MT32: Update MT-32 emulator to latest Munt code

Several changes against original code were made. They were intentionally
kept to the minimum

1 files changed, 135 insertions, 187 deletions

diff --git a/audio/softsynth/mt32/freeverb.h b/audio/softsynth/mt32/freeverb.h
index 39ae463970..ae4d48169e 100644
--- a/audio/softsynth/mt32/freeverb.h
+++ b/audio/softsynth/mt32/freeverb.h
@@ -1,24 +1,32 @@
-/* ScummVM - Graphic Adventure Engine
- *
- * ScummVM is the legal property of its developers, whose names
- * are too numerous to list here. Please refer to the COPYRIGHT
- * file distributed with this source distribution.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
-
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
-
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
- */
+#ifndef _freeverb_
+#define _freeverb_
+
+// Reverb model tuning values
+//
+// Written by Jezar at Dreampoint, June 2000
+// http://www.dreampoint.co.uk
+// This code is public domain
+
+const int   numcombs        = 8;
+const int   numallpasses    = 4;
+const float muted           = 0;
+const float fixedgain       = 0.015f;
+const float scalewet        = 3;
+const float scaledry        = 2;
+const float scaledamp       = 0.4f;
+const float scaleroom       = 0.28f;
+const float offsetroom      = 0.7f;
+const float initialroom     = 0.5f;
+const float initialdamp     = 0.5f;
+const float initialwet      = 1/scalewet;
+const float initialdry      = 0;
+const float initialwidth    = 1;
+const float initialmode     = 0;
+const float freezemode      = 0.5f;
+const int   stereospread    = 23;
+
+const int combtuning[]      = {1116, 1188, 1277, 1356, 1422, 1491, 1557, 1617};
+const int allpasstuning[]   = {556, 441, 341, 225};
 
 // Macro for killing denormalled numbers
 //
@@ -27,215 +35,155 @@
 // Based on IS_DENORMAL macro by Jon Watte
 // This code is public domain
 
-#ifndef FREEVERB_H
-#define FREEVERB_H
-
-// FIXME: Fix this really ugly hack
-inline float undenormalise(void *sample) {
-	if (((*(unsigned int*)sample) &  0x7f800000) == 0)
+static inline float undenormalise(float x) {
+	union {
+		float f;
+		unsigned int i;
+	} u;
+	u.f = x;
+	if ((u.i & 0x7f800000) == 0) {
 		return 0.0f;
-	return *(float*)sample;
+	}
+	return x;
 }
 
-// Comb filter class declaration
+// Allpass filter declaration
+//
+// Written by Jezar at Dreampoint, June 2000
+// http://www.dreampoint.co.uk
+// This code is public domain
 
-class comb {
+class allpass
+{
 public:
-	comb();
-	void setbuffer(float *buf, int size);
-	inline float process(float inp);
-	void mute();
-	void setdamp(float val);
-	float getdamp();
-	void setfeedback(float val);
-	float getfeedback();
-private:
-	float feedback;
-	float filterstore;
-	float damp1;
-	float damp2;
-	float *buffer;
-	int bufsize;
-	int bufidx;
+	                allpass();
+	        void    setbuffer(float *buf, int size);
+	        void    deletebuffer();
+	inline  float   process(float inp);
+	        void    mute();
+	        void    setfeedback(float val);
+	        float   getfeedback();
+// private:
+	float   feedback;
+	float   *buffer;
+	int     bufsize;
+	int     bufidx;
 };
 
 
 // Big to inline - but crucial for speed
 
-inline float comb::process(float input) {
+inline float allpass::process(float input)
+{
 	float output;
+	float bufout;
 
-	output = buffer[bufidx];
-	undenormalise(&output);
-
-	filterstore = (output * damp2) + (filterstore * damp1);
-	undenormalise(&filterstore);
+	bufout = undenormalise(buffer[bufidx]);
 
-	buffer[bufidx] = input + (filterstore * feedback);
+	output = -input + bufout;
+	buffer[bufidx] = input + (bufout*feedback);
 
-	if (++bufidx >= bufsize)
-		bufidx = 0;
+	if (++bufidx>=bufsize) bufidx = 0;
 
 	return output;
 }
 
-// Allpass filter declaration
+// Comb filter class declaration
+//
+// Written by Jezar at Dreampoint, June 2000
+// http://www.dreampoint.co.uk
+// This code is public domain
 
-class allpass {
+class comb
+{
 public:
-	allpass();
-	void setbuffer(float *buf, int size);
-	inline float process(float inp);
-	void mute();
-	void setfeedback(float val);
-	float getfeedback();
+	                comb();
+	        void    setbuffer(float *buf, int size);
+	        void    deletebuffer();
+	inline  float   process(float inp);
+	        void    mute();
+	        void    setdamp(float val);
+	        float   getdamp();
+	        void    setfeedback(float val);
+	        float   getfeedback();
 private:
-	float feedback;
-	float *buffer;
-	int bufsize;
-	int bufidx;
+	float   feedback;
+	float   filterstore;
+	float   damp1;
+	float   damp2;
+	float   *buffer;
+	int     bufsize;
+	int     bufidx;
 };
 
 
 // Big to inline - but crucial for speed
 
-inline float allpass::process(float input) {
+inline float comb::process(float input)
+{
 	float output;
-	float bufout;
 
-	bufout = buffer[bufidx];
-	undenormalise(&bufout);
+	output = undenormalise(buffer[bufidx]);
 
-	output = -input + bufout;
-	buffer[bufidx] = input + (bufout * feedback);
+	filterstore = undenormalise((output*damp2) + (filterstore*damp1));
+
+	buffer[bufidx] = input + (filterstore*feedback);
 
