/*
    Test program for C code from An Introduction to NURBS
    by David F. Rogers. Copyright (C) 2000 David F. Rogers,
    All rights reserved.
    
    Name: tdbez.c
    Purpose: test Bezier curve derivative generator
    Language: C
    Subroutines called: dbezier.c
    Book reference:  Chapter 2, Sec. 2.3, Alg. p. 277
*/
    #include <stdio.h>
    
    main(){

    int i;
    int npts,cpts;
    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];
    float d2[103];

    npts = 4;
    cpts = 11;   /* eleven points on curve */

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

    for (i = 1; i <= 3*cpts; i++){
        p[i] = 0.;
    }
/*
    Define the control polygon, Ex. 2.1 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;

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

    ch = getchar();

    printf("\nFirst Derivative of Curve\n\n");

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

    ch = getchar();

    printf("\nSecond Derivative of Curve\n\n");

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