#define RGB32BIT(a, r, g, b) ( ((a) << 24) + ((g) << 8) + ((r) << 16) + (b) )	//RGB32BIT color mode


DDSURFACEDESC2	ddsd;
	ZeroMemory(&ddsd, sizeof(ddsd));
	ddsd.dwSize = sizeof(ddsd);

	lpPrimarySurface->Lock(NULL, &ddsd, DDLOCK_WAIT, NULL);

	PBYTE	buffer = (PBYTE)ddsd.lpSurface;
	
	BYTE red, blue, green;
	blue = (BYTE)0;
	green = (BYTE)0;
	red = BYTE(255);
	
	for (int i = 0; i < 500; i++)
	{
		for (int j = 0; j < 50; j++)
		{
			buffer[i + ddsd.lPitch * j] = RGB32BIT(0, red, green blue);
		}
	}//end for

	

	lpPrimarySurface->Unlock(NULL);