Movement of Teapot - OpenGL

An openGL program to illustrate the movement of teapot:

#include <cstdlib>

#include <iostream> // C++ I/O

#include <cstdio> // C I/O (for sprintf)

#include <cmath> // standard definitions

#include <GL/glut.h> // GLUT

#include <GL/glu.h> // GLU

#include <GL/gl.h> // OpenGL

using namespace std; // make std accessible

double rotAngle = 10; // rotation angle (BEWARE: Global)

void init()

{

glClearColor(0.96, 0.98, 0.03, 0); // background color

glClearDepth(1.0); // background depth value

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

// gluPerspective(70, 1, 1, 1000); // setup a perspective projection

glMatrixMode(GL_MODELVIEW);

glLoadIdentity();

/* gluLookAt( // set up the camera

0.0, 0.0, 10.0, // eye position

0.0, 0.0, 0.0, // lookat position

0.0, 1.0, 0.0); */ // up direction

glEnable(GL_DEPTH_TEST); // enable hidden surface removal

glEnable(GL_LIGHTING); // enable lighting

glEnable(GL_LIGHT0); // enable

float lpos[] = { 5, 5, 5, 0 };

glLightfv(GL_LIGHT0, GL_POSITION, lpos);

//glShadeModel(GL_FLAT); // flat shading

glShadeModel(GL_SMOOTH); // smooth shading

}

//-----------------------------------------------------------------------

// display callback function

//-----------------------------------------------------------------------

void display()

{

glClear(

GL_COLOR_BUFFER_BIT | // clear the frame buffer (color)

GL_DEPTH_BUFFER_BIT); // clear the depth buffer (depths)

glPushMatrix(); // save the current camera transform

glRotated(rotAngle, 0, 1, 0); // rotate by rotAngle about y-axis

glEnable(GL_COLOR_MATERIAL); // specify object color

glColor3f(0.07, 0.37, 0.85); // redish

glutSolidTeapot(1); // draw the teapot

glPopMatrix(); // restore the modelview matrix

glFlush(); // force OpenGL to render now

glutSwapBuffers(); // make the image visible

}

//-----------------------------------------------------------------------

// keyboard callback function

//-----------------------------------------------------------------------

void keyboard(unsigned char k, int x, int y)

{

switch (k)

{

case 'a':

rotAngle += 5; // increase rotation by 5 degrees

break;

case 's':

rotAngle -= 5; // decrease rotation by 5 degrees

break;

case 'd':

glTranslatef(0.5,0.5,0);

break;

case 'f':

glTranslatef(-0.5,-0.5,0);

break;

case 'g':

glScalef(0.5,0.5,0.5);

break;

case 'h':

glScalef(2.0,2.0,2.0);

break;

case 'q':

exit(0); // exit

}

glutPostRedisplay(); // redraw the image now

}

void usage()

{

cout << "\n\

-----------------------------------------------------------------------\n\

Menu\n\

Inputs keybord:\n\

a: Rotate counterclockwise\n\

s: Rotate clockwise\n\

d: Translate with x=1 y=1 z=0\n\

f: Translate with x= -1 y= -1 z =0 \n\

g: Zoom Out\n\

h: Zoom in\n\

q: Quit\n\

You may need to place the cursor over the graphics window for\n\

keyboard input to be processed.\n\

-----------------------------------------------------------------------\n";

cout.flush();

}

void menu(int value) {

switch (value) {

case 1 : rotAngle +=10;

break;

case 2 : rotAngle -=10;

break;

case 3 : glTranslatef(0.5,0.5,0);

break;

case 4 : glTranslatef(-0.5,-0.5,0);

break;

case 5 : glScalef(0.5,0.5,0.5);

break;

case 6 : glScalef(2.0,2.0,2.0);

break;

case 7 : exit(0);

}

glutPostRedisplay();

}

int main(int argc, char **argv)

{

usage(); // explain how to use

glutInit(&argc, argv);

glutInitDisplayMode(GLUT_DOUBLE |GLUT_DEPTH |GLUT_RGB );

glutCreateWindow("GLUT Example"); // create the window

glutCreateMenu(menu);

glutAddMenuEntry("Clockwise",1);

glutAddMenuEntry("Anticlockwise",2);

glutAddMenuEntry("Translate",3);

glutAddMenuEntry("AntiTranslate",4);

glutAddMenuEntry("Zoom out",5);

glutAddMenuEntry("Zoom in",6);

glutAddMenuEntry("Quit",7);

glutAttachMenu(GLUT_RIGHT_BUTTON);

glutDisplayFunc(display); // call display() to redraw window

glutKeyboardFunc(keyboard); // call keyboard() when key is hit

init(); // our own initializations

glutMainLoop(); // let GLUT take care of everything

return 0;

}