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Re: [udig-devel] Tiled Rendering and MapGraphics
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Hmm I think I get what you are trying to say here.
I would need a single list of mapgraphics layers that are rendered to a
"screen tile". Then when I go to compose my tiles I can extract the
section of the mapgraphic image that corresponds to the section of the
tile I am composing. Hmm sounds like fun to implement!
One question - If I want to start treating MapGraphics as "special"
renderers (so I can do different things based on the type of renderer) I
need a way to distinguish between regular renderers and mapgraphic
renderers. All the mapgraphic classes are in a different package so I
can't simply to an "instanceof MapGraphic" test and I know it's not the
correct thing to add the MapGraphic package as a dependency; so how do I
go about determining if a renderer is a "special" renderer (in this case
a mapgraphic renderer).
Thanks
Emily
Jody Garnett wrote:
Jesse the "tiling" system would still need to suck out a small tile
worth of the main mapgraphic image when composing a "tile" for display
... unless the one specific case where the mapgraphic is "ontop" of the
data layers that are all being tiled up.
Emily I would suggest having the mapgraphic write into an image the size
of the screen; and giving the "tiled renderer" the ability to select out
a rectangle from this large image for use when "composing" the
BufferedImage for an individual Tile...
Not sure if I explained that very well...
Jody
Jesse Eichar wrote:
IMHO I think that MapGraphics should not be part of the tiling. The
reasoning is that they are supposed to be light-weight and fast. They
should normally be fast enough without tiling. And often are
independent of zoom so how would you know when to cache and when not to.
Jesse
On 4-Nov-08, at 11:49 PM, Emily Gouge wrote:
All,
I'm trying to clean up the the tiled rendering system I worked. One
of the things I'm currently looking at is trying to get mapgraphics
to work nicely with it.
My understanding is that currently mapgraphics pay attention to the
bounds of the screen. So in my tiled rendering system they are
paying attention to the bounds of the screen and using that
information to draw onto the tiles. These tiles don't match up with
the screen so as a result you get some fun results:
* legends, north arrows, etc on every tile.
* grids only partially filled in (if then render tiles are bigger
than the screen only what would fit on the screen is filled in on the
render tile).
So how to fix this?
One option is to not use the tiled rendering system for mapgraphics.
As a result mapgraphics would always render on top of the tiles and
you couldn't have map graphics in between layers or at the bottom of
the stack. My feeling is that this is undesirable behaviour.
Another option may be to have the mapgraphics pay attention to the
render bounds as well as the screen bounds and size; but I think this
will cause a lot of unnecessary complexity in the mapgraphics.
Does anybody have an other ideas on how to fix this problem?
Thanks,
Emily
_______________________________________________
User-friendly Desktop Internet GIS (uDig)
http://udig.refractions.net
http://lists.refractions.net/mailman/listinfo/udig-devel
_______________________________________________
User-friendly Desktop Internet GIS (uDig)
http://udig.refractions.net
http://lists.refractions.net/mailman/listinfo/udig-devel
_______________________________________________
User-friendly Desktop Internet GIS (uDig)
http://udig.refractions.net
http://lists.refractions.net/mailman/listinfo/udig-devel
