SCI32: Add palette code for late SCI2.1mid+ games

Sometime during SCI2.1mid, the palette manager was changed to
save and restore the source palette, and to add in-game gamma
correction. Previously, only the vary start and target palettes
were saved, and gamma correction was only configurable in SSCI by
editing RESOURCE.CFG.

7 files changed, 280 insertions, 28 deletions

diff --git a/engines/sci/engine/features.h b/engines/sci/engine/features.h
index 044111a43e..6d9460d61e 100644
--- a/engines/sci/engine/features.h
+++ b/engines/sci/engine/features.h
@@ -124,10 +124,20 @@ public:
 			gid != GID_MOTHERGOOSEHIRES;
 	}
 
-	inline bool hasNewPaletteCode() const {
+	inline bool hasMidPaletteCode() const {
 		return getSciVersion() >= SCI_VERSION_2_1_MIDDLE || g_sci->getGameId() == GID_KQ7;
 	}
 
+	inline bool hasLatePaletteCode() const {
+		return getSciVersion() > SCI_VERSION_2_1_MIDDLE ||
+			g_sci->getGameId() == GID_GK2 ||
+			g_sci->getGameId() == GID_PQSWAT ||
+			// Guessing that Shivers has the late palette code because it has a
+			// brightness slider
+			g_sci->getGameId() == GID_SHIVERS ||
+			g_sci->getGameId() == GID_TORIN;
+	}
+
 	inline bool VMDOpenStopsAudio() const {
 		// Of the games that use VMDs:
 		// Yes: Phant1, Shivers, Torin
diff --git a/engines/sci/engine/kgraphics32.cpp b/engines/sci/engine/kgraphics32.cpp
index 07a63c73d9..ae84e6b8a5 100644
--- a/engines/sci/engine/kgraphics32.cpp
+++ b/engines/sci/engine/kgraphics32.cpp
@@ -934,16 +934,8 @@ reg_t kPaletteFindColor32(EngineState *s, int argc, reg_t *argv) {
 	return make_reg(0, g_sci->_gfxPalette32->matchColor(r, g, b));
 }
 
-/*
- * Used starting in Shivers 1. SCI3 contains 6 gamma look-up tables, with the
- * first table (gamma = 0) being the default one.
- */
 reg_t kPaletteSetGamma(EngineState *s, int argc, reg_t *argv) {
-	const uint8 gamma = argv[0].toUint16();
-	assert(gamma <= 6);
-
-	warning("TODO: kPaletteSetGamma(%d)", gamma);
-
+	g_sci->_gfxPalette32->setGamma(argv[0].toSint16());
 	return s->r_acc;
 }
 
@@ -962,7 +954,7 @@ reg_t kPalVarySetVary(EngineState *s, int argc, reg_t *argv) {
 	int16 fromColor;
 	int16 toColor;
 
-	if (g_sci->_features->hasNewPaletteCode() && argc > 4) {
+	if (g_sci->_features->hasMidPaletteCode() && argc > 4) {
 		fromColor = argv[3].toSint16();
 		toColor = argv[4].toSint16();
 	} else {
diff --git a/engines/sci/engine/savegame.cpp b/engines/sci/engine/savegame.cpp
index e6a6af7d17..04715d6034 100644
--- a/engines/sci/engine/savegame.cpp
+++ b/engines/sci/engine/savegame.cpp
@@ -865,10 +865,18 @@ void GfxPalette32::saveLoadWithSerializer(Common::Serializer &s) {
 		s.syncAsByte(_cycleMap[i]);
 	}
 
