colorbar_ansi Subroutine

    impure subroutine colorbar_ansi(self, width)
        class(Colormap), intent(in) :: self
        integer, intent(in), optional :: width
        integer :: i, n, idx
        integer :: r, g, b
        real(wp) :: factor

        if (present(width)) then
            n = max(1, width)
        else
            n = self%levels
        end if

        factor = real(self%levels - 1, wp) / real(max(1, n - 1), wp)
        do i = 0, n-1
            idx = nint(real(i, wp) * factor)
            idx = min(max(idx, 0), self%levels - 1)
            r = self%map(idx,1)
            g = self%map(idx,2)
            b = self%map(idx,3)
            write(*,'(a,g0,a,g0,a,g0,a)', advance='no') char(27)//'[48;2;', r, ';', g, ';', b, 'm  '
        end do
        write(*,'(a)') char(27)//'[0m'
    end subroutine colorbar_ansi