New abstract class DQ_CoppeliaSimInterface

[juanjqo]

Description of changes

Hi @dqrobotics/developers

This PR aims to discuss strategies to implement a proposes an abstract class DQ_CoppeliaSimInterface. The idea is to have concrete classes with different Coppelia's API. For instance, the Legacy remote API (the one used by DQ Robotics, but currently deprecated), and the ZeroMQ remote API. This feature was internally discussed, and I am working on a prototype based on my own DQ Robotics zmq-based interface.

This PR proposes the following:

• The abstract class DQ_CoppeliaSimInterface
• Rename the current class DQ_VrepInterface to DQ_CoppeliaSimLegacyInterface, and now, this class inherits from DQ_CoppeliaSimInterface
• Create the class DQ_VrepInterface, which inherits from DQ_CoppeliaSimLegacyInterface for backward compatibility.

classdef DQ_VrepInterface < DQ_CoppeliaSimLegacyInterface
    methods
        function obj = DQ_VrepInterface()
            obj@DQ_CoppeliaSimLegacyInterface();
        end
    end
end

I implemented a similar strategy concerning the following classes:

• DQ_CoppeliaSimRobot()
• DQ_SerialCoppeliaSimRobot()
• YouBotCoppeliaSimRobot()
• LBR4pCoppeliaSimRobot()

I'm planning to include the methods get_center_of_mass(), get_mass(), and get_inertia_matrix() (as suggested by @ffasilva) in the abstract class DQ_CoppeliaSimInterface() in future PRs since we are still working on them.

Best regards,

Juancho

---

Is this the best strategy? Please let me know your suggestions.

Alternatively, we could have the same behavior with fewer modifications in this way:

The current DQ_VrepInterface() class inherits form DQ_CoppeliaSimInterface

The DQ_CoppeliaSimLegacyInterface() class inherits from DQ_VrepInterface(). Therefore, no renaming is required.

PS
@bvadorno mentioned specific Matlab tools for managing aliases. But, I am not sure if this is available for C++/Python.

[ffasilva]

Hi @juanjqo,

I don't see the problem with your first suggestion. A user trying to use DQ_VrepInterface would still have access to all its functionalities through DQ_CoppeliaSimLegacyInterface without ever knowing any renaming took place.

As a suggestion, I would only modify DQ_VrepInterface to clarify it is now deprecated.

% For backward compatibility only. Do not use this class.
classdef DQ_VrepInterface < DQ_CoppeliaSimLegacyInterface
    methods
        function obj = DQ_VrepInterface()
            warning('Deprecated. Use DQ_CoppeliaSimLegacyInterface instead.')
            obj@DQ_CoppeliaSimLegacyInterface();
        end
    end
end

Additionally, I believe the abstract class DQ_CoppeliaSimInterface should also have the methods get_center_of_mass(), get_mass(), and get_inertia_matrix().

Kind regards,
Frederico

[juanjqo]

@ffasilva thanks, I'm going to include the modifications you suggested.

[mmmarinho]

Hi @juanjqo could you please clarify who do you want to review this code and in what order.

[juanjqo]

@mmmarinho I don't have any specific preference. May I suggest the following order @ffasilva, @mmmarinho, and @bvadorno?

[bvadorno]

@mmmarinho I don't have any specific preference. May I suggest the following order @ffasilva, @mmmarinho, and @bvadorno?

Sounds good to me. Please proceed.

Kind regards,
Bruno

[ffasilva]

Hi @juanjqo,

Thank you for the pull request. I tested the classes and found no problems with them. I just added two minor comments.

The one regarding the inclusion of the methods get_center_of_mass(), get_mass(), and get_inertia_matrix() is pending on #109. I'll work on this now.

Kind regards,
Frederico

[ffasilva]

Please remember to add the methods get_center_of_mass(), get_mass(), and get_inertia_matrix().

[juanjqo]

@ffasilva, thank you for the reminder.

Note for the future Juancho (since I am going to completely forget this): we discussed this internally. We decided to add those methods in a future PR since they are not available in the master version of the DQ Robotics. We are still working on it at #109

[ffasilva]

Please add a warning message informing that the class is now deprecated:

warning('Deprecated. Use YouBotCoppeliaSimRobot instead.')

[juanjqo]

@ffasilva good catch! I added the warning message.

[juanjqo]

@ffasilva I added the modifications you suggested. Please let me know if something else is required.

[ffasilva]

Hi @juanjqo,

Thank you! I believe we're good to go. Do you have any comments on this PR, @mmmarinho?

Kind regards,
Frederico

[mmmarinho]

Hi @juanjqo and @ffasilva

There are a lot of changes in this pull request so I will need a report showing that you tested this code with the examples that already exist.

We cannot have CoppeliaSim-enabled examples in GithubActions (yet?), so this needs to be tested manually.

[bvadorno]

Hi @juanjqo and @ffasilva

There are a lot of changes in this pull request so I will need a report showing that you tested this code with the examples that already exist.

We cannot have CoppeliaSim-enabled examples in GithubActions (yet?), so this needs to be tested manually.

@juanjqo, could you please use one of your computers (maybe the latest unmanaged one I gave you a couple of weeks ago) to set up CoppeliaSim-enabled examples in GitHub actions?

Thanks,
Bruno

[juanjqo]

@bvadorno Sure, I am going to check if it is possible.

Best regards,
Juancho

[juanjqo]

This PR is deprecated, considering the following remarks:

• There is a new DQ_CoppeliaSimInterface abstract class and its DQ_CoppeliaSimInterfaceZMQ concrete class.
• Furthermore, as we decided previously, the DQ_VrepInterface is now a deprecated class.

Kind regards,

Juancho