Compositional vector graphics in Scala / Scala.JS
Scala Other
Latest commit 76f1e6b Feb 21, 2017 @noelwelsh noelwelsh Speed and memory usage optimisations
Closes #41

Church-encode Renderable. Instead of representing renderable as another
intermediate form, incrementally render using a `Canvas`. This avoids allocation
of another intermediate representation. Convert the Java2D and SVG backends over
to this new representation.

Make calculation of bounding boxes stack safe, by shifting construction into
`Finalised` and memoizing each step.

Low-level optimisation of calculation of bounding boxes, to avoid allocation.

Add SandSpline example, which is a good testbed for optimisations. After
optimisation I am able to render SandSplines that are ~100% larger than before,
but still exhaust memory when `ofSize` is > ~2000. Further refactoring is needed
to avoid all intermediate structures, which should push down memory consumption
to an acceptable level.

Add some more tests.

Doodle: Compositional Graphics

Copyright 2015 Underscore.

A Scala library for compositional vector graphics, with a native back-end via Swing and Java2D, and an HTML SVG backend via Scala.js.

Distributed under the Apache 2.0 license.

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Using Doodle

You can use Doodle in your own project by importing the JARs published to our Bintray repository. The current release is 0.7.0. To use it add the following to your build.sbt:

scalaVersion := "2.11.8" // Doodle is compatible with Scala 2.11 only

resolvers += Resolver.bintrayRepo("underscoreio", "training")

libraryDependencies += "underscoreio" %% "doodle" % "0.7.0"

Alternatively you can git clone or download Doodle and use it directly from the SBT console. See the instructions below.


Creative Scala is currently the main documentation for Doodle. Creative Scala is a free introductory Scala ebook. Follow the link to download your copy from our web site.

Below we have a few tips to get you started.

Getting Started from SBT

  1. Start SBT:

    bash$ sbt
    > # This is the SBT prompt. Press Ctrl+D to quit to the OS.
  2. Start the console:

    > console
    scala> # This is the Scala prompt. Press Ctrl+D to quit to SBT.
  3. Use Scala commands to draw a shape in a native window:

    scala> (circle(10) fillColor

    A window should appear containing a red circle.

  4. You can also save your masterpieces to a file.

    scala> (circle(10) fillColor[Png]("masterpiece.png")

    Doodle currently supports saving to PNG and PDF formats. Just alter the type parameter of save accordingly.

Drawing in the Browser

You can also draw Doodle pictures in the browser. The process is slightly different.

  1. Write your code in js/src/main/scala/Main.scala

  2. Start SBT:

    bash$ sbt
    > # This is the SBT prompt. Press Ctrl+D to quit to the OS.
  3. Compile the JS version:

    > fastOptJS
  4. Open your browser and point to http://localhost:12345/index.html to see an SVG version of the code.

Viewing the Examples

Doodle ships with a set of examples for each of the exercises in Creative Scala. See the shared/src/main/scala/doodle/examples directory for a complete list.

To view an example, simply run the sbt console, and draw the examples from there. For example:

bash$ sbt console

When the console is running, type

scala> Sierpinski.image.draw

Directory Structure

Source code is in the following directories:

 - shared / src / {main,test} / scala
 - jvm    / src / {main,test} / scala
 - js     / src / {main,test} / scala

SBT Commands

We provide three quick aliases for common commands:

> console   runs the console using the JVM codebase
> fastOptJS compiles the JS codebase
> test      runs the unit tests for both codebases


Doodle was written by Noel Welsh and Dave Gurnell with contributions from the contributors listed by Github.