This README is the one indexed from the repository at its latest ref, not from the tag for this version.

crystal-imgui-backends

This shard makes it easy to use ImGui backends from Crystal.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
    imgui-backends:
      github: mattrbeck/crystal-imgui-backends
      tag: v1.90.6 # select your version here by git tag
    imgui: # chances are you want to include imgui as well
      github: oprypin/crystal-imgui
      tag: v1.90.6 # should match version used above

2. Run shards install

Usage

require "imgui-backends"
require "imgui-backends/lib"

# ImGui::<backend name>::method()
ImGui::OpenGL3.new_frame
ImGui::SDL2.new_frame(@window)

All backends are under a module sharing their name (like "SDL2" or OpenGL3"), which is in turn under the module "ImGui".

For a minimal example, run the following:

shards install
make
crystal examples/imgui_impl_opengl3.cr

For a concrete example using this shard, see https://github.com/mattrbeck/crab. The make shard is run as a postinstall step when this shard is installed, so ImGui links are generated automatically.

Development

Development is currently a manual process, and new backends are added as necessary. If you would like to use a backend or method that's not currently supported, you're welcome to add it following the convention in the src/ dir. If you add a new backend, it would be nice to create an example using that backend under examples/ as well.

Contributing

1. Fork it (https://github.com/mattrbeck/crystal-imgui-backends/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Matthew Beck - creator and maintainer

Credit

• Oleh Pyrpin: This shard is heavily inspired by https://github.com/oprypin/crystal-imgui-sfml
• Omar Cornut: The example code is translated nearly directly from https://github.com/ocornut/imgui