o Make GAME_GetFileContext() more object-like

o Font::loadFont() now normally survives zero-length fonts as used in demos
o Removed unused SndRes::ITEVOC_Resample()
o Fixed playing of voice #4 on old DOS targets
o Implemented playing voices in VOX (Oki ADPCM) format
o Support of Win32 and Linux demos. There was old-style Win32 demo, which
  is not supported yet, same is with DOS demo.

svn-id: r15814

1 files changed, 118 insertions, 0 deletions

diff --git a/saga/sound.cpp b/saga/sound.cpp
index a6859134ae..e63f675ca0 100644
--- a/saga/sound.cpp
+++ b/saga/sound.cpp
@@ -25,9 +25,118 @@
 #include "saga/sound.h"
 #include "saga/game_mod.h"
 
+#include "sound/audiostream.h"
 #include "sound/mixer.h"
 
 namespace Saga {
+#define BUFFER_SIZE 4096
+
+// Routines to convert 12 bit linear samples to the
+// Dialogic or Oki ADPCM coding format.
+class VOXInputStream : public AudioStream {
+private:
+	const byte *_buf;
+	uint32 _pos;
+	uint32 _inputLen;
+	bool _evenPos;
+
+	struct adpcmStatus {
+		int16 last;
+		int16 stepIndex;
+	} _status;
+
+	int16 stepAdjust(byte);
+	int16 adpcmDecode(byte);
+
+public:
+	VOXInputStream(const byte *input, int inputLen);
+	~VOXInputStream() {};
+
+	int readBuffer(int16 *buffer, const int numSamples);
+
+	bool endOfData() const	{ return _pos >= _inputLen; }
+	bool isStereo() const	{ return false; }
+	int getRate() const	{ return 22050; }
+};
+
+
+VOXInputStream::VOXInputStream(const byte *input, int inputLen)
+	: _buf(input), _pos(0), _inputLen(inputLen), _evenPos(true) {
+
+	_status.last = 0;
+	_status.stepIndex = 0;
+}
+
+int VOXInputStream::readBuffer(int16 *buffer, const int numSamples) {
+	int samples = 0;
+
+	while (samples < numSamples && !endOfData()) {
+		const int len = MIN(numSamples - samples, (int) (_inputLen - _pos));
+
+		// * 16 effectively converts 12-bit input to 16-bit output
+		for (int i = 0; i < len; i++) {
+			if (_evenPos)
+				buffer[i] = adpcmDecode((_buf[_pos] >> 4) & 0x0f) * 16;
+			else {
+				buffer[i] = adpcmDecode(_buf[_pos] & 0x0f) * 16;
+				_pos++;
+			}
+			_evenPos = !_evenPos;
+		}
+
+		samples += len;
+	}
+	return samples;
+}
+
+// adjust the step for use on the next sample.
+int16 VOXInputStream::stepAdjust(byte code) {
+	static int16 adjusts[] = {-1, -1, -1, -1, 2, 4, 6, 8};
+
+	return adjusts[code & 0x07];
+}
+
+static int16 stepSize[49] = { 16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41,
+	45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143, 157, 173,
+	190, 209, 230, 253, 279, 307, 337, 371, 408, 449, 494, 544, 598, 658,
+	724, 796, 876, 963, 1060, 1166, 1282, 1408, 1552 };
+
+// Decode Linear to ADPCM
+int16 VOXInputStream::adpcmDecode(byte code) {
+	int16 diff, E, SS, samp;
+
+	SS = stepSize[_status.stepIndex];
+	E = SS/8;
+	if (code & 0x01)
+		E += SS/4;
+	if (code & 0x02)
+		E += SS/2;
+	if (code & 0x04)
+		E += SS;
+	diff = (code & 0x08) ? -E : E;
+	samp = _status.last + diff;
+
+    // Clip the values to +/- 2^11 (supposed to be 12 bits)
+	if(samp > 2048)
+		samp = 2048;
+	if(samp < -2048)
+		samp = -2048;
+
+	_status.last = samp;
+	_status.stepIndex += stepAdjust(code);
+	if(_status.stepIndex < 0)
+		_status.stepIndex = 0;
+	if(_status.stepIndex > 48)
+		_status.stepIndex = 48;
+
+	return samp;
+}
+
+AudioStream *makeVOXStream(const byte *input, int size) {
+	AudioStream *audioStream = new VOXInputStream(input, size);
+
+	return audioStream;
+}
 
 Sound::Sound(SagaEngine *vm, SoundMixer *mixer, int enabled) : 
 	_vm(vm), _mixer(mixer), _enabled(enabled) {
@@ -119,6 +228,15 @@ int Sound::playVoice(SOUNDBUFFER *buf) {
 	return playSoundBuffer(&_voiceHandle, buf, 255, false);
 }
 
+int Sound::playVoxVoice(SOUNDBUFFER *buf) {
+	AudioStream *audioStream;
+
+	audioStream = makeVOXStream(buf->s_buf, buf->s_buf_len);
+	_mixer->playInputStream(&_voiceHandle, audioStream, false);
+
+	return SUCCESS;
+}
+
 int Sound::pauseVoice() {
 	if (!_soundInitialized) {
 		return FAILURE;