1 files changed, 310 insertions, 0 deletions
diff --git a/audio/softsynth/mt32/freeverb.cpp b/audio/softsynth/mt32/freeverb.cpp
new file mode 100644
index 0000000000..c62d4f2cf3
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+++ b/audio/softsynth/mt32/freeverb.cpp
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+/* 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+// Comb filter implementation
+//
+// Written by
+// http://www.dreampoint.co.uk
+// This code is public domain
+
+#include "audio/softsynth/mt32/freeverb.h"
+
+comb::comb() {
+	filterstore = 0;
+	bufidx = 0;
+}
+
+void comb::setbuffer(float *buf, int size) {
+	buffer = buf;
+	bufsize = size;
+}
+
+void comb::mute() {
+	for (int i = 0; i < bufsize; i++)
+		buffer[i] = 0;
+}
+
+void comb::setdamp(float val) {
+	damp1 = val;
+	damp2 = 1 - val;
+}
+
+float comb::getdamp() {
+	return damp1;
+}
+
+void comb::setfeedback(float val) {
+	feedback = val;
+}
+
+float comb::getfeedback() {
+	return feedback;
+}
+
+// Allpass filter implementation
+
+allpass::allpass() {
+	bufidx = 0;
+}
+
+void allpass::setbuffer(float *buf, int size) {
+	buffer = buf;
+	bufsize = size;
+}
+
+void allpass::mute() {
+	for (int i = 0; i < bufsize; i++)
+		buffer[i] = 0;
+}
+
+void allpass::setfeedback(float val) {
+	feedback = val;
+}
+
+float allpass::getfeedback() {
+	return feedback;
+}
+
+// Reverb model implementation
+
+revmodel::revmodel() {
+	// Tie the components to their buffers
+	combL[0].setbuffer(bufcombL1,combtuningL1);
+	combR[0].setbuffer(bufcombR1,combtuningR1);
+	combL[1].setbuffer(bufcombL2,combtuningL2);
+	combR[1].setbuffer(bufcombR2,combtuningR2);
+	combL[2].setbuffer(bufcombL3,combtuningL3);
+	combR[2].setbuffer(bufcombR3,combtuningR3);
+	combL[3].setbuffer(bufcombL4,combtuningL4);
+	combR[3].setbuffer(bufcombR4,combtuningR4);
+	combL[4].setbuffer(bufcombL5,combtuningL5);
+	combR[4].setbuffer(bufcombR5,combtuningR5);
+	combL[5].setbuffer(bufcombL6,combtuningL6);
+	combR[5].setbuffer(bufcombR6,combtuningR6);
+	combL[6].setbuffer(bufcombL7,combtuningL7);
+	combR[6].setbuffer(bufcombR7,combtuningR7);
+	combL[7].setbuffer(bufcombL8,combtuningL8);
+	combR[7].setbuffer(bufcombR8,combtuningR8);
+	allpassL[0].setbuffer(bufallpassL1,allpasstuningL1);
+	allpassR[0].setbuffer(bufallpassR1,allpasstuningR1);
+	allpassL[1].setbuffer(bufallpassL2,allpasstuningL2);
+	allpassR[1].setbuffer(bufallpassR2,allpasstuningR2);
+	allpassL[2].setbuffer(bufallpassL3,allpasstuningL3);
+	allpassR[2].setbuffer(bufallpassR3,allpasstuningR3);
+	allpassL[3].setbuffer(bufallpassL4,allpasstuningL4);
+	allpassR[3].setbuffer(bufallpassR4,allpasstuningR4);
+
+	// Set default values
+	allpassL[0].setfeedback(0.5f);
+	allpassR[0].setfeedback(0.5f);
+	allpassL[1].setfeedback(0.5f);
+	allpassR[1].setfeedback(0.5f);
+	allpassL[2].setfeedback(0.5f);
+	allpassR[2].setfeedback(0.5f);
+	allpassL[3].setfeedback(0.5f);
+	allpassR[3].setfeedback(0.5f);
+	setmode(initialmode);
+	setwet(initialwet);
+	setroomsize(initialroom);
+	setdry(initialdry);
+	setdamp(initialdamp);
+	setwidth(initialwidth);
+
+	// Buffer will be full of rubbish - so we MUST mute them
+	mute();
+}
+
+void revmodel::mute() {
+	int i;
+
+	if (getmode() >= freezemode)
+		return;
+
+	for (i = 0; i < numcombs; i++) {
+		combL[i].mute();
+		combR[i].mute();
+	}
+
+	for (i = 0; i < numallpasses; i++) {
+		allpassL[i].mute();
+		allpassR[i].mute();
+	}
+}
+
