[comp.sys.amiga.programmer] AreaFill problems

dsheythe@milton.u.washington.edu (Donald Sheythe) (04/02/91)

I'm having problems with the rom AreaFill routines.  When I try to fill
a polygon that has pieces that go off of the screen, my program crashes 
the machine.  If I keep all of the points on the screen, it doesn't crash.

My question is this: Can the AreaFill routines be used for a polygon that goes
off of the screen or am I doing something wrong? 

Thanks in Advance.

Don
-- 

Don Sheythe

dsheythe@milton.u.washington.edu (Donald Sheythe) (04/02/91)

In article <1991Apr1.231347.16242@milton.u.washington.edu> dsheythe@milton.u.washington.edu (Donald Sheythe) writes:
>
>I'm having problems with the rom AreaFill routines.  When I try to fill
>a polygon that has pieces that go off of the screen, my program crashes 
>the machine.  If I keep all of the points on the screen, it doesn't crash.

A couple of clarifications.  I'm drawing into a window rastport so I think
that it is being clipped.  I'm also passing negative x and y values to
AreaDraw and AreaMove.  

When the program runs, I get a 82011234 GURU GfxNoLCM and I have no idea
what this means.

Help!


--
Don Sheythe     dsheythe@u.washington.edu


-- 

ken@cbmvax.commodore.com (Ken Farinsky - CATS) (04/03/91)

In article <1991Apr1.231347.16242@milton.u.washington.edu> dsheythe@milton.u.washington.edu (Donald Sheythe) writes:
>
>I'm having problems with the rom AreaFill routines.  When I try to fill
>a polygon that has pieces that go off of the screen, my program crashes 
>the machine.  If I keep all of the points on the screen, it doesn't crash.
>
>My question is this: Can the AreaFill routines be used for a polygon that goes
>off of the screen or am I doing something wrong? 

I believe that you have to allocate a TmpRas that is as big as the entire
object to be filled.  Thus, if the object goes off the screen, the TmpRas
must be bigger than the screen (but only one bit-plane...)  I think that
the object is clipped to the window after it is filled.
-- 
--
Ken Farinsky - CATS - (215) 431-9421 - Commodore Business Machines
uucp: ken@cbmvax.commodore.com   or  ...{uunet,rutgers}!cbmvax!ken
bix:  kfarinsky