Distance Proxy. More...

#include <DistanceProxy.hpp>

Collaboration diagram for playrho::d2::DistanceProxy:

Public Types
using	ConstVertexPointer = const Length2 *
	Constant vertex pointer.

using	ConstVertexIterator = ConstVertexPointer
	Constant vertex iterator.

using	ConstNormalPointer = const UnitVec *
	Constant normal pointer.

using	ConstNormalIterator = ConstNormalPointer
	Constant normal iterator.

Public Member Functions
	DistanceProxy (const DistanceProxy &copy) noexcept
	Copy constructor.

	DistanceProxy (const NonNegative< Length > vertexRadius, const VertexCounter count, const Length2 vertices, const UnitVec normals) noexcept
	Initializing constructor. More...

auto	GetVertexRadius () const noexcept
	Gets the vertex radius of the vertices of the associated shape. More...

Range< ConstVertexIterator >	GetVertices () const noexcept
	Gets the range of vertices.

Range< ConstNormalIterator >	GetNormals () const noexcept
	Gets the range of normal.

auto	GetVertexCount () const noexcept
	Gets the vertex count. More...

auto	GetVertex (VertexCounter index) const noexcept
	Gets a vertex by index. More...

auto	GetNormal (VertexCounter index) const noexcept
	Gets the normal for the given index.

Private Attributes
const Length2 *	m_vertices = nullptr
	Vertices.

const UnitVec *	m_normals = nullptr
	Normals.

VertexCounter	m_count = 0
	Count of valid elements of m_vertices.

NonNegative< Length >	m_vertexRadius = 0_m
	Radius of the vertices of the associated shape.

Related Functions
(Note that these are not member functions.)
AABB	ComputeAABB (const DistanceProxy &proxy, const Transformation &xf) noexcept
	Computes the AABB. More...

AABB	ComputeAABB (const DistanceProxy &proxy, const Transformation &xfm0, const Transformation &xfm1) noexcept
	Computes the AABB. More...

bool	operator== (const DistanceProxy &lhs, const DistanceProxy &rhs) noexcept
	Determines with the two given distance proxies are equal.

bool	operator!= (const DistanceProxy &lhs, const DistanceProxy &rhs) noexcept
	Determines with the two given distance proxies are not equal.

template<class T >
VertexCounter	GetSupportIndex (const DistanceProxy &proxy, T dir) noexcept
	Gets the supporting vertex index in the given direction for the given distance proxy. More...

bool	TestPoint (const DistanceProxy &proxy, Length2 point) noexcept
	Tests a point for containment in the given distance proxy. More...

RayCastOutput	RayCast (const DistanceProxy &proxy, const RayCastInput &input, const Transformation &transform) noexcept
	Cast a ray against the distance proxy. More...

Detailed Description

Distance Proxy.

A distance proxy aggregates a convex set of vertices and a vertex radius of those vertices. This can be visualized as a convex N-sided polygon with rounded corners. It's meant to represent any single portion of a shape identified by its child-index. These are used by the G.J.K. algorithm: "a method for determining the minimum distance between two convex sets".

Note: This data structure is 24-bytes.

See also: https://en.wikipedia.org/wiki/Gilbert%2DJohnson%2DKeerthi_distance_algorithm

Constructor & Destructor Documentation

◆ DistanceProxy()

playrho::d2::DistanceProxy::DistanceProxy	(	const NonNegative< Length >	vertexRadius,
		const VertexCounter	count,
		const Length2 *	vertices,
		const UnitVec *	normals
	)

inlinenoexcept

Initializing constructor.

Constructs a distance proxy for n-point shape (like a polygon).

Parameters

vertexRadius	Radius of the given vertices.
count	Count of elements of the vertices and normals arrays.
vertices	Collection of vertices of the shape (relative to the shape's origin).
normals	Collection of normals of the shape.

Note: The vertices collection must have more than zero elements and no more than MaxShapeVertices elements.

