GRAPHICS: Add two new methods to change 'pixels' of a Surface.

One method is a simpler setter for 'pixels'. The other one can be used to
setup a Surface with custom data.

graphics/surface.cpp

@@ -82,6 +82,14 @@ void Surface::free() {
 	format = PixelFormat();
 }
 
+void Surface::init(uint16 width, uint16 height, uint16 newPitch, void *newPixels, const PixelFormat &f) {
+	w = width;
+	h = height;
+	pitch = newPitch;
+	pixels = newPixels;
+	format = f;
+}
+
 void Surface::copyFrom(const Surface &surf) {
 	create(surf.w, surf.h, surf.format);
 	if (surf.pitch == pitch) {

graphics/surface.h

@@ -95,6 +95,15 @@ struct Surface {
 		return pixels;
 	}
 
+	/**
+	 * Sets the pixel data.
+	 *
+	 * Note that this is a simply setter. Be careful what you are doing!
+	 *
+	 * @param newPixels The new pixel data.
+	 */
+	void setPixels(void *newPixels) { pixels = newPixels; }
+
 	/**
 	 * Return a pointer to the pixel at the specified point.
 	 *
@@ -139,6 +148,20 @@ struct Surface {
 	 */
 	void free();
 
+	/**
+	 * Set up the Surface with user specified data.
+	 *
+	 * Note that this simply sets the 'internal' attributes of the Surface. It
+	 * will not take care of freeing old data via free or similar!
+	 *
+	 * @param width Width of the pixel data.
+	 * @param height Height of the pixel data.
+	 * @param pitch The pitch of the pixel data.
+	 * @param pixels The pixel data itself.
+	 * @param format The pixel format of the pixel data.
+	 */
+	void init(uint16 width, uint16 height, uint16 pitch, void *pixels, const PixelFormat &format);
+
 	/**
 	 * Copy the data from another Surface.
 	 *