Adding watch option using dmon

[mwestphal]

This add support for an "--watch" cli option where the current file is reloaded automatically if changed on disk.
It relies on https://github.com/septag/dmon for detecting the changes.

In order to support this properly, F3DStarter is reworked with a proper event loops that currently supports:

• Reloading the current file
• Rendering

This also adds a test for it on linux/apple/windows

Script used:

while :
do
  sleep 1
  cp cowlow.vtp a.vtp
  sleep 1
  cp cow.vtp a.vtp
done

Peek.2024-03-17.12-09.mp4

Fix: #86

[github-actions]

You are modifying libf3d public API! ⚠️Please update bindings accordingly⚠️!
You can find them in their respective directories: python, java, webassembly.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.48%. Comparing base (eb2d844) to head (e1d8811).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1308      +/-   ##
==========================================
+ Coverage   96.45%   96.48%   +0.03%     
==========================================
  Files         146      146              
  Lines        8765     8793      +28     
==========================================
+ Hits         8454     8484      +30     
+ Misses        311      309       -2     

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[snoyer]

Looks like you already have the implementation details covered so I'm left with nitpicking naming:

• ForceRender() just performs the render it doesn't take any extra steps to "force" it -> Render()
• Render() doens't actually perform the render, it only asks for the render to be done (or declares the current render outdated depending on how you want to look at it) -> RequestRender(), InvalidateRender(), ...
• SoftRender is a flag but is named like an action -> RenderRequested, RenderNeeded, RenderFlag, ... (same for ReloadFile -> ReloadRequested, ...)

tldr:

void Render() { SoftRender = true; } // do the thing = don't actually  o_O
if (SoftRender) ForceRender(); // if soft then forceful  o_O

void RequestRender() { RenderRequested = true; } // request the thing = mark it as requested  ^_^
if (RenderRequested) Render(); // do the thing if asked  ^_^

[mwestphal]

As always, the easiest to find out how to do the right thing is just to do the wrong thing and wait for people to fix it for you, thanks @snoyer :)

[Meakk]

small typo to fix and good to go!