Programming and Graphics

7.2 Getting started withVogle 201

The code features the following implementations:

• The graphics window position and size are first defined in screen pixel
  units.


• TheVogledevice is initialized as “X11” to draw on the screen.


• The background color is set to RED, and the window is cleared. The
  menu of available colors is given in Appendix B.


• TheVoglefunctiongetkeymonitors the keyboard; When the window
  is selected and a key is pressed, the session terminates.

Hello

The following code contained in the filehello.cc generates a graphics
window and prints the greeting “Hello”, as shown in Figure 7.2.1(b):

/*-------------

VOGLE to greet

--------------*/

#include<iostream>

#include "VOGLE/voglec++.h"

using namespace std;

int main()

{

//--- Graphics window position and size in pixel units:

prefposition (600,200); // window position

prefsize (300, 300); // window size

//--- Initialize graphics device to be the screen:

vinit("X11");

color (YELLOW);

clear();

//--- Move to a position defined by default coordinates

//--- ranging from -1 to 1 in the x and y direction

move2 (-0.4, 0.0);

//--- Prepare to write: