// Logical size of the output of this effect, ie. the resolution
// you would get if you sampled it as a texture. If it is undefined
// (since the inputs differ in resolution), it will be 0x0.
// Logical size of the output of this effect, ie. the resolution
// you would get if you sampled it as a texture. If it is undefined
// (since the inputs differ in resolution), it will be 0x0.