/*
           
     Name: rdpnp.c  -  b-spline net point input
    
     Author: David F. Rogers (Linda A. Adlum)
    
     Date: 10 August 1987 ( C Version 19 May 89)
    
     System: Silicon Graphics Iris
    
     Language: C
    
     Purpose: To input a B-Spline net.
    
     Method: Read from file input.
    
     Subroutines called: none
    
     Variable list:
           hdstr    = alphanumeric string for file header
           c1    = order of b-spline surface in u direction
           c2    = order of b-spline surface in w direction
           n1    = number polygon net lines in u direction
           n2    = number polygon net lines in w direction
           netpts    = n1n2
           b    = array containing the b-spline net
                   b(i)    = x-componet
                   b(i+1)    = y-componet
                   b(i+2)    = z-componet
                   for fixed u - w varies, thus the first
                   3*n1 values are for the first value of u etc.
*/

#include <stdio.h>

rdpnp(header,hdrlen,c1,c2,n1,n2,b)

char *header;
int *hdrlen,*c1,*c2,*n1,*n2;
float b[];

{

       FILE *pnpfile;
    char pnpname[80];
    int  i;
    int netpts;
    
    /* Get the name of the pnp file to use and open it */
    
    fprintf(stderr,"Enter data file name in the form *.pnp ");
    
    scanf("%s",pnpname);
    
    if((pnpfile = fopen(pnpname,"r")) == NULL)
    {
        fprintf(stderr,"\tThe file: %s\n",pnpname);
        fprintf(stderr,"\tDoes not exist in the current directory.\n");
        fprintf(stderr,"\tThe current directory is: ");
        system("pwd");
        exit(-1);
    }
    
    fprintf(stderr,"Reading from file %s\n", pnpname);
    
    /* Read header string from file */
    
    if(NULL == fgets(header, hdrlen, pnpfile))
    {
        fprintf(stderr,"No header string in preliminary net point file\n");
        fprintf(stderr,"or file is empty.\n");
        exit(-1);
    }
    
    /* Output header string */
    
    fprintf(stderr,"%s",header);
    
    
    /* Read order c1,c2 and number of net points n1,n2 */
    
    if (NULL == fscanf(pnpfile," %d, %d \n", c1, c2) )
    {
        fprintf(stderr,"Missing net order; exit\n");
        return;
    }
    
    if (NULL == fscanf(pnpfile," %d, %d \n", n1, n2) )
    {
        fprintf(stderr,"Missing net order; exit\n");
        return;
    }
    
    /* Output order and net points */
    
    fprintf(stderr,"Order %dx%d Net points %dx%d\n",*c1,*c2,*n1,*n2);
    fprintf(stderr,"Read net points\n");
    
    /*    read the net points */
    
    netpts = (*n1) * (*n2);
    
    for (i=1; i <= (3 * netpts); i+=3)
    {
        if (NULL == fscanf(pnpfile," %f, %f, %f \n", &b[i],&b[i+1],&b[i+2]) )
        {
            fprintf(stderr,"Missing point data\n");
            return;
        }
        fprintf(stderr," %f, %f, %f\n", b[i],b[i+1],b[i+2]);
    }
    
    fprintf(stderr,"Net points read - return to main\n");
    
}