Given a endpoints and control points, compute the coefficients to trace out the curve as p(t) = c[0] + c[1]*t + c[2]*t^2 + c[3]*t^3 - Java java.lang

Java examples for java.lang:Math Operation

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Description

Given a endpoints and control points, compute the coefficients to trace out the curve as p(t) = c[0] + c[1]*t + c[2]*t^2 + c[3]*t^3

Demo Code

/*/*from  w w  w  . ja  va  2 s  .  co  m*/
 * Twirl Editor - Petri-Net Editor
 * 
 * Copyright (C) 2009 Neil Brittliff
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
//package com.java2s;
import java.awt.Point;

public class Main {
    /**
     * Given a curveto's endpoints and control points, compute the coefficients
     * to trace out the curve as p(t) = c[0] + c[1]*t + c[2]*t^2 + c[3]*t^3
     * 
     * @param coefficients
     *            the Coefficients
     * @param startPoint
     *            the Start Point
     * @param endPoint
     *            the End Point
     * @param controlPoint1
     *            the First Control Point
     * @param controlPoint2
     *            the Second Control Point
     * @param padding
     *            the area surrounding the curve
     * 
     */
    static void parameterizeCurve(Point[] coefficients, Point startPoint,
            Point endPoint, Point controlPoint1, Point controlPoint2) {
        Point tangent2 = new Point();

        tangent2.x = (int) (3.0 * (endPoint.x - controlPoint2.x));
        tangent2.y = (int) (3.0 * (endPoint.y - controlPoint2.y));

        coefficients[0] = startPoint;
        coefficients[1] = new Point(
                (int) (3.0 * (controlPoint1.x - startPoint.x)),
                (int) (3.0 * (controlPoint1.y - startPoint.y)));
        // tangent
        coefficients[2] = new Point(
                (int) (3.0 * (endPoint.x - startPoint.x) - 2.0
                        * coefficients[1].x - tangent2.x), (int) (3.0
                        * (endPoint.y - startPoint.y) - 2.0
                        * coefficients[1].y - tangent2.y));
        coefficients[3] = new Point(
                (int) (2.0 * (startPoint.x - endPoint.x)
                        + coefficients[1].x + tangent2.x),
                (int) (2.0 * (startPoint.y - endPoint.y)
                        + coefficients[1].y + tangent2.y));

    }
}

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