#ifndef INTAREACALCUTIL_H
|
#define INTAREACALCUTIL_H
|
#include <iostream>
|
#include <vector>
|
#include <map>
|
using namespace std;
|
struct Point
|
{
|
Point(){}
|
Point(int x1,int y1)
|
{
|
x=x1;
|
y=y1;
|
}
|
int x;
|
int y;
|
};
|
class IntAreaCalcUtil
|
{
|
|
|
public:
|
//若点a大于点b,即点a在点b顺时针方向,返回true,否则返回false
|
static bool PointCmp(const Point &a,const Point &b,const Point ¢er)
|
{
|
if (a.x >= 0 && b.x < 0)
|
return true;
|
if (a.x == 0 && b.x == 0)
|
return a.y > b.y;
|
//向量OA和向量OB的叉积
|
int det = (a.x - center.x) * (b.y - center.y) - (b.x - center.x) * (a.y - center.y);
|
if (det < 0)
|
return true;
|
if (det > 0)
|
return false;
|
//向量OA和向量OB共线，以距离判断大小
|
int d1 = (a.x - center.x) * (a.x - center.x) + (a.y - center.y) * (a.y - center.y);
|
int d2 = (b.x - center.x) * (b.x - center.y) + (b.y - center.y) * (b.y - center.y);
|
return d1 > d2;
|
}
|
static void ClockwiseSortPoints(std::vector<Point> &vPoints)
|
{
|
//计算重心
|
Point center;
|
double x = 0,y = 0;
|
for (int i = 0;i < vPoints.size();i++)
|
{
|
x += vPoints[i].x;
|
y += vPoints[i].y;
|
}
|
center.x = (int)x/vPoints.size();
|
center.y = (int)y/vPoints.size();
|
|
//冒泡排序
|
for(int i = 0;i < vPoints.size() - 1;i++)
|
{
|
for (int j = 0;j < vPoints.size() - i - 1;j++)
|
{
|
if (PointCmp(vPoints[j],vPoints[j+1],center))
|
{
|
Point tmp = vPoints[j];
|
vPoints[j] = vPoints[j + 1];
|
vPoints[j + 1] = tmp;
|
}
|
}
|
}
|
}
|
// The function will return YES if the point x,y is inside the polygon, or
|
// NO if it is not. If the point is exactly on the edge of the polygon,
|
// then the function may return YES or NO.
|
static bool IsPointInPolygon(std::vector<Point> poly,Point pt)
|
{
|
int i,j;
|
bool c = false;
|
for (i = 0,j = poly.size() - 1;i < poly.size();j = i++)
|
{
|
if ((((poly[i].y <= pt.y) && (pt.y < poly[j].y)) ||
|
((poly[j].y <= pt.y) && (pt.y < poly[i].y)))
|
&& (pt.x < (poly[j].x - poly[i].x) * (pt.y - poly[i].y)/(poly[j].y - poly[i].y) + poly[i].x))
|
{
|
c = !c;
|
}
|
}
|
return c;
|
}
|
//排斥实验
|
static bool IsRectCross(const Point &p1,const Point &p2,const Point &q1,const Point &q2)
|
{
|
bool ret = min(p1.x,p2.x) <= max(q1.x,q2.x) &&
|
min(q1.x,q2.x) <= max(p1.x,p2.x) &&
|
min(p1.y,p2.y) <= max(q1.y,q2.y) &&
|
min(q1.y,q2.y) <= max(p1.y,p2.y);
|
return ret;
|
}
|
//跨立判断
|
static bool IsLineSegmentCross(const Point &pFirst1,const Point &pFirst2,const Point &pSecond1,const Point &pSecond2)
|
{
|
long line1,line2;
|
line1 = pFirst1.x * (pSecond1.y - pFirst2.y) +
|
pFirst2.x * (pFirst1.y - pSecond1.y) +
|
pSecond1.x * (pFirst2.y - pFirst1.y);
|
line2 = pFirst1.x * (pSecond2.y - pFirst2.y) +
|
pFirst2.x * (pFirst1.y - pSecond2.y) +
|
pSecond2.x * (pFirst2.y - pFirst1.y);
|
if (((line1 ^ line2) >= 0) && !(line1 == 0 && line2 == 0))
|
return false;
|
|
line1 = pSecond1.x * (pFirst1.y - pSecond2.y) +
|
pSecond2.x * (pSecond1.y - pFirst1.y) +
|
pFirst1.x * (pSecond2.y - pSecond1.y);
|
line2 = pSecond1.x * (pFirst2.y - pSecond2.y) +
|
pSecond2.x * (pSecond1.y - pFirst2.y) +
|
pFirst2.x * (pSecond2.y - pSecond1.y);
