Linking .dll to GDextension using scons

[nowins15]

Godot Version

4.2.2

Question

I’m trying to build a godot extension that uses modules from OpenCV. Within my application folder I have the godot-cpp folder, a src folder containing the code for my extension node as well as register_types.cpp and register_types.h, an include folder which has an opencv2 subfolder that contains all of the opencv headers, and a lib folder that holds opencv_world490.dll and opencv_world490.lib.

I am encountering the error “fatal error C1083: Cannot open include file: ‘opencv2/core/mat.hpp’: No such file or directory” which makes me think scons is not recognizing the opencv headers even though I have listed the folder in the CPPPATH. I found the following post which seems like its trying to do something similar and added those lines to my scon file which is in the root directory.

https://www.reddit.com/r/godot/comments/1deoxn2/how_to_link_a_godot_extension_with_a_precompiled/

Here is my Scon File:

import os
import sys

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

env.Append(CPPPATH=["src/", "include/"])
env.Append(LIBS=["opencv_world490"])
env.Append(LIBPATH=["lib/"])
sources = Glob("src/*.cpp")

if env["platform"] == "macos":
    library = env.SharedLibrary(
        "demoproject/bin/CalibratedCamera.{}.{}.framework/CalibratedCamera.{}.{}".format(
            env["platform"], env["target"], env["platform"], env["target"]
        ),
        source=sources,
    )
else:
    library = env.SharedLibrary(
        "demoproject/bin/CalibratedCamera{}{}".format(env["suffix"], env["SHLIBSUFFIX"]),
        source=sources,
    )

Default(library)

And my file structure with the include headers:

[YanDaik]

have you found solution? does this method of including dlls work?

[nowins15]

Yes it works great just had to change up how I added to dll to the bin, heres what worked for me.

env = SConscript("godot-cpp-godot-4.2.2-stable/SConstruct")

env.Append(CPPPATH=["src/", "include/"])
env.Append(LIBS=["opencv_world490"])
env.Append(LIBPATH=["lib/"])

sources = Glob("src/*.cpp")

if env["platform"] == "macos":
    library = env.SharedLibrary(
        "demoproject/bin/CalibratedCamera.{}.{}.framework/CalibratedCamera.{}.{}".format(
            env["platform"], env["target"], env["platform"], env["target"]
        ),
        source=sources,
    )
else:
    library = env.SharedLibrary(
        "demoproject/bin/CalibratedCamera{}{}".format(env["suffix"], env["SHLIBSUFFIX"]),
        source=sources,
    )

# Ensure the DLLs are copied to the target directory 
if env["platform"] == "windows":
    dlls = [
        "lib/opencv_world490.dll"
    ]
    for dll in dlls:
        env.Command(
            target=os.path.join("demoproject/bin/", os.path.basename(dll)),
            source=dll,
            action=Copy("$TARGET", "$SOURCE")
        )
Default(library)```

[YanDaik]

@nowins15

env.Append(LIBS=["opencv_world490"])
env.Append(LIBPATH=["lib/"])

when i write this two lines scons prints some currupted text to the console and exits with error.

[nowins15]

what dll are you trying to use make sure you have the name spelled right and the dll included in the lib folder

[YanDaik]

I’m trying to use third party dll “tracy.dll”
When i do it like this then scons for some reason seeks a dll with added sufixes to it (like those that he adds to a compiling dll when compiling sources into one).