IMAGE: Allow for choosing dither type

3 files changed, 19 insertions, 12 deletions

diff --git a/image/codecs/cinepak.cpp b/image/codecs/cinepak.cpp
index 9760b5b2a4..de5198812b 100644
--- a/image/codecs/cinepak.cpp
+++ b/image/codecs/cinepak.cpp
@@ -320,12 +320,12 @@ void CinepakDecoder::decodeVectors(Common::SeekableReadStream &stream, uint16 st
 	}
 }
 
-bool CinepakDecoder::canDither() const {
-	return _bitsPerPixel == 24;
+bool CinepakDecoder::canDither(DitherType type) const {
+	return type == kDitherTypeVFW && _bitsPerPixel == 24;
 }
 
-void CinepakDecoder::setDither(const byte *palette) {
-	assert(canDither());
+void CinepakDecoder::setDither(DitherType type, const byte *palette) {
+	assert(canDither(type));
 
 	delete[] _colorMap;
 	delete[] _ditherPalette;
diff --git a/image/codecs/cinepak.h b/image/codecs/cinepak.h
index ce8451bf9a..ccdad0877c 100644
--- a/image/codecs/cinepak.h
+++ b/image/codecs/cinepak.h
@@ -75,8 +75,8 @@ public:
 	bool containsPalette() const { return _ditherPalette != 0; }
 	const byte *getPalette() { _dirtyPalette = false; return _ditherPalette; }
 	bool hasDirtyPalette() const { return _dirtyPalette; }
-	bool canDither() const;
-	void setDither(const byte *palette);
+	bool canDither(DitherType type) const;
+	void setDither(DitherType type, const byte *palette);
 
 private:
 	CinepakFrame _curFrame;
diff --git a/image/codecs/codec.h b/image/codecs/codec.h
index 3a2da9ff1e..9abbb3d183 100644
--- a/image/codecs/codec.h
+++ b/image/codecs/codec.h
@@ -59,6 +59,17 @@ public:
 	virtual ~Codec() {}
 
 	/**
+	 * A type of dithering.
+	 */
+	enum DitherType {
+		/** Video for Windows dithering */
+		kDitherTypeVFW,
+
+		/** QuickTime dithering */
+		kDitherTypeQT
+	};
+
+	/**
 	 * Decode the frame for the given data and return a pointer to a surface
 	 * containing the decoded frame.
 	 *
@@ -89,17 +100,13 @@ public:
 
 	/**
 	 * Can the codec dither down to 8bpp?
-	 *
-	 * @note This should only be used for VFW codecs
 	 */
-	virtual bool canDither() const { return false; }
+	virtual bool canDither(DitherType type) const { return false; }
 
 	/**
 	 * Activate dithering mode with a palette
-	 *
-	 * @note This should only be used for VFW codecs
 	 */
-	virtual void setDither(const byte *palette) {}
+	virtual void setDither(DitherType type, const byte *palette) {}
 };
 
 /**