Integrate Ogre-Next 3.x.x built from source

[sumir0]

🎉 New feature

Related to Integrating Ogre-Next 3.0's atmosphere component

Summary

This PR allows Ogre-Next version 3.x.x to be found by using gz_find_package (for example: gz_find_package(GzOGRE3 VERSION 3). Only 3.x.x versions built from source are supported. The code is heavily based on the cmake/FindGzOGRE2.cmake file and represents a reduced and slightly modified version of that file.

Test it

• Install pkg-config. To do that I typed pacman -S pkg-config in a terminal. For Ubuntu a similar package probably is available.
• Install Ogre-Next version 3.0.0 (or any other 3.x.x version) from source following the instructions from the official documentation. To run examples HlmsPbs, HlmsUnlit, Overlay, Atmosphere components are needed. To do that cmake needs to be run with several special parameters, for example:

cmake \
  -D OGRE_BUILD_COMPONENT_ATMOSPHERE=ON \
  -D OGRE_BUILD_COMPONENT_HLMS_PBS=ON \
  -D OGRE_BUILD_COMPONENT_HLMS_UNLIT=ON \
  -D OGRE_BUILD_COMPONENT_OVERLAY=ON \
  <your_parameters> <path_to_source>

• Follow the instructions in the examples/find_ogre3/README.md file.

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[sumir0]

As it is related to #457, should I try to merge cmake/FindGzOGRE2.cmake and cmake/FindGzOgre3.cmake into something like cmake/FindGzOgreNext.cmake?

PS. Sorry for the commits related to a typo and obsolete documetation. For some strange reason I didn't notice it when I was reviewing my code.

[ahcorde]

Add else just in case Ogre 3 is not installed or something happened

[sumir0]

added a comment on line 11. do we really need an else block?

[ahcorde]

why we are adding a cmake for 3.0 and 3. are there any differences ?

[sumir0]

in fact, i don't precisely know the reasons behind it. i looked at the examples/find_ogre2 directory, found the examples for multiple versions (2, 2.1, 2.2, 2.3) and tried to make a similar thing for ogre3. probably, it makes (manual) testing more complete in the sense not only a major version parameter is tested but also a minor version parameter is tested with several values. but it is duplicate code and i will reduce examples only to 3 then. we can add more examples later if needed.

[ahcorde]

same idea with the else here

[sumir0]

same question here

[sumir0]

in case Ogre-Next 3 is not installed OGRE3_FOUND will be FALSE and the corresponding message will be displayed:

-- OGRE3_FOUND: FALSE

[traversaro]

As mentioned in #457 (comment) since OgreNext 3.0 it should be sufficient to just call find_package(OgreNext CONFIG) and all the required variables and imported target should be defined without any additional complexity, just in case did you checked if that works?

[j-rivero]

Thanks @sumir0 for the PR ! The support for OGRE-3.x and gazebosim/gz-sim#2753 is really cool.

As it is related to #457, should I try to merge cmake/FindGzOGRE2.cmake and cmake/FindGzOgre3.cmake into something like cmake/FindGzOgreNext.cmake?

This is indeed a good idea. Even better would be that we can use the the CMake Module shipped directly by upstream as @traversaro mentioned. If you could give it a try, would be great.

PS. Sorry for the commits related to a typo and obsolete documetation. For some strange reason I didn't notice it when I was reviewing my code.

No worries!

[sumir0]

I checked find_package(OGRE) on my setup (OGRE-Next v3.0.0 built from source) with -D CMAKE_MODULE_PATH=/usr/local/lib/OGRE/cmake. It finds OGRE (classic) when it is installed alongside. It does find OGRE-Next when OGRE (classic) is not installed. But it doesn't find the Atmosphere component which we will, probably, need in future.

Output with OGRE (classic) installed alongside:

-- Looking for OGRE...
-- OGRE_PREFIX_WATCH changed.
-- Found PkgConfig: /usr/bin/pkg-config (found version "2.3.0")
-- Checking for module 'OGRE-Next'
--   Package 'OGRE-Next' not found
-- Checking for module 'OGRE'
--   Found OGRE, version 14.3.2
-- Found Ogre  (..)
-- Found OGRE: optimized;/usr/lib/libOgreMain.so;debug;/usr/local/lib/libOgreMain_d.so
-- Looking for OGRE_Paging...
-- Found OGRE_Paging: optimized;/usr/lib/libOgrePaging.so;debug;/usr/lib/libOgrePaging.so
-- Looking for OGRE_Terrain...
-- Found OGRE_Terrain: optimized;/usr/lib/libOgreTerrain.so;debug;/usr/lib/libOgreTerrain.so
-- Looking for OGRE_Property...
-- Found OGRE_Property: optimized;/usr/lib/libOgreProperty.so;debug;/usr/lib/libOgreProperty.so
-- Looking for OGRE_Volume...
-- Found OGRE_Volume: optimized;/usr/lib/libOgreVolume.so;debug;/usr/lib/libOgreVolume.so
-- Looking for OGRE_Overlay...
-- Found OGRE_Overlay: optimized;/usr/lib/libOgreOverlay.so;debug;/usr/local/lib/libOgreOverlay_d.so
-- Looking for OGRE_HlmsPbs...
-- Could not locate OGRE_HlmsPbs
-- Looking for OGRE_HlmsUnlit...
-- Could not locate OGRE_HlmsUnlit

Output with only OGRE-Next installed (with the Atmosphere component) from source:

-- Looking for OGRE...
-- OGRE_PREFIX_WATCH changed.
-- Found PkgConfig: /usr/bin/pkg-config (found version "2.3.0")
-- Checking for module 'OGRE-Next'
--   Package 'OGRE-Next' not found
-- Checking for module 'OGRE'
--   Package 'OGRE' not found
-- Found Ogre Eris (3.0.0)
-- Found OGRE: /usr/local/lib/libOgreMain_d.so
-- Looking for OGRE_Paging...
-- Could not locate OGRE_Paging
-- Looking for OGRE_Terrain...
-- Could not locate OGRE_Terrain
-- Looking for OGRE_Property...
-- Could not locate OGRE_Property
-- Looking for OGRE_Volume...
-- Could not locate OGRE_Volume
-- Looking for OGRE_Overlay...
-- Found OGRE_Overlay: /usr/local/lib/libOgreOverlay_d.so
-- Looking for OGRE_HlmsPbs...
-- Found OGRE_HlmsPbs: /usr/local/lib/libOgreHlmsPbs_d.so
-- Looking for OGRE_HlmsUnlit...
-- Found OGRE_HlmsUnlit: /usr/local/lib/libOgreHlmsUnlit_d.so

Thank you to all of you! I will convert this PR to draft for now. I will think about possibility of contributing to OGRE-Next, because I need the Atmosphere component for gazebosim/gz-sim#2753. Feel free to comment, any (good) advice would be appreciated.