get GeneralPath Intersect Point - Java 2D Graphics

Java examples for 2D Graphics:Path

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Description

get GeneralPath Intersect Point

Demo Code


//package com.java2s;
import java.awt.geom.PathIterator;
import java.awt.geom.GeneralPath;
import java.awt.geom.Point2D;
import java.awt.geom.Line2D;

public class Main {
    public static Point2D getIntersectPoint(Line2D l, GeneralPath p) {
        return getIntersectPoint(l.getX1(), l.getY1(), l.getX2(),
                l.getY2(), p);/*from  w ww . ja  v  a2 s.  com*/
    }

    public static Point2D getIntersectPoint(double x1, double y1,
            double x2, double y2, GeneralPath p) {
        double x3 = 0, y3 = 0, x4 = 0, y4 = 0;
        int index = 0;
        double seg[] = new double[6];

        for (PathIterator i = p.getPathIterator(null); !i.isDone(); i
                .next()) {
            int segType = i.currentSegment(seg);

            if (index == 0) {
                x3 = seg[0];
                y3 = seg[1];
            } else if (index == 1) {
                x4 = seg[0];
                y4 = seg[1];
            } else if (index > 1) {
                x3 = x4;
                y3 = y4;
                x4 = seg[0];
                y4 = seg[1];
            }
            if (index > 0
                    && Line2D
                            .linesIntersect(x1, y1, x2, y2, x3, y3, x4, y4)) {
                double l1m, l2m;
                //if lines are vertical, cater for a divide by 0:
                if (x2 == x1) {
                    l2m = (y4 - y3) / (x4 - x3);
                    return (new Point2D.Double(x1, (l2m * x1) + y3));
                } else if (x4 == x3) {
                    l1m = (y2 - y1) / (x2 - x1);
                    return (new Point2D.Double(x3, (l1m * x3) + y1));
                } else {
                    l1m = (y2 - y1) / (x2 - x1);
                    l2m = (y4 - y3) / (x4 - x3);

                    double x = ((-l1m) * x1) + y1 + (l2m * x3) - y3;
                    x = x / (l2m - l1m);
                    double y = l1m * (x - x1) + y1;

                    return (new Point2D.Double(x, y));
                }
            }
            index++;
        }
        return null;
    }

    public static Point2D getIntersectPoint(Point2D point, GeneralPath p1,
            GeneralPath p2) {

        Point2D intersectionPoint, returnPoint = null;

        double x1 = 0, y1 = 0, x2 = 0, y2 = 0, closestDist = 100000;
        int index = 0;
        double seg[] = new double[6];

        for (PathIterator i = p1.getPathIterator(null); !i.isDone(); i
                .next()) {
            int segType = i.currentSegment(seg);

            if (index == 0) {
                x1 = seg[0];
                y1 = seg[1];
                x2 = x1;
                y2 = y1;
            }
            if (index > 0) {
                x1 = x2;
                y1 = y2;
                x2 = seg[0];
                y2 = seg[1];

                intersectionPoint = getIntersectPoint(x1, y1, x2, y2, p2);
                if (intersectionPoint != null) {
                    double dist = intersectionPoint.distance(point);
                    if (dist <= closestDist) {
                        returnPoint = intersectionPoint;
                        closestDist = dist;
                    }
                }
            }
            index++;
        }
        return returnPoint;
    }
}

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