Added Audio::Timestamp class, based on SCI's sfx_timestamp_t; also provide a unit test for it, based on the old (and very outdated) timetest.cpp. To be used by Audio::Mixer one day...

svn-id: r39112

6 files changed, 176 insertions, 5 deletions

diff --git a/sound/audiostream.h b/sound/audiostream.h
index 04133936ee..a917957a77 100644
--- a/sound/audiostream.h
+++ b/sound/audiostream.h
@@ -59,6 +59,9 @@ public:
 	/** Is this a stereo stream? */
 	virtual bool isStereo() const = 0;
 
+	/** Sample rate of the stream. */
+	virtual int getRate() const = 0;
+
 	/**
 	 * End of data reached? If this returns true, it means that at this
 	 * time there is no data available in the stream. However there may be
@@ -78,9 +81,6 @@ public:
 	 */
 	virtual bool endOfStream() const { return endOfData(); }
 
-	/** Sample rate of the stream. */
-	virtual int getRate() const = 0;
-
 	/**
 	 * Tries to load a file by trying all available formats.
 	 * In case of an error, the file handle will be closed, but deleting
diff --git a/sound/module.mk b/sound/module.mk
index f00f9e3adb..c11716a107 100644
--- a/sound/module.mk
+++ b/sound/module.mk
@@ -18,6 +18,7 @@ MODULE_OBJS := \
 	musicplugin.o \
 	null.o \
 	shorten.o \
+	timestamp.o \
 	voc.o \
 	vorbis.o \
 	wave.o \
diff --git a/sound/timestamp.cpp b/sound/timestamp.cpp
new file mode 100644
index 0000000000..8b0f660385
--- /dev/null
+++ b/sound/timestamp.cpp
@@ -0,0 +1,75 @@
+/* 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 "sound/timestamp.h"
+
+namespace Audio {
+
+Timestamp::Timestamp() :
+	_msecs(0), _frameRate(0), _frameOffset(0) {
+}
+
+Timestamp::Timestamp(uint32 m, int frameRate) :
+	_msecs(m), _frameRate(frameRate), _frameOffset(0) {
+}
+
+
+Timestamp Timestamp::addFrames(int frames) const {
+	Timestamp timestamp(*this);
+	timestamp._frameOffset += frames;
+
+	if (timestamp._frameOffset < 0) {
+		int secsub = 1 + (-timestamp._frameOffset / timestamp._frameRate);
+
+		timestamp._frameOffset += timestamp._frameRate * secsub;
+		timestamp._msecs -= secsub * 1000;
+	}
+
+	timestamp._msecs += (timestamp._frameOffset / timestamp._frameRate) * 1000;
+	timestamp._frameOffset %= timestamp._frameRate;
+
+	return timestamp;
+}
+
+int Timestamp::frameDiff(const Timestamp &b) const {
+	assert(_frameRate == b._frameRate);
+
+	int msecdelta = 0;
+	if (_msecs != b._msecs)
+		msecdelta = (long(_msecs) - long(b._msecs)) * _frameRate / 1000;
+
+	return msecdelta + _frameOffset - b._frameOffset;
+}
+
+int Timestamp::msecsDiff(const Timestamp &b) const {
+	return long(msecs()) - long(b.msecs());
+}
+
+uint32 Timestamp::msecs() const {
+	return _msecs + _frameOffset * 1000L / _frameRate;
+}
+
+
+} // End of namespace Audio
diff --git a/sound/timestamp.h b/sound/timestamp.h
new file mode 100644
index 0000000000..c68c4b7357
--- /dev/null
+++ b/sound/timestamp.h
@@ -0,0 +1,61 @@
+/* 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#ifndef SOUND_TIMESTAMP_H
+#define SOUND_TIMESTAMP_H
+
+#include "common/scummsys.h"
+
+
+namespace Audio {
+
+class Timestamp {
+protected:
+	uint32 _msecs;
+	int _frameRate;
+	int _frameOffset;
+	/* Total time: msecs + frame_offset/frame_rate */
+
+public:
+	Timestamp();
+	Timestamp(uint32 msecs, int frameRate);
+	
+	/** Adds a number of frames to a timestamp. */
+	Timestamp addFrames(int frames) const;
+	
+	/** Computes the difference (# of frames) between this timestamp and b. */
+	int frameDiff(const Timestamp &b) const;
+	
+	/** Computes the difference (# of milliseconds) between this timestamp and b. */
+	int msecsDiff(const Timestamp &b) const;
+	
+	/** Determines the time in milliseconds described by this timestamp. */
+	uint32 msecs() const;
+};
+
+
+} // End of namespace Audio
+
+#endif
diff --git a/test/module.mk b/test/module.mk
index 22c2dfa2c5..bf6a9efe8a 100644
--- a/test/module.mk
+++ b/test/module.mk
@@ -5,8 +5,8 @@
 #
 ######################################################################
 
-TESTS        := test/common/*.h
-TEST_LIBS    := common/libcommon.a
+TESTS        := test/common/*.h test/sound/*.h
+TEST_LIBS    := common/libcommon.a sound/libsound.a
 
 #
 TEST_FLAGS   := --runner=StdioPrinter
diff --git a/test/sound/timestamp.h b/test/sound/timestamp.h
new file mode 100644
index 0000000000..d6477bc336
--- /dev/null
+++ b/test/sound/timestamp.h
@@ -0,0 +1,34 @@
+#include <cxxtest/TestSuite.h>
+
+#include "sound/timestamp.h"
+
+class TimestampTestSuite : public CxxTest::TestSuite
+{
+	public:
+	void test_diff_add(void) {
+		Audio::Timestamp a(10000, 1000);
+		Audio::Timestamp b(10001, 1000);
+		Audio::Timestamp c(10002, 1000);
+	
+		TS_ASSERT_EQUALS(a.frameDiff(b), -1);
+		TS_ASSERT_EQUALS(b.frameDiff(a), 1);
+		TS_ASSERT_EQUALS(c.frameDiff(a), 2);
+		TS_ASSERT_EQUALS(b.addFrames(2000).frameDiff(a), 2001);
+		TS_ASSERT_EQUALS(a.frameDiff(b), -1);
+		TS_ASSERT_EQUALS(b.frameDiff(a), 1);
+		TS_ASSERT_EQUALS(c.frameDiff(a), 2);
+		TS_ASSERT_EQUALS(b.addFrames(2000).frameDiff(a.addFrames(-1000)), 3001);
+		TS_ASSERT_EQUALS(a.frameDiff(b), -1);
+		TS_ASSERT_EQUALS(b.frameDiff(a), 1);
+		TS_ASSERT_EQUALS(c.frameDiff(a), 2);
+	}
+
+	void test_more_add_diff(void) {
+		const Audio::Timestamp c(10002, 1000);
+
+		for (int i = -10000; i < 10000; i++) {
+			int v = c.addFrames(i).frameDiff(c);
+			TS_ASSERT_EQUALS(v, i);
+		}
+	}
+};