1 files changed, 63 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/libgme/sms_apu.h b/lib/rbcodec/codecs/libgme/sms_apu.h
new file mode 100644
index 0000000000..6dd65591ce
--- /dev/null
+++ b/lib/rbcodec/codecs/libgme/sms_apu.h
@@ -0,0 +1,63 @@
+// Sega Master System SN76489 PSG sound chip emulator
+
+// Sms_Snd_Emu 0.1.2
+#ifndef SMS_APU_H
+#define SMS_APU_H
+
+#include "blargg_common.h"
+#include "blip_buffer.h"
+
+// 0: Square 1, 1: Square 2, 2: Square 3, 3: Noise
+enum { sms_osc_count = 4 }; // 0 <= chan < osc_count
+        
+struct Osc
+{
+        struct Blip_Buffer* outputs [4]; // NULL, right, left, center
+        struct Blip_Buffer* output;
+        int          last_amp;
+        
+        int         volume;
+        int         period;
+        int         delay;
+        unsigned    phase;
+};
+
+struct Sms_Apu {
+        struct Osc     oscs [sms_osc_count];
+        int     ggstereo;
+        int     latch;
+        
+        blip_time_t last_time;
+        int         min_tone_period;
+        unsigned    noise_feedback;
+        unsigned    looped_feedback;
+        struct Blip_Synth synth;
+};
+
+// Basics
+
+void Sms_apu_init( struct Sms_Apu* this );
+
+// Sets buffer(s) to generate sound into, or 0 to mute. If only center is not 0,
+// output is mono.
+void Sms_apu_set_output( struct Sms_Apu* this, int i, struct Blip_Buffer* center, struct Blip_Buffer* left, struct Blip_Buffer* right);
+
+// Emulates to time t, then writes data to Game Gear left/right assignment byte
+void Sms_apu_write_ggstereo( struct Sms_Apu* this, blip_time_t t, int data );
+
+// Emulates to time t, then writes data
+void Sms_apu_write_data( struct Sms_Apu* this, blip_time_t t, int data );
+
+// Emulates to time t, then subtracts t from the current time.
+// OK if previous write call had time slightly after t.
+void Sms_apu_end_frame( struct Sms_Apu* this, blip_time_t t );
+
+// More features
+
+// Resets sound chip and sets noise feedback bits and width
+void Sms_apu_reset( struct Sms_Apu* this, unsigned noise_feedback, int noise_width );
+
+// Sets overall volume, where 1.0 is normal
+void Sms_apu_volume( struct Sms_Apu* this, int vol );
+
+#endif