C# Класс burningmime.curves.CurveFitBase

This is the base class containing implementations common to CurveFit and CurveBuilder. Most of this is ported from http://tog.acm.org/resources/GraphicsGems/gems/FitCurves.c

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Защищенные свойства (Protected)

Свойство	Тип	Описание
_arclen	List
_pts	List
_squaredError	System.Double
_u	List

Защищенные методы

Метод	Описание
ArcLengthParamaterize ( int first, int last ) : void	Initializes the first (last - first) elements of u with scaled arc lengths.
FindMaxSquaredError ( int first, int last, CubicBezier curve, int &split ) : System.Double	Computes the maximum squared distance from a point to the curve using the current parameterization.
FitCurve ( int first, int last, System.Windows.Vector tanL, System.Windows.Vector tanR, CubicBezier &curve, int &split ) : bool	Tries to fit single Bezier curve to the points in [first ... last]. Destroys anything in _u in the process. Assumes there are at least two points to fit.
GenerateBezier ( int first, int last, System.Windows.Vector tanL, System.Windows.Vector tanR ) : CubicBezier	Generates a bezier curve for the segment using a least-squares approximation. for the derivation of this and why it works, see http://read.pudn.com/downloads141/ebook/610086/Graphics_Gems_I.pdf page 626 and beyond. tl;dr: math.
GetCenterTangent ( int first, int last, int split ) : System.Windows.Vector	Gets the tangent at a given point in the curve.
GetLeftTangent ( int last ) : System.Windows.Vector	Gets the tangent for the start of the cure.
GetRightTangent ( int first ) : System.Windows.Vector	Gets the tangent for the the end of the curve.
InitializeArcLengths ( ) : void	Builds the arc length array using the points array. Assumes _pts has points and _arclen is empty.
Reparameterize ( int first, int last, CubicBezier curve ) : void	Attempts to find a slightly better parameterization for u on the given curve.

Описание методов

ArcLengthParamaterize() защищенный Метод

Initializes the first (last - first) elements of u with scaled arc lengths.

protected ArcLengthParamaterize ( int first, int last ) : void
first	int
last	int
Результат	void

FindMaxSquaredError() защищенный Метод

Computes the maximum squared distance from a point to the curve using the current parameterization.

protected FindMaxSquaredError ( int first, int last, CubicBezier curve, int &split ) : System.Double
first	int
last	int
curve	CubicBezier
split	int
Результат	System.Double

FitCurve() защищенный Метод

Tries to fit single Bezier curve to the points in [first ... last]. Destroys anything in _u in the process. Assumes there are at least two points to fit.

protected FitCurve ( int first, int last, System.Windows.Vector tanL, System.Windows.Vector tanR, CubicBezier &curve, int &split ) : bool
first	int	Index of first point to consider.
last	int	Index of last point to consider (inclusive).
tanL	System.Windows.Vector	Tangent at teh start of the curve ("left").
tanR	System.Windows.Vector	Tangent on the end of the curve ("right").
curve	CubicBezier	The fitted curve.
split	int	Point at which to split if this method returns false.
Результат	bool

GenerateBezier() защищенный Метод

Generates a bezier curve for the segment using a least-squares approximation. for the derivation of this and why it works, see http://read.pudn.com/downloads141/ebook/610086/Graphics_Gems_I.pdf page 626 and beyond. tl;dr: math.

protected GenerateBezier ( int first, int last, System.Windows.Vector tanL, System.Windows.Vector tanR ) : CubicBezier
first	int
last	int
tanL	System.Windows.Vector
tanR	System.Windows.Vector
Результат	CubicBezier

GetCenterTangent() защищенный Метод

Gets the tangent at a given point in the curve.

protected GetCenterTangent ( int first, int last, int split ) : System.Windows.Vector
first	int
last	int
split	int
Результат	System.Windows.Vector

GetLeftTangent() защищенный Метод

Gets the tangent for the start of the cure.

protected GetLeftTangent ( int last ) : System.Windows.Vector
last	int
Результат	System.Windows.Vector

GetRightTangent() защищенный Метод

Gets the tangent for the the end of the curve.

protected GetRightTangent ( int first ) : System.Windows.Vector
first	int
Результат	System.Windows.Vector

InitializeArcLengths() защищенный Метод

Builds the arc length array using the points array. Assumes _pts has points and _arclen is empty.

protected InitializeArcLengths ( ) : void
Результат	void

Reparameterize() защищенный Метод

Attempts to find a slightly better parameterization for u on the given curve.

protected Reparameterize ( int first, int last, CubicBezier curve ) : void
first	int
last	int
curve	CubicBezier
Результат	void

Описание свойств

_arclen защищенное свойство

length of curve before each point (so, arclen[0] = 0, arclen[1] = distance(pts[0], pts[1]), arclen[2] = arclen[1] + distance(pts[1], pts[2]) ... arclen[n -1] = length of the entire curve, etc).

protected List _arclen
Результат	List

_pts защищенное свойство

Points in the whole line being used for fitting.

protected List _pts
Результат	List

_squaredError защищенное свойство

maximum squared error before we split the curve

protected Double,System _squaredError
Результат	System.Double

_u защищенное свойство

current parametrization of the curve. When fitting, u[i] is the parametrization for the point in pts[first + i]. This is an optimization for CurveBuilder, since it might not need to allocate as big of a _u as is necessary to hold the whole curve.

protected List _u
Результат	List