Light

#include

//Initializes 3D rendering
void initRendering() {
glEnable(GL_DEPTH_TEST);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_LIGHTING); //Enable lighting
glEnable(GL_LIGHT0); //Enable light #0
glEnable(GL_LIGHT1); //Enable light #1
glEnable(GL_NORMALIZE); //Automatically normalize normals

}


void handleResize(int w, int h) {
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (double)w / (double)h, 1.0, 200.0);
}

float angle = -70.0f;

//Draws the 3D scene
void drawScene() {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();


//Add positioned light
GLfloat lightColor0[] = {0.5f, 0.5f, 0.5f, 1.0f}; //Color (0.5, 0.5, 0.5)
GLfloat lightPos0[] = {4.0f, 0.0f, 8.0f, 1.0f}; //Positioned at (4, 0, 8) & 1.0 means Positioned

glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColor0); //assign the intenisty of light0
glLightfv(GL_LIGHT0, GL_POSITION, lightPos0); // put the light0 at the postion in the position array

//Add directed light
GLfloat lightColor1[] = {0.5f, 0.2f, 0.2f, 1.0f}; //Color (0.5, 0.2, 0.2)
GLfloat lightPos1[] = {-1.0f, 0.5f, 0.5f, 0.0f}; //Coming from the direction (-1, 0.5, 0.5) & 0.0 means Directioned

glLightfv(GL_LIGHT1, GL_DIFFUSE, lightColor1); //assign the intenisty of light1
glLightfv(GL_LIGHT1, GL_POSITION, lightPos1); // put the light0 at the postion in the position array

glRotatef(angle, 0.0f, 1.0f, 0.0f);
glColor3f(1.0f, 1.0f, 0.0f);
glBegin(GL_QUADS);

//Front
glNormal3f(0.0f, 0.0f, 1.0f); // normal to the x,y Plan (+ve direction of z)

glVertex3f(-1.5f, -1.0f, 1.5f);
glVertex3f(1.5f, -1.0f, 1.5f);
glVertex3f(1.5f, 1.0f, 1.5f);
glVertex3f(-1.5f, 1.0f, 1.5f);

//Right
glNormal3f(1.0f, 0.0f, 0.0f); // normal to the y,z Plan (+ve direction of x)

glVertex3f(1.5f, -1.0f, -1.5f);
glVertex3f(1.5f, 1.0f, -1.5f);
glVertex3f(1.5f, 1.0f, 1.5f);
glVertex3f(1.5f, -1.0f, 1.5f);

//Back
glNormal3f(0.0f, 0.0f, -1.0f); // normal to the x,y Plan (-ve direction of z)

glVertex3f(-1.5f, -1.0f, -1.5f);
glVertex3f(-1.5f, 1.0f, -1.5f);
glVertex3f(1.5f, 1.0f, -1.5f);
glVertex3f(1.5f, -1.0f, -1.5f);

//Left
glNormal3f(-1.0f, 0.0f, 0.0f); // normal to the y,z Plan (-ve direction of x)

glVertex3f(-1.5f, -1.0f, -1.5f);
glVertex3f(-1.5f, -1.0f, 1.5f);
glVertex3f(-1.5f, 1.0f, 1.5f);
glVertex3f(-1.5f, 1.0f, -1.5f);

glEnd();

glutSwapBuffers();
}

void update(int value) {
angle += 1.5f;
if (angle > 360) {
angle -= 360;
}

glutPostRedisplay();
glutTimerFunc(25, update, 0);
}

int main(int argc, char** argv) {
//Initialize GLUT
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(800, 600);

//Create the window
glutCreateWindow("Lighting");
initRendering();

//Set handler functions
glutDisplayFunc(drawScene);
glutReshapeFunc(handleResize);

glutTimerFunc(25, update, 0); //Add a timer

glutMainLoop();
return 0;
}