thothbot.parallax.core.shared.utils

Class CurveUtils

java.lang.Object

thothbot.parallax.core.shared.utils.CurveUtils

public class CurveUtils
extends java.lang.Object

This class implements some helpers methods for Curve instances This code is based on js-code written by zz85 http://www.lab4games.net/zz85/blog

Author:

thothbot

Constructor Summary

Constructors

Constructor and Description
CurveUtils()

Method Summary

Modifier and Type	Method and Description
static double	interpolate(double p0, double p1, double p2, double p3, double t) Interpolation of Catmull-Rom Spline
static double	tangentCubicBezier(double t, double p0, double p1, double p2, double p3) This method calculates tangent of Cubic Bezier Curve.
static double	tangentQuadraticBezier(double t, double p0, double p1, double p2) This method calculates tangent of Quadratic Bezier Curve.
static double	tangentSpline(double t, double p0, double p1, double p2, double p3) This method calculates tangent of Spline Curve.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CurveUtils

public CurveUtils()

Method Detail

tangentQuadraticBezier

public static double tangentQuadraticBezier(double t,
                                            double p0,
                                            double p1,
                                            double p2)

This method calculates tangent of Quadratic Bezier Curve.

Parameters:

t - the value in range <0.0, 1.0>. The t in the function for a linear Bezier curve can be thought of as describing how far B(t) is from p0 to p2.

p0 - the p0 Quadratic Bezier Curve point.

p1 - the p1 Quadratic Bezier Curve point.

p2 - the p2 Quadratic Bezier Curve point.

Returns:

the tangent of Quadratic Bezier Curve

tangentCubicBezier

public static double tangentCubicBezier(double t,
                                        double p0,
                                        double p1,
                                        double p2,
                                        double p3)

This method calculates tangent of Cubic Bezier Curve. Puay Bing, thanks for helping with this derivative!

Parameters:

t - the value in range <0.0, 1.0>. The t in the function for a linear Bezier curve can be thought of as describing how far B(t) is from p0 to p3.

p0 - the p0 Cubic Bezier Curve point.

p1 - the p1 Cubic Bezier Curve point.

p2 - the p2 Cubic Bezier Curve point.

p3 - the p3 Cubic Bezier Curve point.

Returns:

the tangent of Cubic Bezier Curve

tangentSpline

public static double tangentSpline(double t,
                                   double p0,
                                   double p1,
                                   double p2,
                                   double p3)

This method calculates tangent of Spline Curve.

Parameters:

t - the value in range <0.0, 1.0>. The t in the function for a linear Bezier curve can be thought of as describing how far B(t) is from p0 to p3.

p0 - the p0 Spline point.

p1 - the p1 Spline point.

p2 - the p2 Spline point.

p3 - the p3 Spline point.

Returns:

the tangent of Spline Curve

interpolate

public static double interpolate(double p0,
                                 double p1,
                                 double p2,
                                 double p3,
                                 double t)

Interpolation of Catmull-Rom Spline

Parameters:

p0 - the p0 Spline point.

p1 - the p1 Spline point.

p2 - the p2 Spline point.

p3 - the p3 Spline point.

t - the value in range <0.0, 1.0>. The t in the function for a linear Bezier curve can be thought of as describing how far B(t) is from p0 to p3.

Returns:

the interpolated value.