csegment

CSegment is a data structure or class commonly used in computational geometry, computer-aided design, and related software to represent a straight line segment defined by two endpoints. It can operate in two-dimensional (2D) or three-dimensional (3D) space and is often part of a broader geometry library that includes points, vectors, lines, and polygons.

A CSegment typically stores its endpoints, such as p1 and p2, as 2D or 3D points. It exposes common geometric properties and operations, including length, the direction vector from p1 to p2, and the midpoint. Practical methods may include distance to a point, projection of a point onto the segment, and checks for containment of a point. More advanced capabilities cover segment-to-segment intersection tests, closest points between segments, and distance from the segment to another geometric entity.

Key operations often supported by a CSegment include:

- length(): the Euclidean distance between p1 and p2

- direction(): the unit vector along the segment

- midpoint(): the point halfway between p1 and p2

- distanceToPoint(p): shortest distance from p to the segment

- closestPointTo(p): the point on the segment nearest to p

- intersectsWith(other): whether this segment intersects another segment (2D) or can be connected to another segment under tolerance (3D)

- projectPoint(p) and containsPoint(p, tol): checks with a numerical tolerance

Variants exist for 2D and 3D contexts, with numerical robustness concerns such as floating-point tolerance and special cases where the segment collapses to a point. CSegment is commonly used in rendering, clipping, path planning, collision detection, and GIS workflows, often alongside related types like CPoint, CVector, CLine, and CPolyline.