Warning: Behavior is undefined if the vertices collection has less than one element or more than MaxShapeVertices elements.; Behavior is undefined if the vertices are not in counter-clockwise order.; Behavior is undefined if the shape defined by the vertices is not convex.; Behavior is undefined if the normals aren't normals for adjacent vertices.; Behavior is undefined if any normal is not unique.

Member Function Documentation

◆ GetVertex()

auto playrho::d2::DistanceProxy::GetVertex ( VertexCounter index ) const

inlinenoexcept

Gets a vertex by index.

Parameters

index Index value less than the count of vertices represented by this proxy.

Warning: Behavior is undefined if the index given is not less than the count of vertices represented by this proxy.; Behavior is undefined if InvalidVertex is given as the index value.

Returns: Vertex linear position (relative to the shape's origin) at the given index.

See also: Distance.

Referenced by playrho::d2::CollideShapes(), playrho::d2::GetManifold(), playrho::d2::GetMaxSeparation(), playrho::d2::GetMaxSeparation4x4(), and playrho::d2::GetSeparationScenario().

◆ GetVertexCount()

auto playrho::d2::DistanceProxy::GetVertexCount ( ) const

inlinenoexcept

Gets the vertex count.

This is the count of valid vertex elements that this object provides.

Returns: Value between 0 and MaxShapeVertices.

Note: This only returns 0 if this proxy was default constructed.

Referenced by playrho::d2::CollideShapes(), playrho::d2::Distance(), playrho::d2::GetManifold(), playrho::d2::GetMaxSeparation(), and playrho::d2::GetSeparationScenario().

◆ GetVertexRadius()

auto playrho::d2::DistanceProxy::GetVertexRadius ( ) const

inlinenoexcept

Gets the vertex radius of the vertices of the associated shape.

Returns: Non-negative distance.

Referenced by playrho::d2::CollideShapes(), playrho::d2::GetManifold(), playrho::d2::GetToiViaSat(), and playrho::d2::TestOverlap().

Friends And Related Function Documentation

◆ ComputeAABB() [1/2]

AABB ComputeAABB	(	const DistanceProxy &	proxy,
		const Transformation &	xf
	)

Computes the Axis Aligned Bounding Box (AABB) for the given child shape at a given a transform.

Warning: Behavior is undefined if the given transformation is invalid.

Parameters

proxy	Distance proxy for the child shape.
xf	World transform of the shape.

Returns: AABB for the proxy shape or the default AABB if the proxy has a zero vertex count.

Examples: World.cpp.

◆ ComputeAABB() [2/2]

AABB ComputeAABB	(	const DistanceProxy &	proxy,
		const Transformation &	xfm0,
		const Transformation &	xfm1
	)

Computes the Axis Aligned Bounding Box (AABB) for the given child shape at the given transforms.

Warning: Behavior is undefined if a given transformation is invalid.

Parameters

proxy	Distance proxy for the child shape.
xfm0	World transform 0 of the shape.
xfm1	World transform 1 of the shape.

Returns: AABB for the proxy shape or the default AABB if the proxy has a zero vertex count.

◆ GetSupportIndex()

template<class T >

VertexCounter GetSupportIndex	(	const DistanceProxy &	proxy,
		T	dir
	)

This finds the vertex that's most significantly in the direction of the given vector and returns its index.

Note: 0 is returned for a given zero length direction vector.

Parameters

proxy	Distance proxy object to find index in if a valid index exists for it.
dir	Direction vector to find index for.

Returns: InvalidVertex if d is invalid or the count of vertices is zero, otherwise a value from 0 to one less than count.

See also: GetVertexCount().

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

DistanceProxy.hpp
AABB.hpp
RayCastOutput.hpp

Public Types

Public Member Functions

Private Attributes

Related Functions

Detailed Description

Constructor & Destructor Documentation

◆ DistanceProxy()

Member Function Documentation

◆ GetVertex()

◆ GetVertexCount()

◆ GetVertexRadius()

Friends And Related Function Documentation

◆ ComputeAABB() [1/2]

◆ ComputeAABB() [2/2]

◆ GetSupportIndex()