gr4-incubator

The gr4-incubator repo is designed to be a staging area for GR4 block development prior to upstreaming blocks to the main gnuradio4 repo. It is intended to collect and triage the "kitchen sink" of useful blocks, schedulers, utilities, but have a lower bar for accepting contributions than the core.

Getting Started

Pre-requisites for compiling this codebase are outlined in docker/Dockerfile. For convenience, example devcontainer.json configurations are given in the .devcontainer directory for VS Code integration

Organization

The tree is organized around creating multiple modules under the blocks directory that live

├── blocks
│   ├── analog
│   │   ├── apps
│   │   ├── benchmarks
│   │   ├── docs
│   │   ├── examples
│   │   ├── include
│   │   ├── plugin
│   │   ├── src
│   │   └── test
│   ├── audio
│   ├── basic
│   ├── pfb
│   ├── soapysdr
│   └── zeromq
├── cmake
│   └── Modules
├── docker
├── examples
│   └── gr3_flowgraphs
└── subprojects

Examples

Examples that exercise multiple modules

Build instructions (CMake)

The CMake path is the active build path for this branch.

Build policy

• System dependencies only (find_package / pkg-config); no subprojects/ or FetchContent.
• Plugins are hard-disabled in CMake (ENABLE_PLUGINS=ON is an error).
• GUI examples are optional and OFF by default.

Configure and build

cmake -S . -B build -G Ninja \
  -DENABLE_EXAMPLES=ON \
  -DENABLE_TESTING=ON \
  -DENABLE_GUI_EXAMPLES=OFF

cmake --build build -j

Run tests

ctest --test-dir build --output-on-failure

Enable GUI examples

ENABLE_GUI_EXAMPLES=ON requires imgui, implot, glfw3, and OpenGL.

If implot is not discoverable through package config or pkg-config, pass explicit paths:

cmake -S . -B build -G Ninja \
  -DENABLE_EXAMPLES=ON \
  -DENABLE_TESTING=ON \
  -DENABLE_GUI_EXAMPLES=ON \
  -DIMPLOT_INCLUDE_DIR=/usr/local/include \
  -DIMPLOT_LIBRARY=/usr/local/lib/libimplot.so

You can also use:

-DIMPLOT_SOURCE_DIR=/path/to/implot

Common Ubuntu devcontainer packages

• librtaudio-dev
• libcli11-dev
• libimgui-dev
• libglfw3-dev
• libopengl-dev

implot is typically not packaged; in this repo's devcontainer it is installed in /usr/local.

TODOs and upstream gating factors

The current CMake setup is intentionally pragmatic. Full canonical cleanup is gated by upstream work in GNU Radio 4 and related packaging.

Local TODOs in gr4-incubator

• Add install/export package config for this repo (install(EXPORT ...), gr4-incubatorConfig.cmake).
• Reduce custom fallback logic for GUI dependency discovery once upstream/system packages are stable.
• Keep CMake and Meson behavior aligned while migration is ongoing.

Upstream gating factors (gnuradio4 and ecosystem)

• Stable exported CMake package targets from gnuradio4 for all required link interfaces.
• Canonical target/package exposure for blocklib components currently consumed as raw libraries.
• Consistent distro packaging (or official CMake package configs) for optional GUI dependencies, especially implot.
• Clear upstream contract for optional/plugin mechanisms to replace Meson bootstrap-specific workflows cleanly in CMake.