Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/bamboo/godot-s7-scheme

Godot engine language binding for the wonderful s7 Scheme
https://github.com/bamboo/godot-s7-scheme

godot s7 scheme

Last synced: about 1 month ago
JSON representation

Godot engine language binding for the wonderful s7 Scheme

Awesome Lists containing this project

README 

        
# Godot scripting via s7 Scheme



[Godot](https://godotengine.org/) integration for the wonderful [s7 Scheme](https://ccrma.stanford.edu/software/snd/snd/s7.html). `s7` interpreters can be added to scenes as `Scheme` nodes which can load and evaluate code.



The Scheme code has access to the Godot API via a simple interface (syntax is still in flux):

- the `Scheme` Godot node, which serves as an entry point into the scene model, is exposed as the `*node*` constant

- Godot nodes can be accessed through their relative path to `*node*` via the `$` macro, e.g. `($ Sprite2D)`

- properties can be read via applicable object syntax, e.g., `(*node* 'owner)` reads the [`owner` property](https://docs.godotengine.org/en/stable/classes/class_node.html#class-node-property-owner) of the enclosing node

- applicable syntax can also read nested properties, e.g., `(*node* 'owner 'name)` reads the name of the owner of the enclosing node

- applicable syntax can call methods, e.g., `(*node* 'owner '(get_child 0) 'name)`, even when the arguments are not constants, ``(*node* `(get_child ,child_index))``

- although explicit syntax for method calls is also provided for when it makes things clearer, `(! (*node* 'owner) 'get_child 0)`

- properties can be set via generalized `set!` syntax, e.g., `(set! (*node* 'owner '(get_child 0) 'name) "Deeply Nested set!")`

- Scheme code can connect to signals via `connect!`



A more complete example of the available syntax:



```scheme

(begin

  ;; Godot objects are exposed as applicable objects.

  (define button (*node* 'owner '(get_child 1)))



  (define (button-append! suffix)

	(let ((text (button 'text)))

	  ;; Godot properties are set via generalized set! syntax

	  ;; and there are two main ways of calling Godot methods:

	  ;;  * (!   &)

	  ;;  * ( '( &))

	  ;; ! is preferred for effectful calls such as

	  ;; 'insert below, and, in general is more amenable

	  ;; to optimisations. Applicable object syntax

	  ;; is convenient for const methods like '(length) below and

	  ;; `(get_child 1) above.

	  (set! (button 'text)

			(! text 'insert (text '(length)) suffix))))



  (define (function-handler)

	(button-append! "!"))



  (define (symbol-handler)

	(button-append! "'"))



  ;; Signals can be connected to symbols, lambdas and arbitrary procedures.

  ;; Symbols provide late binding, i.e., the ability to redefine the

  ;; procedure bound to a symbol / signal via the repl while the program is

  ;; running.

  (connect! button 'pressed 'symbol-handler)

  (connect! button 'pressed (lambda () (button-append! "λ")))

  (connect! button 'pressed function-handler))

```



## Status



Very experimental but a lot of fun to play with. Use it at your own risk.



## Building



Make sure to update all git submodules:



```shell

	git submodule update --init

```



Build and launch the demo project with:



```shell

	scons && godot -e --path demo

```



Build the Android target with:



```shell

	scons platform=android target=template_debug

```



Make sure `ANDROID_HOME` is set.



## Emacs live editing support (WIP)



Install [Geiser](https://www.nongnu.org/geiser/) then add the following to your Emacs configuration:



```elisp

  (add-to-list 'load-path "~/path/to/godot-s7-scheme/emacs/")

  (load "geiser-godot-s7-autoloads.el")

```



The Emacs extension automatically recognize Scheme files inside Godot project directories as `Godot s7 Scheme` files.



### Connecting



1. Add a `SchemeReplServer` to your scene (preferably as a child of a `Scheme` node) and set its `Auto Start` property to `true`.

2. Check the port number in the Godot output window.

3. `M-x connect-to-godot-s7`



## Roadmap



- [x] use Godot API from Scheme

- [o] live coding interface via Emacs (wip)

- [ ] expose tree-sitter API to Scheme

- [ ] Scheme editor with syntax highlighting

- [ ] Scheme notebooks

- [ ] expose Godot signals from Scheme

- [ ] subclass Godot classes from Scheme

- [ ] register Scheme as a proper [script language extension](https://docs.godotengine.org/en/stable/classes/class_scriptlanguageextension.html#class-scriptlanguageextension)