SCI32: Fix broken Remap implementation

Remap would crash SCI2.1early games with 19 remap slots, and
did not actually work in most cases in SCI2.1mid+ games.

1. Avoid accidental corruption of values from the VM that may be
   valid when signed or larger than 8 bits
2. Fix bad `matchColor` function.
3. Remove unnecessary initialisation of SingleRemaps
4. Update architecture to more closely mirror how SSCI worked
5. Split large `apply` function into smaller units
6. Fix buffer overrun when loading a SCI2.1early game with remap
7. Warn instead of crashing with an error on invalid input (to
    match SSCI more closely)
8. Add save/load function

1 files changed, 29 insertions, 1 deletions

diff --git a/engines/sci/engine/savegame.cpp b/engines/sci/engine/savegame.cpp
index 302f046458..0972aec4a4 100644
--- a/engines/sci/engine/savegame.cpp
+++ b/engines/sci/engine/savegame.cpp
@@ -48,8 +48,9 @@
 #include "sci/sound/music.h"
 
 #ifdef ENABLE_SCI32
-#include "sci/graphics/palette32.h"
 #include "sci/graphics/frameout.h"
+#include "sci/graphics/palette32.h"
+#include "sci/graphics/remap32.h"
 #endif
 
 namespace Sci {
@@ -807,6 +808,33 @@ void GfxPalette32::saveLoadWithSerializer(Common::Serializer &s) {
 		}
 	}
 }
+
+void GfxRemap32::saveLoadWithSerializer(Common::Serializer &s) {
+	if (s.getVersion() < 35) {
+		return;
+	}
+
+	s.syncAsByte(_numActiveRemaps);
+	s.syncAsByte(_blockedRangeStart);
+	s.syncAsSint16LE(_blockedRangeCount);
+
+	for (uint i = 0; i < _remaps.size(); ++i) {
+		SingleRemap &singleRemap = _remaps[i];
+		s.syncAsByte(singleRemap._type);
+		if (s.isLoading() && singleRemap._type != kRemapNone) {
+			singleRemap.reset();
+		}
+		s.syncAsByte(singleRemap._from);
+		s.syncAsByte(singleRemap._to);
+		s.syncAsByte(singleRemap._delta);
+		s.syncAsByte(singleRemap._percent);
+		s.syncAsByte(singleRemap._gray);
+	}
+
+	if (s.isLoading()) {
+		_needsUpdate = true;
+	}
+}
 #endif
 
 void GfxPorts::saveLoadWithSerializer(Common::Serializer &s) {