ImNodes example for Dear ImGUI extension for Defold

This project is additional example for Dear ImGUI in Defold extension utilizing ImNodes to show how to create Node/Flow Graphs. Dear ImGUI is described as a "Bloat-free Graphical User interface for C++ with minimal dependencies". It is perfect for quickly creating a debug interface or for creation of in-game tools and settings. ImNodes is described as "a small, dependency-free node editor extension for dear imgui."

ImNodes in Defold build:

Description for ImNodes example in Defold by Pawel Jarosz

Purpose

Purpose of this project is to show how to use Dear ImGUI + ImNodes in Defold to create different Node/Flow based graphs.

Overview

The project enhances Defold extension for Dear ImGUI with functions from ImNodes, hence both are joined here. Files for Imnodes are just added to imgui/src/imgui. Additional Lua bindings were added, but not fully covering Imnodes - all of them you can find in extension_imgui.cpp in section "Node Editor".

Example projects contains a folder with different Lua modules for making Imnodes handling easier - those could be find in imnodes catalog. The modules are used in example_imnodes.script.

Generally, this project is a little mess, but if you have power and knowledge to push it further, I would be glad.

License

Do whatever you like, it's open-source, it's on MIT license, as well as Dear ImGUI extension, Dear ImGUI itself and ImNodes.

Known Issues

• Saving/loading not completed, moreover loading causes a crash.
• Can't set any value persistently.
• Can't remove connected links.
• Generally needs a lot of refactor.

Description for Dear ImGUI by Bjorn Ritzl

Why no auto-generated bindings?

Projects such as cimgui offers Dear ImGUI bindings for a number of different languages, including Lua. It could be used to generate the bindings for this extension, BUT I'm doing this as a way to learn more about the Dear ImGUI API and as such it makes more sense for me to write the bindings by hand.

IMPORTANT

• The project currently only has bindings for a small subset of the Dear ImGUI API.
  • More bindings are added as I need them. Pull requests are accepted!
• The project is not cross-platform - See below for list of supported platforms
  • The current version uses the imgui_impl_opengl3.cpp

Platforms support

The current state of platform support:

• macOS - supported
• Linux - supported
• Windows - supported
• Android - supported
• iOS - supported
• HTML5 - supported

Usage

Refer to example/example.script to learn how to use the extension. Also check the bindings in LuaInit() in extension_imgui.cpp.

Input

You need to update the input state in Dear ImGUI each frame to accurately reflect user input:

• imgui.set_key_down(key, pressed) - Set the pressed state of a key. The key must be one of the imgui.KEY_ constants
• imgui.set_key_modifier_super(pressed)
• imgui.set_key_modifier_alt(pressed)
• imgui.set_key_modifier_ctrl(pressed)
• imgui.set_key_modifier_shift(pressed)
• imgui.add_input_character(text) - Add keyboard input
• imgui.set_mouse_input(x, y, left, right, middle, wheel) - Set mouse state (position, buttons and wheel)

You can add the imgui/imgui.script to a game object and let that handle input for you (also make sure to use imgui/bindings/imgui.input_bindings).

Display size

You need to let Dear ImGUI know of any changes to the window size by calling imgui.set_display_size(w, h) when the screen size changes.