所以我有一个顶点向量,我正在尝试排序,我是新手使用谓词。这就是我目前对顶点进行排序的方法。
void Triangulate::OrderVertices()
{
std::sort(mVertices.begin(), mVertices.end(), Triangulate::ClockWise());
}
这是我的排序谓词
bool Triangulate::ClockWise::operator()(const CVertex2& pointA, const CVertex2& pointB)
{
if(pointA.mPoint.x >= 0 && pointB.mPoint.x < 0)
{
return true;
}
if(pointA.mPoint.x == 0 && pointB.mPoint.x == 0)
{
return true;
}
// Gets the center of my current viewport
CVertex2 centerCoordinate(CClipper::Instance()->GetMidX(), CClipper::Instance()->GetMidY());
// compute the cross product of vectors
int det = (int)((pointA.mPoint.x - centerCoordinate.mPoint.x) *
(pointB.mPoint.y - centerCoordinate.mPoint.y) -
(pointB.mPoint.x - centerCoordinate.mPoint.x) *
(pointA.mPoint.y - centerCoordinate.mPoint.y));
if(det < 0)
{
return true;
}
if(det > 0)
{
return false;
}
int det1 = (int)((pointA.mPoint.x - centerCoordinate.mPoint.x) *
(pointA.mPoint.x - centerCoordinate.mPoint.x) +
(pointA.mPoint.y - centerCoordinate.mPoint.y) *
(pointA.mPoint.y - centerCoordinate.mPoint.y));
int det2 = (int)((pointB.mPoint.x - centerCoordinate.mPoint.x) *
(pointB.mPoint.x - centerCoordinate.mPoint.x) +
(pointB.mPoint.y - centerCoordinate.mPoint.y) *
(pointB.mPoint.y - centerCoordinate.mPoint.y));
return det1 > det2;
}
我目前在我的三角测量类中设置了我的谓词。
class Triangulate
{
friend class ClockWise;
public:
Triangulate(std::vector<CVertex2>& vertices)
:mVertices(vertices) {}
~Triangulate(void);
class ClockWise
{
public:
bool operator()(const CVertex2& pointA, const CVertex2& pointB);
};
private:
};
当我收到错误时,我很确定这是因为我没有正确设置。有人可以帮忙吗?