SetData.c++

	void Texture2D::SetData( uint32 mipmap, const Rectangleu32& source, const void* pixels, ulword pixelbytesize, ulword count ) {
#ifdef FURROVINEDIRECTX
		ID3D11DeviceContext& context = Dx::rnative_handle( *graphicsdevice, Dx::context );
		ID3D11Texture2D* tex2 = Dx::native_handle( *this );
		uint32 dest = D3D11CalcSubresource( mipmap, 0, tex2desc.miplevels );
		uint32 texpixelsize = ToByteSize( tex2desc.surfaceformat );
		
		bool isempty = source.IsEmpty( );
		if ( tex2desc.usage == ResourceUsage::Default ) {
			D3D11_BOX d3dbox;
			d3dbox.front = 0;
			d3dbox.back = 1;
			if ( !isempty ) {
				d3dbox.left = source.left;
				d3dbox.top = source.top;
				d3dbox.right = source.Right( );
				d3dbox.bottom = source.Bottom( );
			}

			context.UpdateSubresource( tex2, dest, isempty ? null : &d3dbox,
				pixels, tex2desc.width * texpixelsize, 0 );

			return;
		}

		D3D11_MAPPED_SUBRESOURCE res = { };
		ResourceMapping mapping = ResourceMapping::WriteAndDiscard;
		dxresultcode r = context.Map( tex2, dest, Dx::ToPlatform<D3D11_MAP>( mapping ), 0, &res );
		if ( FAILED( r ) )
			throw Exception( "Unable to Map Texture2D to device" );
		
		auto dx = make_destructor( [ &context, &tex2 ] { context.Unmap( tex2, 0 ); } );
		
		if ( isempty ) {
			uint32 bytesize = pixelbytesize * count;
			std::memcpy( res.pData, pixels, bytesize );
			return;
		}
		
		bool samewidth = Width( ) == source.Width( ) && ToByteSize( tex2desc.surfaceformat ) == pixelbytesize;
		if ( samewidth ) {
			uint32 bytesize = pixelbytesize * count;
			std::memcpy( res.pData, pixels, bytesize );
			return;
		}
		
		byte* mappeddata = static_cast<byte*>( res.pData );
		const byte* pixeldata = static_cast<const byte*>( pixels );
		uint32 pixelrowsize = source.Width( ) * pixelbytesize;
		for ( ulword h = 0; h < source.Height( ); ++h ) {
			byte* mappedrow = mappeddata + ( res.RowPitch * h );
			const byte* pixelrow = pixeldata + ( pixelrowsize * h );
			std::memcpy( mappedrow, pixelrow, pixelrowsize );
		}
#else
#error Implement for this graphics platform
#endif // DIRECTX || OPENGL
	}