* fixed a bug with setting the transparent color

* changed behaviour when searching for the
  index of the specified to be transparent color:
  if there is no direct hit, the closest match
  is found and adjusted to the specified color,
  so that the transparency always works out


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14296 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/translators/giftranslator/GIFSave.cpp

@@ -104,20 +104,13 @@ GIFSave::GIFSave(BBitmap *bitmap, BPositionIO *output)
 			if (debug)
 				printf("GIFSave::GIFSave() - Using transparent index %d\n", palette->TransparentIndex());
 		} else {
-			bool found = palette->SetTransparentColor((uint8)prefs->transparentred,
-													  (uint8)prefs->transparentred,
-													  (uint8)prefs->transparentblue);
-			if (found) {
-				if (debug) {
-					printf("GIFSave::GIFSave() - Found transparent color %d,%d,%d at index %d\n",
-						   prefs->transparentred, prefs->transparentgreen, prefs->transparentblue,
-						   palette->TransparentIndex());
-				}
-			} else {
-				if (debug) {
-					printf("GIFSave::GIFSave() - Did not find color %d,%d,%d - deactivating transparency\n",
-						   prefs->transparentred, prefs->transparentgreen, prefs->transparentblue);
-				}
+			palette->SetTransparentColor((uint8)prefs->transparentred,
+									     (uint8)prefs->transparentgreen,
+									     (uint8)prefs->transparentblue);
+			if (debug) {
+				printf("GIFSave::GIFSave() - Found transparent color %d,%d,%d at index %d\n",
+					   prefs->transparentred, prefs->transparentgreen, prefs->transparentblue,
+					   palette->TransparentIndex());
 			}
 		}
 	} else {

src/add-ons/translators/giftranslator/SavePalette.cpp

@@ -229,9 +229,9 @@ touch_color_item(SFHash& hash, unsigned int key, uint8 r, uint8 g, uint8 b)
 	} else {
 		ci->count++;
 		// use brightest color
-		ci->red = max_c(ci->red, r);
+/*		ci->red = max_c(ci->red, r);
 		ci->green = max_c(ci->green, g);
-		ci->blue = max_c(ci->blue, b);
+		ci->blue = max_c(ci->blue, b);*/
 	}
 	return true;
 }
@@ -404,11 +404,12 @@ SavePalette::SetTransparentIndex(int index)
 }
 
 // SetTransparentColor
-bool
+void
 SavePalette::SetTransparentColor(uint8 red, uint8 green, uint8 blue)
 {
 	bool found = false;
 
+	// try direct hit first
 	for (int i = 0; i < fSize; i++) {
 		if (pal[i].red == red &&
 			pal[i].green == green &&
@@ -421,10 +422,25 @@ SavePalette::SetTransparentColor(uint8 red, uint8 green, uint8 blue)
 		}
 	}
 	if (!found) {
-		fTransparentIndex = 0;
-		fUseTransparent = false;
+		// find closest match
+		fTransparentIndex = IndexForColor(red, green, blue);
+		// NOTE: This is a tough decision:
+		// -> the exact color might be contained within the image
+		//    but have slipped through the net and is now not in the
+		//    palette, the user still wants those pixels to be
+		//    transparent of course, so it is best to match up a
+		//    color from the palette
+		// -> on the other hand, the setting might still be there
+		//    from some previous image and the color might not
+		//    even appear in the current image at all... but I guess
+		//    handling it like below is the lesser evil.
+		// match up color at index to provided transparent color,
+		// to make sure it actually works
+		pal[fTransparentIndex].red = red;
+		pal[fTransparentIndex].green = green;
+		pal[fTransparentIndex].blue = blue;
+		found = true;
 	}
-	return found;
 }
 
 // GetColors

src/add-ons/translators/giftranslator/SavePalette.h

@@ -47,7 +47,7 @@ class SavePalette {
 			void			SetTransparentIndex(int index);
 	inline	int				TransparentIndex() const
 								{ return fTransparentIndex; }
-			bool			SetTransparentColor(uint8 red,
+			void			SetTransparentColor(uint8 red,
 												uint8 green,
 												uint8 blue);