Re: [AL] Video Bitmaps

[Shawn H. <sh...@ta...>]

Joerg Sharky-X Rueppel <sha...@gm...> writes:
> If I want to use two screen pages for pageflipping under DOS the docs say
> the above macro is defined, so do I need to call:
> 
> set_gfx_mode(GFX_AUTODETECT, 640, 480, 640 * 2, 480);
> page1 = create_video_bitmap(640, 480);
> page2 = create_video_bitmap(640, 480);
> 
> And under Windows, the above macro isn't set, is that the right way to do
> it?:
> 
> set_gfx_mode(GFX_AUTODETECT, 640, 480, 0, 0);
> page1 = screen;
> page2 = create_video_bitmap(640, 480);

That is how it works at the moment, yes, but this will be changing as soon 
as I get around to changing that, so that it works the first way you 
described on all platforms. For now, just put up with wasting a bit of vram 
in your Windows version, and use the first method regardless: that will work 
anywhere. This is, for example, what the exflip and exupdate programs do, 
and they should be considered the canonical reference of what is correct (if 
any of the examples don't work on a given platform, we badly need to fix the 
library :-)


--
Shawn Hargreaves - sh...@ta... - http://www.talula.demon.co.uk/
"A binary is barely software: it's more like hardware on a floppy disk."
>From <all...@ca...> Mon Nov 29 19:01:02 1999
Received: from finch-post-11.mail.demon.net [194.217.242.39] by canvaslink.com with ESMTP
  (SMTPD32-4.06) id A19F392B014C; Mon, 29 Nov 1999 17:43:43 -0500
Received: from talula.demon.co.uk ([194.222.103.32])
	by finch-post-11.mail.demon.net with esmtp (Exim 2.12 #1)
	id 11sZV3-0000nM-0B
	for al...@ca...; Mon, 29 Nov 1999 22:42:28 +0000
Received: (from shawn@localhost)
	by talula.demon.co.uk (8.9.3/8.8.7) id TAA13137
	for al...@ca...; Mon, 29 Nov 1999 19:26:36 GMT
Date: Mon, 29 Nov 1999 19:26:36 +0000
From: Shawn Hargreaves <sh...@ta...>
To: al...@ca...
Subject: Re: [AL] Windows install_timer failure
Message-ID: <199...@ta...>
Mail-Followup-To: al...@ca...
References: <001601bf395e$e523c920$525...@yo...> <199...@al...> <006e01bf39d7$eb685b60$525...@yo...>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Mailer: Mutt 0.95.4us
In-Reply-To: <006e01bf39d7$eb685b60$525...@yo...>; from  Mike Parker on Sun, Nov 28, 1999 at 07:36:51PM -0000
Precedence: bulk
Sender: all...@ca...
Reply-To: al...@ca...
X-UIDL: 927489965
Status: O
Content-Length: 1168
Lines: 29

 Mike Parker <md...@th...> writes:
>>>  if (timer_driver)
>>>       return -1;
>
>> I haven't checked the code, but it looks like it is a lock.  If
>> install_timer() has been called before, then `timer_driver' will be
>> set, so it quits immediately.
>
> Which is what has me puzzled. I'm calling it once and only once in the
> initialization of my prog.

Probably some other part of the library code is installing it (many parts of 
Allegro use timers internally, so this is very likely to happen).

The simple solution is just not to worry about that error code: the timer 
setup can't fail on any current platform (and if it did, very little of the 
rest of Allegro would work either, so you quite likely wouldn't even get as 
far as printing up an error message).

If you really do care to check for this, either install the timer earlier on 
before some other part of Allegro decides to do it for you, or only install 
it if it isn't already running, eg:

   if (!timer_driver)
      install_timer();


--
Shawn Hargreaves - sh...@ta... - http://www.talula.demon.co.uk/
"A binary is barely software: it's more like hardware on a floppy disk."
>From <all...@ca...> Mon Nov 29 19:03:41 1999
Received: from odin.vircom.com [207.96.243.12] by canvaslink.com with ESMTP
  (SMTPD32-4.06) id A4563A4B014C; Mon, 29 Nov 1999 19:03:34 -0500
Received: from gm.gamemaster.qc.ca (bbs.gamemaster.qc.ca [207.96.243.2]) by odin.vircom.com
 (Vircom SMTPRS 4.1.181) with SMTP id <B00...@od...> for <al...@ca...>;
 Mon, 29 Nov 1999 19:02:30 -0500
X-ROUTED: Mon, 29 Nov 1999 19:03:30 -0500
X-TCP-IDENTITY: Ultima
Received: from ultima [207.96.243.215] by gm.gamemaster.qc.ca with smtp
	id BDACDHDE ; Mon, 29 Nov 1999 19:02:54 -0500
Message-ID: <00ca01bf3ac5$d087eb00$ccf360cf@ultima>
From: "Kevin Lang" <ul...@ga...>
To: <al...@ca...>
References: <Pin...@ma...>
Subject: Re: [AL] Truecolor fading
Date: Mon, 29 Nov 1999 18:59:45 -0500
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 5.00.2314.1300
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300
Precedence: bulk
Sender: all...@ca...
Reply-To: al...@ca...
X-UIDL: 927489966
Status: O
Content-Length: 749
Lines: 28

For fading in set up the color blender with just a little alpha

then keep transparently blitting your image on a black background... this
should do a sort of "fade in" effect

for a fade out keep drawing a transparent black rectangle over your image
until it's dark, this should do a "fade out" effect.

This is just a hunch but tell me if it works :-)
----- Original Message -----
From: Ben Crowder <cro...@ne...>
To: <al...@ca...>
Sent: Monday, November 29, 1999 6:22 PM
Subject: [AL] Truecolor fading


>
> Is it possible to fade in and out in truecolor modes?  Obviously the
> fade_in/fade_out routines don't work (as Shawn mentioned in Pot of Gold),
> but I haven't seen anything to replace them.
>
> Thanks,
> Ben
>
>
>