Files
igl/include/igl/predicates/triangle_triangle_intersect.cpp
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322 lines
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C++

#include "triangle_triangle_intersect.h"
#include "predicates.h"
#include "exactinit.h"
#include "orient2d.h"
#include "orient3d.h"
#include <Eigen/Core>
#include <Eigen/Geometry>
template <typename Vector3D>
IGL_INLINE bool igl::predicates::triangle_triangle_intersect(
const Vector3D & p1,
const Vector3D & q1,
const Vector3D & r1,
const Vector3D & p2,
const Vector3D & q2,
const Vector3D & r2,
bool & coplanar)
{
coplanar = false;
// yet another translation of tri_tri_intersect.c [Guigue & Devillers]
exactinit();
using Vector2D = Eigen::Matrix<typename Vector3D::Scalar,2,1>;
constexpr Orientation COPLANAR = igl::Orientation::COPLANAR;
constexpr Orientation NEGATIVE = igl::Orientation::NEGATIVE;
constexpr Orientation POSITIVE = igl::Orientation::POSITIVE;
// Determine for each vertex of one triangle if it's above, below or on the
// plane of the other triangle.
// SUB(v1,p2,r2)
// SUB(v2,q2,r2)
// CROSS(N2,v1,v2)
// SUB(v1,p1,r2)
// dp1 = DOT(v1,N2);
// dp1 = (p1-r2).dot( (p2-r2).cross(q2-r2) );
const Orientation dp1 = orient3d(p2,q2,r2,p1);
const Orientation dq1 = orient3d(p2,q2,r2,q1);
const Orientation dr1 = orient3d(p2,q2,r2,r1);
const auto same_non_coplanar = [&NEGATIVE,&COPLANAR,&POSITIVE](
const Orientation a,
const Orientation b,
const Orientation c)
{
return (a == POSITIVE && b == POSITIVE && c == POSITIVE) ||
(a == NEGATIVE && b == NEGATIVE && c == NEGATIVE);
};
if(same_non_coplanar(dp1,dq1,dr1)) { return false; }
const Orientation dp2 = orient3d(p1,q1,r1,p2);
const Orientation dq2 = orient3d(p1,q1,r1,q2);
const Orientation dr2 = orient3d(p1,q1,r1,r2);
// Theoreticaly, this should have already been fired above
if(same_non_coplanar(dp2,dq2,dr2)) { return false; }
const auto tri_tri_overlap_test_2d = [&NEGATIVE,&COPLANAR,&POSITIVE](
const Vector2D & p1,
const Vector2D & q1,
const Vector2D & r1,
const Vector2D & p2,
const Vector2D & q2,
const Vector2D & r2)->bool
{
const auto ccw_tri_tri_intersection_2d = [&NEGATIVE,&COPLANAR,&POSITIVE](
const Vector2D & p1,
const Vector2D & q1,
const Vector2D & r1,
const Vector2D & p2,
const Vector2D & q2,
const Vector2D & r2)->bool
{
const auto INTERSECTION_TEST_VERTEX = [&NEGATIVE,&COPLANAR,&POSITIVE](
const Vector2D & P1,
const Vector2D & Q1,
const Vector2D & R1,
const Vector2D & P2,
const Vector2D & Q2,
const Vector2D & R2)->bool
{
if (orient2d(R2,P2,Q1) != NEGATIVE)
if (orient2d(R2,Q2,Q1) != POSITIVE)
if (orient2d(P1,P2,Q1) == POSITIVE) {
if (orient2d(P1,Q2,Q1) != POSITIVE) return 1;
else return 0;} else {
if (orient2d(P1,P2,R1) != NEGATIVE)
if (orient2d(Q1,R1,P2) != NEGATIVE) return 1;
else return 0;
else return 0;}
else
if (orient2d(P1,Q2,Q1) != POSITIVE)
if (orient2d(R2,Q2,R1) != POSITIVE)
if (orient2d(Q1,R1,Q2) != NEGATIVE) return 1;
else return 0;
else return 0;
else return 0;
else
if (orient2d(R2,P2,R1) != NEGATIVE)
if (orient2d(Q1,R1,R2) != NEGATIVE)
if (orient2d(P1,P2,R1) != NEGATIVE) return 1;
else return 0;
else
if (orient2d(Q1,R1,Q2) != NEGATIVE) {