-	if (++bufidx >= bufsize)
-		bufidx = 0;
+	if (++bufidx>=bufsize) bufidx = 0;
 
 	return output;
 }
 
-
-// Reverb model tuning values
-
-const int	numcombs	= 8;
-const int	numallpasses	= 4;
-const float	muted		= 0;
-const float	fixedgain	= 0.015f;
-const float	scalewet	= 3;
-const float	scaledry	= 2;
-const float	scaledamp	= 0.4f;
-const float	scaleroom	= 0.28f;
-const float	offsetroom	= 0.7f;
-const float	initialroom	= 0.5f;
-const float	initialdamp	= 0.5f;
-const float	initialwet	= 1 / scalewet;
-const float	initialdry	= 0;
-const float	initialwidth	= 1;
-const float	initialmode	= 0;
-const float	freezemode	= 0.5f;
-const int	stereospread	= 23;
-
-// These values assume 44.1KHz sample rate
-// they will probably be OK for 48KHz sample rate
-// but would need scaling for 96KHz (or other) sample rates.
-// The values were obtained by listening tests.
-const int combtuningL1		= 1116;
-const int combtuningR1		= 1116 + stereospread;
-const int combtuningL2		= 1188;
-const int combtuningR2		= 1188 + stereospread;
-const int combtuningL3		= 1277;
-const int combtuningR3		= 1277 + stereospread;
-const int combtuningL4		= 1356;
-const int combtuningR4		= 1356 + stereospread;
-const int combtuningL5		= 1422;
-const int combtuningR5		= 1422 + stereospread;
-const int combtuningL6		= 1491;
-const int combtuningR6		= 1491 + stereospread;
-const int combtuningL7		= 1557;
-const int combtuningR7		= 1557 + stereospread;
-const int combtuningL8		= 1617;
-const int combtuningR8		= 1617 + stereospread;
-const int allpasstuningL1	= 556;
-const int allpasstuningR1	= 556 + stereospread;
-const int allpasstuningL2	= 441;
-const int allpasstuningR2	= 441 + stereospread;
-const int allpasstuningL3	= 341;
-const int allpasstuningR3	= 341 + stereospread;
-const int allpasstuningL4	= 225;
-const int allpasstuningR4	= 225 + stereospread;
-
-
 // Reverb model declaration
+//
+// Written by Jezar at Dreampoint, June 2000
+// Modifications by Jerome Fisher, 2009
+// http://www.dreampoint.co.uk
+// This code is public domain
 
-class revmodel {
+class revmodel
+{
 public:
-	revmodel();
-	void mute();
-	void processmix(float *inputL, float *inputR, float *outputL, float *outputR, long numsamples, int skip);
-	void processreplace(float *inputL, float *inputR, float *outputL, float *outputR, long numsamples, int skip);
-	void setroomsize(float value);
-	float getroomsize();
-	void setdamp(float value);
-	float getdamp();
-	void setwet(float value);
-	float getwet();
-	void setdry(float value);
-	float getdry();
-	void setwidth(float value);
-	float getwidth();
-	void setmode(float value);
-	float getmode();
+			       revmodel(float scaletuning);
+						 ~revmodel();
+			void   mute();
+			void   process(const float *inputL, const float *inputR, float *outputL, float *outputR, long numsamples);
+			void   setroomsize(float value);
+			float  getroomsize();
+			void   setdamp(float value);
+			float  getdamp();
+			void   setwet(float value);
+			float  getwet();
+			void   setdry(float value);
+			float  getdry();
+			void   setwidth(float value);
+			float  getwidth();
+			void   setmode(float value);
+			float  getmode();
+			void   setfiltval(float value);
 private:
-	void update();
-
-	float gain;
-	float roomsize, roomsize1;
-	float damp, damp1;
-	float wet, wet1, wet2;
-	float dry;
-	float width;
-	float mode;
-
-	// The following are all declared inline
-	// to remove the need for dynamic allocation
-	// with its subsequent error-checking messiness
+			void   update();
+private:
+	float  gain;
+	float  roomsize,roomsize1;
+	float  damp,damp1;
+	float  wet,wet1,wet2;
+	float  dry;
+	float  width;
+	float  mode;
+
+	// LPF stuff
+	float filtval;
+	float filtprev1;
+	float filtprev2;
 
 	// Comb filters
-	comb combL[numcombs];
-	comb combR[numcombs];
+	comb   combL[numcombs];
+	comb   combR[numcombs];
 
 	// Allpass filters
 	allpass	allpassL[numallpasses];
 	allpass	allpassR[numallpasses];
-
-	// Buffers for the combs
-	float bufcombL1[combtuningL1];
-	float bufcombR1[combtuningR1];
-	float bufcombL2[combtuningL2];
-	float bufcombR2[combtuningR2];
-	float bufcombL3[combtuningL3];
-	float bufcombR3[combtuningR3];
-	float bufcombL4[combtuningL4];
-	float bufcombR4[combtuningR4];
-	float bufcombL5[combtuningL5];
-	float bufcombR5[combtuningR5];
-	float bufcombL6[combtuningL6];
-	float bufcombR6[combtuningR6];
-	float bufcombL7[combtuningL7];
-	float bufcombR7[combtuningR7];
-	float bufcombL8[combtuningL8];
-	float bufcombR8[combtuningR8];
-
-	// Buffers for the allpasses
-	float bufallpassL1[allpasstuningL1];
-	float bufallpassR1[allpasstuningR1];
-	float bufallpassL2[allpasstuningL2];
-	float bufallpassR2[allpasstuningR2];
-	float bufallpassL3[allpasstuningL3];
-	float bufallpassR3[allpasstuningR3];
-	float bufallpassL4[allpasstuningL4];
-	float bufallpassR4[allpasstuningR4];
 };
 
-#endif
+#endif//_freeverb_