More Amiga V2/V3 sound updates from _Q_:

1. A Player_MOD class, basically acts as a simplified mixer that mixes at 60Hz intervals (or whatever interval you specify), this gives smooth music playback in player_v3a
2. Some changes to player_v3a as a result of #1, including reduced music volume
3. player_v2a, and the necessary additions to scummvm.cpp/scumm.h

svn-id: r10392

1 files changed, 188 insertions, 0 deletions

diff --git a/scumm/player_mod.cpp b/scumm/player_mod.cpp
new file mode 100644
index 0000000000..828fc3ae7a
--- /dev/null
+++ b/scumm/player_mod.cpp
@@ -0,0 +1,188 @@
+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2001  Ludvig Strigeus
+ * Copyright (C) 2001-2003 The ScummVM project
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * $Header$
+ *
+ */
+
+#include "player_mod.h"
+
+////////////////////////////////////////
+//
+// Generic Amiga MOD mixer - provides a 60Hz 'update' routine.
+//
+////////////////////////////////////////
+
+Player_MOD::Player_MOD(Scumm *scumm) {
+	int i;
+	_mixer = scumm->_mixer;
+	_samplerate = scumm->_system->property(OSystem::PROP_GET_SAMPLE_RATE, 0);
+	_mixamt = 0;
+	_mixpos = 0;
+
+	for (i = 0; i < MOD_MAXCHANS; i++) {
+		_channels[i].id = 0;
+		_channels[i].vol = 0;
+		_channels[i].freq = 0;
+		_channels[i].ptr = NULL;
+		_channels[i].converter = NULL;
+		_channels[i].input = NULL;
+	}
+
+	_playproc = NULL;
+	_playparam = NULL;
+
+	_mixer->setupPremix(premix_proc, this);
+}
+
+Player_MOD::~Player_MOD() {
+	// Detach the premix callback handler
+	_mixer->setupPremix(0, 0);
+	for (int i = 0; i < MOD_MAXCHANS; i++) {
+		if (!_channels[i].id)
+			continue;
+		delete _channels[i].ptr;
+		delete _channels[i].converter;
+		delete _channels[i].input;
+	}
+}
+
+void Player_MOD::setMasterVolume (int vol) {
+	_maxvol = vol;
+}
+
+void Player_MOD::setUpdateProc(ModUpdateProc *proc, void *param, int freq) {
+	_playproc = proc;
+	_playparam = param;
+	_mixamt = _samplerate / freq;
+}
+void Player_MOD::clearUpdateProc() {
+	_playproc = NULL;
+	_playparam = NULL;
+	_mixamt = 0;
+}
+
+void Player_MOD::startChannel (int id, const char *data, int size, int rate, uint8 vol, int loopStart, int loopEnd, int8 pan) {
+	int i;
+	if (id == 0)
+		error("player_mod - attempted to start channel id 0");
+
+	for (i = 0; i < MOD_MAXCHANS; i++) {
+		if (!_channels[i].id)
+			break;
+	}
+	if (i == MOD_MAXCHANS) {
+		warning("player_mod - too many music channels playing (%i max)",MOD_MAXCHANS);
+		return;
+	}
+	_channels[i].id = id;
+	_channels[i].vol = vol;
+	_channels[i].pan = pan;
+	_channels[i].ptr = (byte *)data;
+	_channels[i].freq = rate;
+	_channels[i].input = makeLinearInputStream(SoundMixer::FLAG_AUTOFREE | (loopStart != loopEnd ? SoundMixer::FLAG_LOOP : 0), (byte *)data, size, loopStart, loopEnd - loopStart);
+	_channels[i].converter = makeRateConverter(rate, _mixer->getOutputRate(), false, false);
+}
+
+void Player_MOD::stopChannel(int id) {
+	if (id == 0)
+		error("player_mod - attempted to stop channel id 0");
+	for (int i = 0; i < MOD_MAXCHANS; i++) {
+		if (_channels[i].id == id) {
+			delete _channels[i].ptr;
+			_channels[i].ptr = NULL;
+			delete _channels[i].converter;
+			_channels[i].converter = NULL;
+			delete _channels[i].input;
+			_channels[i].input = NULL;
+			_channels[i].id = 0;
+			_channels[i].vol = 0;
+			_channels[i].freq = 0;
+		}
+	}
+}
+void Player_MOD::setChannelVol(int id, uint8 vol) {
+	if (id == 0)
+		error("player_mod - attempted to set volume for channel id 0");
+	for (int i = 0; i < MOD_MAXCHANS; i++) {
+		if (_channels[i].id == id) {
+			_channels[i].vol = vol;
+			break;
+		}
+	}
+}
+
+void Player_MOD::setChannelPan(int id, int8 pan) {
+	if (id == 0)
+		error("player_mod - attempted to set pan for channel id 0");
+	for (int i = 0; i < MOD_MAXCHANS; i++) {
+		if (_channels[i].id == id) {
+			_channels[i].pan = pan;
+			break;
+		}
+	}
+}
+
+void Player_MOD::setChannelFreq(int id, int freq) {
+	if (id == 0)
+		error("player_mod - attempted to set frequency for channel id 0");
+	for (int i = 0; i < MOD_MAXCHANS; i++) {
+		if (_channels[i].id == id) {
+			_channels[i].freq = freq;
+			delete _channels[i].converter;
+			_channels[i].converter = makeRateConverter(freq, _mixer->getOutputRate(), false, false);
+			break;
+		}
+	}
+}
+
+void Player_MOD::premix_proc(void *param, int16 *buf, uint len) {
+	((Player_MOD *) param)->do_mix(buf, len);
+}
+
+void Player_MOD::do_mix (int16 *data, uint len) {
+	int i;
+	int dpos = 0;
+	uint dlen = 0;
+	memset(data, 0, 2 * len * sizeof(int16));
+	while (len) {
+		if (_playproc) {
+			dlen = _mixamt - _mixpos;
+			if (!_mixpos)
+				_playproc(_playparam);
+			if (dlen <= len) {
+				_mixpos = 0;
+				len -= dlen;
+			} else {
+				_mixpos = _mixamt - len;
+				dlen = len;
+				len = 0;
+			}
+		} else {
+			dlen = len;
+			len = 0;
+		}
+		for (i = 0; i < MOD_MAXCHANS; i++)
+			if (_channels[i].id) {
+				st_volume_t vol_l = (127 - _channels[i].pan) * _channels[i].vol / 127;
+				st_volume_t vol_r = (127 + _channels[i].pan) * _channels[i].vol / 127;
+				_channels[i].converter->flow(*_channels[i].input, &data[dpos*2], dlen, vol_l, vol_r);
+			}
+		dpos += dlen;
+	}
+}