1 files changed, 60 insertions, 31 deletions

diff --git a/engines/sci/graphics/palette.cpp b/engines/sci/graphics/palette.cpp
index d8d788b00a..59abef5550 100644
--- a/engines/sci/graphics/palette.cpp
+++ b/engines/sci/graphics/palette.cpp
@@ -8,12 +8,12 @@
  * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
@@ -65,14 +65,21 @@ GfxPalette::GfxPalette(ResourceManager *resMan, GfxScreen *screen)
 	// the real merging done in earlier games. If we use the copying over, we
 	// will get issues because some views have marked all colors as being used
 	// and those will overwrite the current palette in that case
-	if (getSciVersion() < SCI_VERSION_1_1)
+	if (getSciVersion() < SCI_VERSION_1_1) {
 		_useMerging = true;
-	else if (getSciVersion() == SCI_VERSION_1_1)
+		_use16bitColorMatch = true;
+	} else if (getSciVersion() == SCI_VERSION_1_1) {
 		// there are some games that use inbetween SCI1.1 interpreter, so we have
 		// to detect if the current game is merging or copying
 		_useMerging = _resMan->detectPaletteMergingSci11();
-	else	// SCI32
+		_use16bitColorMatch = _useMerging;
+		// Note: Laura Bow 2 floppy uses the new palette format and is detected
+		//        as 8 bit color matching because of that.
+	} else {
+	    // SCI32
 		_useMerging = false;
+		_use16bitColorMatch = false; // not verified that SCI32 uses 8-bit color matching
+	}
 
 	palVaryInit();
 
@@ -120,6 +127,10 @@ bool GfxPalette::isMerging() {
 	return _useMerging;
 }
 
+bool GfxPalette::isUsing16bitColorMatch() {
+	return _use16bitColorMatch;
+}
+
 // meant to get called only once during init of engine
 void GfxPalette::setDefault() {
 	if (_resMan->getViewType() == kViewEga)
@@ -464,8 +475,8 @@ bool GfxPalette::merge(Palette *newPalette, bool force, bool forceRealMerge) {
 
 		// check if exact color could be matched
 		res = matchColor(newPalette->colors[i].r, newPalette->colors[i].g, newPalette->colors[i].b);
-		if (res & 0x8000) { // exact match was found
-			newPalette->mapping[i] = res & 0xFF;
+		if (res & SCI_PALETTE_MATCH_PERFECT) { // exact match was found
+			newPalette->mapping[i] = res & SCI_PALETTE_MATCH_COLORMASK;
 			continue;
 		}
 
@@ -486,8 +497,8 @@ bool GfxPalette::merge(Palette *newPalette, bool force, bool forceRealMerge) {
 
 		// if still no luck - set an approximate color
 		if (j == 256) {
-			newPalette->mapping[i] = res & 0xFF;
-			_sysPalette.colors[res & 0xFF].used |= 0x10;
+			newPalette->mapping[i] = res & SCI_PALETTE_MATCH_COLORMASK;
+			_sysPalette.colors[res & SCI_PALETTE_MATCH_COLORMASK].used |= 0x10;
 		}
 	}
 
@@ -509,29 +520,47 @@ void GfxPalette::drewPicture(GuiResourceId pictureId) {
 	}
 }
 
-uint16 GfxPalette::matchColor(byte r, byte g, byte b) {
-	byte found = 0xFF;
-	int diff = 0x2FFFF, cdiff;
-	int16 dr,dg,db;
-
-	for (int i = 1; i < 255; i++) {
-		if ((!_sysPalette.colors[i].used))
-			continue;
-		dr = _sysPalette.colors[i].r - r;
-		dg = _sysPalette.colors[i].g - g;
-		db = _sysPalette.colors[i].b - b;
-//		minimum squares match
-		cdiff = (dr*dr) + (dg*dg) + (db*db);
-//		minimum sum match (Sierra's)
-//		cdiff = ABS(dr) + ABS(dg) + ABS(db);
-		if (cdiff < diff) {
-			if (cdiff == 0)
-				return i | 0x8000; // setting this flag to indicate exact match
-			found = i;
-			diff = cdiff;
+uint16 GfxPalette::matchColor(byte matchRed, byte matchGreen, byte matchBlue) {
+	int16 colorNr;
+	int16 differenceRed, differenceGreen, differenceBlue;
+	int16 differenceTotal = 0;
+	int16 bestDifference = 0x7FFF;
+	uint16 bestColorNr = 255;
+
+	if (_use16bitColorMatch) {
+		// used by SCI0 to SCI1, also by the first few SCI1.1 games
+		for (colorNr = 0; colorNr < 256; colorNr++) {
+			if ((!_sysPalette.colors[colorNr].used))
+				continue;
+			differenceRed = ABS(_sysPalette.colors[colorNr].r - matchRed);
+			differenceGreen = ABS(_sysPalette.colors[colorNr].g - matchGreen);
+			differenceBlue = ABS(_sysPalette.colors[colorNr].b - matchBlue);
+			differenceTotal = differenceRed + differenceGreen + differenceBlue;
+			if (differenceTotal <= bestDifference) {
+				bestDifference = differenceTotal;
+				bestColorNr = colorNr;
+			}
+		}
+	} else {
+		// SCI1.1, starting with QfG3 introduced a bug in the matching code
+		// we have to implement it as well, otherwise some colors will be "wrong" in comparison to the original interpreter
+		//  See Space Quest 5 bug #6455
+		for (colorNr = 0; colorNr < 256; colorNr++) {
+			if ((!_sysPalette.colors[colorNr].used))
+				continue;
+			differenceRed = (uint8)ABS<int8>(_sysPalette.colors[colorNr].r - matchRed);
+			differenceGreen = (uint8)ABS<int8>(_sysPalette.colors[colorNr].g - matchGreen);
+			differenceBlue = (uint8)ABS<int8>(_sysPalette.colors[colorNr].b - matchBlue);
+			differenceTotal = differenceRed + differenceGreen + differenceBlue;
+			if (differenceTotal <= bestDifference) {
+				bestDifference = differenceTotal;
+				bestColorNr = colorNr;
+			}
 		}
 	}
-	return found;
+	if (differenceTotal == 0) // original interpreter does not do this, instead it does 2 calls for merges in the worst case
+		return bestColorNr | SCI_PALETTE_MATCH_PERFECT; // we set this flag, so that we can optimize during palette merge
+	return bestColorNr;
 }
 
 void GfxPalette::getSys(Palette *pal) {
@@ -621,7 +650,7 @@ void GfxPalette::kernelSetIntensity(uint16 fromColor, uint16 toColor, uint16 int
 }
 
 int16 GfxPalette::kernelFindColor(uint16 r, uint16 g, uint16 b) {
-	return matchColor(r, g, b) & 0xFF;
+	return matchColor(r, g, b) & SCI_PALETTE_MATCH_COLORMASK;
 }
 
 // Returns true, if palette got changed