#include <gl/glut.h>
#include <math.h>      // For math routines (such as sqrt & trig).
GLfloat xRotated, yRotated, zRotated;
GLdouble radius = 2;
GLfloat qaBlack[] = { 0.0, 0.0, 0.0, 1.0 }; //Black Color
GLfloat qaGreen[] = { 0.0, 1.0, 0.0, 0.0 }; //Green Color
GLfloat qaWhite[] = { 1.0, 1.0, 1.0, 1.0 }; //White Color
GLfloat qaRed[] = { 1.0, 0.0, 0.0, 1.0 }; //Red Color

// Set lighting intensity and color
GLfloat qaAmbientLight[] = { 0.1, 0.1, 0.1, 1.0 };
GLfloat qaDiffuseLight[] = { 1, 1, 1, 1.0 };
GLfloat qaSpecularLight[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat emitLight[] = { 0.9, 0.9, 0.9, 0.01 };
GLfloat Noemit[] = { 0.0, 0.0, 0.0, 1.0 };
// Light source position
GLfloat qaLightPosition[] = { 0, 0, 0, 1 };

void display(void);
void reshape(int x, int y);

void idleFunc(void)
{
	if (zRotated > 360.0) {
		zRotated -= 360.0*floor(zRotated / 360.0);   // Don't allow overflow
	}

	if (yRotated > 360.0) {
		yRotated -= 360.0*floor(yRotated / 360.0);   // Don't allow overflow
	}
	zRotated += 0.01;
	yRotated += 0.01;

	display();
}
void initLighting()
{

	// Enable lighting
	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);

	// Set lighting intensity and color
	glLightfv(GL_LIGHT0, GL_AMBIENT, qaAmbientLight);
	glLightfv(GL_LIGHT0, GL_DIFFUSE, qaDiffuseLight);
	glLightfv(GL_LIGHT0, GL_SPECULAR, qaSpecularLight);


}

int main(int argc, char **argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
	glutInitWindowSize(350, 350);
	glutCreateWindow("Nhóm 7");
	initLighting();

	xRotated = yRotated = zRotated = 0.0;

	glutIdleFunc(idleFunc);
	glutDisplayFunc(display);
	glutReshapeFunc(reshape);
	glutMainLoop();
	return 0;
}

void display(void)
{


	glMatrixMode(GL_MODELVIEW);
	// clear the drawing buffer.
	glClear(GL_COLOR_BUFFER_BIT);
	// clear the identity matrix.
	glLoadIdentity();

	glTranslatef(0.0, 0.0, -20.0);


	// 
	glPushMatrix();


	glTranslatef(0.0, 0.0, 0);
	// Set material properties
	glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, qaRed);

	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, qaRed);

	glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, qaWhite);

	glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 0.2);
	glutSolidSphere(radius, 25, 25);

	glPopMatrix();



	glPushMatrix();


	glRotatef(yRotated, 0.0, 0.0, 1.0);
	glTranslatef(5.0, 0.0, 0.0);

	// Set the light position
	glLightfv(GL_LIGHT0, GL_POSITION, qaLightPosition);
	glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, emitLight);   // Make sphere glow (emissive) 
	glutSolidSphere(radius / 6, 25, 25);
	glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, Noemit);

	glPopMatrix();




	glFlush();
	glutSwapBuffers();

}

void reshape(int x, int y)
{
	if (y == 0 || x == 0) return;
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	gluPerspective(39.0, (GLdouble)x / (GLdouble)y, 0.6, 40.0);
	glMatrixMode(GL_MODELVIEW);
	glViewport(0, 0, x, y);  //Use the whole window for rendering
}

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