8. Listing of the Final Program

The following is the final C program for tutorial # 3:

/*****************************************************************************

      		Example NuGraf Rendering Library Script File # 2
	   25 Spheres Illustrating Different Surface Characteristics.

      See Explanation in the NuGraf Reference Manual - Tutorial Chapter.

               This file can be compiled and run stand-alone.

  Copyright (c) 1988, 2003 Okino Computer Graphics, Inc. All Rights Reserved.

*****************************************************************************/

#include	"ni.h"		/* This is the main NuGraf include file */

#include	<stdio.h>
#include	<stdlib.h>
#include	<string.h>
#include	<math.h>

/* Resolution of the image */
#define	IMAGE_RESOLUTION	512

/* -------------------------------------------------- */

	Nd_Void
main() {
	char	*home_directory = NULL;
	char	*current_working_directory = NULL;
	char	handle_name[30], handle_name2[30];

	/* General variables */
	Nd_Short row, colm, sphere_num, surf_num;

	/* Sphere primitive parameters */
	Nd_Float sph_radius = 1;
	Nd_Int	 sph_u_subdiv = 12;	/* parametric u & v subdivisions */
	Nd_Int	 sph_v_subdiv = 12;
	Nd_Vector sphere_center;

	/* Spacing between the spheres */
	Nd_Float x_inc = 2.5, y_inc = 2.5;

	/* Shading model coefficients */
	Nd_Float 	sphere_ambient_coeff;
	Nd_Float 	sphere_diffuse_coeff;
	Nd_Float 	sphere_specular_coeff;

	/* Specular model coefficients */
	Nd_Int		phong_shininess;
	Nd_Float	c3_coefficient;
	Nd_Float 	metal_coefficient = 1.0;
	Nd_Float	index_of_refraction;

	/* Opacity values */
	Nd_Float Opacity_FaceCoeff;
	Nd_Float Opacity_ReflectCoeff;
	Nd_Float Opacity_EdgeCoeff;
	Nd_Float Opacity_EdgeExp;

	/* Direction of the 'directional' line source (non-normalized vector) */
	Nd_Vector light1_shinefrom = { 1.0, 1.0, 1.0 };

	/* Camera variables */
	Nd_Vector lookat, lookfrom;
	Nd_Float  camera_window[] = { 12.5, 12.5 };

	/* Rendering statistics buffer */
	Nd_Float stats_buffer[Nc_NUM_STATISTIC_PARAMETERS];

	/* Output driver variables */
	Nd_Int	dummy_int = -1L;

	/* Image Resolution */
	Nd_Int		image_res[2];

	/* ----------->>>> Initialize the Library  <<<<<------------- */
   /* Initialize the library and the directory locations */
	Ni_Initialize(home_directory, current_working_directory);

	/*>>>> Define Surfaces <<<<--------------- */
	/* The bottom 5 spheres illustrate different ways of specifying */
	/* the ambient, diffuse and specular surface colors. */
	/* Default colors: white ambient, diffuse and specular colors */
	Ni_Surface("surface 1", Nt_COLOR, Nt_COLORNAME, "white", Nt_CMDSEP, Nt_CMDEND);

	/* White diffuse & specular colors, red ambient color */
	Ni_Surface("surface 2", Nt_COLOR, Nt_COLORNAME, "white", Nt_CMDSEP,
		Nt_AMBIENTCOLOR, Nt_COLOR, Nt_COLORNAME, "red",
		Nt_ENABLED, Nt_ON,
		Nt_CMDSEP, Nt_CMDEND);

	/* White ambient & diffuse colors, red specular color */
	Ni_Surface("surface 3", Nt_COLOR, Nt_COLORNAME, "white", Nt_CMDSEP,
		/* !! NOTE: The "metal" coefficient must be > 0.0 for the */
		/* specular colour to be seen. */
		Nt_SPECULARCOLOR,
			Nt_COLOR, Nt_COLORNAME, "red",
			Nt_ENABLED, Nt_ON,
			Nt_CMDSEP,
		Nt_MODEL, Nt_PHONG,
			Nt_METAL, (Nd_Float *) &metal_coefficient,
			Nt_CMDSEP,
		Nt_CMDEND);

	/* Blue ambient, white diffuse, and red specular colors */
	Ni_Copy(Nt_SURFACE, "surface 3", "surface 4", Nt_CMDEND);
	Ni_Surface("surface 4",
		Nt_AMBIENTCOLOR,
			Nt_COLOR, Nt_COLORNAME, "blue",
			Nt_ENABLED, Nt_ON,
			Nt_CMDSEP,
		Nt_CMDEND);

