ToyMaker::Polytope Class Reference

Primitive for EPA algorithm. More...

#include <types.hpp>

Classes
struct	Face
	Stores the indices of a single face of this polytope. More...

Public Member Functions
	Polytope (const Simplex &simplex)
	Creates a polytope object out of a simplex.
glm::vec3	getNextSearch () const
	Returns the next search direction for a point to add to the polytope.
std::size_t	getNumFaces () const
std::size_t	getNumPoints () const
glm::vec3	getClosestPoint () const
	Returns the closest point to the origin on the triangle face closest to the origin.
glm::vec3	getClosestTriangleNormal () const
	Returns the direction to the closest point on the polytope's surface from the origin.
AreaTriangle	getClosestTriangle () const
	Returns the closest polytope triangle.
AreaTriangle	getClosestTriangleSupportA () const
	Gets the points of shape A that were responsible for generating the closest triangle of the polytope.
AreaTriangle	getClosestTriangleSupportB () const
	Gets the points of shape B that were responsible for generating the closest triangle of the polytope.
bool	append (const glm::vec3 &newPoint, const glm::vec3 &supportA, const glm::vec3 &supportB)
	Appends a new point, replacing the topmost triangle in the polygon with 3 more triangles including the new point.

Private Member Functions
	Polytope ()
glm::vec3	getTriangleCross (const Face &face) const
glm::vec3	getTriangleNorm (const Face &face) const

Private Attributes
std::priority_queue< Face, std::vector< Face >, std::function< bool(const Face &, const Face &)> >	mFaces
	The list of triangle faces representing this polytope.
std::vector< glm::vec3 >	mPoints {}
	List of points representing this polytope.
std::vector< glm::vec3 >	mPointsSupportA {}
	List of points representing support point A, where each point corresponds to the polytope point it generated in mPoints at the same index.
std::vector< glm::vec3 >	mPointsSupportB {}
	List of points representing support point B, where each point corresponds to the polytope point it generated in mPoints at the same index.

Detailed Description

Primitive for EPA algorithm.

Represents a polygonal shape contained within the Minkowski difference of two intersecting shapes. Stores polytope faces in order of their proximity to the origin.

Constructor & Destructor Documentation

Polytope() [1/2]

Polytope::Polytope ( )

private

Initializes an empty polytope

Polytope() [2/2]

Polytope::Polytope

(

const Simplex &

simplex

)

Creates a polytope object out of a simplex.

Simplex must be a tetrahedron enclosing the origin – creation will fail otherwise.

Member Function Documentation

append()

bool Polytope::append	(	const glm::vec3 &	newPoint,
		const glm::vec3 &	supportA,
		const glm::vec3 &	supportB )

Appends a new point, replacing the topmost triangle in the polygon with 3 more triangles including the new point.

Parameters

newPoint	The new point to add to the polytope
supportA	The term on the LHS of the Minkowski difference that created newPoint
supportB	The term on the RHS of the Minkowski difference that created newPoint

Return values

false	New point is not beyond current closest point in latest search direction.
true	Successfully appended triangles including new point to the list.

getClosestTriangle()

AreaTriangle Polytope::getClosestTriangle

(

)

const

Returns the closest polytope triangle.

This is useful when we want to find the barycentric coordinates of this triangle to derive contact points for a pair of intersecting shapes.

getClosestTriangleNormal()

glm::vec3 Polytope::getClosestTriangleNormal

(

)

const

Returns the direction to the closest point on the polytope's surface from the origin.

Directly represents the contact normal between two objects.

getNumFaces()

std::size_t ToyMaker::Polytope::getNumFaces ( ) const

inline

Returns the number of faces that this polytope is comprised of

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

• ToyMaker_Main/include/toymaker/engine/spatial_query/types.hpp
• ToyMaker_Main/src/spatial_query/types.cpp