#include "electronicFence.h"

//----------------param
// 定义多边形的经纬度坐标集合
double polygonLat[REC_COORDINATE_DEPTH] = {0};
double polygonLng[REC_COORDINATE_DEPTH] = {0};

 
/**
* 是否有 横断<br/> 参数为四个点的坐标
*
* @param px1
* @param py1
* @param px2
* @param py2
* @param px3
* @param py3
* @param px4
* @param py4
* @return
*/
static bool isIntersect(double px1, double py1, double px2, double py2,
	double px3, double py3, double px4, double py4) {
	bool flag = false;
	double d = (px2 - px1) * (py4 - py3) - (py2 - py1) * (px4 - px3);
	if (d != 0) {
		double r = ((py1 - py3) * (px4 - px3) - (px1 - px3) * (py4 - py3)) / d;
		double s = ((py1 - py3) * (px2 - px1) - (px1 - px3) * (py2 - py1)) / d;
		if ((r >= 0) && (r <= 1) && (s >= 0) && (s <= 1)) {
			flag = true;
		}
	}
	return flag;
}
 
static double Multiply(double px0, double py0, double px1, double py1,
	double px2, double py2) {
	return ((px1 - px0) * (py2 - py0) - (px2 - px0) * (py1 - py0));
}

/**
* 目标点是否在目标边上边上<br/>
*
* @param px0
* 目标点的经度坐标
* @param py0
* 目标点的纬度坐标
* @param px1
* 目标线的起点(终点)经度坐标
* @param py1
* 目标线的起点(终点)纬度坐标
* @param px2
* 目标线的终点(起点)经度坐标
* @param py2
* 目标线的终点(起点)纬度坐标
* @return
*/
static bool isPointOnLine(double px0, double py0, double px1,
	double py1, double px2, double py2) {
	bool flag = false;
	double ESP = 1e-9;
	if ((fabs(Multiply(px0, py0, px1, py1, px2, py2)) < ESP)
		&& ((px0 - px1) * (px0 - px2) <= 0)
		&& ((py0 - py1) * (py0 - py2) <= 0)) {
		flag = true;
	}
	return flag;
}

 
/**
* 判断目标点是否在多边形内(由多个点组成)<br/>
*
* @param px
* 目标点的经度坐标
* @param py
* 目标点的纬度坐标
* @param polygonXA
* 多边形的经度坐标集合
* @param polygonYA
* 多边形的纬度坐标集合
* @param num
* 多边形的坐标集个数
* @return
*/
bool isPointInPolygon(double px, double py,
	double polygonXA[], double polygonYA[], int num) {
	bool isInside = false;
	double ESP = 1e-9;
	int count = 0;
	double linePoint1x;
	double linePoint1y;
	double linePoint2x = 180;
	double linePoint2y;

	linePoint1x = px;
	linePoint1y = py;
	linePoint2y = py;


	for (int i = 0; i < num; i++) {
		double cx1 = polygonXA[i];
		double cy1 = polygonYA[i];
		double cx2 = polygonXA[i + 1];
		double cy2 = polygonYA[i + 1];
		if (isPointOnLine(px, py, cx1, cy1, cx2, cy2)) {
			return true;
		}
		if (fabs(cy2 - cy1) < ESP) {
			continue;
		}
		if (isPointOnLine(cx1, cy1, linePoint1x, linePoint1y, linePoint2x,
			linePoint2y)) {
			if (cy1 > cy2)
				count++;
		}
		else if (isPointOnLine(cx2, cy2, linePoint1x, linePoint1y,
			linePoint2x, linePoint2y)) {
			if (cy2 > cy1)
				count++;
		}
		else if (isIntersect(cx1, cy1, cx2, cy2, linePoint1x, linePoint1y,
			linePoint2x, linePoint2y)) {
			count++;
		}
	}
	if (count % 2 == 1) {
		isInside = true;
	}

	return isInside;
}