	/* Same as surface # 1 except that default color is yellow */
	Ni_Surface("surface 5",
		Nt_COLOR, Nt_COLORNAME, "yellow", Nt_CMDSEP,
		Nt_CMDEND);

	/* The second row from the bottom varies the ambient, diffuse */
	/* and specular surface coefficients. */
	for (surf_num = 6; surf_num <= 10; ++surf_num)
	{
		sprintf(handle_name, "surface %d", surf_num);
		switch (surf_num)
		{
			case 6: /* All ambient */
				sphere_ambient_coeff=0.5;
				sphere_diffuse_coeff=0.0;
				sphere_specular_coeff=0.0;
				break;
			case 7: /* All diffuse */
				sphere_ambient_coeff=0.0;
				sphere_diffuse_coeff=1.0;
				sphere_specular_coeff=0.0;
				break;
			case 8: /* Diffuse + specular highlight */
				sphere_ambient_coeff=0.0;
				sphere_diffuse_coeff=1.0;
				sphere_specular_coeff=0.7;
				break;
			case 9: /* Ambient + diffuse */
				sphere_ambient_coeff=0.3;
				sphere_diffuse_coeff=0.5;
				sphere_specular_coeff=0.0;
				break;
			case 10: /* Default mixture of ambient, diffuse & specular */
				sphere_ambient_coeff=0.3;
				sphere_diffuse_coeff=0.4;
				sphere_specular_coeff=0.7;
				break;
		}
		Ni_Surface(handle_name, Nt_SHADINGCOEFFS,
			Nt_AMBIENT, (Nd_Float *) &sphere_ambient_coeff,
			Nt_DIFFUSE, (Nd_Float *) &sphere_diffuse_coeff,
			Nt_SPECULAR, (Nd_Float *) &sphere_specular_coeff,
			Nt_CMDSEP, Nt_CMDEND);
		}

	/* The third row from the bottom uses the Phong specular shading */
	/* model and varies the highlight size from left to right. */
	for (surf_num=11; surf_num <=15; ++surf_num)
	{
		sprintf(handle_name, "surface %d", surf_num);

		/* Vary the Phong hightlight size from 4 to 64 */
		phong_shininess=(surf_num-11)/4.0 * 60 + 4;
		Ni_Surface(handle_name, Nt_MODEL, Nt_PHONG,
			Nt_SHININESS, (Nd_Int *) &phong_shininess,
			Nt_CMDSEP, Nt_CMDEND);
	}

	/* The fourth row from the bottom uses the Blinn specular shading */
	/* model and varies the highlight size from left to right. */

	for (surf_num=16; surf_num <=20; ++surf_num)
	{
		sprintf(handle_name, "surface %d", surf_num);

		/* Vary the Blinn IoR parameter from 1 to 60 */
		index_of_refraction=(surf_num-15)/5.0 * 60.0;

		/* Vary the Blinn C3 coefficient from 0.0 to 0.4 */
		/* (this controls the size of the highlight) */
		c3_coefficient=(surf_num-16)/4.0 * 0.4;
		Ni_Surface(handle_name, Nt_MODEL, Nt_BLINN,
			Nt_C3, (Nd_Float *) &c3_coefficient,
			Nt_INDEXREFRACT, (Nd_Float *) &index_of_refraction,
			Nt_CMDSEP, Nt_CMDEND);
	}

	/* The top row varies the surface opacity from left to right. */
	for (surf_num=21; surf_num <=25; ++surf_num)
	{
		sprintf(handle_name, "surface %d", surf_num);
		Opacity_FaceCoeff=(surf_num-20)/8.0 + 0.3;

		Opacity_ReflectCoeff=1.0; 		/* Opaque highlights */
		Opacity_EdgeCoeff=1.0; 		/* Opaque edges */
		Opacity_EdgeExp=0.4;

		Ni_Surface(handle_name, Nt_COLOR, Nt_COLORNAME, "white", Nt_CMDSEP,
			Nt_OPACITY, Nt_FACECOEFF, (Nd_Float *) &Opacity_FaceCoeff,
			Nt_REFLECTCOEFF, (Nd_Float *) &Opacity_ReflectCoeff,
			Nt_EDGECOEFF, (Nd_Float *) &Opacity_EdgeCoeff,
			Nt_EDGEEXP, (Nd_Float *) &Opacity_EdgeExp,
			Nt_EDGE, Nt_ENABLED, Nt_ON,
			Nt_CMDSEP, Nt_CMDEND);
	}

