mirror of https://github.com/CGAL/cgal
modify the internal do_intersect Ray_3 vs Triangle_3 function
to be able to known whether the endpoint of the ray lies inside the plane of the triangle. The running time is the public do_intersect function should remain the same.
This commit is contained in:
Sébastien Loriot
parent
e9372eb7ae
commit
b058a2a4f3
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@ -25,15 +25,45 @@ namespace CGAL {
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namespace internal {
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template <class K>
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bool do_intersect_coplanar(const typename K::Triangle_3 &t,
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const typename K::Ray_3 &r,
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const K & k );
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struct r3t3_do_intersect_empty_visitor{
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typedef bool result_type;
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result_type result(bool b){return b;}
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void update(Orientation){}
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};
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template <class K>
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bool do_intersect(const typename K::Triangle_3 &t,
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struct r3t3_do_intersect_endpoint_position_visitor{
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bool m_endpoint_outside_triangle_plane;
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r3t3_do_intersect_endpoint_position_visitor():
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m_endpoint_outside_triangle_plane(true){}
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typedef std::pair<bool,bool> result_type;
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result_type result(bool b){return std::make_pair(b,m_endpoint_outside_triangle_plane);}
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void update(Orientation orient)
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{
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m_endpoint_outside_triangle_plane &= orient!=ZERO;
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}
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};
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//the template parameter Visitor here is used to offer the posibility to use
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//r3t3_do_intersect_endpoint_position_visitor to track whether the endpoint of
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//the ray lies inside the plane of the triangle or not. It is used for example
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//in the function that checks whether a point is inside a polyhedron; if the ray
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//is on an edge of the triangle, we should try with another random ray as this case does
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//happen often in practise.
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//By default an empty visitor is used to avoid penalizing the running time.
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template <class K,class Visitor>
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typename Visitor::result_type
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do_intersect_coplanar(const typename K::Triangle_3 &t,
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const typename K::Ray_3 &r,
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const K & k)
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const K & k,
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Visitor visitor);
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template <class K,class Visitor>
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typename Visitor::result_type
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do_intersect(const typename K::Triangle_3 &t,
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const typename K::Ray_3 &r,
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const K & k,
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Visitor visitor)
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{
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CGAL_kernel_precondition( ! k.is_degenerate_3_object()(t) ) ;
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@ -70,8 +100,8 @@ bool do_intersect(const typename K::Triangle_3 &t,
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if (ray_direction == COPLANAR ) {
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if (orientation(a,b,c,p) == COPLANAR)
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return do_intersect_coplanar(t,r,k);
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else return false;
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return do_intersect_coplanar(t,r,k,visitor);
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else return visitor.result(false);
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}
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const Orientation abcp = orientation(a,b,c,p);
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@ -82,73 +112,98 @@ bool do_intersect(const typename K::Triangle_3 &t,
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case POSITIVE:
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// the ray lies in the positive open halfspaces defined by the
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// triangle's supporting plane
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return false;
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return visitor.result(false);
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case NEGATIVE:
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case NEGATIVE:{
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// The ray straddles the triangle's plane
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// p sees the triangle in counterclockwise order
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return orientation(p,q,a,b) != POSITIVE
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&& orientation(p,q,b,c) != POSITIVE
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&& orientation(p,q,c,a) != POSITIVE;
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Orientation
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orient=orientation(p,q,a,b);
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if (orient == POSITIVE ) return visitor.result(false);
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visitor.update(orient);
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orient=orientation(p,q,b,c);
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if (orient == POSITIVE ) return visitor.result(false);
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visitor.update(orient);
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orient=orientation(p,q,c,a);
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if (orient == POSITIVE ) return visitor.result(false);
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visitor.update(orient);
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return visitor.result(true);
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}
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// case COPLANAR: should not happen
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default: // should not happen.
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CGAL_kernel_assertion(false);
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return false;
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return visitor.result(false);
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}
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case NEGATIVE:
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switch ( ray_direction ) {
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case POSITIVE:
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case POSITIVE:{
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// The ray straddles the triangle's plane
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// q sees the triangle in counterclockwise order
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Orientation
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orient=orientation(q,p,a,b);
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if (orient == POSITIVE ) return visitor.result(false);
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visitor.update(orient);
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orient=orientation(q,p,b,c);
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if (orient == POSITIVE ) return visitor.result(false);
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visitor.update(orient);
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orient=orientation(q,p,c,a);
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if (orient == POSITIVE ) return visitor.result(false);
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visitor.update(orient);
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return visitor.result(true);
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return orientation(q,p,a,b) != POSITIVE
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&& orientation(q,p,b,c) != POSITIVE
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&& orientation(q,p,c,a) != POSITIVE;
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}
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case NEGATIVE:
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// the ray lies in the negative open halfspaces defined by the
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// triangle's supporting plane
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return false;
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return visitor.result(false);
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// case COPLANAR: should not happen
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default: // should not happen.
