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8448 :: Wrapperless interop with C/C++

• rb3 (orginal) [2021-09-22T15:07:12+02:00] view original

  Hey guys, I've just finished refactoring my C/C++ interop module: https://github.com/n0bra1n3r/cinterop. I started writing it a couple of years ago after stumbling upon nimline, which was its primary inspiration.

  I haven't got a chance to upload it as a nimble package yet, but will probably do so soon.

  I've used this module to successfully interop with the following C/C++ libraries that I use in my game engine so far:

  • Diligent Engine - C++
  • glfw - C
  • NewtonDynamics - C++

  This interop library would probably be useful to someone who uses similar libraries.

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• mantielero (orginal) [2021-09-22T22:56:01+02:00] view original

  I am playing with it, and it feels really good.

  Thanks a lot.

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• rb3 (orginal) [2021-09-23T03:12:49+02:00] view original

  For libraries with lots of functions that don't hang off of classes, this could also be useful. Here is what I did for GLFW:

  # glfw3.nim
  
  csource &"{GLFW}/glfw3.h": # header file
    type CGLFW* {.cgen:"(GLFW_$1)".} = object of CEnum
    
    type cglfw* {.cgen:"(glfw$1(@))".} = object of CClass
  Run

  # canvas.nim
  ...
  cauto^cglfw.GetMouseButton(self.window, button) == cauto^CGLFW.PRESS
  # generates something like `glfwGetMouseButton(self.window, button) == GLFW_PRESS`
  ...
  Run

  What I did here is create a "namespace type" in Nim that is not visible in C++. I used Nim's importcpp under the hood to tell the compiler (via my cgen pragma) how cglfw.field and CGLFW.FIELD should be generated.

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• reversem3 (orginal) [2021-09-28T23:08:37+02:00] view original

  Wow really good stuff , so you can interface with Diligent Engine now with nim? Do you have a repo of what you have done so far with that?

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• rb3 (orginal) [2021-09-29T03:52:02+02:00] view original

  Hi, yes I can interface with it now, with almost zero effort. DiligentEngine was basically the whole reason I wrote this library; it was extremely difficult to write a wrapper for due to the sheer number of classes, enums, and dependencies. And I couldn't figure out how to do it with the existing wrapper generators without spending too much time.

  Unfortunately I haven't had a chance to opensource other parts of my game engine yet. cinterop is basically the first component of the whole thing; I'll slowly refactor and release the other parts as I go.

  I can give examples of how I use cinterop to interface with the different libraries over on the github though, if you want to try out using it.

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• reversem3 (orginal) [2021-12-19T22:02:17+01:00] view original

  Anyway you have time to get me started with diligent engine and nim?

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