This function checks for intersection of a axis aligned box and a parallelepiped.
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| real(kind=rk), | intent(in) | :: | center_a(3) | |||
| real(kind=rk), | intent(in) | :: | dim_a(3) | |||
| real(kind=rk), | intent(in) | :: | center_b(3) | |||
| real(kind=rk), | intent(in) | :: | dim_b(3) |
Halflength of the parallelepiped in each direction. Todo HK: Dim is a bad naming here, halflength would be better. |
||
| real(kind=rk), | intent(in) | :: | norm_b(3,3) |
function boxBoxOverlap(center_a, dim_a, center_b, dim_b, norm_b) & & result(overlap) real(kind=rk), intent(in) :: center_a(3) !< Center of the axis aligned box real(kind=rk), intent(in) :: dim_a(3) !< Length of the AAB in each direction real(kind=rk), intent(in) :: center_b(3) !< Center of the parallelepiped !> Halflength of the parallelepiped in each direction. !!@todo HK: Dim is a bad naming here, halflength would be better. real(kind=rk), intent(in) :: dim_b(3) real(kind=rk), intent(in) :: norm_b(3,3) !< normal vector of parallelepiped logical :: overlap ! Local Variables real(kind=rk) :: vec_ab(3) ! Vector connecting center_a and ! center_b !HK! real(kind=rk) :: coeffs(3,3) ! Matrix for Coefficients needed !HK! ! for the algorithm. !HK! !HK! real(kind=rk) :: norm_a(3,3) ! edge directions of the axis ! aligned box ! Initialize variable overlap = .true. vec_ab = center_b - center_a !HK! norm_a(:,1) = (/1., 0., 0./) !HK! norm_a(:,2) = (/0., 1., 0./) !HK! norm_a(:,3) = (/0., 0., 1./) ! coeffs Matrix is structured as follows: ! --> second dimension ! xx xy xz ! yx yy yz ! zx zy zz ! Case 1: ! Calculation of so far needed Coefficients: !HK! coeffs(1,1) = dot_product(norm_a(:,1),norm_b(:,1)) !HK! coeffs(1,2) = dot_product(norm_a(:,1),norm_b(:,2)) !HK! coeffs(1,3) = dot_product(norm_a(:,1),norm_b(:,3)) if ( abs(vec_ab(1)) & & .gt. dim_a(1) + abs(dim_b(1)*norm_b(1,1)) & & + abs(dim_b(2)*norm_b(1,2)) & & + abs(dim_b(3)*norm_b(1,3))) then overlap = .false. return end if ! Case 2: ! Calculation of so far needed Coefficients: !HK! coeffs(2,1) = dot_product(norm_a(:,2),norm_b(:,1)) !HK! coeffs(2,2) = dot_product(norm_a(:,2),norm_b(:,2)) !HK! coeffs(2,3) = dot_product(norm_a(:,2),norm_b(:,3)) if ( abs(vec_ab(2)) & & .gt. dim_a(2) + abs(dim_b(1)*norm_b(2,1)) & & + abs(dim_b(2)*norm_b(2,2)) & & + abs(dim_b(3)*norm_b(2,3))) then overlap = .false. return end if ! Case 3: ! Calculation of so far needed Coefficients: !HK! coeffs(3,1) = dot_product(norm_a(:,3),norm_b(:,1)) !HK! coeffs(3,2) = dot_product(norm_a(:,3),norm_b(:,2)) !HK! coeffs(3,3) = dot_product(norm_a(:,3),norm_b(:,3)) if ( abs(vec_ab(3)) & & .gt. dim_a(3) + abs(dim_b(1)*norm_b(3,1)) & & + abs(dim_b(2)*norm_b(3,2)) & & + abs(dim_b(3)*norm_b(3,3))) then