Inkwell

Inkwell is a companion library to Quil. Quil brings Processing to Clojure. Inkwell makes it fit in by making it simple to program interactively with pure functions.

A separation of purely functional logic and impure rendering

An Inkwell sketch consists of two parts:

1. handle-event, a pure function that calculates a new sketch state based on a previous state and an event. (That is, its type is [State Event -> State]).

2. draw, an impure function that takes a sketch state and renders it using Quil. (That is, its type is [State -> Any]).

This approach naturally leads to most of your code living on the purely functional side, where it is easy to test and reason about, without sacrificing the ease of rendering of vanilla Quil.

Improved support for interactive programming in the REPL

When an exception is thrown from either handle-event or draw, the Inkwell sketch becomes paused. While paused, neither handle-event nor draw are called. This prevents you from being bombarded with sixty stack traces per second when you make a mistake. When the mistake is fixed, call inkwell.core/resume! to unpause the sketch.

Not only does Inkwell make sure to not flood you with stack traces, it makes sure they are printed where you can see them. Quil prints exceptions to System/out, whereas Inkwell redirects them to *out* to make sure they end up in your REPL.

Usage

Leiningen dependency information:

[inkwell "0.1.0"]

To create a sketch, call inkwell.core/make-sketch! with a map of settings. There are three keys in the settings map that Inkwell cares about: :handle-event and :draw, whose values must be functions as described above, and :initial-state, whose value must be the sketch's initial state (the value first passed to the :handle-event and :draw functions).

The rest of the keys, such as :title or :size, are passed on to Quil.

Events

The event parameter of handle-event may take one of the following values:

{:type :tick} ; Sent after each `draw`

{:type :mouse-moved
 :position [123 ; mouse x
            456 ; mouse y
]}

{:type :mouse-pressed
 :button :left  ; or :center or :right
 :position [123 ; mouse x
            456 ; mouse y
]}

{:type :mouse-released
 :button :left  ; or :center or :right
 :position [123 ; mouse x
            456 ; mouse y
]}

{:type :key-pressed
 :key \c      ; from quil.core/raw-key
 :key-code 67 ; from quil.core/key-code
 :key-name :c ; from quil.core/key-as-keyword
}

{:type :key-released
 :key \c      ; from quil.core/raw-key
 :key-code 67 ; from quil.core/key-code
 :key-name :c ; from quil.core/key-as-keyword
}

{:type :mouse-wheel
 :direction :up ; or :down
}

As you can see, for the most part, the event types correspond to Quil's event type callbacks, and their values come directly from Quil's state lookup functions.

License

Copyright © 2014 Solita

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.