time >= 0 );
+
+ if ( output_ )
+ output_->set_modified();
+}
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