update readme (#442)

* update readme

* update with comments

* tiny update

Co-authored-by: Cynthia Jiang <[email protected]>

Author: cynthiajoan

README.md

@@ -1,101 +1,142 @@
-
-# Firebase Unity #
-
----
-
+# Firebase Unity Open Source Development
+
+The repository contains the Firebase Unity SDK source, with support for Android,
+iOS, and desktop platforms. It includes the following Firebase libraries:
+
+- [Google Analytics for Firebase](https://firebase.google.com/docs/analytics/)
+- [Firebase Authentication](https://firebase.google.com/docs/auth/)
+- [Firebase Crashlytics](https://firebase.google.com/docs/crashlytics)
+- [Firebase Realtime Database](https://firebase.google.com/docs/database/)
+- [Firebase Dynamic Links](https://firebase.google.com/docs/dynamic-links/)
+- [Cloud Firestore](https://firebase.google.com/docs/firestore/)
+- [Cloud Functions for Firebase](https://firebase.google.com/docs/functions/)
+- [Firebase Invites](https://firebase.google.com/docs/invites/)
+- [Firebase Cloud Messaging](https://firebase.google.com/docs/cloud-messaging/)
+- [Firebase Remote Config](https://firebase.google.com/docs/remote-config/)
+- [Cloud Storage for Firebase](https://firebase.google.com/docs/storage/)
+
+Firebase is an app development platform with tools to help you build, grow and
+monetize your app. More information about Firebase can be found at
+<https://firebase.google.com>.
+
+More information about the Firebase Unity SDK can be found at <https://firebase.google.com/docs/unity/setup>.  Samples on how to use the
+Firebase Unity SDK can be found at <https://github.com/firebase/quickstart-unity>.
+
+## Table of Contents
+
+- [Firebase Unity Open Source Development](#firebase-unity-open-source-development)
+  - [Table of Contents](#table-of-contents)
+  - [Getting Started](#getting-started)
+  - [Prerequisites](#prerequisites)
+    - [Install Unity](#install-unity)
+  - [Building](#building)
+    - [Building for certain library](#building-for-certain-library)
+  - [Packaging](#packaging)
+    - [Packaging unitypackage](#packaging-unitypackage)
+    - [Packaging tgz](#packaging-tgz)
+    - [Packing for certain library](#packing-for-certain-library)
+  - [Including in Project](#including-in-project)
+  - [Contributing](#contributing)
+  - [License](#license)
 
 ## Getting Started
+
 You can clone the repo with the following command:
 
 ``` bash
 git clone https://github.com/firebase/firebase-unity-sdk.git
 ```
 
 ## Prerequisites
-The prerequisites for firebase cpp are required. Please install the following
-packages outlined in [README.md for firebase cpp](https://github.com/firebase/firebase-cpp-sdk/blob/master/README.md#prerequisites).
-
-The following prerequisites are required for all platforms.  Be sure to add any
-directories to your PATH as needed.
 
-- [CMake](https://cmake.org/) version 3.13.3, or newer.
-- [Mono](https://www.mono-project.com/) version 5 or newer.
-- [Unity](https://unity.com/) version 2019 or newer.
-- [Swig](http://www.swig.org/) version 4 or newer.
+Please follow [Firebase C++ SDK Prerequisites](https://github.com/firebase/firebase-cpp-sdk/blob/main/README.md#prerequisites) first.
 
-### Prerequisites for Windows
-On windows, to work around path length issues with google unity resolver enable
-long path support in git:
+- [Swig](https://www.swig.org/), version 4 or newer
 
-> **git config --system core.longpaths true**
+### Install Unity
 
-### Prerequisites for Mac
-Home brew can be used to install required dependencies:
+- [Unity](https://unity.com/download), version 2019 or newer
 
-```bash
-# https://github.com/protocolbuffers/protobuf/blob/master/kokoro/macos/prepare_build_macos_rc#L20
-ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
-source $HOME/.rvm/scripts/rvm
-brew install cmake protobuf python mono swig
-sudo chown -R $(whoami) /usr/local
-```
+While installing through UnityHub, when you decide which version to install, it will pop up a dialog to select necessary support modules. Please check the boxes based on your dev machine OS and dev platform. For most common case while dev on macOS, we should select Android + Android SDK & NDK Tool, iOS Build Support and Mac Build Support (IL2CPP)
 
