www.pudn.com > 3dsMFCRender.rar > LSPLINE.CPP, change:1998-03-21,size:3285b

#include "stdafx.h" 
#include "lspline.h" 
 
#ifdef _DEBUG 
#define new DEBUG_NEW 
#endif 
 
void LSpline::Init() { 
	float last=(*y)[0];	// test case for constant 
	IsConstantCase=TRUE; 
 
	if(N==0) { 
		return; 
	}; 
 
	if(N==1) { 
		return; 
	}; 
	for(int i=0;i=N;++i) { 
		float mid=(*y)[i]; 
		if(fabs(last-mid)>0.00001) { 
			IsConstantCase=FALSE; 
			break; 
		}; 
	}; 
 
	if(IsConstantCase) { 
		return; 
	};  
 
	h=new LSplineNumbers(); 
	b=new LSplineNumbers(); 
	u=new LSplineNumbers(); 
	v=new LSplineNumbers(); 
	z=new LSplineNumbers(); 
	h->SetSize(N);  // ReSize Vectors 
	b->SetSize(N);  // ReSize Vectors 
	u->SetSize(N);  // ReSize Vectors 
	v->SetSize(N);  // ReSize Vectors 
	z->SetSize(N+1);  // ReSize Vectors 
 
	A.SetSize(N);  // ReSize Vectors 
	B.SetSize(N);  // ReSize Vectors 
	C.SetSize(N);  // ReSize Vectors 
	D.SetSize(N);  // ReSize Vectors 
} 
 
 
void LSpline::FreeMemory() { 
	h->RemoveAll(); 
	delete h; 
	b->RemoveAll(); 
	delete b; 
	u->RemoveAll(); 
	delete u; 
	v->RemoveAll(); 
	delete v; 
	z->RemoveAll(); 
	delete z; 
//	y->RemoveAll(); 
//	delete y; 
} 
 
void LSpline::Build() { 
	Step1(); 
	Step2(); 
	Step3(); 
	Step4(); 
	FreeMemory(); 
	lasts=1; 
	lastt=0.0; 
} 
 
float LSpline::operator()(unsigned i, float x) { 
/*	if(i>N) { 
		cout < "LSpline: Out of Valid Bounds..." < endl; 
		};   */ 
	float	TVal=x-(*t)[i]; 
	return A[i]+TVal*(B[i]+TVal*(C[i]+TVal*D[i])); 
		 
//		A[i]+B[i]*TVal+C[i]*TVal*TVal+D[i]*TVal*TVal*TVal; 
} 
 
static int tm; 
 
float LSpline::operator()(float x) { 
	if(IsConstantCase) { return (*y)[0]; }; 
	tm=(int)x; 
// This line is the special case with time linear splines 
	if(x==tm) return (*y)[tm]; 
 
// Linear time step 
 
/*	if(x>((*t)[t->GetSize()-1])) x=(*t)[t->GetSize()-1]; 
 
	if( ((x-(*t)[lasts])>=0) & ((x-(*t)[lasts+1])<0)) 
		return (*this)(lasts,x); 
 
	for(i=(N-1);i>=0;i--) { 
		if( (x-(*t)[i])>=0 ) break; 
		}; 
 
	if(i<0) { 
		i=0; 
		lasts=0; 
		return 0.0; 
	} 
	else { 
		lasts=i; 
	}; */ 
//	return (*this)(i,x); 
 
	float	TVal=x-tm; 
	return A[tm]+TVal*(B[tm]+TVal*(C[tm]+TVal*D[tm])); 
//	return (*this)((int)x,x); 
 
} 
 
 
void LSpline::DisplayEquation(unsigned i) { 
 
/*	cout.precision(5); 
	cout < "S[" < i < "](x) = " 
		  < A[i] < " + " 
		  < B[i] < "*(x-(" < (*t)[i] < ")) + " 
		  < C[i] < "*(x-(" < (*t)[i] < "))^2 + " 
		  < D[i] < "*(x-(" < (*t)[i] < "))^3" < endl; */ 
} 
 
void LSpline::Step1() { 
	for(i=0;i=(N-1);i++) { 
		(*h)[i]=(float) (*t)[i+1]-(*t)[i]; 
      if((*h)[i]==0) (*h)[i]=0.00001; 
		(*b)[i]=(float) ((*y)[i+1]-(*y)[i])/(*h)[i]; 
		}; 
} 
 
void LSpline::Step2() { 
 
	(*u)[0]=2*((*h)[0]+(*h)[1]); 
	(*v)[0]=6*((*b)[1]-(*b)[0]); 
 
	for(i=1;i=(N-1);i++) { 
		(*u)[i]=(float) 2*((*h)[i]+(*h)[i-1])-((*h)[i-1]*(*h)[i-1])/((*u)[i-1]); 
		(*v)[i]=(float) 6*((*b)[i]-(*b)[i-1])-((*h)[i-1]*(*v)[i-1])/((*u)[i-1]); 
		}; 
 
} 
 
void LSpline::Step3() { 
	(*z)[N]=0.0; 
	(*z)[0]=0.0; 
	for(i=(N-1);i>=1;i--) { 
		(*z)[i]=(float) ((*v)[i]-((*h)[i]*(*z)[i+1]))/(*u)[i]; 
		}; 
} 
 
void LSpline::Step4() { 
	for(i=0;i=(N-1);i++) { 
		A[i]=(float) (*y)[i]; 
		C[i]=(float) (*z)[i]/2; 
		B[i]=(float) - (*h)[i]/6*(*z)[i+1]-(*h)[i]/3*(*z)[i]+1/(*h)[i]*((*y)[i+1]-(*y)[i]); 
		D[i]=(float) 1/(6*(*h)[i])*((*z)[i+1]-(*z)[i]); 
		}; 
}