From ac23a92e306dc892e062006f604a816dff0d940c Mon Sep 17 00:00:00 2001
From: athrxx <athrxx@scummvm.org>
Date: Sun, 14 Apr 2024 15:06:50 +0200
Subject: [PATCH] SCUMM: (MI1/Amiga/Hercules/CGA) - fix bug 4535 (Voodoo lady
 palette glitches)

MI1 Amiga does set up the shadow palette at the beginning
and also updates it from o5_roomOps()[SO_ROOM_PALETTE].
But it never actually applies any use of the shadow palette when
doing screen palette adjustments. I've also confirmed that the
shadow is ignored in DOS CGA and Hercules mode.
---
 engines/scumm/palette.cpp | 6 +-----
 engines/scumm/scumm.cpp   | 9 +++++++++
 engines/scumm/scumm.h     | 1 +
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/engines/scumm/palette.cpp b/engines/scumm/palette.cpp
index 5ea8bd00812..0f7e1bd028c 100644
--- a/engines/scumm/palette.cpp
+++ b/engines/scumm/palette.cpp
@@ -1630,11 +1630,7 @@ void ScummEngine::updatePalette() {
 		for (i = _palDirtyMin; i <= _palDirtyMax; i++) {
 			byte *data;
 
-			// In b/w Mac rendering mode, the shadow palette is
-			// handled by the renderer itself. See comment in
-			// mac_drawStripToScreen().
-
-			if (_game.features & GF_SMALL_HEADER && _game.version > 2 && _renderMode != Common::kRenderMacintoshBW)
+			if (_shadowPalRemap)
 				data = _currentPalette + _shadowPalette[i] * 3;
 			else
 				data = _currentPalette + i * 3;
diff --git a/engines/scumm/scumm.cpp b/engines/scumm/scumm.cpp
index 5d2ce11b487..5cfb5b72310 100644
--- a/engines/scumm/scumm.cpp
+++ b/engines/scumm/scumm.cpp
@@ -520,6 +520,10 @@ ScummEngine_v4::ScummEngine_v4(OSystem *syst, const DetectorResult &dr)
 	: ScummEngine_v5(syst, dr) {
 	_resourceHeaderSize = 6;
 	_game.features |= GF_SMALL_HEADER;
+	// MI1 Amiga ignores the shadow palette (bug #4535 - Voodoo lady palette glitches).
+	// I haven't checked other Amiga targets, so I'm limiting it to MI1.
+	_shadowPalRemap = (!(_game.platform == Common::kPlatformAmiga && _game.id == GID_MONKEY_VGA) &&
+		_renderMode != Common::kRenderCGA && _renderMode != Common::kRenderHercA && _renderMode != Common::kRenderHercG);
 }
 
 ScummEngine_v3::ScummEngine_v3(OSystem *syst, const DetectorResult &dr)
@@ -527,6 +531,10 @@ ScummEngine_v3::ScummEngine_v3(OSystem *syst, const DetectorResult &dr)
 	// All v3 and older games only used 16 colors with exception of the GF_OLD256 games.
 	if (!(_game.features & GF_OLD256))
 		_game.features |= GF_16COLOR;
+	// In b/w Mac rendering mode, the shadow palette is handled by the renderer itself.
+	// See comment in mac_drawStripToScreen().
+	_shadowPalRemap = (_renderMode != Common::kRenderMacintoshBW &&
+		_renderMode != Common::kRenderCGA && _renderMode != Common::kRenderHercA && _renderMode != Common::kRenderHercG);
 }
 
 ScummEngine_v3old::ScummEngine_v3old(OSystem *syst, const DetectorResult &dr)
@@ -538,6 +546,7 @@ ScummEngine_v3old::ScummEngine_v3old(OSystem *syst, const DetectorResult &dr)
 ScummEngine_v2::ScummEngine_v2(OSystem *syst, const DetectorResult &dr)
 	: ScummEngine_v3old(syst, dr) {
 
+	_shadowPalRemap = false;
 	_inventoryOffset = 0;
 	_flashlight.xStrips = 6;
 	_flashlight.yStrips = 4;
diff --git a/engines/scumm/scumm.h b/engines/scumm/scumm.h
index 91e02d699bf..10ad5fdbc52 100644
--- a/engines/scumm/scumm.h
+++ b/engines/scumm/scumm.h
@@ -1521,6 +1521,7 @@ protected:
 	int _saveSound = 0;
 	bool _native_mt32 = false;
 	bool _copyProtection = false;
+	bool _shadowPalRemap = false;
 
 	// Indy4 Amiga specific
 	uint16 _amigaFirstUsedColor = 0;