playrho::d2::Sweep Class Reference

Description of a "sweep" of motion in 2-D space. More...

#include <Sweep.hpp>

Collaboration diagram for playrho::d2::Sweep:

Public Member Functions
	Sweep ()=default
	Default constructor.
constexpr	Sweep (const Sweep &copy)=default
	Copy constructor.
constexpr	Sweep (const Position p0, const Position p1, const Length2 lc=Length2{0_m, 0_m}, Real a0=0) noexcept
	Initializing constructor.
constexpr	Sweep (const Position p, const Length2 lc=Length2{0_m, 0_m})
	Initializing constructor.
Length2	GetLocalCenter () const noexcept
	Gets the local center of mass position. More...
Real	GetAlpha0 () const noexcept
	Gets the alpha 0 for this sweep. More...
void	Advance0 (Real alpha) noexcept
	Advances the sweep by a factor of the difference between the given time alpha and the sweep's alpha 0. More...
void	ResetAlpha0 () noexcept
	Resets the alpha 0 value back to zero. More...

Public Attributes
Position	pos0
	Center world position and world angle at time "0".
Position	pos1
	Center world position and world angle at time "1".

Private Attributes
Length2	localCenter = Length2{0_m, 0_m}
	Local center of mass position. More...
Real	alpha0 = 0
	Fraction of the current time step in the range [0,1]. More...

Related Functions
(Note that these are not member functions.)
Sweep	GetNormalized (Sweep sweep) noexcept
	Gets a sweep with the given sweep's angles normalized. More...
constexpr bool	operator== (const Sweep &lhs, const Sweep &rhs)
	Equals operator.
constexpr bool	operator!= (const Sweep &lhs, const Sweep &rhs)
	Not-equals operator.
template<>
constexpr bool	IsValid (const d2::Sweep &value) noexcept
	Determines if the given value is valid.

Detailed Description

Description of a "sweep" of motion in 2-D space.

This describes the motion of a body/shape for TOI computation. Shapes are defined with respect to the body origin, which may not coincide with the center of mass. However, to support dynamics we must interpolate the center of mass position.

Note

This data structure is likely 36-bytes (at least on 64-bit platforms).

Examples

Body.cpp.

Member Function Documentation

Advance0()

void playrho::d2::Sweep::Advance0 ( Real  alpha )

inlinenoexcept

Advances the sweep by a factor of the difference between the given time alpha and the sweep's alpha 0.

This advances position 0 (pos0) of the sweep towards position 1 (pos1) by a factor of the difference between the given alpha and the alpha 0.

Parameters

alpha

Valid new time factor in [0,1) to update the sweep to. Behavior is undefined if value is invalid.

Referenced by playrho::d2::Body::Advance(), and playrho::d2::Body::Advance0().

GetAlpha0()

Real playrho::d2::Sweep::GetAlpha0 ( ) const

inlinenoexcept

Gets the alpha 0 for this sweep.

Returns

Value between 0 and less than 1.

Referenced by playrho::d2::GetToiViaSat(), and playrho::d2::operator==().

GetLocalCenter()

Length2 playrho::d2::Sweep::GetLocalCenter ( ) const

inlinenoexcept

Gets the local center of mass position.

Note

This value can only be set via a sweep constructed using an initializing constructor.

Referenced by playrho::d2::operator==().

ResetAlpha0()

void playrho::d2::Sweep::ResetAlpha0 ( )

inlinenoexcept

Resets the alpha 0 value back to zero.

Postcondition

Getting the alpha 0 value after calling this method will return zero.

Referenced by playrho::d2::Body::ResetAlpha0().

Friends And Related Function Documentation

GetNormalized()

Sweep GetNormalized ( Sweep  sweep )

related

Gets a sweep with the given sweep's angles normalized.

Parameters

sweep

Sweep to return with its angles normalized.

Returns

Sweep with its position 0 angle to be between -2 pi and 2 pi and its position 1 angle reduced by the amount the position 0 angle was reduced by.

Member Data Documentation

alpha0

Real playrho::d2::Sweep::alpha0 = 0

private

Fraction of the current time step in the range [0,1].

Note

pos0.linear and pos0.angular are the positions at alpha0.

4-bytes.

Referenced by GetAlpha0(), and ResetAlpha0().

localCenter

Length2 playrho::d2::Sweep::localCenter = Length2{0_m, 0_m}

private

Local center of mass position.

Note

8-bytes.

Referenced by GetLocalCenter().

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

• Sweep.hpp
• Math.hpp