No Fragments Archive 10: Diskmags/nf_archive_10.iso/MAGS/ST_NEWS/STN_01_C.MSA/DATA_DOC24

Text File | 1994-03-14 | 6KB | 132 lines

üGFA BASIC TIPS & TRICKS Çby Richard Karsmakers

Originally  published in üST NEWSÇ Volume 1 Issue  6,  launched  on
November 15th 1986.

Most  people  already  know about the new GfA  Basic  that's  been
finished  recently:   Version  2.0.  It  contains  over  30  extra
commands,  which  will be discussed in a seperate article  in  the
next issue of üST NEWSÇ.  To obtain the newest version,  you'll have
to do the following (in Germany):  1) Send the original GfA  Basic
(old version) to: GfA Systemtechnik GmbH, Heerdter Sandberg 30, D-
4000  Düsseldorf  11  (telephone  [phone])  2)  Enclose   your
registration  card  (if you haven's sent it to  them  already)  3)
Enclose an envelope for the way back (C-5 size,  with air bubbles,
with  DM  2,50 stamps on it) 4) Enclose DM 20,- cash (this  is  to
cover  for  all  kinds of costs,  including the  36  pages  manual
extra).

I promised to have a chat about SETTIME, SPRITE, UPPER$, PSAVE and
GET/PUT this time, so I'll start right away.


The SETTIME command has the following syntax:

               SETTIME timestring,datastring

This  command is really very simple to use.  You'll just  have  to
make sure that all data is entered with two digits.  So the  first
of Januari 1987 would be "01.01.1987".  The time is also given  in
two  digits each,  with which you have to watch out for PM  or  AM
times.  So 9 o' clock in the morning would be "09:00:00",  "09:00"
or "0900", whereas the '09' should be replaced by '21' if you mean
9 o' clock in the evening.  Note: when you enter the time, the ':'
and even the seconds can be left away,  whereas the date has to be
entered  with '.' as seperation.  When you enter a faulty date  or
time, they aren't changed.
Now,  let's  go on to the SPRITE command (for which I  bet  you've
been waiting all the time!).  In the previous issue of üST NEWSÇ  we
published a program called "Pattern Editor",  from which you might
have guessed a bit about the SPRITE command already. The format is
as follows:
                    SPRITE A$[,x,y]


'A$' can be another string expression if you want to,  of  course.
If  you  enter  SPRITE A$,  the sprite will be  removed  from  the
screen,  whereas  entering e.g.  SPRITE A$,100,100 will  put  your
sprite  on x-and y-position 100 and 100.  The action point of  the
sprite will then be located at those exact coördinates.
The 'A$' is built up like this:

     A$=MKI$(x-coördinate of the action point)
       +MKI$(y-coördinate of the action point)
       +MKI$(0)   If this value is 0, the sprite will be displayed
                  normally, if it is 1 it will be displayed XORed
       +MKI$(mask color)   this will be 0 most of the time
       +MKI$(sprite color) this will be 1 most of the time
       +PAT$ (this is the bit pattern of the mask and the sprite)

The complete 'A$' can be made with the help of the Pattern  Editor
we published in the previous issue of üST NEWSÇ.
Now, let's go on with the UPPER$ function. Actually, this function
will  not be used very often by most programmers,  but it  can  be
very useful in certain routines.
The format is:
                  UPPER$(string)
This  function  converts all the alpha-characters of a  string  to
capitals,  including  occasional 'umlauts' (in German).  All  non-
alpha-characters will be left unchanged.
Examples:  "abcde" will be turned into "ABCDE"
           "4574hf" will be turned into "4574HF"
Two other GfA Basic commands,  GET and PUT will be talked about at
once.  These can be very useful in drawing programs,  as they  can
'cut'  pieces  from screen memory and put them somewhere  else  in
screen memory (as you will be able to read in the next issue of üST
NEWSÇ,  these commands will also be added in a special version - to
move  pieces of normal memory quickly - in the new version of  GfA
Basic). Their formats are:
                    GET x0,y0,x1,y1,A$
                    PUT x0,y0,A$[,mode]
With  the  GET  command,  x0 and y0 comprise  the  upper  lefthand
coördinates of the box that has to be put into A$ (here, again, A$
can  be any other string expression),  whereas x1 and y1  are  the
coördinates of the lower righthand point of the box to be  stored.
Once A$ is GET,  you can later use the PUT command to put A$  back
on the screen again, on any spot you wish, where x0 and y0 are the
coördinates of the upper lefthand point where the box will be put.

Of  course,  the other coördinates will not have to be  specified,
since the size of the box was already defined using GET.  The  PUT
command  also  enables the user to specify an  optional  parameter
('mode').  This parameter determines the mode in which the box  is
put on screen. The values can range from 0 to 15:
(S is the string, I is the image that was there before)
     0    Erase
     1    S and I
     2    S and (not I)
     3    S (overwrite)
     4    (not S) and I
     5    I (do nothing)
     6    S xor I
     7    S or I
     8    not (S or I)
     9    not (S xor I)
    10    not I (invert)
    11    S or (not I)
    12    not S (reverse overwrite)
    13    (not S) or I
    14    not (S and I)
    15    1
Next time, I'll talk about the new GfA Basic commands in GfA Basic
V2.0, but here's already a sneak preview:
The  run-only interpreter of the new version has been  changed  as
well.  It  is  now possible to execute the  run-only  interpreter,
after which it will immediately load the actual GfA Basic program.
This way,  you could call the Run-only interpreter "YOURFILE.PRG",
and  the GfA Basic file "YOURFILE.RSC".  This tends to  look  very
professional!
Make sure to have a backup of the run-only interpreter before  you
enter this small program:

OPEN "U",#1,"YOURFILE.PRG"
SEEK #1,30
PRINT #1,CHR$(0);"YOURFILE.RSC"
CLOSE #1

That's  all.  Thanks to Pim Coenradie (who received the  new  user
manual before I did) for telling me this;  he also used it in  his
program "Simple Draw".