Aleph::SegmentSegmentIntersection Class Reference

Dedicated exact intersection for a single pair of segments. More...

#include <geom_algorithms.H>

Classes
struct	Result
	Detailed result of a segment-segment intersection test. More...

Public Types
enum class	Kind { NONE , POINT , OVERLAP }
	Types of intersection between two segments. More...

Public Member Functions
Result	operator() (const Segment &s1, const Segment &s2) const
	Computes the intersection of two line segments.

Static Private Member Functions
static bool	point_less_on_axis (const Point &a, const Point &b, const bool vertical_axis)
static Point	point_max_on_axis (const Point &a, const Point &b, const bool vertical_axis)
static Point	point_min_on_axis (const Point &a, const Point &b, const bool vertical_axis)
static Segment	collinear_overlap (const Segment &s1, const Segment &s2)

Detailed Description

Dedicated exact intersection for a single pair of segments.

This utility solves the 2-segment case directly in constant time using exact predicates from point.H, instead of routing through a sweep-line structure meant for many segments.

Returned intersection kinds:

• Kind::NONE: no intersection.
• Kind::POINT: unique intersection point (proper cross, endpoint touch, or degenerate point-on-segment).
• Kind::OVERLAP: collinear overlap interval (non-zero length).

Complexity

• Time: O(1)
• Space: O(1)

Definition at line 5572 of file geom_algorithms.H.

Member Enumeration Documentation

Kind

enum class Aleph::SegmentSegmentIntersection::Kind

strong

Types of intersection between two segments.

Enumerator
NONE	No intersection.
POINT	Intersection at a single point.
OVERLAP	Intersection over a collinear interval.

Definition at line 5578 of file geom_algorithms.H.

Member Function Documentation

collinear_overlap()

static Segment Aleph::SegmentSegmentIntersection::collinear_overlap ( const Segment &  s1, const Segment &  s2  )

inlinestaticprivate

Definition at line 5632 of file geom_algorithms.H.

References Aleph::divide_and_conquer_partition_dp(), Aleph::Segment::get_src_point(), Aleph::Point::get_x(), point_less_on_axis(), point_max_on_axis(), and point_min_on_axis().

Referenced by operator()().

operator()()

Result Aleph::SegmentSegmentIntersection::operator() ( const Segment &  s1, const Segment &  s2  ) const

inline

Computes the intersection of two line segments.

Parameters

s1	First segment.
s2	Second segment.

Returns

Result structure with intersection type and details.

Definition at line 5659 of file geom_algorithms.H.

References collinear_overlap(), Aleph::divide_and_conquer_partition_dp(), Aleph::SegmentSegmentIntersection::Result::kind, OVERLAP, POINT, and Aleph::segments_intersect().

point_less_on_axis()

static bool Aleph::SegmentSegmentIntersection::point_less_on_axis ( const Point &  a, const Point &  b, const bool  vertical_axis  )

inlinestaticprivate

Definition at line 5602 of file geom_algorithms.H.

References Aleph::divide_and_conquer_partition_dp(), Aleph::Point::get_x(), and Aleph::Point::get_y().

Referenced by collinear_overlap(), point_max_on_axis(), and point_min_on_axis().

point_max_on_axis()

static Point Aleph::SegmentSegmentIntersection::point_max_on_axis ( const Point &  a, const Point &  b, const bool  vertical_axis  )

inlinestaticprivate

Definition at line 5618 of file geom_algorithms.H.

References Aleph::divide_and_conquer_partition_dp(), and point_less_on_axis().

Referenced by collinear_overlap().

point_min_on_axis()

static Point Aleph::SegmentSegmentIntersection::point_min_on_axis ( const Point &  a, const Point &  b, const bool  vertical_axis  )

inlinestaticprivate

Definition at line 5625 of file geom_algorithms.H.

References Aleph::divide_and_conquer_partition_dp(), and point_less_on_axis().

Referenced by collinear_overlap().

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The documentation for this class was generated from the following file:

• geom_algorithms.H