/* Copyrighted Pixar 1989 */
/* From the RenderMan Companion p. 65 */
/* Listing 4.2   Using hyperboloids to create a surface of revolution */

#include <ri.h>
#include <stdio.h>

#include "hcontour.h"

RtColor color = {.9,.9,.5};
Go() { 
    RiColor(color);
    RiRotate(-90.0, 1.0, 0.0, 0.0);
    SurfOR(points, NPOINTS);
}


/* Listing 4.2  Using hyperboloids to create a surface of revolution */

SurfOR(points, npoints) 
Point2D points[]; 
int npoints; 
{ 
    int pt; 
    RtPoint point1, point2; 
    RtFloat *pp1, *pp2, *tmp; 
        pp1 = point1; 
        pp2 = point2; 

    /*   
     * For each adjacent pair of x,y points in the outline description, 
     *  draw a hyperboloid by sweeping the line segment defined by  
     *  those points about the z axis. 
     */ 
    pp1[0] = points[0].y; 
    pp1[1] = 0; 
    pp1[2] = points[0].x; 
    for(pt = 1; pt < npoints; pt++) { 
        pp2[0] = points[pt].y; 
        pp2[1] = 0; 
        pp2[2] = points[pt].x; 
        RiHyperboloid(pp1, pp2, 360.0, RI_NULL); 
        tmp = pp1; pp1 = pp2; pp2 = tmp;          /* Swap pointers */ 
    } 
}