SLCurveBezier Class Reference

The SLCurveBezier class implements a Bezier curve interpolation. More...

#include <SLCurveBezier.h>

Inheritance diagram for SLCurveBezier:

Public Member Functions
	SLCurveBezier (const SLVVec4f &points)
	SLCurveBezier (const SLVVec4f &points, const SLVVec3f &controlPoints)
	~SLCurveBezier ()
void	dispose ()
	Deletes all curve arrays. More...
void	init (const SLVVec4f &points, const SLVVec3f &controlPoints)
void	draw (const SLMat4f &wm)
SLVec3f	evaluate (const SLfloat t)
SLVec3f	velocity (SLfloat t)
SLVec3f	acceleration (SLfloat t)
SLfloat	segmentArcLength (SLuint i, SLfloat u1, SLfloat u2)
SLfloat	subdivideLength (const SLVec3f &P0, const SLVec3f &P1, const SLVec3f &P2, const SLVec3f &P3)
void	subdivideRender (SLVVec3f &points, const SLMat4f &wm, SLfloat epsilon, const SLVec3f &P0, const SLVec3f &P1, const SLVec3f &P2, const SLVec3f &P3)
SLfloat	arcLength (SLfloat t1, SLfloat t2)
SLfloat	findParamByDist (SLfloat t1, SLfloat s)
SLint	numControlPoints ()
SLVVec3f &	controls ()
Public Member Functions inherited from SLCurve
	SLCurve ()
virtual	~SLCurve ()
virtual void	dispose ()=0
virtual SLVec3f	evaluate (const SLfloat t)=0
virtual void	draw (const SLMat4f &wm)=0

Protected Attributes
SLVVec3f	_controls
	Control points of Bezier curve. More...
SLGLVertexArrayExt	_vao
	Vertex array object for rendering. More...
Protected Attributes inherited from SLCurve
SLVVec4f	_points
	Sample points (x,y,z) and time (w) of curve. More...
SLVfloat	_lengths
	Length of each curve segment. More...
SLfloat	_totalLength
	Total length of curve. More...

Detailed Description

The SLCurveBezier class implements a Bezier curve interpolation.

The SLCurveBezier class implements a Bezier curve interpolation. The math is originally based on the implementation from the book: "Essential Mathematics for Games and Interactive Applications" from James M. Van Verth and Lars M. Bishop.

Constructor & Destructor Documentation

SLCurveBezier() [1/2]

SLCurveBezier::SLCurveBezier

(

const SLVVec4f &

points

)

SLCurveBezier() [2/2]

SLCurveBezier::SLCurveBezier	(	const SLVVec4f &	points,
		const SLVVec3f &	controlPoints
	)

~SLCurveBezier()

SLCurveBezier::~SLCurveBezier

(

)

Member Function Documentation

acceleration()

SLVec3f SLCurveBezier::acceleration

(

SLfloat

t

)

SLCurveBezier::curveAcceleration determines the acceleration vector on the curve at time t. It is the second derivative at point t.

arcLength()

SLfloat SLCurveBezier::arcLength	(	SLfloat	t1,
		SLfloat	t2
	)

Calculate length of curve between parameters t1 and t2

controls()

SLVVec3f & SLCurveBezier::controls ( )

inline

dispose()

void SLCurveBezier::dispose ( )

virtual

Deletes all curve arrays.

Implements SLCurve.

draw()

void SLCurveBezier::draw ( const SLMat4f &  wm )

virtual

SLCurveBezier::draw does the rendering of the Bezier curve in world space.

Implements SLCurve.

evaluate()

SLVec3f SLCurveBezier::evaluate ( const SLfloat  t )

virtual

SLCurveBezier::curveEvaluate determines the position on the curve at time t.

Implements SLCurve.

findParamByDist()

SLfloat SLCurveBezier::findParamByDist	(	SLfloat	t1,
		SLfloat	s
	)

SLCurveBezier::findParamByDist gets parameter s distance in arc length from Q(t1). Returns max SLfloat if can't find it.

init()

void SLCurveBezier::init	(	const SLVVec4f &	points,
		const SLVVec3f &	controlPoints
	)

Init curve with curve points and times. If no control points are passed they will be calculated automatically

Parameters

points	Array of points on the Bezier curve (w = time)
controlPoints	Array of control points with size = 2*(numPointsAndTimes-1)

numControlPoints()

SLint SLCurveBezier::numControlPoints ( )

inline

segmentArcLength()

SLfloat SLCurveBezier::segmentArcLength	(	SLuint	i,
		SLfloat	u1,
		SLfloat	u2
	)

SLCurveBezier::segmentArcLength calculate length of curve segment between parameters u1 and u2 by recursively subdividing the segment.

subdivideLength()

SLfloat SLCurveBezier::subdivideLength	(	const SLVec3f &	P0,
		const SLVec3f &	P1,
		const SLVec3f &	P2,
		const SLVec3f &	P3
	)

SLCurveBezier::subdivideLength calculates length of Bezier curve by recursive midpoint subdivision.

subdivideRender()

void SLCurveBezier::subdivideRender	(	SLVVec3f &	renderPoints,
		const SLMat4f &	wm,
		SLfloat	epsilon,
		const SLVec3f &	P0,
		const SLVec3f &	P1,
		const SLVec3f &	P2,
		const SLVec3f &	P3
	)

SLCurveBezier::subdivideRender adds points along the curve to the point vector renderPoints by recursively subdividing the curve with the Casteljau scheme.

velocity()

SLVec3f SLCurveBezier::velocity

(

SLfloat

t

)

SLCurveBezier::curveVelocity determines the velocity vector on the curve at point t. The velocity vector direction is the tangent vector at t an is the first derivative at point t. The velocity vector magnitude is the speed at point t.

Member Data Documentation

_controls

SLVVec3f SLCurveBezier::_controls

protected

Control points of Bezier curve.

_vao

SLGLVertexArrayExt SLCurveBezier::_vao

protected

Vertex array object for rendering.

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

• SLCurveBezier.h
• SLCurveBezier.cpp