+	if (g_sci->_features->hasLatePaletteCode() && s.getVersion() >= 41) {
+		s.syncAsSint16LE(_gammaLevel);
+		saveLoadPalette32(s, &_sourcePalette);
+		++_version;
+		_needsUpdate = true;
+		_gammaChanged = true;
+	}
+
 	saveLoadOptionalPalette32(s, &_varyTargetPalette);
 	saveLoadOptionalPalette32(s, &_varyStartPalette);
-	// NOTE: _sourcePalette and _nextPalette are not saved
-	// by SCI engine
+
+	// _nextPalette is not saved by SSCI
 
 	for (int i = 0; i < ARRAYSIZE(_cyclers); ++i) {
 		PalCycler *cycler = nullptr;
diff --git a/engines/sci/engine/savegame.h b/engines/sci/engine/savegame.h
index 274df25dc2..72982469e0 100644
--- a/engines/sci/engine/savegame.h
+++ b/engines/sci/engine/savegame.h
@@ -37,6 +37,7 @@ struct EngineState;
  *
  * Version - new/changed feature
  * =============================
+ *      41 - palette support for newer SCI2.1 games
  *      40 - always store palvary variables
  *      39 - Accurate SCI32 arrays/strings, score metadata, avatar metadata
  *      38 - SCI32 cursor
@@ -65,7 +66,7 @@ struct EngineState;
  */
 
 enum {
-	CURRENT_SAVEGAME_VERSION = 40,
+	CURRENT_SAVEGAME_VERSION = 41,
 	MINIMUM_SAVEGAME_VERSION = 14
 };
 
diff --git a/engines/sci/graphics/palette32.cpp b/engines/sci/graphics/palette32.cpp
index febb6820d0..d13ae2c097 100644
--- a/engines/sci/graphics/palette32.cpp
+++ b/engines/sci/graphics/palette32.cpp
@@ -122,9 +122,212 @@ const Palette HunkPalette::toPalette() const {
 }
 
