Feature/add arrow strip marker

[rr-tom-noble]

ROS2 port of this PR

1. Adds conversion methods between Ogre::ColourValue and msg::ColorRGBA types
2. Refactors the Arrow class:
   • Splits set() into setHeadLength(), setHeadDiameter(), setShaftLength(), setShaftDiameter() for clarity.
   • adds a setLength() method for setting the total arrow length, preserving shaft and head proportions.
   • adds a setShaftHeadRadio() method for setting shaft and head proportions, preserving the total arrow length.
3. Refactors code depending on Arrow to use the new methods
4. Adds an ArrowStripMarker class for rendering batches of arrows efficiently

Note:

While working on point 3, I noticed that there are inconsistencies in the way values are being passed to the (now removed) Arrow::set method. The documentation suggests it accepts shaft and head diameters, whereas the usage suggests some callers are passing in radii.

I've stuck to using diameter for now to preserve existing behaviour and for consistency with the original documentation. It's also more obvious now through the method names i.e. set..Diameter(...radius) where these inconsistencies exist, so it should be clearer for a future PR.

TODO:

• Finish ArrowStripMarker implementation
• Port files that don't seem to have ROS2 analogue
• Apply formatting
• Add unit tests

[rr-tom-noble]

Hi @ahcorde

The ROS1 version of this PR used a CI mechanism to pull in and compile against unmerged branches from other repositories, which will be required to resolve the dependencies between this one and the common msgs PR adding the new ARROW_STRIP Marker type. Does such a mechanism exist in rviz2?

Also, that PR featured a test Python script demonstrating rendering of the new marker type. Is there a place for these kinds of scripts in rviz2, or should writing the unit tests for the ArrowMarkerStrip class be sufficient?

Also, if you could let me know what tools I should be using to lint & format the code, that'd be super helpful.

[rr-tom-noble]

@ahcorde
Bump as I won't have much time to work on this from next week

[rr-tom-noble]

Hi @clalancette, would you be able to answer the questions above?

[rr-tom-noble]

@ahcorde @clalancette Bump as I'd really like to get this merged soon

[ahcorde]

This PR is block with this other PR ros2/common_interfaces#218

[clalancette]

First, I'm sorry for the long delay. May is an extremely busy month leading up to the release, so I just didn't have time to look at this back then. I can answer some questions now.

The ROS1 version of this PR used a CI mechanism to pull in and compile against unmerged branches from other repositories, which will be required to resolve the dependencies between this one and the common msgs PR adding the new ARROW_STRIP Marker type. Does such a mechanism exist in rviz2?

Yes, though it is somewhat more manual. In this case, we use jobs launched on https://ci.ros2.org to do the same thing. Assuming we go forward with this and ros2/common_interfaces#218 , that's the mechanism we'll use.

Also, that PR featured a test Python script demonstrating rendering of the new marker type. Is there a place for these kinds of scripts in rviz2, or should writing the unit tests for the ArrowMarkerStrip class be sufficient?

Um, that's a good question. I don't really know. What I think we should probably do for now is just to keep that separate, but if you could put a link to it somewhere for testing that would be helpful.

Also, if you could let me know what tools I should be using to lint & format the code, that'd be super helpful.

If you follow the installation procedure on http://docs.ros.org/en/rolling/Installation/Alternatives/Ubuntu-Development-Setup.html, you should have all the tools you need. Then you can checkout this branch and the one in common_interfaces, and do:

$ colcon build
$ colcon test --packages-select rviz_common rviz_default_plugins

That should tell you what you need to change.

[ahcorde]

do you have plan to continue working on this PR @rr-tom-noble ?