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CGAL_kernel_assertion(false);
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return false;
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return visitor.result(false);
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}
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case COPLANAR: // p belongs to the triangle's supporting plane
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visitor.update(ZERO);
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switch ( ray_direction ) {
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case POSITIVE:
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// q sees the triangle in counterclockwise order
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return orientation(q,p,a,b) != POSITIVE
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return visitor.result(
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orientation(q,p,a,b) != POSITIVE
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&& orientation(q,p,b,c) != POSITIVE
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&& orientation(q,p,c,a) != POSITIVE;
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&& orientation(q,p,c,a) != POSITIVE);
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case NEGATIVE:
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// q sees the triangle in clockwise order
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return orientation(p,q,a,b) != POSITIVE
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return visitor.result(
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orientation(p,q,a,b) != POSITIVE
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&& orientation(p,q,b,c) != POSITIVE
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&& orientation(p,q,c,a) != POSITIVE;
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&& orientation(p,q,c,a) != POSITIVE);
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// case COPLANAR: should not happen
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default: // should not happen.
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CGAL_kernel_assertion(false);
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return false;
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return visitor.result(false);
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}
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default: // should not happen.
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CGAL_kernel_assertion(false);
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return false;
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return visitor.result(false);
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}
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}
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template <class K>
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bool do_intersect(const typename K::Triangle_3 &t,
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const typename K::Ray_3 &r,
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const K & k)
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{
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return do_intersect(t,r,k,r3t3_do_intersect_empty_visitor());
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}
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template <class K>
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inline
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@ -160,12 +215,14 @@ bool do_intersect(const typename K::Ray_3 &r,
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}
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template <class K>
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bool do_intersect_coplanar(const typename K::Triangle_3 &t,
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template <class K,class Visitor>
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typename Visitor::result_type
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do_intersect_coplanar(const typename K::Triangle_3 &t,
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const typename K::Ray_3 &r,
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const K & k )
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const K & k,
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Visitor visitor)
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{
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visitor.update(ZERO);
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CGAL_kernel_precondition( ! k.is_degenerate_3_object()(t) ) ;
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CGAL_kernel_precondition( ! k.is_degenerate_3_object()(r) ) ;
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@ -217,81 +274,81 @@ bool do_intersect_coplanar(const typename K::Triangle_3 &t,
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if (pqc == POSITIVE)
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// the triangle lies in the positive halfspace
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// defined by the ray's supporting line.
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return false;
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return visitor.result(false);
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// c is isolated on the negative side
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return coplanar_orientation(*a,*c,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*a,*c,p) != POSITIVE );
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case NEGATIVE:
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if (pqc == POSITIVE) // b is isolated on the negative side
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return coplanar_orientation(*c,*b,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*c,*b,p) != POSITIVE );
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// a is isolated on the positive side
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return coplanar_orientation(*a,*c,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*a,*c,p) != POSITIVE );
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case COLLINEAR:
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if (pqc == POSITIVE) // b is isolated on the negative side
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return coplanar_orientation(*c,*b,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*c,*b,p) != POSITIVE );
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// a is isolated on the positive side
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return coplanar_orientation(*a,*c,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*a,*c,p) != POSITIVE );
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default: // should not happen.
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CGAL_kernel_assertion(false);
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return false;
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return visitor.result(false);
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}
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case NEGATIVE:
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switch ( pqb ) {
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case POSITIVE:
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if (pqc == POSITIVE) // a is isolated on the negative side
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return coplanar_orientation(*b,*a,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*b,*a,p) != POSITIVE );
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// b is isolated on the positive side
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return coplanar_orientation(*b,*a,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*b,*a,p) != POSITIVE );
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case NEGATIVE:
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if (pqc == NEGATIVE)
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// the triangle lies in the negative halfspace
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// defined by the ray's supporting line.
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return false;
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return visitor.result( false );
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// c is isolated on the positive side
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return coplanar_orientation(*c,*b,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*c,*b,p) != POSITIVE );
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case COLLINEAR:
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if (pqc == NEGATIVE) // b is isolated on the positive side
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return coplanar_orientation(*b,*a,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*b,*a,p) != POSITIVE );
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// a is isolated on the negative side
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return coplanar_orientation(*b,*a,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*b,*a,p) != POSITIVE );
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default: // should not happen.
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CGAL_kernel_assertion(false);
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return false;
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return visitor.result(false);
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}
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case COLLINEAR:
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switch ( pqb ) {
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case POSITIVE:
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if (pqc == POSITIVE) // a is isolated on the negative side
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return coplanar_orientation(*b,*a,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*b,*a,p) != POSITIVE );
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// b is isolated on the positive side
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return coplanar_orientation(*b,*a,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*b,*a,p) != POSITIVE );
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case NEGATIVE:
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if (pqc == NEGATIVE) // a is isolated on the positive side
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return coplanar_orientation(*a,*c,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*a,*c,p) != POSITIVE );
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// b is isolated on the negative side
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return coplanar_orientation(*c,*b,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*c,*b,p) != POSITIVE );
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case COLLINEAR:
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if (pqc == POSITIVE) // c is isolated on the positive side
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return coplanar_orientation(*c,*b,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*c,*b,p) != POSITIVE );
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// c is isolated on the negative side
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return coplanar_orientation(*a,*c,p) != POSITIVE ;
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return visitor.result( coplanar_orientation(*a,*c,p) != POSITIVE );
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// case pqc == COLLINEAR is imposiible
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default: // should not happen.
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CGAL_kernel_assertion(false);
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return false;
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return visitor.result(false);
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}
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default: // should not happen.
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CGAL_kernel_assertion(false);
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return false;
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return visitor.result(false);
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}
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}
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