| From: | Steffen |
| Date: | 06 Aug 99 at 08:24:00 |
| Subject: | Re: Drawing images on Intution |
From: Steffen <steffen.mars@stenloese.mail.telia.com>
Hello Allan
On 05-Aug-99, Allan Odgaard claimed:
> From: Allan Odgaard <Duff@DIKU.DK>
>
> On 04-Aug-99, Steffen wrote:
>
>> [...] You'll need to copy the display before each
>> animation starts though, but not for every blit.
>
> I know that - it was the initial blit I was refering to, this will make your
> solution slow.
> To re-generate the background with a few blits (one for each visible card)
> should not be a problem, in principle it's actually very similar to the
> "LayerDemo" program you can find at my homepage, except that this is one is
> probably more "flexible", so I do know what I'm talking about!
Slow ??? It's half a second on AGA at 640x512x256 ! The speed is needed during the animation. Depending on the amount of animation needed, this may be even be faster in total. I disagree that your method should make the animation faster. Allthough it may be faster in total.
>> [...] As i pointed out '....You can allso use BltBitMap() and use
>> RPort->BitMap, provided your graphics don't exceed the bitmap boundaries'.
>
> It's not (only) the boundaries which is the problem. If another window covers
> your window then the bitmap will also hold that window, so blitting to it will
> destroy windows ontop of yours, blitting from it will give you the wrong data.
> In the latter case this is only a problem with smart-refresh, because the
> actual data does not exist for simple-refresh, which is also a problem for
> your double-buffer suggestion.
But we're talking about making fast graphics, for wich simple- and smart refresh is not suitable, you should use superbitmap, and in that case, the above is not true. Actually, the window should be a backdrop window on a seperate screen (if you want speed).
> Regards Allan
Steffen