#include "ri.h"
#include "patches.h"

#define NU 13
#define MAXNPTS 100
#define F .5522847 

/* Listing 6.3  Version of SurfOR() taking profile points */
/*              and producing a bicubic                   */
float coeff[NU][2] = { 
    { 1, 0 }, { 1, F }, { F, 1 }, { 0, 1 }, {-F, 1 }, {-1, F }, 
    {-1, 0 }, {-1,-F }, {-F,-1 }, { 0,-1 }, { F,-1 }, { 1,-F }, { 1, 0} };

RtPoint    mesh[MAXNPTS][NU];

void SurfOR(Point2D points[], int npoints)
{
    int        u, v;

/*    coeff holds a matrix of coefficients for sweeping a point on the XZ
 *    plane circularly around the Z axis, with the circle approximated by 
 *    4 Bezier curves
 */
    for (v = 0; v < npoints; v++) {    
        /* 
         *  Start at the upper left of the mesh.  For each 
         *  control point on the circle being swept out, 
         *  rotate every point on the XZ curve into position
         */
        for (u = 0; u < NU; u++) {    
            /*  Here comes each point on the XZ curve */
            mesh[v][u][0] = points[v].x * coeff[u][0];
            mesh[v][u][1] = points[v].x * coeff[u][1];
            mesh[v][u][2] = points[v].y;
        }
    }
//    RiBasis(RiPowerBasis, RI_POWERSTEP, RiPowerBasis, RI_POWERSTEP);
//    RiBasis(RiHermiteBasis, RI_HERMITESTEP, RiHermiteBasis, RI_HERMITESTEP);
//    RiBasis(RiCatmullRomBasis, RI_CATMULLROMSTEP, RiCatmullRomBasis, RI_CATMULLROMSTEP);
//    RiBasis(RiBSplineBasis, RI_BSPLINESTEP, RiBSplineBasis, RI_BSPLINESTEP);
    RiBasis(RiBezierBasis, RI_BEZIERSTEP, RiBezierBasis, RI_BEZIERSTEP);
    RiPatchMesh(RI_BICUBIC, 
           (RtInt) NU, RI_NONPERIODIC,
           (RtInt) npoints, RI_NONPERIODIC,
           RI_P, (RtPointer) mesh, 
           RI_NULL);
}