www.pudn.com > roll.rar > INTERSEC.CPP

 
#include "stdafx.h" 
#include "intersec.h" 
#include "comnfun.h" 
#include  
 
int AsinBcosC(double a,double b,double c,double *x) 
{ 
	int FLAG=0; 
	double t; 
	t=sqrt(a*a+b*b); 
	if(fabs(t-fabs(c)) 0.0 && t1 < 1.0 && t2 > 0.0 && t2 < 1.0 ) return 1; 
	if((t1 == 0.0 || t1 == 1.0) && (t2 == 0.0 || t2 == 1.0)) return 4; 
	if( t1 == 0.0 || t1 == 1.0 ) return 2; 
	if( t2 == 0.0 || t2 == 1.0 ) return 3; 
	return 0; 
} 
 
// the function Arc_Arc_Int(...) calculate the intersection points 
// between two arcs describled below: 
// the one arc equation is  x = x1+r1*cos(a1) and y = y1+r1*sin(a1); 
// another arc equation is  x = x2+r2*cos(a2) and y = y2+r2*sin(a2); 
// in addition {  s1 <= a1 <= e1 ,  s2 <= a2 <= e2  }. 
// the output is the a1[2] and the a2[2]. 
// return 0 implied there is not intersection point, 
// return 1 implied there is one intersection point[1], 
// return 2 implied there is one intersection point[2], 
// return 3 implied there is two intersection point[1] and point[2]. 
 
int Arc_Arc_Int (double x1,double y1,double s1,double e1,double r1,double x2,double y2,double s2,double e2,double r2,double x[2],double y[2]) 
{ 
	int ret = 2; 
	int num = 0; 
	int index = 0; 
	double alf[2],bit[2]; 
	if(Circle_Circle_InterSection(x1,y1,r1,x2,y2,r2,alf,bit)) return 0; 
	x[0]=x1+r1*cos(alf[0]); 
	x[1]=x1+r1*cos(alf[1]); 
	y[0]=y1+r1*sin(alf[0]); 
	y[1]=y1+r1*sin(alf[1]); 
	if(fabs(x[1]-x[0])= t ) bWithin = 1; 
		if( bWithin ) { 
			t = bit[i]; 
			if( s2 <= t && e2 >= t ) { 
				num++; 
				index = i; 
			} 
		} 
	} 
	return num+index; 
} 
 
// the function Line_Arc_Int(...) calculate the intersection points of 
// the line and the arc describled below: 
// the line equation is  x = x0+(xx1-x0)*t and y = y0+(yy1-y0)*t; 
// the arc equation is x = x1+r*cos(a) and y = y1+r*sin(a) {s<=a<=e}; 
// the output is the x[2] and y[2]; 
// return 0 implied there is not interpoint. 
// return 1 implied there is one intersection point[1], 
// return 2 implied there is one intersection point[2], 
// return 3 implied there is two intersection point[1] and point[2]. 
 
int Line_Arc_Int (double x0,double y0,double xx1,double yy1,double x1,double y1,double s,double e,double r,double x[2],double y[2]) 
{ 
	double t[2]; 
	int index=0; 
	int num = 0; 
	double Dx = xx1-x0; 
	double Dy = yy1-y0; 
	if( !Line_Circle_Int(x0,y0,Dx,Dy,x1,y1,r,t)) return 0; 
	for(int i=0;i<2;i++) { 
		if( t[i]<0.0 || t[i]>1.0 ) continue; 
		x[i] = x0+Dx*t[i]; 
		y[i] = y0+Dy*t[i]; 
		double tt; 
		tt = atan2(y[i]-y1,x[i]-x1); 
		if( stt ) { 
			num++; 
			index = i; 
		} 
	} 
	return num+index; 
} 
 
// the function Line_Circle_Int(...) calculate the intersection points of 
// the line and the circle describled below: 
// the line equation is  x = x0+Dx*t and y = y0+Dy*t; 
// the circle equation is (x-x1)**2+(y-y1)**2 = r**2; 
// the output is the t[2]; 
// return 0 implied there is not interpoint. 
 
int Line_Circle_Int (double x0,double y0,double Dx,double Dy,double x1,double y1,double r,double t[2]) 
{ 
	double DDXY = Dx*Dx+Dy*Dy; 
	double DXDY = Dx*(x0-x1)+Dy*(y0-y1); 
	double delta = DXDY*DXDY-DDXY*((x0-x1)*(x0-x1)+(y0-y1)*(y0-y1)-r*r); 
	if( delta < 0.0 ) return 0; 
	delta = sqrt( delta ); 
	DDXY = 1.0/DDXY; 
	t[0] = (-DXDY+delta)*DDXY; 
	t[1] = (-DXDY-delta)*DDXY; 
	return 1; 
} 
 
// the function Circle_Circle_Int(...) calculate the intersection points of 
// the circle and the circle describled below: 
// the one circle equation is (x-x1)**2+(y-y1)**2 = r1**2; 
// the another circle equation is (x-x2)**2+(y-y2)**2 = r2**2; 
// the output is the x[2] and y[2]; 
// return 0 implied there is not interpoint, 
// return 1 implied there are two interpoint, 
// return 2 implied two circle are tangent. 
 
int Circle_Circle_Int (double x1,double y1,double r1,double x2,double y2,double r2,double x[2],double y[2]) 
{ 
	int ret=1; 
	double delt; 
	double t1,t2,t3; 
	double a=x2-x1; 
	double b=y2-y1; 
	double c=r1*r1-r2*r2+x2*x2-x1*x1+y2*y2-y1*y1; 
	if(fabs(a)>fabs(b)) { 
		t1=1.0+(b*b)/(a*a); 
		t2=(c/a-x1)*b/a-y1; 
		t3=(c/a-x1)*(c/a-x1)+y1*y1-r1*r1; 
		delt=t2*t2-t1*t3; 
		if(fabs(delt)