Fixed segfault caused by OgreRTShaderSystem

[WilliamLewww]

🦟 Fixed segfault caused by OgreRTShaderSystem

Fixes Segfault in

• Add support for wide angle camera in sensors system gz-sim#1215

Summary

Fixes the segfault that occurs after running any ign-gazebo test that uses OGRE1.

The removal of the this->Fini() is safe because OgreRTShaderSystem's Fini() method is already being ran in OgreRenderEngine:
https://github.com/ignitionrobotics/ign-rendering/blob/e0ed1b1732e654dab8084fc7821df05b4da7c759/ogre/src/OgreRenderEngine.cc#L108

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
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[codecov]

Codecov Report

Merging #563 (f110893) into main (063510c) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #563   +/-   ##
=======================================
  Coverage   53.13%   53.14%           
=======================================
  Files         213      213           
  Lines       21217    21219    +2     
=======================================
+ Hits        11273    11276    +3     
+ Misses       9944     9943    -1     

Impacted Files	Coverage Δ
ogre/src/OgreRTShaderSystem.cc	43.54% <100.00%> (+0.41%)	⬆️
...e/ignition/rendering/base/BaseGaussianNoisePass.hh	100.00% <0.00%> (+3.33%)	⬆️

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[iche033]

I'm testing this branch with the integration test in gazebosim/gz-sim#1215. This fixes the segfault for me. However I think the Fini function is also not being called by OgreRenderEngine because when I tried adding a print statement, I don't see it printed when running the test.

This leads me to think that it's a threading issue. The OgreRTShaderSystem is created in the rendering thread but destroyed when it goes out of scope in the test's main thread. For now, we can do something like the Ogre2RayQuery class and add a check in the OgreRTShaderSystem destructor to make sure that this function is only called in the thread it's created in. Something like:

if (std::this_thread::get_id() == this->dataPtr->threadId)
  this->Fini();

A more involved fix is to make sure we destroy the render engine in ign-gazebo's sensors system properly in the RenderThread but that's needs a bit more work and testing.

[iche033]

looks good to me