+void revmodel::processreplace(float *inputL, float *inputR, float *outputL, float *outputR, long numsamples, int skip) {
+	float outL, outR, input;
+
+	while (numsamples-- > 0) {
+		int i;
+
+		outL = outR = 0;
+		input = (*inputL + *inputR) * gain;
+
+		// Accumulate comb filters in parallel
+		for (i = 0; i < numcombs; i++) {
+			outL += combL[i].process(input);
+			outR += combR[i].process(input);
+		}
+
+		// Feed through allpasses in series
+		for (i = 0; i < numallpasses; i++) {
+			outL = allpassL[i].process(outL);
+			outR = allpassR[i].process(outR);
+		}
+
+		// Calculate output REPLACING anything already there
+		*outputL = outL * wet1 + outR * wet2 + *inputL * dry;
+		*outputR = outR * wet1 + outL * wet2 + *inputR * dry;
+
+		// Increment sample pointers, allowing for interleave (if any)
+		inputL += skip;
+		inputR += skip;
+		outputL += skip;
+		outputR += skip;
+	}
+}
+
+void revmodel::processmix(float *inputL, float *inputR, float *outputL, float *outputR, long numsamples, int skip) {
+	float outL, outR, input;
+
+	while (numsamples-- > 0) {
+		int i;
+
+		outL = outR = 0;
+		input = (*inputL + *inputR) * gain;
+
+		// Accumulate comb filters in parallel
+		for (i = 0; i < numcombs; i++) {
+			outL += combL[i].process(input);
+			outR += combR[i].process(input);
+		}
+
+		// Feed through allpasses in series
+		for (i = 0; i < numallpasses; i++) {
+			outL = allpassL[i].process(outL);
+			outR = allpassR[i].process(outR);
+		}
+
+		// Calculate output MIXING with anything already there
+		*outputL += outL * wet1 + outR * wet2 + *inputL * dry;
+		*outputR += outR * wet1 + outL * wet2 + *inputR * dry;
+
+		// Increment sample pointers, allowing for interleave (if any)
+		inputL += skip;
+		inputR += skip;
+		outputL += skip;
+		outputR += skip;
+	}
+}
+
+void revmodel::update() {
+	// Recalculate internal values after parameter change
+
+	int i;
+
+	wet1 = wet * (width / 2 + 0.5f);
+	wet2 = wet * ((1 - width) / 2);
+
+	if (mode >= freezemode) {
+		roomsize1 = 1;
+		damp1 = 0;
+		gain = muted;
+	} else {
+		roomsize1 = roomsize;
+		damp1 = damp;
+		gain = fixedgain;
+	}
+
+	for (i = 0; i < numcombs; i++) {
+		combL[i].setfeedback(roomsize1);
+		combR[i].setfeedback(roomsize1);
+	}
+
+	for (i = 0; i < numcombs; i++) {
+		combL[i].setdamp(damp1);
+		combR[i].setdamp(damp1);
+	}
+}
+
+// The following get/set functions are not inlined, because
+// speed is never an issue when calling them, and also
+// because as you develop the reverb model, you may
+// wish to take dynamic action when they are called.
+
+void revmodel::setroomsize(float value) {
+	roomsize = (value * scaleroom) + offsetroom;
+	update();
+}
+
+float revmodel::getroomsize() {
+	return (roomsize - offsetroom) / scaleroom;
+}
+
+void revmodel::setdamp(float value) {
+	damp = value * scaledamp;
+	update();
+}
+
+float revmodel::getdamp() {
+	return damp / scaledamp;
+}
+
+void revmodel::setwet(float value) {
+	wet = value * scalewet;
+	update();
+}
+
+float revmodel::getwet() {
+	return wet / scalewet;
+}
+
+void revmodel::setdry(float value) {
+	dry = value * scaledry;
+}
+
+float revmodel::getdry() {
+	return dry / scaledry;
+}
+
+void revmodel::setwidth(float value) {
+	width = value;
+	update();
+}
+
+float revmodel::getwidth() {
+	return width;
+}
+
+void revmodel::setmode(float value) {
+	mode = value;
+	update();
+}
+
+float revmodel::getmode() {
+	if (mode >= freezemode)
+		return 1;
+	else
+		return 0;
+}