Box2D.Polygon Struct Reference

A solid convex polygon. It is assumed that the interior of the polygon is to the left of each edge. Polygons have a maximum number of vertices equal to B2_MAX_POLYGON_VERTICES. In most cases you should not need many vertices for a convex polygon. Warning: DO NOT fill this out manually, instead use a helper function like MakePolygon or MakeBox. More...

Public Member Functions
	Polygon (ReadOnlySpan< Vec2 > points, float radius=0f)
	Construct a polygon shape with a set of vertices and an optional radius.
static Polygon	MakePolygon (in Hull hull, float radius)
	Make a convex polygon from a convex hull. This will assert if the hull is not valid.
static Polygon	MakeOffsetPolygon (in Hull hull, Vec2 position, Rotation rotation)
	Make an offset convex polygon from a convex hull. This will assert if the hull is not valid.
static Polygon	MakeOffsetRoundedPolygon (in Hull hull, Vec2 position, Rotation rotation, float radius)
	Make an offset convex polygon from a convex hull. This will assert if the hull is not valid.
static Polygon	MakeSquare (float halfWidth)
	Make a square polygon, bypassing the need for a convex hull.
static Polygon	MakeBox (float halfWidth, float halfHeight)
	Make a box (rectangle) polygon, bypassing the need for a convex hull.
static Polygon	MakeRoundedBox (float halfWidth, float halfHeight, float radius)
	Make a rounded box, bypassing the need for a convex hull.
static Polygon	MakeOffsetBox (float halfWidth, float halfHeight, Vec2 center, Rotation rotation)
	Make an offset box, bypassing the need for a convex hull.
static Polygon	MakeOffsetRoundedBox (float halfWidth, float halfHeight, Vec2 center, Rotation rotation, float radius)
	Make an offset rounded box, bypassing the need for a convex hull.
static Polygon	TransformPolygon (Transform transform, in Polygon polygon)
	Transform a polygon. This is useful for transferring a shape from one body to another.
MassData	ComputeMass (float density)
	Compute mass properties of this polygon.
AABB	ComputeAABB (in Transform transform)
	Compute the bounding box of this transformed polygon.
bool	TestPoint (in Vec2 point)
	Test this point for overlap with a convex polygon in local space.
CastOutput	RayCast (in RayCastInput input)
	Ray cast versus this polygon shape in local space. Initial overlap is treated as a miss.
CastOutput	ShapeCast (in ShapeCastInput input)
	Shape cast versus this convex polygon. Initial overlap is treated as a miss.

Static Public Member Functions
static Polygon	MakePolygon (ReadOnlySpan< Vec2 > points, float radius)
	Make a convex polygon from a set of points. This will create a hull and assert if it is not valid.
static Polygon	MakeOffsetPolygon (Span< Vec2 > points, Vec2 position, Rotation rotation)
	Make an offset convex polygon from a set of points. This will create a hull and assert if it is not valid.
static Polygon	MakeOffsetRoundedPolygon (Span< Vec2 > points, Vec2 position, Rotation rotation, float radius)
	Make an offset convex polygon from a set of points. This will create a hull and assert if it is not valid.

Public Attributes
Vec2	Centroid
	The centroid of the polygon.
float	Radius
	The external radius for rounded polygons.

Properties
ReadOnlySpan< Vec2 >	Vertices [get]
	The polygon vertices.
ReadOnlySpan< Vec2 >	Normals [get]
	The outward normal vectors of the polygon sides.

Detailed Description

A solid convex polygon. It is assumed that the interior of the polygon is to the left of each edge. Polygons have a maximum number of vertices equal to B2_MAX_POLYGON_VERTICES. In most cases you should not need many vertices for a convex polygon. Warning: DO NOT fill this out manually, instead use a helper function like MakePolygon or MakeBox.

Constructor & Destructor Documentation

Polygon()

Box2D.Polygon.Polygon ( ReadOnlySpan< Vec2 >  points, float  radius = 0f  )

inline

Construct a polygon shape with a set of vertices and an optional radius.

This constructor implicitly creates a Hull from the points. The hull is computed in the order of the points. The hull is assumed to be convex.
A radius greater than 0 will create a rounded polygon. A negative radius is invalid.

Member Function Documentation

MakeBox()

static Polygon Box2D.Polygon.MakeBox	(	float	halfWidth,
		float	halfHeight
	)

Make a box (rectangle) polygon, bypassing the need for a convex hull.

Parameters

halfWidth	the half-width (x-axis)
halfHeight	the half-height (y-axis)

MakeOffsetBox()

static Polygon Box2D.Polygon.MakeOffsetBox	(	float	halfWidth,
		float	halfHeight,
		Vec2	center,
		Rotation	rotation
	)

Make an offset box, bypassing the need for a convex hull.

Parameters

halfWidth	the half-width (x-axis)
halfHeight	the half-height (y-axis)
center	the local center of the box
rotation	the local rotation of the box

MakeOffsetPolygon()

static Polygon Box2D.Polygon.MakeOffsetPolygon	(	in Hull	hull,
		Vec2	position,
		Rotation	rotation
	)

Make an offset convex polygon from a convex hull. This will assert if the hull is not valid.

Warning: Do not manually fill in the hull data, it must come directly from b2ComputeHull

MakeOffsetRoundedBox()

static Polygon Box2D.Polygon.MakeOffsetRoundedBox	(	float	halfWidth,
		float	halfHeight,
		Vec2	center,
		Rotation	rotation,
		float	radius
	)

Make an offset rounded box, bypassing the need for a convex hull.

Parameters

halfWidth	the half-width (x-axis)
halfHeight	the half-height (y-axis)
center	the local center of the box
rotation	the local rotation of the box
radius	the radius of the rounded extension

MakeOffsetRoundedPolygon()

static Polygon Box2D.Polygon.MakeOffsetRoundedPolygon	(	in Hull	hull,
		Vec2	position,
		Rotation	rotation,
		float	radius
	)

Make an offset convex polygon from a convex hull. This will assert if the hull is not valid.

Warning: Do not manually fill in the hull data, it must come directly from b2ComputeHull

MakePolygon()

static Polygon Box2D.Polygon.MakePolygon	(	in Hull	hull,
		float	radius
	)

Make a convex polygon from a convex hull. This will assert if the hull is not valid.

Warning: Do not manually fill in the hull data, it must come directly from b2ComputeHull

MakeRoundedBox()

static Polygon Box2D.Polygon.MakeRoundedBox	(	float	halfWidth,
		float	halfHeight,
		float	radius
	)

Make a rounded box, bypassing the need for a convex hull.

Parameters

halfWidth	the half-width (x-axis)
halfHeight	the half-height (y-axis)
radius	the radius of the rounded extension

MakeSquare()

static Polygon Box2D.Polygon.MakeSquare

(

float

halfWidth

)

Make a square polygon, bypassing the need for a convex hull.

Parameters

halfWidth

the half-width

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

• src/Box2DBindings/Shapes/Polygon.cs