/* drawfile.cpp * This program demonstrates the drawing of polylines stored in a file * The data file is "dino.dat" * * Click the right button of the mouse to exit. */ #include << X11/Xlib.h> #include << fstream.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) { int i,j; const char InputFileName [] = "dino.dat"; fstream inStream; inStream.open(InputFileName, ios::in); // open the file if (inStream.fail()) return; glClear (GL_COLOR_BUFFER_BIT); // clear the screen GLint numpolys, numLines, x, y; inStream >> numpolys; // read the number of polylines for (j = 0; j < numpolys; j++) { inStream >> numLines; glBegin(GL_LINE_STRIP); // draw the next polyline for (i = 0; i < numLines; i++) { inStream >> x >> y; // read the next x, y pair glVertex2i (x, y); } glEnd(); } glFlush (); // send all out to display inStream.close(); } 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 myMouse function glutMainLoop(); // go into a perpetual loop return 0; }