Re: GUI/back changes in CVS

[Fred Kiefer]

Nicolas Roard wrote:
> On 7/11/05, Fred Kiefer <address@hidden> wrote:
>>Adrian Robert wrote:
>>>On Jul 8, 2005, at 8:17 PM, Fred Kiefer wrote:
>>>
>>>>I just added changes to GUI and back that will in the end allow pattern
>>>>images for GNUstep and the new MacOSX composite operator that uses an
>>>>addtional alpha value. I wanted these changes to go into the next
>>>>release as this will break binary compatibility between GUI and back. I
>>>>have tested this change with xlib. It would be great, if somebody could
>>>>test it before the release with art and winlib.
>>>Is there an easy way to test it?  Is there something in the new test
>>>suite that exercises this facility?
>>>
>>>
>>Here is the simple application I tested with. But I am not even sure if
>>the different operators have been implemented correctly for xlib, but
>>thenm only one of the images I use has alpha values. Perhaps I should
>>test with to transparent images.
> 
> This test is only for composition, but what about the pattern images ? 
> The "filling patterns"  you are talking about, is setting an image to
> a color and then fill something with this color, right ?
>  
> I'm asking because when I profiled Camaelon, pattern filling was one
> of the thing that took lots of time, and i'm hoping that by having the
> possibility to use filling pattern directly it will be faster (as you
> shouldn't need context switching during the filling).
> 
> And, does it properly follow the current path mask ? (actually I think
> that doesn't work on xlib, only with art, anyway...)
> 

Sorry, some things seem to have gotten mixed here. I wrote that "in the
end" this will "allow pattern images". They are not already there after
the first patch. Support for pattern colours requires two steps in the
backend: It needs to know, which image pattern to use, which is what I
implemented (the result of a pattern colour set command). And it needs
to draw this image, when a fill operation happens. I did not even work
on this second bit.

Now art has an implementation of the very powerfull shfill PS command.
This allows, amongst other things, a pattern fill. So here the second
bit is already persent, while the first bit was missing. It should be
rather simple to implement full pattern colours drawing for the art
backend now. But this is nothing I am planning to do. The whole
structure of the art backend is very foreign to me. I don't dare to
touch anything here, because I may easily break things in an environment
that is so contrary to the way I normally program.
What I was planning to do was add a simple (and of course slow) pattern
drawing mechanism for the gsc classes and perhaps overwrite this with a
faster one for the xlib backend.

Perhaps you could add the art pattern fill bit and I provide the rest?

Fred