Crossplatform screensavers

SDL Development
1

create simple screen savers using SDL.

Linux is easy (just add the hack to the xscreensaver list, or tweak
some of the old code), in Win the only data I
had found is that *.scr are *.exe renamed and I have not clue about
Macs.

Can anybody more skilled than me give some tips about that topic?

Un saludo
Paco

2

fmunoz at geocities.com wrote:

I wonder if somebody tried it before… a basic code to
create simple screen savers using SDL.

Linux is easy (just add the hack to the xscreensaver list, or tweak
some of the old code), in Win the only data I
had found is that *.scr are *.exe renamed and I have not clue about
Macs.

Can anybody more skilled than me give some tips about that topic?

I think that win32 screensavers are prettymuch standard apps, but there
are some special commandline options the system uses to invoke them.

Did a quick search of the Microsoft knowledgebase, and found article
Q182383 with some more details. At the risk of being sued by MS, I’ve
pasted it below.

Hope it’s interesting,
Ben.

Q182383------------------------------------------------------
INFO: Screen Saver Command Line
Arguments

The information in this article applies to:

   Microsoft Win32 Software Development Kit (SDK) 
   Microsoft Windows 2000

SUMMARY

Windows communicates with Screen Savers through command line
arguments.
The ScrnSave.lib library handles this for Screen Savers that are
written to use
it, but other Win32 Screen Savers marked 4.0 or higher must handle the
following command line arguments:

 ScreenSaver           - Show the Settings dialog box.
 ScreenSaver /c        - Show the Settings dialog box, modal to the
                         foreground window.
 ScreenSaver /p <HWND> - Preview Screen Saver as child of window

.
ScreenSaver /s - Run the Screen Saver.

In addition, Windows 95 Screen Savers must handle:

 ScreenSaver /a <HWND> - change password, modal to window <HWND>

is a HWND presented on the command line as an unsigned decimal
number.

MORE INFORMATION

You need to create the preview window as a child of this window. It
should
cover the parent’s entire client area.

You need to create the password dialog box as owned by HWND if it is
supplied or as owned by the foreground window if HWND is not supplied.

Additional query words:

Keywords : kbNTOS kbWinOS2000 kbScreenSaver kbSDKWin32 kbGrpUser
kbWinOS
Version : WINDOWS:
Platform : WINDOWS
Issue type : kbinfo

3

Windows screen savers are slightly more involved than that, they have
to have certain bits of data in them and support certain command line
switches, you’d be best off trying to find some windows screen saver
code or a tutorial to find out exactly what all is required.

Wesley Poole
AKA Phoenix Kokido
Tired of hiding behind a on-line only identity…
members.xoom.com/kokido
@Wes_Poole

fmunoz at geocities.com wrote:> create simple screen savers using SDL.

Linux is easy (just add the hack to the xscreensaver list, or tweak
some of the old code), in Win the only data I
had found is that *.scr are *.exe renamed and I have not clue about
Macs.

Can anybody more skilled than me give some tips about that topic?

Un saludo
Paco

4

El Sat, 22 Apr 2000 17:35:56 +0200, fmunoz at geocities.com escribi?:

in Win the only data I had found is that *.scr are *.exe renamed

remember to check too if your own application is running to prevent
launching more than one copy of your screensaver. Say that you have
the delay time to 1 minute and your scr starts. After 2 minutes,
a second copy of your screensaver can be loaded if you don’t detect
if a process similar to yours is running… I don’t remember how
to detect this (I’m not an experienced windows programmer).

Can anybody more skilled than me give some tips about that topic?

Well, I just wanted to remember you what I’ve said because I once
coded an screensaver (using the GDI) and forgot that. When I tested
it (it was a Blue Screen Of Death screensaver) I found that the
screensaver executed more than once :)–
Windows it’s real multitasking: it can execute 2 bugs simultaenously.

-----------------------------------------------------

NoP / Compiler – nop @ todolinux.org
POWERED BY - Linux RedHat 6.0 - Reg. User #74.821
http://www.ctv.es/USERS/sromero

~-----------------------------------------------------~

5

Ben Campbell wrote:

@fmunoz_at_geocities wrote:

I wonder if somebody tried it before… a basic code to
create simple screen savers using SDL.

……

Can anybody more skilled than me give some tips about that topic?

I think that win32 screensavers are prettymuch standard apps, but there
are some special commandline options the system uses to invoke them.

Did a quick search of the Microsoft knowledgebase, and found article
Q182383 with some more details. At the risk of being sued by MS, I’ve
pasted it below.

Hope it’s interesting,
Ben.

Q182383

……

Thanks I tried it too but somehow this
article was hiding itself from me :slight_smile:

Un saludo
Paco