1 files changed, 66 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/libgme/hes_apu.h b/lib/rbcodec/codecs/libgme/hes_apu.h
new file mode 100644
index 0000000000..0265e6a3ad
--- /dev/null
+++ b/lib/rbcodec/codecs/libgme/hes_apu.h
@@ -0,0 +1,66 @@
+// Turbo Grafx 16 (PC Engine) PSG sound chip emulator
+
+// Game_Music_Emu 0.5.2
+#ifndef HES_APU_H
+#define HES_APU_H
+
+#include "blargg_common.h"
+#include "blargg_source.h"
+#include "blip_buffer.h"
+
+enum { amp_range = 0x8000 };
+enum { osc_count = 6 }; // 0 <= chan < osc_count
+
+// Registers are at io_addr to io_addr+io_size-1
+enum { apu_io_addr = 0x0800 };
+enum { apu_io_size = 10 };
+
+struct Hes_Osc
+{
+        byte wave [32];
+        int  delay;
+        int  period;
+        int  phase;
+        
+        int  noise_delay;
+        byte noise;
+        unsigned lfsr;
+        
+        byte control;
+        byte balance;
+        byte dac;
+        short volume [2];
+        int last_amp [2];
+        
+        blip_time_t last_time;
+        struct Blip_Buffer* output [2];
+        struct Blip_Buffer* outputs [3];
+};
+
+void Osc_run_until( struct Hes_Osc* this, struct Blip_Synth* synth, blip_time_t );
+
+struct Hes_Apu {
+        
+        int latch;
+        int balance;
+        struct Blip_Synth synth;
+        struct Hes_Osc oscs [osc_count];
+};
+
+// Init HES apu sound chip
+void Apu_init( struct Hes_Apu* this );
+
+// Reset HES apu couns chip
+void Apu_reset( struct Hes_Apu* this );
+
+void Apu_osc_output( struct Hes_Apu* this, int index, struct Blip_Buffer* center, struct Blip_Buffer* left, struct Blip_Buffer* right );
+
+// Emulates to time t, then writes data to addr
+void Apu_write_data( struct Hes_Apu* this, blip_time_t, int addr, int data );
+
+// Emulates to time t, then subtracts t from the current time.
+// OK if previous write call had time slightly after t.
+void Apu_end_frame( struct Hes_Apu* this, blip_time_t );
+
+static inline void Apu_volume( struct Hes_Apu* this, int v ) { Synth_volume( &this->synth, (v*9)/5 / osc_count / amp_range ); }
+#endif