GLUT Light

#include "windows.h"
#include "GL/glut.h"
#include "stdio.h"
#include "math.h"

#define G_PI 3.14159265358979323846f

void prepare_lighting();
void display();
void keyboard(unsigned char key, int x, int y);

float theta, phi;

int main()
{
  theta = G_PI/2;
  phi = -G_PI/2;

  glutInitDisplayMode( GLUT_DOUBLE | GLUT_DEPTH | GLUT_RGB );
  glutInitWindowSize( 640, 640 );
  glutCreateWindow( "hihi" );

  glutDisplayFunc(display);
  glutKeyboardFunc( keyboard );

  prepare_lighting();

  glutMainLoop();
  return 0;
}

void keyboard(unsigned char key, int x, int y)
{
  switch( key )
  {
    case 'w':
     theta -= .05;
     prepare_lighting();
     glutPostRedisplay();
    break;

    case 's':
     theta += .05;
     prepare_lighting();
     glutPostRedisplay();
    break;

    case 'a':
     phi -= .05;
     prepare_lighting();
     glutPostRedisplay();
    break;

    case 'd':
     phi += .05;
     prepare_lighting();
     glutPostRedisplay();
    break;
  };
}


void display()
{
  glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

    glMatrixMode(GL_PROJECTION);
     glLoadIdentity();
     gluPerspective( 20, 1, 0.1, 10 );

    glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();
     gluLookAt(
     0,0,1,
     0,0,0,
     0,1,0 );

    glEnable( GL_LIGHTING );
    glEnable( GL_DEPTH_TEST );
    glutSolidTeapot( .1 );

  glutSwapBuffers();
}

void prepare_lighting()
{
const GLfloat light_ambient[]  = { 0.0f, 0.0f, 0.0f, 1.0f };
const GLfloat light_diffuse[]  = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
GLfloat light_position[4] = { sinf(theta) * cosf(phi), cosf(theta), -sinf(theta) * sinf(phi), 0 };

const GLfloat mat_ambient[]    = { 0.7f, 0.7f, 0.7f, 1.0f };
const GLfloat mat_diffuse[]    = { 0.8f, 0.8f, 0.8f, 1.0f };
const GLfloat mat_specular[]   = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat high_shininess[] = { 100.0f };

  theta = fmodf( theta, 2*G_PI );
  phi = fmodf( phi, 2*G_PI );


    glLightfv(GL_LIGHT0, GL_AMBIENT,  light_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE,  light_diffuse); //
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    glMaterialfv(GL_FRONT, GL_AMBIENT,   mat_ambient);
    glMaterialfv(GL_FRONT, GL_DIFFUSE,   mat_diffuse);  //
    glMaterialfv(GL_FRONT, GL_SPECULAR,  mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess);

    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
    glEnable( GL_LIGHT0 );
}