[Scummvm-git-logs] scummvm master -> 0b8d7cf0f45cf8193fc1f53c65359d84693d3616

[athrxx]

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Summary:
0b8d7cf0f4 SCUMM: (IMS) - fix transpose clipping boundaries


Commit: 0b8d7cf0f45cf8193fc1f53c65359d84693d3616
    https://github.com/scummvm/scummvm/commit/0b8d7cf0f45cf8193fc1f53c65359d84693d3616
Author: athrxx (athrxx at scummvm.org)
Date: 2022-09-08T20:49:42+02:00

Commit Message:
SCUMM: (IMS) - fix transpose clipping boundaries

These are a bit different between DOTT and the earlier
games.

Changed paths:
    engines/scumm/imuse/imuse.cpp
    engines/scumm/imuse/imuse_internal.h
    engines/scumm/imuse/imuse_part.cpp
    engines/scumm/imuse/imuse_player.cpp
    engines/scumm/imuse/sysex_scumm.cpp


diff --git a/engines/scumm/imuse/imuse.cpp b/engines/scumm/imuse/imuse.cpp
index efae39612a8..dae413e4906 100644
--- a/engines/scumm/imuse/imuse.cpp
+++ b/engines/scumm/imuse/imuse.cpp
@@ -513,6 +513,7 @@ uint32 IMuseInternal::property(int prop, uint32 value) {
 
 	case IMuse::PROP_GAME_ID:
 		_game_id = value;
+		_version = (_game_id == GID_SAMNMAX) ? 2 : (_game_id == GID_TENTACLE ? 1 : 0);
 		break;
 
 	case IMuse::PROP_PC_SPEAKER:
diff --git a/engines/scumm/imuse/imuse_internal.h b/engines/scumm/imuse/imuse_internal.h
index 462e5a5f30d..2f0135785b1 100644
--- a/engines/scumm/imuse/imuse_internal.h
+++ b/engines/scumm/imuse/imuse_internal.h
@@ -415,6 +415,7 @@ protected:
 	TimerCallbackInfo _timer_info_native;
 
 	uint32 _game_id;
+	int _version; // V0: MI2 + INDY4, V1: DOTT, V2: SAM
 
 	// Plug-in SysEx handling. Right now this only supports one
 	// custom SysEx handler for the hardcoded IMUSE_SYSEX_ID
diff --git a/engines/scumm/imuse/imuse_part.cpp b/engines/scumm/imuse/imuse_part.cpp
index 04a8ec89b74..1bdc0c474e8 100644
--- a/engines/scumm/imuse/imuse_part.cpp
+++ b/engines/scumm/imuse/imuse_part.cpp
@@ -148,20 +148,16 @@ void Part::set_pan(int8 pan) {
 
 void Part::set_transpose(int8 transpose) {
 	_transpose = transpose;
-
-	if (_se->_isAmiga) {
-		// The Amiga version does a check like this. While this is probably a bug (a signed int8 can never be 128),
-		// the playback depends on this being implemented exactly like in the original driver. I found this bug with
-		// the WinUAE debugger. I don't know whether this is an Amiga only thing...
-		_transpose_eff = /*(_transpose == 128) ? 0 : */transpose_clamp(_transpose + _player->getTranspose(), -12, 12);
+	// MI2 and INDY4 use bounds of -24/24, DOTT uses -12/12. SAMNMAX doesn't seem to do this clipping any more.
+	int lim = (_se->_version == 1) ? 12 : 24;
+	// The Amiga version has a signed/unsigned bug which makes the check for _transpose == -128 impossible. It actually checks for
+	// a value of 128 with a signed int8 (a signed int8 can never be 128). The playback depends on this being implemented exactly
+	// like in the original driver. I found this bug with the WinUAE debugger. The DOS versions do not have that bug.
+	_transpose_eff = (_se->_version == 0 && !_se->_isAmiga && _transpose == -128) ? 0 : transpose_clamp(_transpose + _player->getTranspose(), -lim, lim);
+	if (_player->isAdLibOrFMTowns() || _se->_isAmiga)
 		sendTranspose();
-	} else {
-		_transpose_eff = (_transpose == -128) ? 0 : transpose_clamp(_transpose + _player->getTranspose(), -24, 24);
-		if (_player->isAdLibOrFMTowns())
-			sendTranspose();
-		else
-			sendPitchBend();
-	}
+	else
+		sendPitchBend();
 }
 
 void Part::sustain(bool value) {
diff --git a/engines/scumm/imuse/imuse_player.cpp b/engines/scumm/imuse/imuse_player.cpp
index cdd1633a96b..067f8f5a1e7 100644
--- a/engines/scumm/imuse/imuse_player.cpp
+++ b/engines/scumm/imuse/imuse_player.cpp
@@ -573,7 +573,7 @@ int Player::setTranspose(byte relative, int b) {
 	if (b > 24 || b < -24 || relative > 1)
 		return -1;
 	if (relative)
-		b = transpose_clamp(_transpose + b, -24, 24);
+		b = transpose_clamp(_transpose + b, -7, 7);	
 
 	_transpose = b;
 
diff --git a/engines/scumm/imuse/sysex_scumm.cpp b/engines/scumm/imuse/sysex_scumm.cpp
index b94bddda058..bfc72a8ee34 100644
--- a/engines/scumm/imuse/sysex_scumm.cpp
+++ b/engines/scumm/imuse/sysex_scumm.cpp
@@ -72,7 +72,9 @@ void sysexHandler_Scumm(Player *player, const byte *msg, uint16 len) {
 			part->volume(buf[3]);
 			part->set_pan(buf[4]);
 			part->_percussion = player->_supportsPercussion ? ((buf[5] & 0x80) > 0) : false;
-			part->set_transpose(buf[5]);
+			// Basically the same thing that happens inside Part::set_transpose() (including the Amiga signed/unsigned bug),
+			// but with a different clipping range for MI2 and INDY4. For DOTT it its the exact same thing.
+			part->set_transpose((buf[5] != 0x80 || se->_isAmiga) ? transpose_clamp((int8)buf[5] + player->getTranspose(), -12, 12) : -128);
 			part->set_detune(buf[6]);
 			part->pitchBendFactor(buf[7]);
 			if (part->_percussion) {