/* drawfunc.c * This program demonstrates the dot plot of the following function * f(x) = e**(-x) cos (2 pi x ) * * Click the right button of the mouse within the opened * window to exit the program. */ #include << X11/Xlib.h> #include << math.h> #include << GLUT/glut.h> // #include << OpenGL/gl.h> #include << stdlib.h> #include << stdio.h> const int screenWidth = 640; const int screenHeight = 480; GLdouble A, B, C, D; void myInit(void) { glClearColor (1.0, 1.0, 1.0, 0.0); // set black background color glColor3f (0.0f, 0.0f, 0.0f); // set the drawing color glPointSize (2.0); // set dot size 2 x 2 glMatrixMode (GL_PROJECTION); // set "camera shape" glLoadIdentity (); // clear the matrix // viewing transformation gluOrtho2D (0.0, (GLdouble)screenWidth, 0.0, (GLdouble)screenHeight); // set the Worlk Window A = screenWidth / 4.0 ; //set values used for scaling and shifting B = 0.0 ; C = D = screenHeight / 2.0 ; } void myDisplay(void) { GLdouble x, func; glClear (GL_COLOR_BUFFER_BIT); // clear the screen glBegin(GL_POINTS); for (x = 0; x < 4.0; x += 0.005) { func = exp( -x ) * cos ( 2 * 3.14159 * x ); glVertex2d (A * x + B, C * func + D ); } glEnd(); glFlush (); // send all out to display } void myMouse(int button, int state, int x, int y) { switch (button) { case GLUT_RIGHT_BUTTON: if (state == GLUT_DOWN) exit (-1); break; default: break; } } int main(int argc, char** argv) { glutInit(&argc, argv); // initialize the toolkit glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // set display mode glutInitWindowSize (screenWidth, screenHeight); // set screen window size glutInitWindowPosition (100, 150); // set window position on screen glutCreateWindow (argv[0]); // open the screen window myInit (); glutDisplayFunc(myDisplay); // register redraw function glutMouseFunc(myMouse); // register the mouse action function glutMainLoop(); // go into a perpetual loop return 0; }