 #pragma mark -
+#pragma mark Gamma correction tables
+
+static const uint8 gammaTables[GfxPalette32::numGammaTables][256] = {
+	{ 0, 2, 3, 5, 6, 7, 9, 10,
+	11, 13, 14, 15, 16, 18, 19, 20,
+	21, 22, 23, 25, 26, 27, 28, 29,
+	30, 32, 33, 34, 35, 36, 37, 38,
+	39, 41, 42, 43, 44, 45, 46, 47,
+	48, 49, 50, 51, 52, 54, 55, 56,
+	57, 58, 59, 60, 61, 62, 63, 64,
+	65, 66, 67, 68, 69, 70, 71, 72,
+	74, 75, 76, 77, 78, 79, 80, 81,
+	82, 83, 84, 85, 86, 87, 88, 89,
+	90, 91, 92, 93, 94, 95, 96, 97,
+	98, 99, 100, 101, 102, 103, 104, 105,
+	106, 107, 108, 109, 110, 111, 112, 113,
+	114, 115, 116, 117, 118, 119, 120, 121,
+	122, 123, 124, 125, 126, 127, 128, 128,
+	129, 130, 131, 132, 133, 134, 135, 136,
+	137, 138, 139, 140, 141, 142, 143, 144,
+	145, 146, 147, 148, 149, 150, 151, 152,
+	153, 153, 154, 155, 156, 157, 158, 159,
+	160, 161, 162, 163, 164, 165, 166, 167,
+	168, 169, 170, 171, 171, 172, 173, 174,
+	175, 176, 177, 178, 179, 180, 181, 182,
+	183, 184, 185, 186, 186, 187, 188, 189,
+	190, 191, 192, 193, 194, 195, 196, 197,
+	198, 199, 199, 200, 201, 202, 203, 204,
+	205, 206, 207, 208, 209, 210, 211, 211,
+	212, 213, 214, 215, 216, 217, 218, 219,
+	220, 221, 222, 222, 223, 224, 225, 226,
+	227, 228, 229, 230, 231, 232, 232, 233,
+	234, 235, 236, 237, 238, 239, 240, 241,
+	242, 242, 243, 244, 245, 246, 247, 248,
+	249, 250, 251, 251, 252, 253, 254, 255 },
+
+	{ 0, 3, 5, 6, 8, 10, 11, 13,
+	14, 16, 17, 19, 20, 22, 23, 24,
+	26, 27, 28, 30, 31, 32, 33, 35,
+	36, 37, 38, 40, 41, 42, 43, 44,
+	46, 47, 48, 49, 50, 51, 53, 54,
+	55, 56, 57, 58, 59, 60, 62, 63,
+	64, 65, 66, 67, 68, 69, 70, 71,
+	73, 74, 75, 76, 77, 78, 79, 80,
+	81, 82, 83, 84, 85, 86, 87, 88,
+	89, 90, 91, 92, 93, 94, 95, 96,
+	97, 99, 100, 101, 102, 103, 104, 105,
+	106, 107, 108, 108, 109, 110, 111, 112,
+	113, 114, 115, 116, 117, 118, 119, 120,
+	121, 122, 123, 124, 125, 126, 127, 128,
+	129, 130, 131, 132, 133, 134, 135, 136,
+	136, 137, 138, 139, 140, 141, 142, 143,
+	144, 145, 146, 147, 148, 149, 150, 151,
+	151, 152, 153, 154, 155, 156, 157, 158,
+	159, 160, 161, 162, 162, 163, 164, 165,
+	166, 167, 168, 169, 170, 171, 172, 172,
+	173, 174, 175, 176, 177, 178, 179, 180,
+	180, 181, 182, 183, 184, 185, 186, 187,
+	188, 188, 189, 190, 191, 192, 193, 194,
+	195, 196, 196, 197, 198, 199, 200, 201,
+	202, 202, 203, 204, 205, 206, 207, 208,
+	209, 209, 210, 211, 212, 213, 214, 215,
+	215, 216, 217, 218, 219, 220, 221, 221,
+	222, 223, 224, 225, 226, 227, 227, 228,
+	229, 230, 231, 232, 233, 233, 234, 235,
+	236, 237, 238, 238, 239, 240, 241, 242,
+	243, 243, 244, 245, 246, 247, 248, 249,
+	249, 250, 251, 252, 253, 254, 254, 255 },
+
+	{ 0, 4, 6, 8, 10, 12, 14, 16,
+	18, 19, 21, 23, 24, 26, 27, 29,
+	30, 32, 33, 35, 36, 37, 39, 40,
+	41, 43, 44, 45, 47, 48, 49, 50,
+	52, 53, 54, 55, 57, 58, 59, 60,
+	61, 62, 64, 65, 66, 67, 68, 69,
+	71, 72, 73, 74, 75, 76, 77, 78,
+	79, 81, 82, 83, 84, 85, 86, 87,
+	88, 89, 90, 91, 92, 93, 94, 95,
+	96, 97, 98, 99, 100, 102, 103, 104,
+	105, 106, 107, 108, 109, 110, 111, 112,
+	112, 113, 114, 115, 116, 117, 118, 119,
+	120, 121, 122, 123, 124, 125, 126, 127,
+	128, 129, 130, 131, 132, 133, 134, 135,
+	135, 136, 137, 138, 139, 140, 141, 142,
+	143, 144, 145, 146, 146, 147, 148, 149,
+	150, 151, 152, 153, 154, 155, 156, 156,
+	157, 158, 159, 160, 161, 162, 163, 163,
+	164, 165, 166, 167, 168, 169, 170, 170,
+	171, 172, 173, 174, 175, 176, 177, 177,
+	178, 179, 180, 181, 182, 183, 183, 184,
+	185, 186, 187, 188, 188, 189, 190, 191,
+	192, 193, 194, 194, 195, 196, 197, 198,
+	199, 199, 200, 201, 202, 203, 203, 204,
+	205, 206, 207, 208, 208, 209, 210, 211,
+	212, 212, 213, 214, 215, 216, 217, 217,
+	218, 219, 220, 221, 221, 222, 223, 224,
+	225, 225, 226, 227, 228, 229, 229, 230,
+	231, 232, 233, 233, 234, 235, 236, 237,
+	237, 238, 239, 240, 240, 241, 242, 243,
+	244, 244, 245, 246, 247, 247, 248, 249,
+	250, 251, 251, 252, 253, 254, 254, 255 },
+
