/* simple cave program*/

#include <cave_ogl.h>
#include <unistd.h>
#include <GL/glut.h>
#include <iostream.h>


#define SPEED 5 /* Max navigation speed in feet per second */


//**************** Declare Global Variables *****************


static GLuint greenMat, blueMat; 	
static GLUquadricObj *sphereObj;
float ball1_y, ball2_y;


// *************** Declare Functions **********************

void navigate(void);
void init_gl(void);
void draw_balls(void);
void update(void);


// *************** Main **********************

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

	CAVEConfigure(&argc, argv, NULL);
	CAVEFar = 500.;   
	// these funcs are called in the draw process
	CAVEInitApplication((CAVECALLBACK) init_gl, 0);
	CAVEFrameFunction((CAVECALLBACK) update, 0 );
	CAVEDisplay((CAVECALLBACK) draw_balls, 0 );
	
	CAVEInit();
	
	// this loop is in the parent process
	while( ! CAVEgetbutton(CAVE_ESCKEY) )
	    {
	     navigate();
		 //usleep is in micro-seconds 
	     usleep (10000);
	    }
	   
	CAVEExit();
}

// *************** Define Functions **********************


/* navigate - perform the navigation calculations. This checks the joystick
  state and uses that to move and rotate. The Y position of the joystick
  determines the speed of motion in the direction of the wand. The X position
  of the joystick determines the speed of rotation about the CAVE's Y axis.
  Joystick values in the range -.2 to .2 are ignored; this provides a dead
  zone to eliminate noise. The motion is scaled by dt, the time passed since
  the last call to navigate(), in order to maintain a smooth speed. */
void navigate(void)
{
 
 float jx=CAVE_JOYSTICK_X,jy=CAVE_JOYSTICK_Y,dt,t;
 static float prevtime = 0;
 t = CAVEGetTime();
 dt = t - prevtime;
 prevtime = t;
 if (fabs(jy)>0.2)
        {
        float wandFront[3];
        CAVEGetVector(CAVE_WAND_FRONT,wandFront);
        CAVENavTranslate(wandFront[0]*jy*SPEED*dt, wandFront[1]*jy*SPEED*dt,
                        wandFront[2]*jy*SPEED*dt);
        }
 if (fabs(jx)>0.2)
        CAVENavRot(-jx*90.0f*dt,'y');
}


/* init_gl - initialize GL lighting & materials */
void init_gl(void)
{
 float greenMaterial[] = { 0, 1, 0, 1 };
 float blueMaterial[] = { 0, 0, 1, 1 };
 glEnable(GL_LIGHT0);
 greenMat = glGenLists(1);
 glNewList(greenMat, GL_COMPILE);
 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, greenMaterial);
 glEndList();
 blueMat = glGenLists(1);
 glNewList(blueMat, GL_COMPILE);
 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blueMaterial);
 glEndList();
 sphereObj = gluNewQuadric();
}

void draw_balls(void)
{
 glClearColor(0., 0., 0., 0.);
 glClear(GL_DEPTH_BUFFER_BIT|GL_COLOR_BUFFER_BIT);
 glEnable(GL_LIGHTING);

/* Apply the navigation transformation */
 CAVENavTransform();

 glCallList(greenMat);
 glPushMatrix();
 glTranslatef(2.0, ball1_y, -5.0);
 gluSphere(sphereObj, 1.0, 8, 8);
 glPopMatrix();

 glCallList(blueMat);
 glPushMatrix();
 glTranslatef(-2.0, ball2_y, -5.0);
 gluSphere(sphereObj, 1.0, 8, 8);
 glPopMatrix();

 glDisable(GL_LIGHTING);
}


void update(void)
{
    
float t = CAVEGetTime();
 ball1_y = fabs(sin(t)) * 6 + 1;
 ball2_y = fabs(sin(t*1.2)) * 4 + 1;	
	
}

///////////////////////////////////////////////////////////////////////////////////////////