[Xastir] [tiling] reading tiles slow

[Jerry Dunmire]

If there were a way to switch projections that would likely be better,
but I didn't see any support in the code for such a switch. Maybe I
missed something?

Of course there would still be a problem when combining bitmaps from
different projections, UTM is far different than Mercator and that is
only two of several possible projections. One of the combined maps
would be slow to load. On the other hand, combining bitmaps might not
be a common and useful enough feature and perhaps it should be dropped
in order to speed up the load times.

...jerry


On Tue, Aug 17, 2010 at 1:18 AM, Piotr Gluszenia Slawinski
<curious at bwv190.internetdsl.tpnet.pl> wrote:
> wouldn't it be easier to just switch ... xastir projection
> while osm maps are used?
>
> --
>
> On Mon, 16 Aug 2010, Jerry Dunmire wrote:
>
>> All the ones I've looked at require some sort of transformation. It
>> all depends on the projection used to generate the raster map. I'm
>> starting to look at Terraserver tiles now and the transformation
>> from/to UTM will be a bear. There's a library (Proj.4), so that's
>> where I'll start.
>>
>> ...jerry
>>
>>
>> On Mon, Aug 16, 2010 at 5:52 PM, Jason KG4WSV <kg4wsv at gmail.com> wrote:
>>>
>>> On Fri, Aug 13, 2010 at 3:36 PM, Jerry Dunmire <jerry at dunmire.org> wrote:
>>>>
>>>> The root of
>>>> the problem is that projection mapping that must occur between the
>>>> Mercator projection of OSM tiles and the 'un-projected' Xastir view.
>>>> Each pixel requires a multiple trig operations.
>>>
>>> Is this something OSM-specific, or does it apply to all xastir raster
>>> maps?
>>>
>>> -Jason
>>> kg4wsv
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