reflect_refract Subroutine

public subroutine reflect_refract(I, N, n1, n2, rflag, Ri)

Uses

wrapper routine for fresnel calculation

Arguments

Type IntentOptional Attributes Name
type(vector), intent(inout) :: I

incident vector
type(vector), intent(inout) :: N

normal vector
real(kind=wp), intent(in) :: n1

refractive indices
real(kind=wp), intent(in) :: n2

refractive indices
logical, intent(out) :: rflag

reflection flag
real(kind=wp), intent(out) :: Ri

Source Code

    subroutine reflect_refract(I, N, n1, n2, rflag, ri)
    !! wrapper routine for fresnel calculation

        use random, only : ran2

        !> incident vector
        type(vector),  intent(INOUT) :: I
        !> normal vector
        type(vector),  intent(INOUT) :: N
        !> refractive indices
        real(kind=wp), intent(IN)    :: n1, n2
        real(kind=wp), intent(OUT)   :: Ri
        !> reflection flag
        logical,       intent(OUT)   :: rflag

        rflag = .FALSE.

        !draw random number, if less than fresnel coefficents, then reflect, else refract
        Ri = fresnel(I, N, n1, n2)
        if(ran2() <= Ri)then
            call reflect(I, N)
            rflag = .true.
        else
            call refract(I, N, n1/n2)
        end if

    end subroutine reflect_refract