VkLive - A Vulkan Live Coding Editor

This is a work in progress Vulkan/Shader editing project. It runs on Windows, builds on Mac and Linux but has not recently been tested on those platforms. I've been building live editing tools for years, but they always got too big and I never got to the point of shipping anything. This project pulls in the best/working bits of the visual tools I've built and ships it ;) I've paid attention to managing the basics, and making things work well. I'd love to know what you think.

Currently, you can edit a simple description of your scene in terms of passes and geometry, then you can edit the shader files in your project folder. The main selling point is the easy UI, and great error feedback when editing shaders. Mostly the code is c-like, with structs and functions. It should be relatively easy to follow. The ImGui bits are ported to Vulkan hpp, which might be useful to some; it is certainly more manageable this way.

Audio input is now supported, and the audio data is converted to a frequency spectrum and uploaded as a texture containing right/left stereo spectrum and right/left audio. See the example template to play with it.

If you like live coding, shaders, shadertoy, or are learning how to use Vulkan to render, then this might be a fun tool for you to play with. If you make a nice project, please send it along, or add a screenshot to the screenshot thread! Built for fun, and to update my GPU graphics knowledge.

Video Overview

Audio Input

An audio spectrum analysis; best seen live! This is from a ShaderToy example, provided as a template in the file menu:

Features

• CTRL+ENTER to evaluate the project/shader you are viewing.
• Can edit/save the files in modal VIM or Notepad style mode (CTRL+2 or CTRL+1).
• Scene description for passes and geometry, rendertargets and textures.
• Fragment, Vertex and Geometry Shaders have been tested so far.
• Can declare rendertargets, write to them, and sample them in later passes.
• Can declare textures and read them in shaders
• A special texture name 'AudioAnalysis' represents the audio input data.
• Load/Save projects in different folders
• All API objects are debug-labelled, including the ImGui ones, making it easy to diagnose errors in tools like NVIDIA Nsight, and find your way around.
• Default project has background and foreground geometry and time input. Template examples show off features.

TODO

• More error checking of device creation problems.
• More flexible UBO. You can't change the UBO yet (eventually you will get an automatically built UBO based on your spec)
• Ray tracing support.
• Low DPI/Mac DPI. You may not have a good experience on a low DPI setup, and on Mac there are tweaks required too.

Build

Use do.py as the single project workflow entrypoint. It configures CMake presets, uses Ninja, exposes compile_commands.json at the repo root for clangd/Vim LSP, and launches the app from the configured build folder.

python3 do.py setup
python3 do.py config debug
python3 do.py build debug
python3 do.py run debug

Short forms default to Debug:

python3 do.py config
python3 do.py build
python3 do.py run

Useful maintenance commands:

python3 do.py doctor
python3 do.py test debug
python3 do.py clean debug
python3 do.py sync
python3 do.py push

If your shell aliases dr to python3 do.py, the same commands work as dr run debug, dr sync, and so on. On Windows, use python do.py ... if that is your Python launcher.

See docs/dependencies.md for the dependency and build workflow. On Mac, Metal is the default renderer feature; Windows and Linux default to Vulkan. Windows development can still use Visual Studio after python do.py config debug if you prefer the IDE.

Design

So how does it work? Firstly, all text editing is handled by Zep. It does the heavy lifting of showing tabs, editing text, flashing when you evaluate, syntax coloring, error popups, etc. The windows are created by SDL, and the UI is drawn by ImGui. The rendering engine is designed as a simple collection of C-like functions and structs. There is a thread in the main application which can spot changes to the code, rebuild the vulkan pipeline and send the new state into an update queue if it works. If it doesn't, the previous state is maintained until it is fixed. The Vulkan validation layers catch all problems so far, which helps keep the app stable while the user tweaks things. The scenegraph is a simple language parsed by MPC, and controls the render passes. Shaders are now partially reflected, so that bindings can be dynamically built. I'll write more here when I get time ;)

Built On

Built on the Zep editor, the project I built that started this journey several years ago: https://github.com/Rezonality/Zep

Vulkan - The project currently uses Vulkan for all rendering. I may do Metal/DX12 at some point for fun.

VCPKG - Microsoft's freaking awesome cross platform manager with an unfortunate 'not sounding cross platform at all' name. The following packages are used currently: Freetype - Better font rendering assimp - Asset import for loading models clipp - Commandline parser for command line arguments fmt - String formatting library imgui - ImGui API reproc++ - Process launch library for loading shader compiler binary SDL2 - SDL UI library for creating windows, etc. tomlplusplus - Toml file format parser for reading config files unofficial-concurrentqueue - Concurrent lock/free queue for thread interactions tinyfiledialogs - File dialogs that look OS specific and more standard unofficial-nativefiledialog - File dialogs that look OS specific and more standard mpc - The parser used in the scene graph file kissfft - For spectrum analysis of audio