/*
	Test program for C code from An Introduction to NURBS
	by David F. Rogers. Copyright (C) 2000 David F. Rogers,
	All rights reserved.
	
	Name: tdbsplu.c
	Purpose: Periodic B-spline curve and derivative generator
	Language: C
	Subroutines called: dbsplinu.c
	Book reference:  Chapter 3, Sec. 3.12, Ex. 3.8, Alg. p. 290
*/
	#include <stdio.h>
	
	main(){

	int i;
	int npts,k,p1;
	int ch;

	float b[31];  /* allows for up to 10  control vertices */
	float p[103];  /* allows for up to 100 points on curve */
	float d1[103];  /* allows for up to 100 points on curve */
	float d2[103];  /* allows for up to 100 points on curve */

	npts = 4;
	k = 2;     /* second order, change to 4 to get fourth order */
	p1 = 11;   /* eleven points on curve */

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

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


/*
	Define the control polygon, Ex. 3.4 in the z=1 plane because
    this is three dimensional routine. x=b[1], y=b[2], z=b[3], etc.
*/	
	b[1]=1;
	b[2]=1;
	b[3]=1;
	b[4]=2;
	b[5]=3;
	b[6]=1;
	b[7]=4;
	b[8]=3;
	b[9]=1;
	b[10]=3;
	b[11]=1;
	b[12]=1;

	dbspline(npts,k,p1,b,p,d1,d2);

	printf("\nPolygon points\n\n");

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

	ch = getchar();

	printf("\nCurve points\n\n");

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

	ch = getchar();

	printf("\nCurve first derivatives\n\n");

	for (i = 1; i <= 3*p1; i=i+3){
		printf(" %f %f %f \n",d1[i],d1[i+1],d1[i+2]);
	}
	ch = getchar();

	printf("\nCurve second derivatives\n\n");

	for (i = 1; i <= 3*p1; i=i+3){
		printf(" %f %f %f \n",d2[i],d2[i+1],d2[i+2]);
	}
}