	/*>>>> Define Sphere Objects <<<<------------- */
	/* Create 25 spheres in a grid pattern */
	sphere_num=1;

	for (row=1; row <=5; ++row)
	{
		for (colm=1; colm <=5; ++colm)
		{
			sprintf(handle_name, "sphere object %d", sphere_num);
			sphere_center[0]=(colm-1) * x_inc;
			sphere_center[1]=(row-1) * y_inc;
			sphere_center[2]=0.0;
			Ni_Object_Define(handle_name, Nt_CMDEND);
			Ni_Primitive(Nt_SPHERE, Nt_CENTERVERTEX, sphere_center, Nt_CMDSEP,
				Nt_RADIUS, (Nd_Float *) &sph_radius,
				Nt_CMDSEP, Nt_CMDEND);

			Ni_Object_End(Nt_CMDEND);
			sprintf(handle_name2, "sphere instance %d", sphere_num);
			Ni_Add_Instance(Nt_INSTANCE, handle_name2,
				Nt_OBJECT, handle_name, Nt_CMDEND);

			Ni_Attach(Nt_INSTANCE, handle_name2,
				Nt_INSTANCE, "world", Nt_CMDEND);

			/* Link surface to each object */
			sprintf(handle_name2, "surface %d", sphere_num);
			Ni_Surfacelink(Nt_SURFACE, handle_name2,
				Nt_OBJECT, handle_name,
				Nt_CMDEND);

			++sphere_num;
		}
	}

	/*>>>> Render <<<<------------------ */
	/* Set the resolution of the image */
	image_res[Na_X_VALUE]=IMAGE_RESOLUTION;
	image_res[Na_Y_VALUE]=IMAGE_RESOLUTION;
	Ni_Option( Nt_CULLING, Nt_BACK, Nt_CMDSEP,
		Nt_RESOLUTION, (Nd_Int *) image_res, Nt_CMDSEP,
		Nt_SHADING, Nt_SMOOTH, Nt_CMDSEP,
		Nt_SUBDIVISIONS, Nt_SPHERE,
		Nt_USUBDIV, (Nd_Int *) &sph_u_subdiv,
		Nt_VSUBDIV, (Nd_Int *) &sph_v_subdiv,
		Nt_CMDSEP, Nt_CMDEND);

	/* Add one directional light source to the scene */
	Ni_Light("light1", Nt_MODEL, Nt_DIRECTION, Nt_CMDSEP,
		Nt_SHINEFROM, light1_shinefrom,
		Nt_CMDSEP, Nt_CMDEND);

	/* Background color scheme */
	Ni_Background(Nt_COLORSCHEME, Nt_PATTERN, Nt_TYPE1, Nt_CMDEND);

	/* Modify the default camera to use an orthohraphic projection and */
	/* view the spheres from the +ve Z axis towards the center of the spheres. */
	lookfrom[0]=(2 * x_inc);
	lookfrom[1]=(2 * y_inc);
	lookfrom[2]=15.0;
	lookat[0]=(2 * x_inc);
	lookat[1]=(2 * y_inc);
	lookat[2]=0.0;
	Ni_Camera("default", Nt_ACTIVE, Nt_CMDSEP,
		/* Make it the active camera */
		Nt_LOOKFROM, lookfrom, Nt_CMDSEP,
		Nt_LOOKAT, lookat, Nt_CMDSEP,
		Nt_PROJECTION, Nt_ORTHOGRAPHIC, Nt_CMDSEP,
		Nt_WINDOW, (Nd_Float *) camera_window,
		Nt_CMDSEP, Nt_CMDEND);

	/* Select the GIF file output driver. Send image to 'example2.gif' */
	/* and quantize the image down from 24-bits to 256 colors. */
	Ni_Output_Driver("driver#1", Nt_FILE, Nt_GIF, Nt_CMDSEP,
		Nt_FILENAME, "example2.gif", Nt_CMDSEP,
		Nt_OPTIONSTRING, "gif89a="off"," Nt_CMDSEP,
		Nt_IMAGEQUANTIZE, Nt_ENABLED, Nt_ON,
		/* The number of quantization colors is taken */
		/* from the device's colormap length. */
		Nt_NUMCOLORS, (Nd_Int *) &dummy_int,
		Nt_CMDSEP, Nt_CMDEND);

	/* Now render the scene to the GIF output file and return rendering */
	/* statistics in the 'stats_buffer' array of floats. */

	Ni_Render(Nt_STATISTICS, stats_buffer, Nt_CMDEND);

	/* Print out some of the rendering statistics */
	printf("Total memory used (during rendering only)="%ldkb.\n","
		(long) stats_buffer[Na_STATS_MEMORY_USED] / 1024L);
	printf("Number of polygons processed (after culling)="%ld.\n","
		(long) stats_buffer[Na_STATS_NUM_POLYGONS]);

	Ni_Exit_Cleanup();
}