Calculating Distance
Volume Number: 4
Issue Number: 3
Column Tag: VIP Views
Calculating Distance for Navigation 
By Bill Luckie, Contributing Editor, Simi Valley, CA
V.I.P. 2.2
Mainstay has released version 2.2 which is a significant upgrade and is free to all
registered owners. V.I.P. 2.2 includes 25 additional procedures, improved keyboard
control, 5 new intrinsic functions to provide added flexibility in handling Point and
Rectangle objects, and the ability to create a true “About...” under the Apple menu. If
you are a V.I.P. owner and haven’t sent in your registration card, you are missing some
neat features.
In the beginning
In a previous article (April 1987), I presented a ‘shell’ program which
implemented some of the common user interface actions e.g., Menus, Windows, File
handling, and Events. In this program you will see that the same routines are used. In
some cases these routines have been expanded to handle the specifics required of our
program, and of course additional routines have been added. The only change brought
about by changes to V.I.P. itself is the ‘About’ routine, which is now called Gee_Whiz.
As mentioned earlier V.I.P. programmers can now create a “About (program name)”
entry under the Apple menu and have it display whatever they choose. In this case
selecting ‘About GC_Dist...’ displays the same window and information as presented at
program startup.
The guts and feathers
The purpose of this program is to illustrate by example some of the most
commonly used procedures. In addition to the already explored subjects we will create
Dialogs, obtain user input data organized as records and save them to disk, work with
some of V.I.P.’s intrinsic functions, and most importantly, have some fun
programming. As is the case with most programs there is certainly more than one way
to accomplish a particular objective. What I present here is not advocated as the only