LAB 2A

BIT20203: Graphics Programming

LAB SHEET 2

Title                          : Graphics Programming using OpenGL

Objectives           : At the end of the session, students are able to:

                                          i.         Draw a simple 2D graphics using OpenGL.

Duration               : 2 Hours

Tasks                       :

1.     Write the following code. Compile and run.

#include <GL/glut.h>

void display(void)

{

        /* clear window */

         glClear(GL_COLOR_BUFFER_BIT); 

        /* draw unit square polygon */

        glBegin(GL_POLYGON);

                glVertex2f(-0.5, -0.5);

                glVertex2f(-0.5, 0.5);

                glVertex2f(0.5, 0.5);

                glVertex2f(0.5, -0.5);

        glEnd();

        /* flush GL buffers */

        glFlush(); 

}

void init()

{

        /* set clear color to black */

        /*      glClearColor (0.0, 0.0, 0.0, 0.0); */

        /* set fill  color to white */

        /*      glColor3f(1.0, 1.0, 1.0); */

        /* set up standard orthogonal view with clipping */

        /* box as cube of side 2 centered at origin */

        /* This is default view and these statement could be removed */

        /* glMatrixMode (GL_PROJECTION);

        glLoadIdentity ();

        glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);  */

}

int main(int argc, char** argv)

{

        /* Initialize mode and open a window in upper left corner of screen */

        /* Window title is name of program (arg[0]) */

        /* You must call glutInit before any other OpenGL/GLUT calls */

        glutInit(&argc,argv); 

        glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);  

        glutInitWindowSize(500,500);

        glutInitWindowPosition(0,0); 

        glutCreateWindow("simple"); 

        glutDisplayFunc(display);

        init();

        glutMainLoop();

        return 0;

}

2.     Copy the sample code in the Page 80 of your textbook. Compile and run.

~ end ~