#include <gl.h>      /* replaces 5 pager in GUIDE sec 9.2.1 */
#include <device.h>  /* MOUSEX MOUSEY */
#include <math.h>    /* fcos  fsin    */
#include <stdio.h>   /* NULL would you believe */



#define	DG	.01745
#define	SSTEP	15


int	step, t = 1, dtime;

Matrix id = {1.,0.,0.,0.,  0.,1.,0.,0.,  0.,0.,1.,0.,  0.,0.,0.,1.};
float vv[3],nn[3]; 

float white[]={ DIFFUSE, 0.4, 0.4, 0.4,    /* MATERIAL list */
		SPECULAR,0.0,0.0,0.0,
		LMNULL};

float	plain[] = {DIFFUSE, 1.0, 0.8, 0.0,
		   SPECULAR, 1.0, 1.0, 1.0,
		   SHININESS, 100.0,
		   LMNULL};

float moon[] ={ LCOLOR, 1.0, 1.0, 1.0,     /* LIGHT list */
		POSITION, 1.0, 0.0, 0.3, 0.0,
		AMBIENT, 0.1, 0.1, 0.1,
		LMNULL};
 
float	satmat[] = {DIFFUSE, 0.5, 0.0, 0.0,
		    SPECULAR, 0.5, 0.5, 0.5,
		    SHININESS, 128.0,
		    EMISSION, 0.4, 0.0, 0.0,
		    AMBIENT, 0.0, 0.0, 0.0,
		    LMNULL};

lightit(spec, shine)
float	spec, shine;
{
	plain[5] = plain[6] = plain[7] = spec;
	plain[9] = shine;

	lmdef(DEFMATERIAL,1,11,plain);
	lmdef(DEFMATERIAL,2,19,satmat);
   	lmdef(DEFLIGHT,1,14,moon);
   	lmdef(DEFLMODEL,1,0,NULL);       /* #1 atmosphere is default */
}

bindall()
{
	bindmaterial();
	bindlight();
	bindmodel();
}

bindmodel()
{
   	lmbind(LMODEL,1);
}

bindmaterial()
{
	lmbind(MATERIAL,1);            /*  ? to be explained */
}

bindlight(i)
int	i;
{
   	lmbind(LIGHT0,1);
	lmbind(LIGHT1,i);
}

hair(th,ta) int th,ta;{ float fth,fta; /* sphere normals are easy */
      fth = DG * (float)th; fta = DG * (float)ta;
      vv[0] = fcos(fth)*(1. + 0.5*fcos(fta));
      vv[1] = fsin(fth)*(1. + 0.5*fcos(fta));
      vv[2] = 0.5*fsin(fta);
      nn[0] = fcos(fth)*fcos(fta);
      nn[1] = fsin(fth)*fcos(fta);
      nn[2] = fsin(fta); }

drawit()
{ 
	int th,ta; 
	
	for(th=0;th<=360;th +=step){  
     		bgntmesh();   
		for(ta= (0); ta<=380; ta +=step){
           		hair(th,ta);    n3f(nn);  v3f(vv);  
           		hair(th+step,ta); n3f(nn);  v3f(vv);
		}
     		endtmesh();
	}
} 
	  
orbit()
{
	int	th,ta;
	float	posy, posz;

	posy = 1 + fsin(DG * t * dtime);
	posz = fcos(DG * t * dtime);

	for(th = 0; th <= 360; th += SSTEP){
		bgntmesh();
		for(ta = -90; ta <= 90; ta += SSTEP){
			sphere(posy, posz, 0.1, th,ta);		
			n3f(nn); 	
			v3f(vv);

			sphere(posy, posz, 0.1, th + SSTEP,ta); 	
			n3f(nn); 	
			v3f(vv);
		}
		endtmesh();
	}
}

sphere(py, pz, r, th, ta)
float	py, pz, r;
int	th, ta;
{
	float	fth, fta;

      	fth = DG * (float)th; fta = DG * (float)ta;
     	vv[0] = r * fcos(fth)*fcos(fta);
     	vv[1] = py + r * fsin(fth)*fcos(fta);
     	vv[2] = pz + r * fsin(fta); 
     	nn[0] = fcos(fth)*fcos(fta);
     	nn[1] = fsin(fth)*fcos(fta);
     	nn[2] = fsin(fta); 
}


float	orbitl[] =	{LCOLOR, 0.4, 0.0, 0.0,
			 POSITION, 0.0, 0.0, 0.0, 1.0,
			 LMNULL};
deforbits(dtime)
int	dtime;
{
	int	i,increments;
	float	posy,posz;

	increments = (int)360/dtime;

	for(i = 1; i <= increments; i++){
		posy = 1 + fsin(DG * i * dtime);
		posz = fcos(DG * i * dtime);

		orbitl[6] = posy;
		orbitl[7] = posz;

		lmdef(DEFLIGHT, i+1, 10, orbitl);
	}
}



main(argc, argv) 
int	argc;
char	**argv;
{ 

/*	if (argc != 5){
		printf("enter spec reflectance (sp) shininess (sp) step size (sp) orbit step\n");
		printf("example:        ltor2 1.0 128.0 10 20 \n");
		exit(0);
	}
 no more command liners*/
	
	/* step = atoi(argv[3]); dtime = atoi(argv[4]); */
	step = 10; dtime = 10;

	keepaspect(1,1);  /*new style, corrected gkf 4dec94 */
      	winopen("light"); 

	doublebuffer(); 
	RGBmode();
	gconfig(); 
	lsetdepth(0, 0x7FFFFF);
      	zbuffer(1); 
     
     	mmode(MVIEWING);
   
	deforbits(dtime);

     /*	lightit(atof(argv[1]), atof(argv[2])); was */
     	lightit(.7, 80.0);

	bindmaterial();
	bindmodel();

	perspective(900, 1.0, 0.1, 100.0);

	while(1)	{
                reshapeviewport(); /* added 21mar08 gkf */
		loadmatrix(id);
		polarview(4.0, getvaluator(MOUSEX)*4, getvaluator(MOUSEY)*4, 0);

		if(t >= (int)360/dtime)
			t = 1;
		else
			t++;

		bindlight(t + 1);

		cpack(0);
		clear();
		zclear();

		lmbind(MATERIAL,1);
		drawit();
		lmbind(MATERIAL,2);
		orbit();

		swapbuffers(); 
   	} 
}