Class Quadrilateral

Namespace: LMKit.Graphics.Geometry

Assembly: LM-Kit.NET.dll

Represents a quadrilateral (four-corner polygon) defined by four points. Immutable: all operations return new instances. Suitable for rotated rectangles, skewed boxes, or arbitrary four-cornered regions such as OCR bounding boxes. Provides geometric operations, transformations, and access to an axis-aligned bounding box (AABB).

public sealed class Quadrilateral : IBounds, ISize, IEquatable<Quadrilateral>

Inheritance: object

Quadrilateral

Implements: IBounds

ISize

IEquatable<Quadrilateral>

Inherited Members: object.Equals(object, object)

object.GetType()

object.ReferenceEquals(object, object)

Constructors

Quadrilateral(Point, Point, Point, Point): Initializes a new instance of the Quadrilateral class from four corner points. The inputs may be in any order; corners are normalized to (TopLeft, TopRight, BottomRight, BottomLeft), clockwise.

Fields

Empty: An empty quadrilateral positioned at the origin (0,0) with zero width and height.

Properties

Area: Gets the area of the quadrilateral, computed via the shoelace formula.

AxisAlignedBounds: Gets a Rectangle representing the axis-aligned bounding box (AABB) of this quadrilateral.

Bottom: Gets the largest Y-coordinate of the quadrilateral (bottom edge of the AABB). Computed lazily and cached.

BottomLeft: Gets the bottom-left corner of the quadrilateral.

BottomRight: Gets the bottom-right corner of the quadrilateral.

Centroid: Gets the polygon centroid (geometric center) computed via the shoelace formula. If the area is approximately zero, falls back to the average of the four corners.

Height: Gets the height of the axis-aligned bounding box (AABB) surrounding this quadrilateral. Computed lazily from Top and Bottom and cached.

Left: Gets the smallest X-coordinate of the quadrilateral (left edge of the AABB). Computed lazily and cached.

MidX: Gets the horizontal midpoint of the quadrilateral's axis-aligned bounds.

MidY: Gets the vertical midpoint of the quadrilateral's axis-aligned bounds.

Right: Gets the largest X-coordinate of the quadrilateral (right edge of the AABB). Computed lazily and cached.

Top: Gets the smallest Y-coordinate of the quadrilateral (top edge of the AABB). Computed lazily and cached.

TopLeft: Gets the top-left corner of the quadrilateral.

TopRight: Gets the top-right corner of the quadrilateral.

Width: Gets the width of the axis-aligned bounding box (AABB) surrounding this quadrilateral. Computed lazily from Left and Right and cached.

Methods

Contains(double, double): Determines whether the specified point lies inside (or on the edges of) the quadrilateral.

Deconstruct(out Point, out Point, out Point, out Point): Deconstructs the quadrilateral into corner points (TopLeft, TopRight, BottomRight, BottomLeft). Enables tuple-style deconstruction: var (tl, tr, br, bl) = quad;

Equals(Quadrilateral): Determines whether another quadrilateral has identical corner coordinates.

Equals(object): Determines whether the specified object is equal to the current quadrilateral.

FromBounds(IBounds): Creates a quadrilateral from an axis-aligned IBounds.

FromBounds(IBounds, double, Point): Creates a quadrilateral by rotating axis-aligned bounds about a given pivot point.

FromCenterSizeAngle(double, double, double, double, double): Creates a quadrilateral by specifying its center, size, and rotation angle.

FromRectangle(Rectangle): Creates a quadrilateral from a Rectangle.

FromRectangle(Rectangle, double, Point): Creates a quadrilateral by rotating a Rectangle about a given pivot point.

FromRectangle(double, double, double, double): Creates a quadrilateral from rectangle parameters (left, top, width, height).

FromRectangle(double, double, double, double, double, Point): Creates a quadrilateral from rectangle parameters and rotates it around a specified pivot point.

GetHashCode(): Returns a hash code for this quadrilateral based on its four corners.

Normalize(): Returns a new quadrilateral with corners normalized to (TopLeft, TopRight, BottomRight, BottomLeft), clockwise.

Rotate(double, Point): Returns a new quadrilateral rotated around a specified pivot point.

RotateAroundCenter(double): Returns a new quadrilateral rotated around its polygon centroid.

Scale(double, double): Returns a new quadrilateral scaled by the specified factors relative to the origin (0,0).

ToString(): Returns a string representation of the quadrilateral and its axis-aligned bounding box (AABB).

Translate(Point): Returns a new quadrilateral translated by a vector Point.

Translate(double, double): Returns a new quadrilateral translated (moved) by the specified offsets.

Union(IBounds): Returns the smallest axis-aligned quadrilateral that contains this quadrilateral and other. This is the union of their axis-aligned bounding boxes (AABB).

Union(Quadrilateral): Returns the AABB union of this quadrilateral and another quadrilateral, as a new axis-aligned quadrilateral.

Union(Quadrilateral, Quadrilateral): Returns the AABB union of two quadrilaterals as an axis-aligned quadrilateral.

Operators

operator +(Point, Quadrilateral): Translates a quadrilateral by a point offset.

operator +(Quadrilateral, Point): Translates a quadrilateral by a point offset.

operator /(Quadrilateral, double): Uniformly scales a quadrilateral relative to the origin by dividing by a scalar.

operator ==(Quadrilateral, Quadrilateral): Determines whether two quadrilaterals have identical corner coordinates (after normalization).

operator !=(Quadrilateral, Quadrilateral): Determines whether two quadrilaterals differ in any corner coordinate.

operator *(Quadrilateral, double): Uniformly scales a quadrilateral relative to the origin.

operator *(double, Quadrilateral): Uniformly scales a quadrilateral relative to the origin.