Vector opacity (Re: Raster layer opacity)

[Bernhard Reiter]

Am 23. Mar 2005 um 10:41:44 schrieb Jonathan Coles:
> sorry I disappeared for a couple of months, but I had a little matter of
> a master's thesis to attend to. :)

Hi Jonathan,
glad to see you are back and in good shape, this is a good sign for
the thetis I presume. ;)

> I've just commited changes that allow the opacity of a raster layer to
> be changed. Previously, (in anticipation of these changes) a raster
> layer had an opacity property but it was not used. I've added a new
> control to the layer properties box for raster layers. The level is then
> used in MapRenderer.draw_raster_data() to scale the alpha values to the
> proper opacity. 

Very Cool!
I had to change laptops and my development environment is not there yet,
so I cannot immedeately try it out. It will take few more days...  :)

> Here'a question: Is opacity a property of all layers or just raster
> layers? perhaps we can't support opacity in vectors layers just yet, but
> should that mean we shouldn't anticipate it? If opacity is a property of
> all layers then I can refactor the opacity methods in RasterLayer into
> BaseLayer.

I also think that vectors can have opacity, the question is if this
will be per vector layer or per drawing style per class.
And it we have that drawing style option, do we want another layer wide option?
Both seems to be nice features with the per style opacity being more
general, but the per layer one might be consistant and easier to add.

I have not real conclusion, I consider a layer side attribute for okay 
and useful, though.


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