Add aprroximated implementation of one of the 2d image methods in Nulldriver....

Add aprroximated implementation of one of the 2d image methods in Nulldriver. This enables support in the software drivers as well.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@2795 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/CNullDriver.cpp

@@ -697,6 +697,9 @@ void CNullDriver::draw2DImage(const video::ITexture* texture, const core::rect<s
 	const core::rect<s32>& sourceRect, const core::rect<s32>* clipRect,
 	const video::SColor* const colors, bool useAlphaChannelOfTexture)
 {
+	draw2DImage(texture, core::position2d<s32>(destRect.UpperLeftCorner),
+				sourceRect, clipRect, colors?colors[0]:0xffffffff,
+				useAlphaChannelOfTexture);
 }