+	{ 0, 5, 9, 11, 14, 16, 19, 21,
+	23, 25, 26, 28, 30, 32, 33, 35,
+	37, 38, 40, 41, 43, 44, 46, 47,
+	49, 50, 52, 53, 54, 56, 57, 58,
+	60, 61, 62, 64, 65, 66, 67, 69,
+	70, 71, 72, 73, 75, 76, 77, 78,
+	79, 80, 82, 83, 84, 85, 86, 87,
+	88, 89, 91, 92, 93, 94, 95, 96,
+	97, 98, 99, 100, 101, 102, 103, 104,
+	105, 106, 107, 108, 109, 110, 111, 112,
+	113, 114, 115, 116, 117, 118, 119, 120,
+	121, 122, 123, 124, 125, 126, 127, 128,
+	129, 130, 131, 132, 133, 134, 134, 135,
+	136, 137, 138, 139, 140, 141, 142, 143,
+	144, 144, 145, 146, 147, 148, 149, 150,
+	151, 152, 152, 153, 154, 155, 156, 157,
+	158, 158, 159, 160, 161, 162, 163, 164,
+	164, 165, 166, 167, 168, 169, 169, 170,
+	171, 172, 173, 174, 174, 175, 176, 177,
+	178, 179, 179, 180, 181, 182, 183, 183,
+	184, 185, 186, 187, 187, 188, 189, 190,
+	191, 191, 192, 193, 194, 195, 195, 196,
+	197, 198, 199, 199, 200, 201, 202, 202,
+	203, 204, 205, 205, 206, 207, 208, 209,
+	209, 210, 211, 212, 212, 213, 214, 215,
+	215, 216, 217, 218, 218, 219, 220, 221,
+	221, 222, 223, 224, 224, 225, 226, 227,
+	227, 228, 229, 230, 230, 231, 232, 232,
+	233, 234, 235, 235, 236, 237, 238, 238,
+	239, 240, 240, 241, 242, 243, 243, 244,
+	245, 245, 246, 247, 248, 248, 249, 250,
+	250, 251, 252, 252, 253, 254, 255, 255 },
+
+	{ 0, 9, 14, 18, 21, 24, 27, 29,
+	32, 34, 37, 39, 41, 43, 45, 47,
+	48, 50, 52, 54, 55, 57, 59, 60,
+	62, 63, 65, 66, 68, 69, 71, 72,
+	73, 75, 76, 77, 79, 80, 81, 83,
+	84, 85, 86, 88, 89, 90, 91, 92,
+	94, 95, 96, 97, 98, 99, 100, 102,
+	103, 104, 105, 106, 107, 108, 109, 110,
+	111, 112, 113, 114, 115, 116, 117, 118,
+	119, 120, 121, 122, 123, 124, 125, 126,
+	127, 128, 129, 130, 131, 132, 133, 134,
+	135, 136, 137, 137, 138, 139, 140, 141,
+	142, 143, 144, 145, 145, 146, 147, 148,
+	149, 150, 151, 151, 152, 153, 154, 155,
+	156, 156, 157, 158, 159, 160, 161, 161,
+	162, 163, 164, 165, 165, 166, 167, 168,
+	169, 169, 170, 171, 172, 173, 173, 174,
+	175, 176, 176, 177, 178, 179, 179, 180,
+	181, 182, 182, 183, 184, 185, 185, 186,
+	187, 188, 188, 189, 190, 191, 191, 192,
+	193, 194, 194, 195, 196, 196, 197, 198,
+	199, 199, 200, 201, 201, 202, 203, 203,
+	204, 205, 206, 206, 207, 208, 208, 209,
+	210, 210, 211, 212, 212, 213, 214, 214,
+	215, 216, 216, 217, 218, 218, 219, 220,
+	220, 221, 222, 222, 223, 224, 224, 225,
+	226, 226, 227, 228, 228, 229, 230, 230,
+	231, 231, 232, 233, 233, 234, 235, 235,
+	236, 237, 237, 238, 238, 239, 240, 240,
+	241, 242, 242, 243, 243, 244, 245, 245,
+	246, 247, 247, 248, 248, 249, 250, 250,
+	251, 251, 252, 253, 253, 254, 254, 255 },
+
+	{ 0, 16, 23, 28, 32, 36, 39, 42,
+	45, 48, 50, 53, 55, 58, 60, 62,
+	64, 66, 68, 70, 71, 73, 75, 77,
+	78, 80, 81, 83, 84, 86, 87, 89,
+	90, 92, 93, 94, 96, 97, 98, 100,
+	101, 102, 103, 105, 106, 107, 108, 109,
+	111, 112, 113, 114, 115, 116, 117, 118,
+	119, 121, 122, 123, 124, 125, 126, 127,
+	128, 129, 130, 131, 132, 133, 134, 135,
+	135, 136, 137, 138, 139, 140, 141, 142,
+	143, 144, 145, 145, 146, 147, 148, 149,
+	150, 151, 151, 152, 153, 154, 155, 156,
+	156, 157, 158, 159, 160, 160, 161, 162,
+	163, 164, 164, 165, 166, 167, 167, 168,
+	169, 170, 170, 171, 172, 173, 173, 174,
+	175, 176, 176, 177, 178, 179, 179, 180,
+	181, 181, 182, 183, 183, 184, 185, 186,
+	186, 187, 188, 188, 189, 190, 190, 191,
+	192, 192, 193, 194, 194, 195, 196, 196,
+	197, 198, 198, 199, 199, 200, 201, 201,
+	202, 203, 203, 204, 204, 205, 206, 206,
+	207, 208, 208, 209, 209, 210, 211, 211,
+	212, 212, 213, 214, 214, 215, 215, 216,
+	217, 217, 218, 218, 219, 220, 220, 221,
+	221, 222, 222, 223, 224, 224, 225, 225,
+	226, 226, 227, 228, 228, 229, 229, 230,
+	230, 231, 231, 232, 233, 233, 234, 234,
+	235, 235, 236, 236, 237, 237, 238, 238,
+	239, 240, 240, 241, 241, 242, 242, 243,
+	243, 244, 244, 245, 245, 246, 246, 247,
+	247, 248, 248, 249, 249, 250, 250, 251,
+	251, 252, 252, 253, 253, 254, 254, 255 }
+};
+
+#pragma mark -
 #pragma mark GfxPalette32
 