if (orient2d(R2,R1,Q2) != NEGATIVE) return 1;
else return 0; }
else return 0;
else return 0;
};
const auto INTERSECTION_TEST_EDGE = [&NEGATIVE,&COPLANAR,&POSITIVE](
const Vector2D & P1,
const Vector2D & Q1,
const Vector2D & R1,
const Vector2D & P2,
const Vector2D & Q2,
const Vector2D & R2)->bool
{
if (orient2d(R2,P2,Q1) != NEGATIVE) {
if (orient2d(P1,P2,Q1) != NEGATIVE) {
if (orient2d(P1,Q1,R2) != NEGATIVE) return 1;
else return 0;} else {
if (orient2d(Q1,R1,P2) != NEGATIVE){
if (orient2d(R1,P1,P2) != NEGATIVE) return 1; else return 0;}
else return 0; }
} else {
if (orient2d(R2,P2,R1) != NEGATIVE) {
if (orient2d(P1,P2,R1) != NEGATIVE) {
if (orient2d(P1,R1,R2) != NEGATIVE) return 1;
else {
if (orient2d(Q1,R1,R2) != NEGATIVE) return 1; else return 0;}}
else return 0; }
else return 0; }
};
if ( orient2d(p2,q2,p1) != NEGATIVE ) {
if ( orient2d(q2,r2,p1) != NEGATIVE ) {
if ( orient2d(r2,p2,p1) != NEGATIVE ) return 1;
else return INTERSECTION_TEST_EDGE(p1,q1,r1,p2,q2,r2);
} else {
if ( orient2d(r2,p2,p1) != NEGATIVE )
return INTERSECTION_TEST_EDGE(p1,q1,r1,r2,p2,q2);
else return INTERSECTION_TEST_VERTEX(p1,q1,r1,p2,q2,r2);}}
else {
if ( orient2d(q2,r2,p1) != NEGATIVE ) {
if ( orient2d(r2,p2,p1) != NEGATIVE )
return INTERSECTION_TEST_EDGE(p1,q1,r1,q2,r2,p2);
else return INTERSECTION_TEST_VERTEX(p1,q1,r1,q2,r2,p2);}
else return INTERSECTION_TEST_VERTEX(p1,q1,r1,r2,p2,q2);}
return false;
};
if ( orient2d(p1,q1,r1) == NEGATIVE )
if ( orient2d(p2,q2,r2) == NEGATIVE )
return ccw_tri_tri_intersection_2d(p1,r1,q1,p2,r2,q2);
else
return ccw_tri_tri_intersection_2d(p1,r1,q1,p2,q2,r2);
else
if ( orient2d(p2,q2,r2) == NEGATIVE )
return ccw_tri_tri_intersection_2d(p1,q1,r1,p2,r2,q2);
else
return ccw_tri_tri_intersection_2d(p1,q1,r1,p2,q2,r2);
};
const auto coplanar_tri_tri3d = [&tri_tri_overlap_test_2d,&NEGATIVE,&COPLANAR,&POSITIVE](
const Vector3D & p1,
const Vector3D & q1,
const Vector3D & r1,
const Vector3D & p2,
const Vector3D & q2,
const Vector3D & r2)->bool
{
Vector3D normal_1 = (q1-p1).cross(r1-p1);
const auto n_x = ((normal_1[0]<0)?-normal_1[0]:normal_1[0]);
const auto n_y = ((normal_1[1]<0)?-normal_1[1]:normal_1[1]);
const auto n_z = ((normal_1[2]<0)?-normal_1[2]:normal_1[2]);
Vector2D P1,Q1,R1,P2,Q2,R2;
if (( n_x > n_z ) && ( n_x >= n_y )) {
// Project onto plane YZ
P1[0] = q1[2]; P1[1] = q1[1];
Q1[0] = p1[2]; Q1[1] = p1[1];
R1[0] = r1[2]; R1[1] = r1[1];
P2[0] = q2[2]; P2[1] = q2[1];
Q2[0] = p2[2]; Q2[1] = p2[1];
R2[0] = r2[2]; R2[1] = r2[1];
} else if (( n_y > n_z ) && ( n_y >= n_x )) {
// Project onto plane XZ
P1[0] = q1[0]; P1[1] = q1[2];
Q1[0] = p1[0]; Q1[1] = p1[2];
R1[0] = r1[0]; R1[1] = r1[2];
P2[0] = q2[0]; P2[1] = q2[2];
Q2[0] = p2[0]; Q2[1] = p2[2];
R2[0] = r2[0]; R2[1] = r2[2];
} else {
// Project onto plane XY
P1[0] = p1[0]; P1[1] = p1[1];
Q1[0] = q1[0]; Q1[1] = q1[1];
R1[0] = r1[0]; R1[1] = r1[1];
P2[0] = p2[0]; P2[1] = p2[1];
Q2[0] = q2[0]; Q2[1] = q2[1];
R2[0] = r2[0]; R2[1] = r2[1];
}
return tri_tri_overlap_test_2d(P1,Q1,R1,P2,Q2,R2);
exit(1);
return false;
};
const auto TRI_TRI_3D = [&coplanar_tri_tri3d,&coplanar,&NEGATIVE,&COPLANAR,&POSITIVE](
const Vector3D & p1,
