/*
	Test program for C code from An Introduction to NURBS
	by David F. Rogers. Copyright (C) 2000 David F. Rogers,
	All rights reserved.
	
	Name: trbsplin.c
	Purpose: Test rational B-spline curve generator Chapter 4
	Language: C
	Subroutines called: rbspline.c
	Book reference:  Chapter 4, Ex. 4.1, Alg. p 297
*/
	main(){

	int i;
	int npts,k,p1;

	float b[31];  /* allows for up to 10  control vertices */
	float h[11];  /* allows for up to 10  control vertices */
	float p[103]; /* allows for up to 100 points on curve */

	npts = 5;
	k = 3;     /* third order, change for other orders */
	p1 = 11;   /* eleven points on curve */

	for (i = 1; i <= 3*npts; i++){
		b[i] = 0.;
	}

/*	set all homogeneous weighting factros to 1.0 */

		for (i=1; i <= npts; i++){
		h[i] = 1.0;
	}

/*  vary the homogeneous weighting factor 0, 0.25, 1.0, 5.0 */

	h[3] = 1;

	for (i = 1; i <= 3*p1; i++){
		p[i] = 0.;
	}

/*
	Define the control polygon, Ex. 4.1, p. 140 in the z=1 plane because
    this is three dimensional routine. x=b[1], y=b[2], z=b[3], etc.
*/	
	b[1]=0;
	b[2]=0;
	b[3]=1;
	b[4]=1;
	b[5]=2;
	b[6]=1;
	b[7]=2.5;
	b[8]=0;
	b[9]=1;
	b[10]=4;
	b[11]=2;
	b[12]=1;
	b[13]=5;
	b[14]=0;
	b[15]=1;
	
	rbspline(npts,k,p1,b,h,p);

	printf("\nPolygon points\n");

	for (i = 1; i <= 3*npts; i=i+3){
		printf(" %f %f %f \n",b[i],b[i+1],b[i+2]);
	}

	printf("\nHomogeneous weighting vector is \n");
	for (i = 1; i <= npts; i++){
		printf(" %f ", h[i]);
	}
	printf("\n");
	

	printf("\nCurve points\n");

	for (i = 1; i <= 3*p1; i=i+3){
		printf(" %f %f %f \n",p[i],p[i+1],p[i+2]);
	}
}