Show HN: Hokusai Pocket (WIP) – Portable GUIs with MRuby

A project for making portable apps and games using hokusai

Work in progress, expect changes. ideas and contributions are welcome.

prerequisites

• make and build tools
• a c compiler
• ruby/rake

Running hokusai-pocket new will walk you through setting up a project

It will create the following project structure

project/ .pocket (a config file that defines the gems) src/ app.rb (default app entrypoint) dist/ default/ (the app gets compiled here) web/ vendor/ (source code for mruby / raylib / tree-sitter) ... target/ default/ (default target is the build host) bin/ mrbc mruby ... include/ raylib.h mruby.h hokusai-pocket.h ... lib/ libmruby.a libtree-sitter.a libpocket.a ... web/ (addtional targets) ...

• hokusai-pocket compile -t <target>

After setup, the compile command will recompile the vendor source for different targets.

• hokusai-pocket dev -t <target> -a <hokusai app>

This command will compile and run src/app.rb for <target>, omit the target to build for the host system.

The target hokusai application must end with a Hokusai::Backend statement

An example app:

class App < Hokusai::Block style <<-EOF [style] style { radius: 40.0; color: rgb(222, 222, 0); } EOF template <<-EOF [template] circle { ...style } EOF uses(circle: Hokusai::Blocks::Circle) end # Need to declare `Hokusai::Backend::run` Hokusai::Backend.run(App) do |config| # configure backend config.title = "Counter" config.fps = 60 config.width = 700 config.height = 500 config.after_load do # need to register a font to use text Hokusai.fonts.register "default", Hokusai::Backend::Font.default Hokusai.fonts.activate "default" # or load one from a file Hokusai.fonts.register "some-file", Hokusai::Backend::Font.from("some-file.ttf") # to load specific codepoints codepoints = "abcdefhijklmnop" Hokusai.fonts.register "some-file", Hokusai::Backend::Font.from_ext("some-file.ttf", 120, codepoints) end end

prerequisites

• make and build tools
• a c compiler
• ruby/rake
• crystal

1. clone this repository and cd into it.
2. build the hokusai-pocket binary shards build
3. setup a project with vendor code ./bin/hokusai-pocket new example
4. run system tests against the installation ./bin/hokusai-pocket system-test example.

dev tour

The project structure is

/bin hokusai-pocket /builder (a barista project for the hokusai-pocket binary) /grammar (the tree sitter grammar for the templates) /ruby (the hokusai ruby project) /include (supporting headers) /ast /hp /src (supporting c files) /ast (template code for the tree-sitter ast) /hp (glues raylib/mruby/ast code) /test (c tests using GREATEST.h)

hokusai-pocket system-test <installation> will compile the project using the setup source from <installation>

hokusai pocket supports a basic implementation of require_relative in the ruby code. It will perform basic subsitution and generate one large ruby file to be compiled using mrbc

shards build will bake the ruby and c source code into the resulting executable. Running hokusai-pocket setup will write these files back to the file system to be compiled.

The executable is built with a tool called Barista, which runs a dependency graph of tasks concurrently via cli entrpoints. It has support for platform detection, running arbitrary commands and using templates.

For more information on the barista project, please see: the repository