is there any way to port our code to any other sdk? i know direct x is better than opengl.but it only supports microsft platforms. i just want to know if we want ot make a multiplatform engine what is best way? write our whole code in open gl or port our code in opengl or psgl for other platforms like linux mac and ps? foe example unreal engine is based on direcx but supports all platforms. how is it? a proggram does it?