/* lighting.c */

/*
     Purpose: demonstrate lighting
*/


#ifdef __APPLE__
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#include <stdlib.h>

#define KEY_ESC 27      /* glut doesn't define this one  */

/*
	Functions
*/

GLvoid display( GLvoid )
{
	glClear( GL_COLOR_BUFFER_BIT );

	/* Note that glut defines the normals for its 3D objects */
	glutSolidTorus( 0.3, 0.6, 50, 50 );
	glFlush();
}


GLvoid keyboard( GLubyte key, GLint x, GLint y)
{
	switch (key)
	{
	case KEY_ESC:   /* exit when escape key is pressed */
    	exit(0);
   	break;

	case 'l':
	case 'L':
	{
		static GLboolean lightOn = GL_FALSE;
		/* Toggle the light on/off */
		lightOn = !lightOn;
		/* Turn on/off the OpenGL lighting calculations */
		lightOn ? glEnable( GL_LIGHTING ) : glDisable( GL_LIGHTING );
		glutPostRedisplay();
	}
	break;
	
	}
}


void init( void )
{	
	/* What colour is the ambient light */	
	GLfloat pAmbientLightModel[] = { 0.3, 0.3, 0.3, 1.0 };
	
	/* Where is the infinite directional light */
	GLfloat pLight0Pos[] = { 10.0, 10.0, 2.0 , 0.0 };
	
	/* What are the ambient, diffuse, and specular material 
	   properties for our torus 
	*/   
	GLfloat pMatAmbDiff[]   = { 1.0, 1.0, 1.0, 1.0 };
	GLfloat pMatSpecular[]  = { 1.0, 1.0, 1.0, 1.0 };

	/* Get some ambient light */
	glLightModelfv(	GL_LIGHT_MODEL_AMBIENT, pAmbientLightModel );
	
	/* Get an infinite, but directional light (like a sun) */
	glEnable( GL_LIGHT0 );
	glLightfv( GL_LIGHT0, GL_POSITION, pLight0Pos );
	
	/* Set up a material for our torus */	
	glMaterialfv( GL_FRONT, GL_SPECULAR, pMatSpecular );	
	glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, pMatAmbDiff );	
}


int main( int argc, char *argv[] )
{

	glutInit( &argc, argv );
	glutCreateWindow( argv[0] );

	glutDisplayFunc( display ); 
	glutKeyboardFunc( keyboard );
	init();
	
	glutMainLoop();
	
	return 0;
}