kicad-developers team mailing list archive

[Tomasz Wlostowski <tomasz.wlostowski@xxxxxxx>]

On 04/10/2013 06:07 PM, Lorenzo Marcantonio wrote:
> On Wed, Apr 10, 2013 at 05:05:27PM +0200, Maciej Suminski wrote:
> > As far as I could see, it was not looking this bad with Cairo in pcbnew.
> > I hope soon I will fix Cairo's GAL bugs and everyone can judge.
>
> Cairo use a pretty standard transparency blend, so the usual alpha
> opengl behaviour should be the same..
>
> How did you handle overlapping part of traces, i.e. how to avoid them
> getting brighter at junctions and still have transparency on the layers
> below? I'm curious
Hi Lorenzo,

In OpenGL, it's done with by a simple depth test (i.e. GL_LESS) and 
drawing layers in depth-sorted order. Cairo backend needs to be improved 
here (currently trace joints on the same layer "accumulate" transparency).

Regards,
Tom Wlostowski