bool operator()( const Point1& a, const Point2& b ) const
{
BOOST_CONCEPT_ASSERT((Point2DConcept<Point1>));
BOOST_CONCEPT_ASSERT((Point2DConcept<Point2>));
const vector_double_2d da = a - m_origin, db = b - m_origin;
const double detb = exterior_product_area( m_reference, db );
//! If v2 is along reference it is smallest.
if( m_cmp.equals(detb, 0) && m_cmp.greater_than_or_equal(dot_product( db, m_reference ), 0) )
return false;
const double deta = exterior_product_area( m_reference, da );
//! If v1 is along reference it is smallest.
if( m_cmp.equals(deta, 0) && m_cmp.greater_than_or_equal(dot_product( da, m_reference ), 0) )
return true;
//! If detv1 and detv2 have the same sign, they are on the same side of reference and can be compared directly.
if( m_cmp.greater_than_or_equal(deta * detb, 0) )
{
//! both on same side of reference: compare to each other
return m_cmp.greater_than(exterior_product_area( da, db ), 0);
}
//! At this point one of the two detvX is negative. A negative detvX means a large angle WRT reference.
//! If v1 is positive it must be smaller than v2, else the opposite must be true.
return m_cmp.greater_than(deta, 0);
}
//! Generate a new item to visit based on the adjacent triangle at index next.
boost::optional<edge_item> prepare_adjacent_traversal( std::size_t next, const edge_item& item )
{
comparison_policy cmp( 0 );
bool allAround = get<0>( item.lo ) == constants::infinity<coordinate_type>() && get<0>( item.hi ) == constants::negative_infinity<coordinate_type>();
const std::size_t* fromIndices = m_mesh.get_triangle_indices( item.to );
const std::size_t* toIndices = m_mesh.get_triangle_indices( next );
std::size_t side = get_triangle_adjacent_side( fromIndices, toIndices );
auto pointLo = m_mesh.get_triangle_vertices( item.to )[side];
auto pointHi = m_mesh.get_triangle_vertices( item.to )[(side + 1) % 3];
if( exterior_product_area( pointHi - pointLo, m_origin - pointLo ) < constants::zero<decltype(std::declval<coordinate_type>() * std::declval<coordinate_type>())>() )
std::swap( pointLo, pointHi );
if (!is_segment_in_range_2d(make_segment(pointLo, pointHi), item.lo, item.hi, m_origin))
return boost::none;
#if GEOMETRIX_TEST_ENABLED(GEOMETRIX_DEBUG_VISIBLE_VERTICES_MESH_SEARCH)
//polygon2 pTri(mMesh.get_triangle_vertices(item.from), mMesh.get_triangle_vertices(item.from) + 3);
typedef std::vector<point_t> polygon2;
typedef segment<point_t> segment2;
polygon2 cTri(m_mesh.get_triangle_vertices(item.to), m_mesh.get_triangle_vertices(item.to) + 3);
polygon2 nTri(m_mesh.get_triangle_vertices(next), m_mesh.get_triangle_vertices(next) + 3);
segment2 sLo{ m_origin, m_origin + item.lo };
segment2 sHi{ m_origin, m_origin + item.hi };
segment2 cLo{ m_origin, pointLo };
segment2 cHi{ m_origin, pointHi };
#endif
vector_t vecLo, vecHi;
if( !numeric_sequence_equals_2d(m_origin, pointLo, cmp) && !numeric_sequence_equals_2d(m_origin, pointHi, cmp) )
{
assign( vecLo, pointLo - m_origin );
assign( vecHi, pointHi - m_origin );
if (!allAround)
{
vecLo = is_vector_between(item.lo, item.hi, vecLo, false, cmp) ? vecLo : item.lo;
vecHi = is_vector_between(item.lo, item.hi, vecHi, false, cmp) ? vecHi : item.hi;
}
if (get_orientation(vecHi, vecLo, cmp) == geometrix::oriented_left)
return boost::none;
}
else
{
assign( vecLo, constants::infinity<coordinate_type>(), constants::zero<coordinate_type>() );
assign( vecHi, constants::negative_infinity<coordinate_type>(), constants::zero<coordinate_type>() );
}
#if GEOMETRIX_TEST_ENABLED(GEOMETRIX_DEBUG_VISIBLE_VERTICES_MESH_SEARCH)
segment2 nLo{ m_origin, m_origin + vecLo };
segment2 nHi{ m_origin, m_origin + vecHi };
#endif
return edge_item( item.to, next, vecLo, vecHi );
}