修改3太比较函数

Author: zhitaogpt

computationGeometry/planeGeometry.cpp

@@ -1,3 +1,4 @@
+#define dcmp(x) (fabs(x) < eps? 0:((x) <0?-1:1))
 struct Point{
     double x,y;
     Point(double _x=0,double _y=0):x(_x),y(_y){}

computationGeometry/二维几何.md

@@ -4,7 +4,7 @@
 ## 向量与点的基本算法
 
 ```c++
-
+#define dcmp(x) (fabs(x) < eps? 0:((x) <0?-1:1))
 struct Point{
     double x,y;
     Point(double _x=0,double _y=0):x(_x),y(_y){}
@@ -33,7 +33,7 @@ double Area2(Point A,Point B,Point C){return Cross(B-A,C-A);}
 ## 点和直线
 
 ```c++
-Point GetLineIntersection(Point &P,Vector & v, Point & Q,Vector w){
+Point GetLineIntersection(Point P,Vector  v, Point  Q,Vector w){
     //计算交点,当v,w平行时无效
     Point u = P-Q;
     double t = Cross(v,u) / Cross(v,w);
@@ -45,17 +45,17 @@ double Dis2Line(Point &P,Point & A,Point & B){
     Vector u2 = B-A;
     return abs(Cross(u1,u2)/Length(u2));
 }
-Point GetLineProjection(Point &P,Point &A,Point & B){
+Point GetLineProjection(Point P,Point A,Point  B){
     //the projection Point Q of P to Line A,B;
     Vector v = B-A;
     return A+ v*(Dot(v,P-A)/Dot(v,v));
 }
-bool SegInsertion(Point &A1,Point &A2,Point &B1,Point &B2){
+bool SegInsertion(Point A1,Point A2,Point B1,Point B2){
     double c1 = Cross(A2-A1,B1-A1),c2 = Cross(A2-A1,B2-A1);
     double c3 = Cross(B2-B1,A1-B1),c4 = Cross(B2-B1,A2-B1);
     return dcmp(c1)*dcmp(c2) <0 && dcmp(c3)*dcmp(c4) <0;
 }
-bool onSegment(Point & P,Point &A,Point &B){
+bool onSegment(Point P,Point A,Point B){
     return dcmp(Cross(A-P,B-P))==0 && dcmp(Dot(A-P,B-P)) <0;
 }
 ```