Hi Karim,
On Thu, Sep 13, 2012 at 7:29 PM, Karim 'Kasi Mir' Senoucci
<direc...@tvetc.de> wrote:
> Hi,
> Am 13.09.2012 17:41, schrieb Ezequiel Garcia:
>
>>> What do you mean by this? Are you suggesting that I should "simply"
>>> rotate
>>> every of my roughly 800 calls to DirectFB instead of rotating just the
>>> surface (or layer) once?
>>>
>> Well, I'm not familiar with your app. But, I would think to be wise to
>> have
>> just one call to Flip(). You simply have to rotate before flipping.
>
> Rotate what, exactly, and with which call?
>
>> Of course, I might be wrong. But, do you have 800 different places
>> where you call Flip()?
>
> No, I said calls to DirectFB, not calls to Flip(), that one I have just
> once. But how do I "rotate" the surface I am about to flip? I know how to
> set rotation on a layer (in theory, as it doesn't work in practice) and a
> window, but for a surface, I'm at a loss.
>
Well, if I wasn't so busy I would write a small test for you. Sorry.
I would do this:
1. Locate Flip(). Flip updates one surface, it's the one that "shows"
the image on screen. So if you do this: (seudo-code!)
new_surf = Rotate(surf);
surf = new_surf // of course, using Blit()
surf->Flip(surf);
I guess you would have your image rotated on screen.
2. You will have to implement Rotate() yourself.
This means two steps:
* create another surface to put the rotated image.
* pixels are just dots, they don't have orientation.
so rotate means pixel relocation for us.
* use Lock() / Unlock() to access pixels.
If you're thinking: "Heck, this is an awful dirty hack".
Then: you're right. I call it "Last resource software butchery".
If you need to see how to access pixels, take a look
at the "colorize" example from DFBTutorials repo:
http://git.directfb.org/?p=extras/DFBTutorials.git;a=blob;f=src/colorize/colorize.c;h=95af990fcc70a88df3c41943dd469622ed20ce6c;hb=65dec947d045f7b0e2d83a454afd0b5d5764f7cc
If you have some luck with this, don't forget to tell us :-)
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