Ticket #377: unkroomfunc3.diff

scummvm/scummvm.cpp

@@ -799 +799 @@
         return a;
 }
 
-void Scumm::unkRoomFunc3(int a, int b, int c, int d, int e)
+void Scumm::unkRoomFunc3(int unk1, int unk2, int rfact, int gfact, int bfact)
 {
-        warning("stub unkRoomFunc3(%d,%d,%d,%d,%d)", a, b, c, d, e);
+        byte *pal = _currentPalette;
+        byte *table = _shadowPalette;
+        int i;
+
+        warning("unkRoomFunc3(%d,%d,%d,%d,%d): not fully implemented", unk1, unk2, rfact, gfact, bfact);
+
+        // unkRoomFunc3(16, 255, 200, 200, 200)
+        //
+        // FOA: Sets up the colors for the boat and submarine shadows in the
+        // diving scene. Are the shadows too light? Maybe unk1 is used to
+        // darken the colors?
+        //
+        // unkRoomFunc3(0, 255, 700, 700, 700)
+        //
+        // FOA: Sets up the colors for the subway car headlight when it first
+        // goes on. This seems to work ok.
+        //
+        // unkRoomFunc3(160, 191, 300, 300, 300)
+        // unkRoomFunc3(160, 191, 289, 289, 289)
+        //     ...
+        // unkRoomFunc3(160, 191, 14, 14, 14)
+        // unkRoomFunc3(160, 191, 3, 3, 3)
+        //
+        // FOA: Sets up the colors for the subway car headlight for the later
+        // half of the trip, where it fades out. This currently doesn't work
+        // at all. The colors are too dark to be brightened. At first I thought
+        // unk1 and unk2 were used to tell which color interval to manipulate,
+        // but as far as I can tell the colors 160-191 aren't used at all to
+        // draw the light, that can't be it. Apparently unk1 and/or unk2 are
+        // used to brighten the colors.
+        
+        for (i = 0; i <= 255; i++) {
+                int r = (int) (*pal++ * rfact) >> 8;
+                int g = (int) (*pal++ * gfact) >> 8;
+                int b = (int) (*pal++ * bfact) >> 8;
+
+                *table++ = remapPaletteColor(r, g, b, (uint) -1);
+        }
 }