Added optional xoffset/yoffset/width/height arguments to Image:refresh, to specify a sub-rectangle. Specifying a small sub-rectangle can improve the performance of Image:refresh.

--HG--
branch : minor

src/modules/graphics/opengl/Image.h

@@ -133,7 +133,7 @@ public:
 	 * Re-uploads the ImageData or CompressedData associated with this Image to
 	 * the GPU.
 	 **/
-	bool refresh();
+	bool refresh(int xoffset, int yoffset, int w, int h);
 
 	const Flags &getFlags() const;
 
@@ -153,10 +153,18 @@ public:
 
 private:
 
-	void uploadDefaultTexture();
-
 	void drawv(const Matrix &t, const Vertex *v);
 
+	void preload();
+
+	void generateMipmaps();
+	void loadDefaultTexture();
+	void loadTextureFromCompressedData();
+	void loadTextureFromImageData();
+	void uploadImageData(int xoffset, int yoffset, int w, int h);
+
+	GLenum getCompressedFormat(image::CompressedData::Format cformat) const;
+
 	// The ImageData from which the texture is created. May be null if
 	// Compressed image data was used to create the texture.
 	Object::StrongRef<love::image::ImageData> data;
@@ -183,19 +191,11 @@ private:
 
 	size_t textureMemorySize;
 
-	void preload();
-
-	void uploadCompressedData();
-	void uploadImageData();
-	void uploadTexture();
-
 	static float maxMipmapSharpness;
 
 	static FilterMode defaultMipmapFilter;
 	static float defaultMipmapSharpness;
 
-	GLenum getCompressedFormat(image::CompressedData::Format cformat) const;
-
 	static StringMap<FlagType, FLAG_TYPE_MAX_ENUM>::Entry flagNameEntries[];
 	static StringMap<FlagType, FLAG_TYPE_MAX_ENUM> flagNames;