Date   : Mon, 26 Jan 2004 18:25:15 +0000
From   : Richard Gellman <splodge@...>
Subject: Re: Graphics Rendering in BeebEm

IMO, there is no speed difference in the whole DirectX vs OpenGL debate. 
You pick one when you start, and then you stick with it. BeebEm is 
DirectX-based ( at least in windows ), and so it shall remain.

To respond to another email: The dropping of GDI support won't 
necessarily have an effect on the speed (the speed/timing issue is being 
looked at separately), the reason for asking is that I didn't want to go 
ahead and drop GDI access, only to have a flood of emails saying "why 
did you force DirectDraw upon us?". The dropping of GDI support is 
necessary (in the windows model at least) because the GDI and DirectX 
methods of screen update are almost mutually exclusive. Implementing 
both is possible, but not without creating drastic slow downs for one or 
both methods.

<almost-rant>
Please don't take the following as a dig against anybody or BBC Micro 
fans (this list i particular) as a whole, but I would really appreciate 
it if people would answer the question asked rather than going down a 
semi-related tangent. While I appreciate the problems the current 
versions of BeebEm are suffering from, and the fact that I haven't been 
doing any work on BeebEm for over a year (due to reality creeping in), I 
am trying to tie up the loose ends with BeebEm to make sure the emulator 
runs as smoothly as possible. At the same time, I don't want to go and 
disappoint people by removing a featuer that is commonly used, or by 
wasting time on something that nobody wants.

The speed/timing issues will be fixed. There will be hard drive support, 
and a future version will support plugins. But these things take time, 
and when I'm trying to get one part to operate correctly, I would 
gratefully appreciate if people could stick to the matter in hand. All 
feedback is welcomed and appreciated, as are suggestions for bug fixes, 
code contributions, plugin suggestions, and anything else that anybody 
feels may be of use.

Once again, none of that was personal or in any way intended to be negative.
</almost rant>

Thanks

-- Richard Gellman

Side note: In case anyone's confused about what GDI support is, it is 
the windows interface that allows the BBC screen to be drawn on the PC 
screen without using DirectX, OpenGL, etc. It draws via the window 
management system, and thus the process has to take into account other 
windows in the area. For this reason, it is a much slower process, and 
definitely not preferred for smooth framerate graphics.

Charles Blackburn wrote:

>one thing you could do, make an open GL version or something like that that
>way it might run a bit faster too..
>
>----- Original Message ----- 
>From: "Richard Gellman" <splodge@...>
>To: "BBC Micro Mailing List" <bbc-micro@...>
>Sent: Sunday, January 25, 2004 2:59 PM
>Subject: [BBC-Micro] Graphics Rendering in BeebEm
>
>
>  
>
>>Hi
>>
>>I'd like to collate opinion on dropping the old GDI interface for the
>>graphics rendering of BeebEm. The problem is this:
>>    
>>
>
><cut>
>
>  
>
>>So, after all this great long explanation, whats the general opinion on
>>dropping GDI support?
>>    
>>
>
>
>
>  
>