Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Copyright (C) 2013 Peng fei Pan <sky@xiaopan.me>
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import android.graphics.PointF;

public class Main {

    public static boolean isPolygonContainPoint(PointF point, PointF[] vertexPoints) {
        int nCross = 0;
        for (int i = 0; i < vertexPoints.length; i++) {
            PointF p1 = vertexPoints[i];
            PointF p2 = vertexPoints[(i + 1) % vertexPoints.length];
            if (p1.y == p2.y)
                continue;
            if (point.y < Math.min(p1.y, p2.y))
                continue;
            if (point.y >= Math.max(p1.y, p2.y))
                continue;
            double x = (double) (point.y - p1.y) * (double) (p2.x - p1.x) / (double) (p2.y - p1.y) + p1.x;
            if (x > point.x)
                nCross++;
        }
        return (nCross % 2 == 1);
    }
}