ADL: Add Sound class

Author: waltervn

engines/adl/adl.cpp

@@ -39,14 +39,13 @@
 #include "adl/display.h"
 #include "adl/detection.h"
 #include "adl/graphics.h"
-#include "adl/speaker.h"
+#include "adl/sound.h"
 
 namespace Adl {
 
 AdlEngine::~AdlEngine() {
 	delete _display;
 	delete _graphics;
-	delete _speaker;
 	delete _console;
 	delete _dumpFile;
 }
@@ -56,7 +55,6 @@ AdlEngine::AdlEngine(OSystem *syst, const AdlGameDescription *gd) :
 		_dumpFile(nullptr),
 		_display(nullptr),
 		_graphics(nullptr),
-		_speaker(nullptr),
 		_isRestarting(false),
 		_isRestoring(false),
 		_isQuitting(false),
@@ -461,7 +459,25 @@ void AdlEngine::drawPic(byte pic, Common::Point pos) const {
 }
 
 void AdlEngine::bell(uint count) const {
-	_speaker->bell(count);
+	Tones tones;
+
+	for (uint i = 0; i < count - 1; ++i) {
+		tones.push_back(Tone(940.0, 100.0));
+		tones.push_back(Tone(0.0, 12.0));
+	}
+
+	tones.push_back(Tone(940.0, 100.0));
+
+	Audio::SoundHandle handle;
+	Audio::AudioStream *stream = new Sound(tones);
+
+	g_system->getMixer()->playStream(Audio::Mixer::kPlainSoundType, &handle, stream);
+
+	while (!g_engine->shouldQuit() && g_system->getMixer()->isSoundHandleActive(handle)) {
+		Common::Event event;
+		pollEvent(event);
+		g_system->delayMillis(16);
+	}
 }
 
 const Region &AdlEngine::getRegion(uint i) const {
@@ -644,7 +660,6 @@ Common::Error AdlEngine::run() {
 	initGraphics(DISPLAY_WIDTH * 2, DISPLAY_HEIGHT * 2, true);
 
 	_console = new Console(this);
-	_speaker = new Speaker();
 	_display = new Display();
 
 	setupOpcodeTables();

engines/adl/adl.h

@@ -53,7 +53,6 @@ namespace Adl {
 class Console;
 class Display;
 class GraphicsMan;
-class Speaker;
 struct AdlGameDescription;
 class ScriptEnv;
 
@@ -347,7 +346,6 @@ friend class Console;
 
 	Display *_display;
 	GraphicsMan *_graphics;
-	Speaker *_speaker;
 
 	// Opcodes
 	typedef Common::Functor1<ScriptEnv &, int> Opcode;

engines/adl/module.mk

@@ -19,7 +19,7 @@ MODULE_OBJS := \
 	hires4.o \
 	hires5.o \
 	hires6.o \
-	speaker.o
+	sound.o
 
