[comp.sys.amiga.tech] Trying to do page-flipping style animation

jack@stevie.cs.unlv.edu (Jack Alexander) (10/27/89)

I am trying to do simple full screen animation by using page flipping.
I am running into problems because I don't know how to re-assign bitmaps
to the screen (change the bitmap pointer, etc).  Do I have to actually copy
the bitmap into the bitmap area being used by the screen?

I've tried setting the screen's bitmap pointer to one of my bitmaps, but to
no avail.

Any help would be appreciated....

						-- Jack Alexander
						jack@jimi.UUCP
						jack@marley.UUCP

rap@peck.ardent.com (Rob Peck) (10/28/89)

In article <1359@jimi.cs.unlv.edu> jack@jimi.cs.unlv.edu (Jack Alexander) writes:
>I am trying to do simple full screen animation by using page flipping.
>I am running into problems because I don't know how to re-assign bitmaps
> .....
>I've tried setting the screen's bitmap pointer to one of my bitmaps, but to
>no avail.



Here is what you might NOT be doing, but must do to make the new bitmap show:

	Forbid();

	/* HERE: modify the bitmap pointer for the your screen ("myscreen")
		 to point to your bitmap.  Jim Mackraz code examples usually
		 put the Forbid() and Permit() here I believe to prevent
		 Intuition from remaking the display while you are fiddling
		 with internal data structures which would affect the
		 display.  User could pull down a screen just when you are
		 munging the pointers and the task running the screen
		 recreation could get a wierd value for the bitmap pointer.
	*/
	
	Permit();

	MakeScreen(myscreen);
	RethinkDisplay();


Rob Peck