Path: utzoo!utgpu!water!watmath!clyde!burl!codas!ufcsv!gatech!gtss!chas
From: chas@gtss.UUCP (Charles Cleveland)
Newsgroups: comp.sys.amiga
Subject: Re: font structures
Message-ID: <197@gtss.UUCP>
Date: 21 Jan 88 15:14:32 GMT
References: <196@gtss.UUCP>
Reply-To: chas@gtss.UUCP (Charles Cleveland)
Organization: Georgia Tech School of Physics
Lines: 71
Summary:OK, I give up.

Re font structures per se, conflicting reports are still coming in.  But
perhaps one of you can help me with a related problem alluded to in my
original posting.

Here is a reduced version, OFT.c, of the program in which I have a problem
with an OpenFont call.  This program was compiled with Lattice 3.03 with no
options except that stack checking was disabled so that I could link just
to AStartup.obj, although it is likely to compile under anything.
It was compiled via

	lc1 OFT
        lc2 -v OFT

and linked using Blink 6.5 like this:

	blink lib amiga.lib from Astartup.obj,OFT.o

It is imagined that the program will be executed from a system running
without the benefit of SetFont or its brethren, that is, one using only one
of the ROM topaz fonts, so that OpenFont will suffice and diskfont.library
does not need to be opened.  However, the program still SHOULD not
misbehave even if this condition does not hold.

If I compile the program as listed and run it, I just get a window that
opens and closes quick as a bunny.  If I redefine CRASH to be TRUE and
recompile, running the program generates a GURU indicating an illegal
instruction trap although I think I should still just get a window that
opens and closes quick as a bunny.

I do not understand.  I hesitate to infer that the WorkBench Screen the system
provides by default has not a NULL TextAttr but a garbaged one.  Would someone
please point out the manifestation of my brain damage in the next 34 lines?

#define INTUITION_REV 33
#include <exec/types.h>
#include <exec/exec.h>
#include <intuition/intuition.h>
#include <graphics/gfxbase.h>

#define CRASH FALSE

struct TextFont *font;
struct TextAttr *TAttr;
struct IntuitionBase *IntuitionBase;
struct GfxBase *GfxBase;
struct Window *wp;

struct NewWindow NewWindow={
 0,0,320,100,3,1,NULL,NULL,NULL,NULL,"OpenFontTest",NULL,NULL,0,0,0,0,
 WBENCHSCREEN
};

main()
{
 IntuitionBase=(struct IntuitionBase *)
		OpenLibrary("intuition.library",INTUITION_REV);
 if(IntuitionBase==NULL)Exit(300);

 if((wp=(struct Window *)OpenWindow(&NewWindow))==NULL)Exit(301);
 TAttr=wp->WScreen->Font;
 if(TAttr){
  if(CRASH)font=(struct TextFont *)OpenFont(TAttr);
 }
 CloseWindow(wp);
 CloseLibrary(IntuitionBase);
}
-- 
-Life would be so much easier if we could just look at the source code.-

Charles Cleveland    Georgia Tech School of Physics    Atlanta, GA 30332
UUCP: ...!gatech!gtss!chas         INTERNET:  chas@ss.physics.gatech.edu