Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!gem.mps.ohio-state.edu!wuarchive!udel!mmdf
From: jwhitman@stl-06sima.army.mil (Jerry Whitman)
Newsgroups: comp.sys.amiga
Subject: Changing Fonts via LIBRARY functions
Message-ID: <4669@lab.udel.EDU>
Date: 23 Nov 89 01:17:14 GMT
Sender: mmdf@udel.EDU
Lines: 76

This message is aimed primarily at the CATS, but I could use help from any
source.

WB1.3 contains several BASIC program demos. One demonstrates the manipulation
of topaz font size and style.  Since Carolyn Scheppner did the accompanying
write-up on the BASIC bmaps I am assuming she did the demo program also.  I
have not seen Caroyln publish anything lately so I anm not sure she is still
available, but here goes.

I did some experimenting with the demo to see how much I could affect the
actual text line height and thereby the number of lines in a BASIC window.
The actual code follows with line numbers added for reference:

1   DECLARE FUNCTION AskSoftStyle& LIBRARY
2   DECLARE FUNCTION OpenFont& LIBRARY
3   DECLARE FUNCTION Execute& LIBRARY

4     LIBRARY "graphics.library"

5     enable%=AskSoftStyle&(WINDOW(8))
6     Font "topaz.font",8,0,0
7     FOR i=25 TO 1 Step -1
        PRINT "LINE";i
8     next i
9     SetStyle 0
10    Font "",0,0,0  'Causes last pFont to be closed
11    LIBRARY CLOSE
12  END

13  SUB Font*fontName$, height%, style, prefs%)
14    SHARED pFont&
15    IF pFont&<>0 THEN PRINT "pFont";pFont&:CALL CloseFont(pFont&)
16    fontName0$=fontName$+chr$(0)
17    textAttr&(0)=SADD(fontName0$)
18    textAttr&(1)=height%*65536 + style%*256 + prefs%
19    pFont&=OpenFont&VARPTR(textAttr&(0)))
20    IF pFont& <> 0 THEN PRINT "PFONT";pFont&:SetFont WINDOW(8),pFont&
21  ENDSUB

22  SUB SetStyle(mask%) STATIC
23    SHARED enable%
24    SetSoftStyle WINDOW(8),mask%,enable%
25    PRINT "SetSoftStyle("mask%")"
26  ENDSUB

Now for the questions!! (Output window is 600 x 200)
1.  I can vary the font size in line 6 to 8 or 9 and get corresponding height
changes in the output window.  Values lower than 8 or higher than 9 make no
change, but appear to process without error.  Why?  Can I cause topaz to be
rendered with more or less height?  

2.If I change the fontName$ in line 6 to any other font than topaz then lines
15 and 20 test as false and the THEN clause is not executed.   Also no font
change takes place?  Why?  How can I cause fonts other than topaz to be 
recognized in this routine?  The Fonts directory shows all 10 fonts present.

3.  If I can get to other fonts how to I describe which point size I want to
use?  I am trying to get to Helvetica 9 point!

4.  I also varied the values for style and prefs in line 6 to various non-
zero values but saw no apparent change.  Besides computing what seems to be
a bitmap size (textAttr%(1)) in line 18, what are these parameters used 
for and what are valid values/results?

If I am missing some fundamental concepts please whack me on the head to 
get my attention!!  I have read the descriptions of the sample program in 
the AMIGA BASIC manual and cannot find clues to the above questions.

Any and all help greatly appreciated.

(BTW I know 'REAL' programmers do not use BASIC, but then I never claimed
to be a 'REAL" programmer.  The amount of time I get to spend on my AMY
does not allow for a 'C' or ASM learning curve, so I am trying to meet my
modest needs with BASIC.)

Regards, Jerry