 MODULE_DIRS += \
 	engines/adl

engines/adl/sound.cpp

@@ -0,0 +1,144 @@
+/* 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.
+ *
+ */
+
+#include "common/system.h"
+
+#include "audio/mixer.h"
+
+#include "adl/sound.h"
+
+namespace Adl {
+
+// Generic PC-speaker synth
+// This produces more accurate frequencies than Audio::PCSpeaker, but only
+// does square waves.
+class Speaker {
+public:
+	Speaker(int sampleRate);
+
+	void startTone(double freq);
+	void stopTone();
+	void generateSamples(int16 *buffer, int numSamples);
+
+private:
+	int _rate;
+	frac_t _halfWaveLen, _halfWaveRem;
+	int16 _curSample;
+};
+
+Speaker::Speaker(int sampleRate) :
+		_rate(sampleRate),
+		_curSample(32767) {
+
+	stopTone();
+}
+
+void Speaker::startTone(double freq) {
+	_halfWaveLen = _halfWaveRem = doubleToFrac(_rate / freq / 2);
+
+	if (_halfWaveLen < FRAC_ONE) {
+		// Tone out of range at this sample rate
+		stopTone();
+	}
+}
+
+void Speaker::stopTone() {
+	_halfWaveLen = 0;
+	_halfWaveRem = intToFrac(32767);
+}
+
+void Speaker::generateSamples(int16 *buffer, int numSamples) {
+	int offset = 0;
+
+	while (offset < numSamples) {
+		if (_halfWaveRem >= 0 && _halfWaveRem < FRAC_ONE) {
+			// Rising/falling edge
+			// Switch level
+			_curSample = ~_curSample;
+			// Use transition point fraction for current sample value
+			buffer[offset++] = _halfWaveRem ^ _curSample;
+			// Compute next transition point
+			_halfWaveRem += _halfWaveLen - FRAC_ONE;
+		} else {
+			// Low/high level (incl. silence)
+			// Generate as many samples as we can
+			const int samples = MIN(numSamples - offset, (int)fracToInt(_halfWaveRem));
+			Common::fill(buffer + offset, buffer + offset + samples, _curSample);
+			offset += samples;
+
+			// Count down to level transition point, unless we're playing silence
+			if (_halfWaveLen > 0)
+				_halfWaveRem -= intToFrac(samples);
+		}
+	}
+}
+
+Sound::Sound(const Tones &tones) :
+		_tones(tones),
+		_toneIndex(0),
+		_samplesRem(0) {
+
+	_rate = g_system->getMixer()->getOutputRate();
+	_speaker = new Speaker(_rate);
+}
+
+Sound::~Sound() {
+	delete _speaker;
+}
+
+bool Sound::endOfData() const {
+	return _samplesRem == 0 && _toneIndex == _tones.size();
+}
+
+int Sound::readBuffer(int16 *buffer, const int numSamples) {
+	int offset = 0;
+
+	while (offset < numSamples) {
+		if (_samplesRem == 0) {
+			// Set up next tone
+
+			if (_toneIndex == _tones.size()) {
+				// No more tones
+				return offset;
+			}
+
+			if (_tones[_toneIndex].freq == 0.0)
+				_speaker->stopTone();
+			else
+				_speaker->startTone(_tones[_toneIndex].freq);
+
+			// Compute length of tone
+			_samplesRem = _rate * _tones[_toneIndex++].len / 1000;
+		}
+
+		// Generate as many samples as we can
+		const int samples = MIN(numSamples - offset, _samplesRem);
+		_speaker->generateSamples(buffer + offset, samples);
+
+		_samplesRem -= samples;
+		offset += samples;
+	}
+
+	return numSamples;
+}
+
+} // End of namespace Adl

engines/adl/speaker.h renamed to engines/adl/sound.h

@@ -20,28 +20,45 @@
  *
  */
 
-#ifndef ADL_SPEAKER_H
-#define ADL_SPEAKER_H
+#ifndef ADL_SOUND_H
+#define ADL_SOUND_H
 
-#include "common/types.h"
+#include "audio/audiostream.h"
 
-#include "audio/mixer.h"
-
-namespace Audio {
-class AudioStream;
-}
+#include "common/array.h"
+#include "common/frac.h"
 
 namespace Adl {
 
-class Speaker {
+class Speaker;
+
+struct Tone {
+	double freq; // Hz
+	double len; // ms
+
+	Tone(double frequency, double length) : freq(frequency), len(length) { }
+};
+
+typedef Common::Array<Tone> Tones;
+
+class Sound : public Audio::AudioStream {
 public:
-	Speaker();
-	~Speaker();
+	Sound(const Tones &tones);
+	~Sound();
 
-	void bell(uint count);
+	// AudioStream
+	int readBuffer(int16 *buffer, const int numSamples);
+	bool isStereo() const { return false; }
+	bool endOfData() const;
+	int getRate() const	{ return _rate; }
 
 private:
-	byte *_bell, *_silence;
+	const Tones &_tones;
+
+	Speaker *_speaker;
+	int _rate;
+	uint _toneIndex;
+	int _samplesRem;
 };
 
 } // End of namespace Adl