Addition of GDExtension docs

[paddy-exe]

Aims to implement #5618 in its basic form (more can be added later in additional PRs)

Part of #5121

What this PR explains:

• Getting the necessary files to work on
• What each file in there does
• Generate the bindings (for each platform, and cross-platform)
• Creating the First Extension
• Overriding/Extending Engine features (if possible)
• Compiling your extension
• Adding properties to the Node you are extending from
  • Adding a property hint range to show one option for further customizability
• Signals

[paddy-exe]

@mhilbrunner Since your last commit, I noticed that the SConstruct file you put in the folder structure doesn't actually run. Also, it is quite complex to understand. Since the build system was revamped the SConstruct doesn't need to that complicated anymore. At least for my template I have it way simpler so my reworked version would be this:

#!/usr/bin/env python
import os
import sys

env = SConscript("godot-cpp/SConstruct")

# For the reference:
# - CCFLAGS are compilation flags shared between C and C++
# - CFLAGS are for C-specific compilation flags
# - CXXFLAGS are for C++-specific compilation flags
# - CPPFLAGS are for pre-processor flags
# - CPPDEFINES are for pre-processor defines
# - LINKFLAGS are for linking flags

# tweak this if you want to use different folders, or more folders, to store your source code in.
env.Append(CPPPATH=["src/"])
sources = Glob("src/*.cpp")

if env["platform"] == "macos":
    library = env.SharedLibrary(
        "demo/bin/osx/libgdexample.{}.framework".format(
            env["platform"],
        ),
        source=sources,
    )
elif env["platform"] == "windows":
    library = env.SharedLibrary(
        "demo/bin/win64/libgdexample.{}.{}{}".format(env["platform"], env["arch"], env["SHLIBSUFFIX"]),
        source=sources,
    )
else:
    library = env.SharedLibrary(
        "demo/bin/linux/libgdexample.{}.{}{}".format(env["platform"], env["arch"], env["SHLIBSUFFIX"]),
        source=sources,
    )

Default(library)

And the .gdextension file:

[configuration]

entry_symbol = "example_library_init"

[libraries]

linux.64="res://bin/linux/libgdexample.linux.64.so"
windows.x86_64="res://bin/win64/libgdexample.windows.x86_64.dll"
macos="res://bin/osx/libgdexample.macos.framework"

Imho this would be clearer for new users. What do you think?

[Zireael07]

Nitpick: I'd rephrase to make it clearer that 3.5 and 3.6 don't have GDExtension at all (unless I missed something, GDExtension was NOT backported to 3.x branch)

[paddy-exe]

Good point👍🏻 I made it clearer that GDExtension isn't compatible with GDNative

[Zireael07]

Hmm. If all that GDExtension does is call on a dll, could I have some logic NOT using any Godot specific stuff e.g. in Golang and call on it WITHOUT having any Golang bindings?

[paddy-exe]

Hmm. If all that GDExtension does is call on a dll, could I have some logic NOT using any Godot specific stuff e.g. in Golang and call on it WITHOUT having any Golang bindings?

Good question! Not sure how that applies to other languages but I think in Python used with GDNative it was possible to use some modules assuming they were imported properly.

[Zireael07]

Something that just occurred to me, and which IIRC is also missing from GDNative docs in 3.5, what's the debugger/remote tree situation? I expect to have to use the debugger for the language I'm using, but what about remote tree variables if I use a gdns straight on a node, e.g. the player, as is the case with many of the demo projects out there?

[paddy-exe]

Something that just occurred to me, and which IIRC is also missing from GDNative docs in 3.5, what's the debugger/remote tree situation? I expect to have to use the debugger for the language I'm using, but what about remote tree variables if I use a gdns straight on a node, e.g. the player, as is the case with many of the demo projects out there?

I am not sure what you mean with your question. Could you elaborate?

[Zireael07]

Literally what I said. Suppose I use a gdns file for my player node. Can I see e.g. the player's position or speed in the Godot remote tree?

[paddy-exe]

Literally what I said. Suppose I use a gdns file for my player node. Can I see e.g. the player's position or speed in the Godot remote tree?

This here is the GDExtension docs addition, not GDNative.
There are no gdns files with GDExtension.
GDExtension is very much just extending Godot itself so you can see it like if it's programmed inside of Godot itself.

[Zireael07]

Ah, I was confused (again) by the fact you started from renaming the GDNative docs :P of course I meant Extension

[yudi-azvd]

Suggested change

	GD_CLASS(GDExample, Sprite2D)
	GDCLASS(GDExample, Sprite2D)

I think you meant GDCLASS. I got stuck here for a little while 🤓

[paddy-exe]

@yudi-azvd Thanks for noticing! It's updated now.

[paddy-exe]

Alright, here's a little update what is already done in this PR and works (tested locally by me):

• Getting the necessary files to work on
• What is each file in there does
• Generate the bindings (for each platform, and cross-platform)
• Creating the First Extension
• Overriding/Extending Engine features (if possible)
• Compiling your extension
• Adding properties to the Node you are extending from

What still needs to be done:

• Signals

[BastiaanOlij]

Generally looks good to me, just a few things that I guess were translated from the GDNative version but now work slightly differently in GDExtensions.

[paddy-exe]

I worked in the feedback, added a property hint example (with PROPERTY_HINT_RANGE), squashed all commits and rebased my changes on master

[BastiaanOlij]

Looking pretty good so far to me.

[mhilbrunner]

Looks good to me, gave it another read and spotted nothing else!

Could you convert the .pngs to .webp? We decided to change format for the docs.
Besides that, I'm happy to merge this. :)

[paddy-exe]

@mhilbrunner Awesome! I converted the .png's to .webp now :D should be ready to merge

[paddy-exe]

Alright, the redirect.csv should now be correctly done (I hope). I rebased everyting as well

[YuriSizov]

Yep, redirects are now fine, good work! :)

[paddy-exe]

It is done :O 😅 there was an issue with the renaming of the .png to .webp inside the documents themselves. Is fixed now. ready to merge @mhilbrunner

[mhilbrunner]

Merged, finally! 🎉 Amazing work. Thanks for keeping up with all the reviews and change requests for so long.

Amazing docs contribution and nice we have that in now for 4.0 launch. :)