[comp.sys.amiga.tech] Does BltPattern clip?

denis@vlsisj.VLSI.COM (/) (09/07/89)

I wrote a little program that animates a dinosaur running across
the screen. The problem is that sometimes it crashes with the
guru #81000009 freeing memory already freed. If I remove one
of my calls to BltPattern then the problem appears to go away.
I looked at the documentation for this call in the RKM but it
has a very terse description. My question is: does BltPattern
clip to the destination or do I have to do this myself?


Denis Bohm    (usenet: decwrl!vlsisj!denis)
              (internet: vlsisj!denis@decwrl.dec.com)
-- 
Denis Bohm    (usenet: decwrl!vlsisj!denis)
              (internet: vlsisj!denis@decwrl.dec.com)

dale@boing.UUCP (Dale Luck) (09/09/89)

In article <15304@vlsisj.VLSI.COM> denis@vlsisj.UUCP () writes:
>My question is: does BltPattern
>clip to the destination or do I have to do this myself?

All graphics calls clip to the layer associated with the RastPort.
If there is no RastPort, as in a screens bitmap then no clipping
is done.
-- 
Dale Luck     GfxBase/Boing, Inc.
{uunet!cbmvax|pyramid}!amiga!boing!dale