|
if (((line1 ^ line2) >= 0) && !(line1 == 0 && line2 == 0))
|
return false;
|
return true;
|
}
|
|
static bool GetCrossPoint(const Point &p1,const Point &p2,const Point &q1,const Point &q2,long &x,long &y)
|
{
|
if(IsRectCross(p1,p2,q1,q2))
|
{
|
if (IsLineSegmentCross(p1,p2,q1,q2))
|
{
|
//求交点
|
long tmpLeft,tmpRight;
|
tmpLeft = (q2.x - q1.x) * (p1.y - p2.y) - (p2.x - p1.x) * (q1.y - q2.y);
|
tmpRight = (p1.y - q1.y) * (p2.x - p1.x) * (q2.x - q1.x) + q1.x * (q2.y - q1.y) * (p2.x - p1.x) - p1.x * (p2.y - p1.y) * (q2.x - q1.x);
|
|
x = (int)((double)tmpRight/(double)tmpLeft);
|
|
tmpLeft = (p1.x - p2.x) * (q2.y - q1.y) - (p2.y - p1.y) * (q1.x - q2.x);
|
tmpRight = p2.y * (p1.x - p2.x) * (q2.y - q1.y) + (q2.x- p2.x) * (q2.y - q1.y) * (p1.y - p2.y) - q2.y * (q1.x - q2.x) * (p2.y - p1.y);
|
y = (int)((double)tmpRight/(double)tmpLeft);
|
return true;
|
}
|
}
|
return false;
|
}
|
static bool PolygonClip(const vector<Point> &poly1,const vector<Point> &poly2, std::vector<Point> &interPoly)
|
{
|
if (poly1.size() < 3 || poly2.size() < 3)
|
{
|
return false;
|
}
|
|
long x,y;
|
//计算多边形交点vector<Point> poly1;
|
for (int i = 0;i < poly1.size();i++)
|
{
|
int poly1_next_idx = (i + 1) % poly1.size();
|
for (int j = 0;j < poly2.size();j++)
|
{
|
int poly2_next_idx = (j + 1) % poly2.size();
|
if (GetCrossPoint(poly1[i],poly1[poly1_next_idx],
|
poly2[j],poly2[poly2_next_idx],
|
x,y))
|
{
|
if(x<0 || y<0) continue;
|
interPoly.push_back(Point(x,y));
|
}
|
}
|
}
|
|
//计算多边形内部点
|
for(int i = 0;i < poly1.size();i++)
|
{
|
if (IsPointInPolygon(poly2,poly1[i]))
|
{
|
interPoly.push_back(poly1[i]);
|
}
|
}
|
for (int i = 0;i < poly2.size();i++)
|
{
|
if (IsPointInPolygon(poly1,poly2[i]))
|
{
|
interPoly.push_back(poly2[i]);
|
}
|
}
|
|
if(interPoly.size() <= 0)
|
return false;
|
|
//点集排序
|
ClockwiseSortPoints(interPoly);
|
return true;
|
}
|
static float intAreaCalc(vector<Point> &vecPoly)//求解多边形的面积(知道多边形的顶点，按顺时针或者逆时针)
|
{
|
int i_count=vecPoly.size();
|
// iCycle=0;
|
int area_temp=0;
|
for(int i=0;i<i_count;i++)
|
{
|
area_temp=area_temp+(vecPoly[i].x*vecPoly[(i+1) % i_count].y-vecPoly[(i+1) % i_count].x*vecPoly[i].y);
|
}
|
return abs(area_temp*100/2);
|
}
|
|
//int main()
|
//{
|
// vector<Point> poly1;
|
// poly1.push_back(Point(1,0));
|
// poly1.push_back(Point(1,2));
|
// poly1.push_back(Point(3,0));
|
// // poly1.push_back(Point(1,2));
|
// vector<Point> poly2;
|
//// poly2.push_back(Point(2,0));
|
//// poly2.push_back(Point(7,0));
|
//// poly2.push_back(Point(7,5));
|
//// poly2.push_back(Point(2,5));
|
// poly2.push_back(Point(0,0));
|
// poly2.push_back(Point(4,0));
|
// poly2.push_back(Point(4,4));
|
// poly2.push_back(Point(0,4));
|
// vector<Point> poly3;
|
// PolygonClip(poly1,poly2,poly3);
|
// float inter = intAreaCalc(poly3);
|
// float total = intAreaCalc(poly2);
|
// int perset1 = (int)(inter / total * 100);
|
// if(ALARM_PERCENT <= perset)
|
// {
|
|
// }
|
|
|
|
|
// for(int i=0;i<poly3.size();++i)
|
// {
|
|
// }
|
// return 0;
|
//}
|
|
};
|
|
#endif // INTAREACALCUTIL_H
|
