Avoid the warning about unsupported format when creating FBOs, and try to be...

Avoid the warning about unsupported format when creating FBOs, and try to be more clever with choosing the proper fbo format.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3376 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/COpenGLTexture.cpp

@@ -605,7 +605,7 @@ static bool checkFBOStatus(COpenGLDriver* Driver);
 //! RTT ColorFrameBuffer constructor
 COpenGLFBOTexture::COpenGLFBOTexture(const core::dimension2d<u32>& size,
 					const io::path& name, COpenGLDriver* driver,
-					const ECOLOR_FORMAT format)
+					ECOLOR_FORMAT format)
 	: COpenGLTexture(name, driver), DepthTexture(0), ColorFrameBuffer(0)
 {
 	#ifdef _DEBUG
@@ -615,6 +615,9 @@ COpenGLFBOTexture::COpenGLFBOTexture(const core::dimension2d<u32>& size,
 	ImageSize = size;
 	TextureSize = size;
 
+	if (ECF_UNKNOWN == format)
+		format = getBestColorFormat(driver->getColorFormat());
+
 	GLint FilteringType;
 	InternalFormat = getOpenGLFormatAndParametersFromColorFormat(format, FilteringType, PixelFormat, PixelType);