Article View: comp.sys.amiga.tech
Article #4818Re: Clearing the Window
From: John J. Szucs
Date: Fri, 10 Aug 1990 15:13
Date: Fri, 10 Aug 1990 15:13
68 lines
2980 bytes
2980 bytes
In article <1990Aug10.022609.9022@ariel.unm.edu> kchiu@carina.unm.edu writes:
>
> Ok, this might sound like a stupid question,
The only kind of stupid question is an important one that isn't asked.
>but Is there a function
>for clearing the Window? Or do you have to fill the window with background
>color?
There is no function for clearing a window per se.
However, there are calls in graphics.library that can be used for this
purpose.
If you are using a GIMMEZEROZERO window (specified with the GIMMEZEROZERO
flag in the Flags field of the NewWindow structure):
#define BACKGROUND_PEN 0 /* Define constant for background color */
struct Window *Window;
...
/* Set window to background color */
SetRast(Window->RPort,BACKGROUND_PEN);
...
This method applies only to GIMMEZEROZERO windows. However, the use of
GIMMEZEROZERO windows has an adverse effect on system performance and should be
avoided if at all possible.
For non-GIMMEZEROZERO windows (windows for which the GIMMEZEROZERO flag
in the Flags field of the NewWindow structure was not set):
#define BACKGROUND_PEN 0 /* Define constant for background color */
struct Window *Window;
...
/* Set area and outline pens to background color */
SetAPen(Window->RPort,BACKGROUND_PEN);
SetOPen(Window->RPort,BACKGROUND_PEN);
/* Set window to background color */
RectFill(Window->RPort,Window->BorderLeft,Window->BorderTop,
Window->Width-Window->BorderRight-1,
Window->Height-Window->BorderTop-1);
For more information on windows and the graphics.library calls (including
SetRast and RectFill), see the Intuition and Graphics sections, respectively,
of the ROM Kernel Manual: Libraries and Devices and the includes and
AutoDocs files (all available for Commodore Applications and Technical
Support).
> Thanks in advance.
>
>kchiu@carina.unm.edu
================================================================================
|| John J. Szucs || The opinions expressed are my own and ||
|| Systems Evaluation Group || in no way represent the opinions or ||
|| Product Assurance Department || policies of Commodore Technology, Inc. ||
|| Commodore Technology, Inc. || or any associated entity. ||
================================================================================
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!cbmvax!jjszucs From: jjszucs@cbmvax.commodore.com (John J. Szucs) Newsgroups: comp.sys.amiga.tech Subject: Re: Clearing the Window Message-ID: <13749@cbmvax.commodore.com> Date: 10 Aug 90 15:13:33 GMT References: <1990Aug10.022609.9022@ariel.unm.edu> Reply-To: jjszucs@cbmvax (John J. Szucs) Distribution: na Organization: Commodore, West Chester, PA Lines: 68