1 files changed, 53 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6pre/gme/Spc_Filter.h b/plugins/gme/game-music-emu-0.6pre/gme/Spc_Filter.h
new file mode 100644
index 00000000..9de56b18
--- /dev/null
+++ b/plugins/gme/game-music-emu-0.6pre/gme/Spc_Filter.h
@@ -0,0 +1,53 @@
+// Simple low-pass and high-pass filter to better match sound output of a SNES
+
+// Game_Music_Emu 0.5.5
+#ifndef SPC_FILTER_H
+#define SPC_FILTER_H
+
+#include "blargg_common.h"
+
+struct SPC_Filter {
+public:
+	
+	// Filters count samples of stereo sound in place. Count must be a multiple of 2.
+	typedef short sample_t;
+	void run( sample_t* io, int count );
+	
+// Optional features
+
+	// Clears filter to silence
+	void clear();
+	
+	// Sets gain (volume), where gain_unit is normal. Gains greater than gain_unit
+	// are fine, since output is clamped to 16-bit sample range.
+	enum { gain_unit = 0x100 };
+	void set_gain( int gain );
+	
+	// Enables/disables filtering (when disabled, gain is still applied)
+	void enable( bool b );
+	
+	// Sets amount of bass (logarithmic scale)
+	enum { bass_none =  0 };
+	enum { bass_norm =  8 }; // normal amount
+	enum { bass_max  = 31 };
+	void set_bass( int bass );
+	
+public:
+	SPC_Filter();
+	BLARGG_DISABLE_NOTHROW
+private:
+	enum { gain_bits = 8 };
+	int gain;
+	int bass;
+	bool enabled;
+	struct chan_t { int p1, pp1, sum; };
+	chan_t ch [2];
+};
+
+inline void SPC_Filter::enable( bool b )  { enabled = b; }
+
+inline void SPC_Filter::set_gain( int g ) { gain = g; }
+
+inline void SPC_Filter::set_bass( int b ) { bass = b; }
+
+#endif