Using ImGui Bundle as a C++ submodule for widgets and Python bindings (without HelloImGui/OpenCV)

[Lumengine]

Hi,

I am a user of Dear ImGui and several related libraries (imgui-node-editor, ImPlot, etc.). I've noticed that imgui_bundle often includes fixes that aren't yet in the original repositories, and having everything in one place is very appealing.

I am considering cloning this repo to manage my dependencies, but I have a specific use case:

No HelloImGui: I already have my own window management and rendering backend.

Minimal Dependencies: I would like to compile the bundle without OpenCV, SDL2, or GLFW.

Core Needs: I only need Dear ImGui, the specific widgets (Node Editor, ImPlot, etc.), and the Python bindings (nanobind/pybind11).

Is there a supported way to configure the CMake to build only these components as a "library only" mode? Or would you recommend forking the repo and stripping the CMakeLists.txt for my own specific needs?

Thanks for your help!

[pthom]

Hi,

Partial solution for C++ only

At the moment, you can disable specific features using the main CMake file:

option(IMGUI_BUNDLE_DISABLE_NANOVG "Disable nanovg" OFF)
option(IMGUI_BUNDLE_DISABLE_IMGUI_TEX_INSPECT "Disable imgui_tex_inspect" OFF)
option(IMGUI_BUNDLE_DISABLE_IMGUIZMO "Disable ImGuizmo" OFF)
option(IMGUI_BUNDLE_DISABLE_IMFILEDIALOG "Disable ImFileDialog" OFF)
option(IMGUI_BUNDLE_DISABLE_IMGUI_NODE_EDITOR "Disable imgui-node-editor" OFF)
option(IMGUI_BUNDLE_DISABLE_IMPLOT "Disable implot" OFF)
option(IMGUI_BUNDLE_DISABLE_IMPLOT3D "Disable implot3d" OFF)
option(IMGUI_BUNDLE_DISABLE_IMMVISION "Disable immvision" OFF)

Caveats

• this works only in C++ (not for the bindings)
• there is (yet) no option to disable hello imgui and immap

Future addition to the bundle?

Your suggestion is interesting, so I started to investigate possible solutions (including for the python bindings). This would require a few days of work.

Notes about suppressing hello imgui

Some (limited) elements will not work

If Hello ImGui and Immapp are not active, you should know that some elements will not work. Here is a quick overview

• using imgui_test_engine from python: requires passing the GIL to/from python and C++. Hello ImGui handles this well but this is very tricky
• using markdown wrappers provided in external/imgui_md/imgui_md_wrapper/imgui_md_wrapper.h
• using nanovg / imgui_text / ImFileDialog from python (they require the initialization of an opengl context + some textures)

You may lose some services provided by hello imgui

• Smooth handling of idling to preserve CPU usage
• Better DPI handling

Misc

Thanks for contacting me! Are you working at lumiverse? Can you tell me a bit more about it? (I am based in Paris too).

Can you tell me more about your work in progress at https://github.com/Lumengine/lumengine_imgui_bundle ? As a way to build C++ libraries I think it might work (although complex). However as python bindings are concerned, I'm afraid this is not the good approach (ImGui bundle is huge, and maintaining / autogenerating the bindings is key for it to work correctly).

Feel free to contact me by direct email about this.

[pthom]

I did some adaptations on the CMake side. May be it will help you.
Below is an extract from the doc inside the main CMakeLists.

imgui_bundle/CMakeLists.txt

Lines 158 to 213 in 4a5ef0f

	# =============================================================================
	# Module Selection
	# =============================================================================
	# Control which imgui_bundle sub-modules are built using IMGUI_BUNDLE_WITH_* options.
	# Set to ON to include (default), or OFF to exclude.
	#
	# -----------------------------------------------------------------------------
	# 1. ImmVision (Computer Vision Widgets)
	# -----------------------------------------------------------------------------
	# ImmVision requires OpenCV and is OFF by default in C++, ON in Python/Emscripten.
	#
	# • C++ Usage:
	# Recommended: cmake -DIMMVISION_FETCH_OPENCV=ON ..
	# (This automatically enables IMGUI_BUNDLE_WITH_IMMVISION and fetches OpenCV)
	#
	# Advanced: cmake -DIMGUI_BUNDLE_WITH_IMMVISION=ON ..
	# (Requires you to provide OpenCV via find_package)
	#
	# • Python Usage:
	# To exclude: CMAKE_ARGS="-DIMGUI_BUNDLE_WITH_IMMVISION=OFF" pip install -v .
	#
	# • OpenCV Fetching (when IMMVISION_FETCH_OPENCV=ON):
	# - Windows/Emscripten: Downloads precompiled OpenCV package
	# - Linux/macOS: Compiles minimal OpenCV from source
	#
	# -----------------------------------------------------------------------------
	# 2. Hello ImGui (Application Framework & Window Management)
	# -----------------------------------------------------------------------------
	# Hello ImGui provides windowing, rendering backends, and app lifecycle management.
	# Setting IMGUI_BUNDLE_WITH_HELLO_IMGUI=OFF automatically excludes these dependent modules:
	# • immapp (high-level application wrapper)
	# • imgui_md (markdown renderer wrapper)
	# • im_file_dialog (requires OpenGL context)
	# • imgui_tex_inspect (requires OpenGL context)
	# • immvision (requires OpenGL for image display)
	# • imgui_test_engine (requires context management)
	# • GLFW backend (not needed without window management)
	#
	# • C++ Usage:
	# cmake -DIMGUI_BUNDLE_WITH_HELLO_IMGUI=OFF ..
	#
	# • Python Usage:
	# CMAKE_ARGS="-DIMGUI_BUNDLE_WITH_HELLO_IMGUI=OFF" pip install -v .
	#
	# -----------------------------------------------------------------------------
	# Available Modules (all default to ON except immvision)
	# -----------------------------------------------------------------------------
	# Core Framework:
	# IMGUI_BUNDLE_WITH_HELLO_IMGUI, IMGUI_BUNDLE_WITH_IMMAPP
	# UI Extensions:
	# IMGUI_BUNDLE_WITH_IMMVISION,
	# IMGUI_BUNDLE_WITH_IMPLOT, IMGUI_BUNDLE_WITH_IMPLOT3D,
	# IMGUI_BUNDLE_WITH_IMGUI_NODE_EDITOR, IMGUI_BUNDLE_WITH_IMGUI_MD,
	# IMGUI_BUNDLE_WITH_IMFILEDIALOG, IMGUI_BUNDLE_WITH_IMGUI_TEX_INSPECT
	# IMGUI_BUNDLE_WITH_NANOVG, IMGUI_BUNDLE_WITH_IMGUIZMO
	# =============================================================================