[Qgis-developer] Re: Value tool plugin makes QGIS crash

[Martin Dobias]

On Mon, Mar 28, 2011 at 4:17 PM, Jürgen E. <jef at norbit.de> wrote:
> [cc trimmed]
>
> Hi Radim,
>
> On Mon, 28. Mar 2011 at 15:47:56 +0200, Radim Blazek wrote:
>> That would be possible. Do you mean a cache on driver level? Is it a
>> cache used  in QGIS for rendering somewhere at this moment? Is it
>> desired? 1000x800x8 = 64MB / layer, 10 layers ~ 0.6GB. What about
>> threads (map composer, globe)?
>
> The layer has a cacheImage(), which the map renderer fills if render caching is
> enabled.  identify could probably use that - if the data is available in the
> raw image at all.

In the rendering branch I have already deprecated that cacheImage()
method: it causes various bugs with multiple map renderers in use
(they overwrite the cached image) and with threaded rendering it gets
completely wrong. I have implemented caching of map layers that is
handled by map renderers.

But there is still a problem that cached layer image does not contain
the original raster values.

Martin