/* Jeremy Stribling

 * cs184-cf, Fall 2000

 * Final project

 * 

 * This file contains serveral functions for generating surfaces of revolutions.  They are 

 * modified versions of the SurfOR function found on page 102 of The Renderman Companion, 

 * by Steve Upsill.

 */



#include "F:\cs184\bmrt2.5\include\ri.h"

#include "u:\final\apple\rendcomp.h"

#include <stdlib.h>

#include <time.h>



#define NU 24

#define MAXNPTS 100

#define F (.4142135*4/3)

#define G ( (.5 + F/2) + .0185 )



float coeff[NU][2] = {

	{ 1, 0 }, {1, F/2}, { 1, F }, {G, G}, {F, 1}, {F/2, 1}, 

	{ 0, 1 }, {-F/2, 1}, { -F, 1 }, {-G, G}, { -1, F }, {-1, F/2},

	{ -1, 0 }, {-1, -F/2}, { -1, -F }, {-G, -G}, { -F, -1 }, {-F/2, -1}, 

	{ 0, -1 }, {F/2, -1}, { F, -1 }, {G, -G}, { 1, -F }, {1, -F/2} };



RtPoint last[NU];	



/*

 * Make a surface of rotation given a set of a certain number of points in 2D,

 * but randomize the position of the point around the rotation, to give the bottom

 * edge of the object created appear randomly jagged at certain intervals.

 */



void SurfORJagged( Point2D points[], int npoints ) {



	RtPoint mesh[MAXNPTS][NU];

	int u,v;



	srand( time(NULL) );



	float r;



	for( v = 0; v < npoints; v++ ) {



		for( u = 0; u < NU; u++ ) {





			mesh[v][u][0] = points[v].x * coeff[u][0];

			mesh[v][u][1] = points[v].x * coeff[u][1];

			if( v == npoints-1 ) {

				float r = (rand() % 100);

				mesh[v][u][2] = points[v].y - (r / 75) * ( (rand()%2) * -2 + 1);

				last[u][0] = mesh[v][u][0];

				last[u][1] = mesh[v][u][1];

				last[u][2] = mesh[v][u][2];

			} else {

				mesh[v][u][2] = points[v].y;

			}



		}



	}





	RtFloat nu = NU;

	RtFloat np = npoints;



	RiBasis( RiBezierBasis, RI_BEZIERSTEP, RiBezierBasis, RI_BEZIERSTEP );

	RiPatchMesh( RI_BICUBIC, (RtInt) NU, RI_PERIODIC, (RtInt) npoints, RI_PERIODIC, RI_P, (RtPointer) mesh, RI_NULL );



}



/*

 * Make a jagged surface of rotation as above, but make the top edge of this one join up with the

 * bottom edge of the last surface emitted.

 */

void joinJagged( Point2D points[], int npoints ) {



	RtPoint mesh[MAXNPTS][NU];

	int u,v;



	srand( time(NULL) );



	float r;



	for( v = 0; v < npoints; v++ ) {



		for( u = 0; u < NU; u++ ) {





			mesh[v][u][0] = points[v].x * coeff[u][0];

			mesh[v][u][1] = points[v].x * coeff[u][1];

			if( v == npoints-1 ) {

				float r = (rand() % 100);

				mesh[v][u][2] = points[v].y - (r / 75) * ( (rand()%2) * -2 + 1);

				last[u][0] = mesh[v][u][0];

				last[u][1] = mesh[v][u][1];

				last[u][2] = mesh[v][u][2];

			} else if( v == 0 ) {

				mesh[v][u][0] = last[u][0];

				mesh[v][u][1] = last[u][1];

				mesh[v][u][2] = last[u][2];

			} else {

				mesh[v][u][2] = points[v].y;

			}



		}



	}





	RtFloat nu = NU;

	RtFloat np = npoints;



	RiBasis( RiBezierBasis, RI_BEZIERSTEP, RiBezierBasis, RI_BEZIERSTEP );

	RiPatchMesh( RI_BICUBIC, (RtInt) NU, RI_PERIODIC, (RtInt) npoints, RI_PERIODIC, RI_P, (RtPointer) mesh, RI_NULL );







}



/*

 * Make a joined jagged surface of rotation as above, but perturb the entire surface as it is rotated about,

 * resulting in various peaks and valleys around th esurface, like an eaten apple core.

 */



void joinJaggedCore( Point2D points[], int npoints ) {



	RtPoint mesh[MAXNPTS][NU];

	int u,v;



	srand( time(NULL) );



	float r;



	for( v = 0; v < npoints; v++ ) {



		for( u = 0; u < NU; u++ ) {





			mesh[v][u][0] = points[v].x * coeff[u + ( (rand()%3) - 1 ) ][0]*(1+(rand() % 100)/100*( (rand()%2) * -2 + 1));

			mesh[v][u][1] = points[v].x * coeff[u + ( (rand()%3) - 1 ) ][1]*(1+(rand() % 100)/100*( (rand()%2) * -2 + 1));

			if( v == npoints-1 ) {

				float r = (rand() % 100);

				mesh[v][u][2] = points[v].y + (r / 75) * ( (rand()%2) * -2 + 1);

				last[u][0] = mesh[v][u][0];

				last[u][1] = mesh[v][u][1];

				last[u][2] = mesh[v][u][2];

			} else if( v == 0 ) {

				mesh[v][u][0] = last[u][0];

				mesh[v][u][1] = last[u][1];

				mesh[v][u][2] = last[u][2];

			} else {

				mesh[v][u][2] = points[v].y + ((rand() % 100) / 75) * ( (rand()%2) * -2 + 1);

			}



		}



	}





	RtFloat nu = NU;

	RtFloat np = npoints;



	RiBasis( RiBezierBasis, RI_BEZIERSTEP, RiBezierBasis, RI_BEZIERSTEP );

	RiPatchMesh( RI_BICUBIC, (RtInt) NU, RI_PERIODIC, (RtInt) npoints, RI_PERIODIC, RI_P, (RtPointer) mesh, RI_NULL );







}