overlap = .false. return end if ! Case 4: if ( abs(dot_product(vec_ab, norm_b(:,1))) & & .gt. dim_b(1) + abs(dim_a(1)*norm_b(1,1)) & & + abs(dim_a(2)*norm_b(2,1)) & & + abs(dim_a(3)*norm_b(3,1))) then overlap = .false. return end if ! Case 5: if ( abs(dot_product(vec_ab, norm_b(:,2))) & & .gt. dim_b(2) + abs(dim_a(1)*norm_b(1,2)) & & + abs(dim_a(2)*norm_b(2,2)) & & + abs(dim_a(3)*norm_b(3,2))) then overlap = .false. return end if ! Case 6: if ( abs(dot_product(vec_ab, norm_b(:,3))) & & .gt. dim_b(3) + abs(dim_a(1)*norm_b(1,3)) & & + abs(dim_a(2)*norm_b(2,3)) & & + abs(dim_a(3)*norm_b(3,3))) then overlap = .false. return end if ! Case 7: if ( abs(vec_ab(3))*norm_b(2,1) - vec_ab(2)*norm_b(3,1) & & .gt. abs(dim_a(2)*norm_b(3,1)) + abs(dim_a(3)*norm_b(2,1)) & & + abs(dim_b(2)*norm_b(1,3)) + abs(dim_b(3)*norm_b(1,2)) ) then overlap = .false. return end if ! Case 8: if ( abs(vec_ab(3))*norm_b(2,2) - vec_ab(2)*norm_b(3,2) & & .gt. abs(dim_a(2)*norm_b(3,2)) + abs(dim_a(3)*norm_b(2,2)) & & + abs(dim_b(1)*norm_b(1,3)) + abs(dim_b(3)*norm_b(1,1)) ) then overlap = .false. return end if ! Case 9: if ( abs(vec_ab(3))*norm_b(2,3) - vec_ab(2)*norm_b(3,3) & & .gt. abs(dim_a(2)*norm_b(3,3)) + abs(dim_a(3)*norm_b(2,3)) & & + abs(dim_b(1)*norm_b(1,2)) + abs(dim_b(2)*norm_b(1,1)) ) then overlap = .false. return end if ! Case 10: if ( abs(vec_ab(1))*norm_b(3,1) - vec_ab(3)*norm_b(1,1) & & .gt. abs(dim_a(1)*norm_b(3,1)) + abs(dim_a(3)*norm_b(1,1)) & & + abs(dim_b(2)*norm_b(2,3)) + abs(dim_b(3)*norm_b(2,2)) ) then overlap = .false. return end if ! Case 11: if ( abs(vec_ab(1))*norm_b(3,2) - vec_ab(3)*norm_b(1,2) & & .gt. abs(dim_a(1)*norm_b(3,2)) + abs(dim_a(3)*norm_b(1,2)) & & + abs(dim_b(1)*norm_b(2,3)) + abs(dim_b(3)*norm_b(2,1)) ) then overlap = .false. return end if ! Case 12: if ( abs(vec_ab(1))*norm_b(3,3) - vec_ab(3)*norm_b(1,3) & & .gt. abs(dim_a(1)*norm_b(3,3)) + abs(dim_a(3)*norm_b(1,3)) & & + abs(dim_b(1)*norm_b(2,2)) + abs(dim_b(2)*norm_b(2,1)) ) then overlap = .false. return end if ! Case 13: if ( abs(vec_ab(2))*norm_b(1,1) - vec_ab(1)*norm_b(2,1) & & .gt. abs(dim_a(1)*norm_b(2,1)) + abs(dim_a(2)*norm_b(1,1)) & & + abs(dim_b(2)*norm_b(3,3)) + abs(dim_b(3)*norm_b(3,2)) ) then overlap = .false. return end if ! Case 14: if ( abs(vec_ab(2))*norm_b(1,2) - vec_ab(1)*norm_b(2,2) & & .gt. abs(dim_a(1)*norm_b(2,2)) + abs(dim_a(2)*norm_b(1,2)) & & + abs(dim_b(1)*norm_b(3,3)) + abs(dim_b(3)*norm_b(3,1)) ) then overlap = .false. return end if ! Case 15: if ( abs(vec_ab(2))*norm_b(1,3) - vec_ab(1)*norm_b(2,3) & & .gt. abs(dim_a(1)*norm_b(2,3)) + abs(dim_a(2)*norm_b(1,3)) & & + abs(dim_b(1)*norm_b(3,2)) + abs(dim_b(2)*norm_b(3,1)) ) then overlap = .false. return end if end function boxBoxOverlap