-GfxPalette32::GfxPalette32(ResourceManager *resMan)
+	GfxPalette32::GfxPalette32(ResourceManager *resMan)
 	: _resMan(resMan),
 
 	// Palette versioning
@@ -147,7 +350,12 @@ GfxPalette32::GfxPalette32(ResourceManager *resMan)
 
 	// Palette cycling
 	_cyclers(),
-	_cycleMap() {
+	_cycleMap(),
+
+	// Gamma correction
+	_gammaLevel(-1),
+	_gammaChanged(false) {
+
 	_varyPercent = _varyTargetPercent;
 	for (int i = 0, len = ARRAYSIZE(_fadeTable); i < len; ++i) {
 		_fadeTable[i] = 100;
@@ -248,7 +456,7 @@ void GfxPalette32::updateFFrame() {
 }
 
 void GfxPalette32::updateHardware(const bool updateScreen) {
-	if (_currentPalette == _nextPalette) {
+	if (_currentPalette == _nextPalette && !_gammaChanged) {
 		return;
 	}
 
@@ -257,21 +465,21 @@ void GfxPalette32::updateHardware(const bool updateScreen) {
 	for (int i = 0; i < ARRAYSIZE(_currentPalette.colors) - 1; ++i) {
 		_currentPalette.colors[i] = _nextPalette.colors[i];
 
