Viewer LL 3.3.4 and before sometimes fail to properly redisplay dynamic textures that have a small data length compared to pixel size when pulled from cache.
This appears to happen when the data length is smaller than the estimate discard level 2 size the viewer uses when making this GetTexture request.
This commit works around this by always regenerating dynamic textures that fall below this threshold rather than reusing them if ReuseDynamicTextures = true
This can be controlled by the [Textures] ReuseDynamicLowDataTextures config setting which defaults to false.
This is because recent viewers (3.2.1, 3.3.4) and probably earlier ones using the http GetTexture capability will sometimes make such invalid range requests.
This appears to happen if the viewer's estimate of texture sizes at discard levels > 0 (chiefly 2) exceeds the total texture size.
I believe this does not normally happen but can occur for dynamic textures with are large but mainly blank.
If this happens, returning a RequestedRangeNotSatisfiable will cause the viewer to not render the texture at the final resolution.
However, returning a PartialContent (or OK) even with 0 data will allow the viewer to render the final texture.
If true, this setting reuses dynamically generated textures (i.e. created through osSetDynamicTextureData() and similar OSSL functions) where possible rather than always regenerating them.
This results in much quicker updates viewer-side but may bloat the asset cache (though this is fixable).
Also, sometimes issue have been seen where dynamic textures do not transfer to the viewer properly (permanently blurry).
If this happens and that flag is set then they are not regenerated, the viewer has to clear cache or wait for 24 hours before all cached uuids are invalidated.
CUrrently experimental. Default is false, as before.
type for an HTTP request. Since the "official" LSL function limits
the use of the response type, it is implemented as osSetContentType
with a string for the content mime type and a threat level of high.
With this function you should be able to implement rather functional
media-on-a-prim application with much less difficulty.
Disabled (status quo) by default.
This flag makes the dynamic texture module reuse cache previously dynamically generated textures given the same input commands and extra params for 24 hours.
This occurs as long as those commands would always generate the same texture (e.g. they do not contain commands to fetch data from the web).
This makes texture changing faster as a viewer-cached texture uuid is sent and may reduce simulator load in regions with generation of lots of dynamic textures.
A downside is that this stops expiry of old temporary dynamic textures from the cache,
Another downside is that a jpeg2000 generation that partially failed is currently not regenerated until restart or after 24 hours.
In testing, it appears that if multiple threads dispose of separate GDI+ objects simultaneously,
the native malloc heap can become corrupted, possibly due to a double free(). This may be due to
bugs in the underlying libcairo used by mono's libgdiplus.dll on Linux/OSX. These problems were
seen with both libcario 1.10.2-6.1ubuntu3 and 1.8.10-2ubuntu1. They go away if disposal is perfomed
under lock.
The convention is that if an object implements IDiposable() the code must explicitly call Dispose() or call it via the using statement.
This may be particularly important for GDI+ objects since they encapsulate native code entities.
