[Tilesathome] Maplint Layer

[D Tucny]

On 13/06/07, Frederik Ramm <frederik at remote.org> wrote:
>
>
>
> I'm still in favour of going back to where we were before the disk space
> hysteria. But I have also tried to implement a change mentioned by you
> in another post, namely making the maplint background semi-transparent
> so that the map gets toned down a bit.
>
> Unfortunately I didn't succeed, maybe someone has an idea why. It seems
> that the PNG files produced by Inkscape do not have an "alpha channel",
> they just have three colour channels. Then, tilesGen.pl uses libGD's
> transparency option to flag one colour (the background colour specified
> in the .map-background style) as transparent. This works, but it is
> always 100% transparency. What I wanted was something like 50% white,
> 50% transparent, i.e. an extra alpha channel.
>
> For this, I tried numerous things:
>
> * setting "fill: #ffffff; fill-opacity: 0.5" in the style file;
> * setting "fill: none" and using Inkscape's -b and -y options
> * playing around with tilesGen.pl, removing the "transparent" call and
>    enabling "saveAlpha"
>
> Nothing, including combinations of these, has actually created a PNG
> file with a transparent background; the background was always solid. (I
> dropped pngcrush to be safe but this didn't change anything.)


Couldn't the viewing interface (openlayers) fade the background when maplint
is active rather than needing the maplint overlay to include this? Maybe
serving a semitransparent tile size image between the background tile and
the maplint tile? or something more clever?

d
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