Template Class Frustum

Class Documentation

template<typename value_t, size_t DIM, size_t SIDES>
class Acts::Frustum

Class representing a frustum shape.

The frustum is defined using an origin, a direction and an opening angle. These parameters are then used to calculate a number of side planes, each having a position and a normal vector. The “near plane” is assumed to coincide with the origin point, and the normal with the “direction” of the frustum. No far plane is defined.

Template Parameters

  • value_t: The floating point value to use

  • DIM: The number of dimensions of ambient space

  • SIDES: The number of sides (= side planes) the frustum has (exactly 2 in 2D, minimum 3 in 3D)

Public Types

using transform_type = Eigen::Transform<value_t, DIM, Eigen::Affine>

Associated transform type.

using value_type = value_t

Re expose the value type.

using vertex_array_type = Eigen::Array<value_t, DIM, 1>

Vertex array type corresponding to the vertex type.

using VertexType = Eigen::Matrix<value_t, DIM, 1>

Vertex type based on the value type and dimension.

Public Functions

template<size_t D = DIM, std::enable_if_t<D == 2, int> = 0>
Frustum(const VertexType &origin, const VertexType &dir, value_type opening_angle)

Constructor for the 2D case.

Note

The opening_angle is defined as the angle between opposing side planes. The opening angle needs to be < pi.

Parameters

  • origin: The origin of the frustum

  • dir: The direction of the frustum

  • opening_angle: The opening angle

template<size_t D = DIM, std::enable_if_t<D == 3, int> = 0>
Frustum(const VertexType &origin, const VertexType &dir, value_type opening_angle)

Constructor for the 3D case.

Note

The opening_angle is defined as the angle between opposing side planes. The opening angle needs to be < pi.

Parameters

  • origin: The origin of the frustum

  • dir: The direction of the frustum

  • opening_angle: The opening angle

const VertexType &dir() const

Getter for the direction of the frustum.

Return

The direction of the frustum

template<size_t D = DIM, std::enable_if_t<D == 3, int> = 0>
void draw(IVisualization3D &helper, value_type far_distance = 10) const

Draw a representation of this frustum using a visualization helper.

Note

This is only available for the 3D case.

Parameters

  • helper: The visualization helper

  • far_distance: The distance to the virtual “far plane” at which point the side planes terminate visually.

const std::array<VertexType, SIDES + 1> &normals() const

Getter for the normal vectors of the planes defining this frustum.

Return

Array containing the normal vectors for all planes.

Note

The size of the array that is returned is fixed to number of sides

const VertexType &origin() const

Getter for the oriogin of the frustum.

Return

The origin of the frustum

template<size_t D = DIM, std::enable_if_t<D == 2, int> = 0>
std::ostream &svg(std::ostream &os, value_type w, value_type h, value_type far_distance = 1, value_type unit = 20.) const

Draw a representation of this frustum as an SVG string to an outstream.

Note

This is only available for the 2D case.

Parameters

  • os: The out stream to write to

  • w: The width of the output SVG

  • h: The height of the output SVG

  • far_distance: The distance to the virtual “far line” at which point the side lines terminate visually.

  • unit: Multiplicative factor to apply to internal distances

Frustum<value_t, DIM, SIDES> transformed(const transform_type &trf) const

Transforms this frustum using a given transform and returns a new instance.

Return

A copy of this frustum with the transform trf applied.

Parameters

  • trf: The transform to apply

Public Static Attributes

constexpr size_t dim = DIM

Re expose the number of dimensions.

constexpr size_t sides = SIDES

Re expose the number of sides.