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.

paweljarosz / defold_imnodes