README.md

MinGvrApp

This is a minimal Clojure + Android + GVR application. It uses the official Google VR SDK at https://github.com/googlevr/gvr-android-sdk but Clojure is an unofficial and unsupported platform.

Background

• Clojure is a Lisp that targets the JVM: http://clojure.org/
  • Brave Clojure has a good crash course: http://www.braveclojure.com/do-things/
  • http://clojure.org/api/cheatsheet is a good reference for syntax.
• Lein-droid is a build system for creating Android apps in Clojure: https://github.com/clojure-android/lein-droid/
• GVR is the Cardboard & Daydream framework: https://developers.google.com/vr/android/get-started

Steps to write a minimal Cardboard app in Clojure

1. Make sure you can create a new lein-droid project using the steps at https://github.com/clojure-android/lein-droid/wiki/Tutorial
2. Run lein new droid mingvrapp my.company.app :activity MinGvrActivity :target-sdk 25 :app-name MinGvrApp to create the new GVR project using a standard template. Running lein droid doall at this point will just install and run that template.
3. Add GVR to the dependencies by editing project.clj and modifying the :dependencies lines to:

:repositories [["googlevr" {:url "http://google.bintray.com/googlevr/"}]]
:dependencies [[org.clojure-android/clojure "1.7.0-r4"]
               [neko/neko "4.0.0-alpha5"]
               [com.google.vr/sdk-base "1.0.3" :extension "aar"]]

This will add the google.bintray.com/googlevr repo and download the sdk-base library from it.

1. Edit your src/clojure/my/company/app/main.clj as desired. src/clojure/me/sxp/gvrclojure/main.clj in this repo shows a basic example that renders a different color for each eye in a Cardboard app. Using the Cardboard Trigger input will toggle monoscopic rendering mode.
2. Run lein droid doall as usual to build, install, and run this new app.
3. Use a REPL to change the app while it's running. Run lein droid repl to launch a Clojure REPL and connect to the app via ADB. Then type the following commands into the prompt and note how the left eye's color changes. Make sure to use the right namespace for the in-ns command below. It should match your main.clj namespace.

REPL-y 0.3.7, nREPL 0.2.10
Clojure 1.7.0
Dalvik 0.9
        Exit: Control+D or (exit) or (quit)
    Commands: (user/help)
        Docs: (doc function-name-here)
              (find-doc "part-of-name-here")
      Source: (source function-name-here)

user=> (in-ns 'my.company.app.main)
#object[clojure.lang.Namespace 0x2f87340 "my.company.app.main"]

my.company.app.main=> (def leftColor [1 1 1 1])
#'my.company.app.main/leftColor