From 440fcb1d5abb1100074b3fdf69f8df26850c390a Mon Sep 17 00:00:00 2001
From: Eugene Sandulenko
Date: Sat, 28 Feb 2009 10:53:45 +0000
Subject: Patch #2638336: Broken Sword PSX Support  Part 2 of 2

svn-id: r38957
---
 engines/sword1/vag.cpp | 114 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)
 create mode 100644 engines/sword1/vag.cpp

(limited to 'engines/sword1/vag.cpp')

diff --git a/engines/sword1/vag.cpp b/engines/sword1/vag.cpp
new file mode 100644
index 0000000000..afd064ad4a
--- /dev/null
+++ b/engines/sword1/vag.cpp
@@ -0,0 +1,114 @@
+/* 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+ 
+#include "sword1/vag.h"
+
+namespace Sword1 {
+
+VagStream::VagStream(Common::SeekableReadStream *stream, bool loop) : _stream(stream) {
+	_samplesRemaining = 0;
+	_predictor = 0;
+	_s1 = _s2 = 0.0;
+	_loop = loop;
+}
+
+
+VagStream::~VagStream() {
+}
+
+double f[5][2] = { { 0.0, 0.0 },
+                    {  60.0 / 64.0,  0.0 },
+                    {  115.0 / 64.0, -52.0 / 64.0 },
+                    {  98.0 / 64.0, -55.0 / 64.0 },
+                    {  122.0 / 64.0, -60.0 / 64.0 } };
+
+int VagStream::readBuffer(int16 *buffer, const int numSamples) {
+	int32 samplesDecoded = 0;
+	
+	if (_samplesRemaining) {
+		byte i = 0;
+		
+		for (i = 28 - _samplesRemaining; i < 28 && samplesDecoded < numSamples; i++) {
+			_samples[i] = _samples[i] + _s1 * f[_predictor][0] + _s2 * f[_predictor][1];
+			_s2 = _s1;
+			_s1 = _samples[i];
+			int16 d = (int) (_samples[i] + 0.5);
+			buffer[samplesDecoded] = d;
+			samplesDecoded++;
+		}
+		
+		assert(i == 28); // We're screwed if this fails :P
+		_samplesRemaining = 0;
+	}
+	
+	while (samplesDecoded < numSamples) {
+		byte i = 0;
+	
+		_predictor = _stream->readByte();
+		byte shift = _predictor & 0xf;
+		_predictor >>= 4;
+	
+		if (_stream->readByte() == 7)
+			return samplesDecoded;
+	
+		for (i = 0; i < 28; i += 2) {
+			byte d = _stream->readByte();
+			int16 s = (d & 0xf) << 12;
+			if (s & 0x8000)
+				s |= 0xffff0000;
+			_samples[i] = (double)(s >> shift);
+			s = (d & 0xf0) << 8;
+			if (s & 0x8000)
+				s |= 0xffff0000;
+			_samples[i + 1] = (double)(s >> shift);
+		}
+	
+		for (i = 0; i < 28 && samplesDecoded < numSamples; i++) {
+			_samples[i] = _samples[i] + _s1 * f[_predictor][0] + _s2 * f[_predictor][1];
+			_s2 = _s1;
+			_s1 = _samples[i];
+			int16 d = (int) (_samples[i] + 0.5);
+			buffer[samplesDecoded] = d;
+			samplesDecoded++;
+		}
+		
+		if (i != 27)
+			_samplesRemaining = 28 - i;
+	}
+
+	if(_loop && _stream->eos())
+		rewind();
+
+	return samplesDecoded;
+}
+
+void VagStream::rewind() {
+	_stream->seek(0);
+	_samplesRemaining = 0;
+	_predictor = 0;
+	_s1 = _s2 = 0.0;
+}
+
+}
-- 
cgit v1.2.3