const Vector3D & q1,
const Vector3D & r1,
const Vector3D & p2,
const Vector3D & q2,
const Vector3D & r2,
const Orientation dp2,
const Orientation dq2,
const Orientation dr2)->bool
{
const auto CHECK_MIN_MAX = [&NEGATIVE,&COPLANAR,&POSITIVE](
const Vector3D & p1,
const Vector3D & q1,
const Vector3D & r1,
const Vector3D & p2,
const Vector3D & q2,
const Vector3D & r2)->bool
{
if (orient3d(p2,p1,q1,q2) == POSITIVE) { return false; }
if (orient3d(p2,r1,p1,r2) == POSITIVE) { return false; }
return true;
};
if (dp2 == POSITIVE) {
if (dq2 == POSITIVE) return CHECK_MIN_MAX(p1,r1,q1,r2,p2,q2) ;
else if (dr2 == POSITIVE) return CHECK_MIN_MAX(p1,r1,q1,q2,r2,p2);
else return CHECK_MIN_MAX(p1,q1,r1,p2,q2,r2);
} else if (dp2 == NEGATIVE) {
if (dq2 == NEGATIVE) return CHECK_MIN_MAX(p1,q1,r1,r2,p2,q2);
else if (dr2 == NEGATIVE) return CHECK_MIN_MAX(p1,q1,r1,q2,r2,p2);
else return CHECK_MIN_MAX(p1,r1,q1,p2,q2,r2);
} else {
if (dq2 == NEGATIVE) {
if (dr2 == POSITIVE || dr2 == COPLANAR) return CHECK_MIN_MAX(p1,r1,q1,q2,r2,p2);
else return CHECK_MIN_MAX(p1,q1,r1,p2,q2,r2);
}
else if (dq2 == POSITIVE) {
if (dr2 == POSITIVE) return CHECK_MIN_MAX(p1,r1,q1,p2,q2,r2);
else return CHECK_MIN_MAX(p1,q1,r1,q2,r2,p2);
}
else {
if (dr2 == POSITIVE) return CHECK_MIN_MAX(p1,q1,r1,r2,p2,q2);
else if (dr2 == NEGATIVE) return CHECK_MIN_MAX(p1,r1,q1,r2,p2,q2);
else
{
coplanar = coplanar_tri_tri3d(p1,q1,r1,p2,q2,r2);
return coplanar;
}
}
}
};
if (dp1 == POSITIVE) {
if (dq1 == POSITIVE) return TRI_TRI_3D(r1,p1,q1,p2,r2,q2,dp2,dr2,dq2);
else if (dr1 == POSITIVE) return TRI_TRI_3D(q1,r1,p1,p2,r2,q2,dp2,dr2,dq2) ;
else return TRI_TRI_3D(p1,q1,r1,p2,q2,r2,dp2,dq2,dr2);
} else if (dp1 == NEGATIVE) {
if (dq1 == NEGATIVE) return TRI_TRI_3D(r1,p1,q1,p2,q2,r2,dp2,dq2,dr2);
else if (dr1 == NEGATIVE) return TRI_TRI_3D(q1,r1,p1,p2,q2,r2,dp2,dq2,dr2);
else return TRI_TRI_3D(p1,q1,r1,p2,r2,q2,dp2,dr2,dq2);
} else {
if (dq1 == NEGATIVE) {
// why COPLANAR here? It seems so haphazard.
if (dr1 == POSITIVE || dr1 == COPLANAR) return TRI_TRI_3D(q1,r1,p1,p2,r2,q2,dp2,dr2,dq2);
else return TRI_TRI_3D(p1,q1,r1,p2,q2,r2,dp2,dq2,dr2);
}
else if (dq1 == POSITIVE) {
if (dr1 == POSITIVE) return TRI_TRI_3D(p1,q1,r1,p2,r2,q2,dp2,dr2,dq2);
else return TRI_TRI_3D(q1,r1,p1,p2,q2,r2,dp2,dq2,dr2);
}
else {
if (dr1 == POSITIVE) return TRI_TRI_3D(r1,p1,q1,p2,q2,r2,dp2,dq2,dr2);
else if (dr1 == NEGATIVE) return TRI_TRI_3D(r1,p1,q1,p2,r2,q2,dp2,dr2,dq2);
else
{
coplanar = coplanar_tri_tri3d(p1,q1,r1,p2,q2,r2);
return coplanar;
}
}
}
}
#ifdef IGL_STATIC_LIBRARY
// Explicit template specialization
// template using Eigen::Vector3d.
template bool igl::predicates::triangle_triangle_intersect<Eigen::Vector3d>(
const Eigen::Vector3d & p1,
const Eigen::Vector3d & q1,
const Eigen::Vector3d & r1,
const Eigen::Vector3d & p2,
const Eigen::Vector3d & q2,
const Eigen::Vector3d & r2,
bool & coplanar);
template bool igl::predicates::triangle_triangle_intersect<Eigen::RowVector3d>(
const Eigen::RowVector3d & p1,
const Eigen::RowVector3d & q1,
const Eigen::RowVector3d & r1,
const Eigen::RowVector3d & p2,
const Eigen::RowVector3d & q2,
const Eigen::RowVector3d & r2,
bool & coplanar);
#endif