/imgui-nodes

Node based graph editor for Dear ImGui

Primary LanguageC++BSD 3-Clause "New" or "Revised" LicenseBSD-3-Clause

Nodes for Dear ImGui

This project wants to be a generic node based graph editor addon for Dear ImGui based projects. It tries to use ImGui paradigmas where possible by keeping or duplicating as little state as possible. Like in ImGui the application is responsible for holding and updating its own data model - a node graph. Thus the library offers facilites to display, interact and manipulate such a node graph but does not store its state.

This project is work in progress. Test carefully if you want to use it in productive software. Also note that the API is not final yet - be prepared for changes without preceding deprecation.

Mouse Bindings

  • Node Editor Background:
    • LMB: Deselect all nodes/edges
    • Drag LMB: Select nodes/edges touching the dragged box (clears previous selection)
    • ALT+Drag LMB: Select nodes/edges enclosed in the dragged box (clears previous selection)
    • SHIFT+Drag LMB: Add nodes/edges touching the dragged box from the selection
    • SHIFT+ALT+Drag LMB: Add nodes/edges enclosed in the dragged box from the selection
    • CTRL+SHIFT+Drag LMB: Remove nodes/edges touching the dragged box from the selection
    • CTRL+SHIFT+ALT+Drag LMB: Remove nodes/edges enclosed in the dragged box from the selection
    • Scroll Wheel: Zoom in/Zoom out at current cursor position
    • RMB: Opens context menu for adding new nodes (in the sample)
  • Node body:
    • LMB: Select node and deselect all other nodes/edges
    • SHIFT+LMB: Toggle selection
    • Drag LMB: Add edge
  • Edge:
    • LMB: Select edge and deselect all other nodes/edges
    • SHIFT+LMB: Toggle selection
  • Socket:
    • Drag LMB: Add edge

Key Bindings

  • ESC: Cancel actions like adding a edge or selecting nodes
  • HOME: Centers the node editor view and resets the zoom level
  • CTRL+A: Selects all nodes and edges (in the sample)
  • DEL: Deletes selected nodes and edges (in the sample)

Notes

  • The Nodes library itself requires C++11 to build, the sample currently requires C++17.
  • Currently there are only project files for Microsoft Visual Studio 2022.
  • The project is using some ImGui internals which can change at any time. Things might not work out of the box if you use a different ImGui version than the one referenced here.
  • It is recommended to oversample the font loaded into imgui by the maximum amount of pixels (8) for best results of zoomed text. Example: 
    ImGuiIO& io = ImGui::GetIO();

ImFontConfig fontcfg;
fontcfg.OversampleH = 8;
fontcfg.OversampleV = 8;
io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\SegoeUI.ttf", 18.0f, &fontcfg);