-		// NOTE: If the brightness option in the user configuration file is set,
-		// SCI engine adjusts palette brightnesses here by mapping RGB values to
-		// values in some hard-coded brightness tables. There is no reason on
-		// modern hardware to implement this, unless it is discovered that some
-		// game uses a non-standard brightness setting by default
-
 		// All color entries MUST be copied, not just "used" entries, otherwise
 		// uninitialised memory from bpal makes its way into the system palette.
 		// This would not normally be a problem, except that games sometimes use
 		// unused palette entries. e.g. Phant1 title screen references palette
 		// entries outside its own palette, so will render garbage colors where
 		// the game expects them to be black
-		bpal[i * 3    ] = _currentPalette.colors[i].r;
-		bpal[i * 3 + 1] = _currentPalette.colors[i].g;
-		bpal[i * 3 + 2] = _currentPalette.colors[i].b;
+		if (_gammaLevel == -1) {
+			bpal[i * 3    ] = _currentPalette.colors[i].r;
+			bpal[i * 3 + 1] = _currentPalette.colors[i].g;
+			bpal[i * 3 + 2] = _currentPalette.colors[i].b;
+		} else {
+			bpal[i * 3    ] = gammaTables[_gammaLevel][_currentPalette.colors[i].r];
+			bpal[i * 3 + 1] = gammaTables[_gammaLevel][_currentPalette.colors[i].g];
+			bpal[i * 3 + 2] = gammaTables[_gammaLevel][_currentPalette.colors[i].b];
+		}
 	}
 
 	if (g_sci->getPlatform() != Common::kPlatformMacintosh) {
@@ -289,6 +497,8 @@ void GfxPalette32::updateHardware(const bool updateScreen) {
 	if (updateScreen) {
 		g_system->updateScreen();
 	}
+
+	_gammaChanged = false;
 }
 
 Palette GfxPalette32::getPaletteFromResource(const GuiResourceId resourceId) const {
@@ -560,7 +770,7 @@ void GfxPalette32::setCycle(const uint8 fromColor, const uint8 toColor, const in
 	}
 
 	uint16 numColorsToCycle = toColor - fromColor;
-	if (g_sci->_features->hasNewPaletteCode()) {
+	if (g_sci->_features->hasMidPaletteCode()) {
 		numColorsToCycle += 1;
 	}
 	cycler->fromColor = fromColor;
diff --git a/engines/sci/graphics/palette32.h b/engines/sci/graphics/palette32.h
index d6d7d0dbd1..267ec39d96 100644
--- a/engines/sci/graphics/palette32.h
+++ b/engines/sci/graphics/palette32.h
@@ -572,6 +572,37 @@ private:
 	 * The intensity levels of each palette entry, in percent. Defaults to 100.
 	 */
 	uint16 _fadeTable[256];
+
+#pragma mark -
+#pragma mark Gamma correction
+public:
+	enum {
+		/**
+		 * The number of available gamma corrections.
+		 */
+		numGammaTables = 6
+	};
+
+	/**
+	 * Sets the gamma correction level, from 0 (off) to `numGammaTables`,
+	 * inclusive.
+	 */
+	void setGamma(const int16 level) {
+		_gammaLevel = CLIP<int16>(level, 0, numGammaTables) - 1;
+		_gammaChanged = true;
+	}
+
+private:
+	/**
+	 * The current gamma correction level. -1 means no correction.
+	 */
+	int8 _gammaLevel;
+
+	/**
+	 * Whether the gamma correction has changed since the last call to update
+	 * the hardware palette.
+	 */
+	bool _gammaChanged;
 };
 
 } // End of namespace Sci
diff --git a/engines/sci/graphics/remap32.cpp b/engines/sci/graphics/remap32.cpp
index 768594f974..9b5ffcd2f7 100644
--- a/engines/sci/graphics/remap32.cpp
+++ b/engines/sci/graphics/remap32.cpp
@@ -301,7 +301,7 @@ GfxRemap32::GfxRemap32() :
 	// match the highest possible value of `_remapStartColor`
 	assert(_remapStartColor == 236);
 
-	if (g_sci->_features->hasNewPaletteCode()) {
+	if (g_sci->_features->hasMidPaletteCode()) {
 		_remaps.resize(9);
 	} else {
 		_remaps.resize(19);