 ## Building
-The build uses CMake to generate the necessary build files, and supports out of
-source builds.
 
-The following CMake options are avaliable:
+Under the repo root folder, call
 
-* **FIREBASE_INCLUDE_UNITY**: Build for unity only (no mono support)
-* **FIREBASE_INCLUDE_MONO**: Build for mono only (no unity support)
-* **FIREBASE_UNI_LIBRARY**: Build all native modules as one dynamic lib
-* **FIREBASE_CPP_SDK_DIR**: Local path to firebase cpp
-* **FIREBASE_UNITY_SDK_VERSION**: Set version string of firebase unity package
-* **UNITY_ROOT_DIR**: Local path to Unity's installation directory
-  (path should end with version number)
-* **MONO_DIR**: Local path to mono's xbuild executable directory
-* **OPENSSL_ROOT_DIR**: Open ssl root directory
-* **PROTOBUF_SRC_ROOT_FOLDER**: Protobuf root directory
+``` bash
+python scripts/build_scripts/build_zips.py –platform=<target platform>
+```
+
+> **Note:** Supported target platform names: linux,macos,windows,ios,android
 
-> Note:<br/>
-> &nbsp;&nbsp;&nbsp;**UNITY_ROOT_DIR** is a recommended setting for building
-> unity, else CMake will make an effort to auto find unity.
+Expected output artifact is
+[Repo Root]/<*platform_unity, eg macos_unity*>/firebase_unity-< *version* >-< *platform* >.zip
 
-> Note:<br/>
-> &nbsp;&nbsp;&nbsp;On windows, **MONO_DIR** is a required setting.
+> **Note:**
+>
+> - Linux zip requires linux machine to build.
+> - Windows zip requires windows machine to build
+> - macOS, iOS and android zips can be built by mac.(Although android zip could be built on both linux and windows machine as well, but we recommend to run it with mac, to get align with our CI)
 
-Example build command for linux:
+### Building for certain library
 
 ``` bash
-mkdir build && cd build
-cmake .. -DFIREBASE_INCLUDE_MONO=ON -DFIREBASE_CPP_SDK_DIR=../../firebase-cpp-sdk
-make -j 8
+python scripts/build_scripts/build_zips.py —-platform=<target platform> --targets=<lib1> -–targets=<lib2>
 ```
 
-> Note:<br/>
-> &nbsp;&nbsp;&nbsp;There are build helper scripts in the root folder that will
-> build the most common variants and can be used as examples on how to build
-> firebase unity.
+> **Note:** Supported library names: analytics, auth, crashlytics, database, dynamic_links, firestore, functions, installations, messaging, remote_config, storage
 
-### Building for iOS
-CMake needs an extra argument specifing the tool chain to use:
+## Packaging
 
-> -DCMAKE_TOOLCHAIN_FILE=../cmake/unity_ios.cmake -G Xcode
+We can package the built artifacts to better imported by Unity Editor.
 
-### Building for Android
-Run script ./build_android.sh on linux machine.
+### Packaging unitypackage
 
+Copy the zip file for each platforms to one folder, referred to as assets_zip_dir below, for example usually looks like this
+
+- firebase_unity-< *version* >-Android.zip
+- firebase_unity-< *version* >-Darwin.zip
+- firebase_unity-< *version* >-Linux.zip
+- firebase_unity-< *version* >-iOS.zip
+- firebase_unity-< *version* >-win64.zip
+  
+And then run:
+
+``` bash
+python scripts/build_scripts/build_package.py --zip_dir=<assets_zip_dir> –output=<output dir>
+```
 
-## Unity Package Command ##
+### Packaging tgz
 
-CPack is used to generate platform zip files with the same folder structure of
-the Unity plugin. Once each platform zip file is built, run
-*unity packaging tool* to generate a `.unitypackage` file.
+With the same assets_zip_dir, we can run:
 
+``` bash
+python scripts/build_scripts/build_package.py --zip_dir=<assets_zip_dir> –output=<output dir> --output_upm=True
 ```
-cd build
-cpack .
-cd ../unity_packer
-python export_unity_package.py --config_file=exports.json --guids_file=guids.json --assets_dir=.. --assets_zip=../build/*.zip --output_dir=../build/
+
+### Packing for certain library
+
+If we build only certain subset of the libraries like in [Building for certain library](#building-for-certain-library), we can copy the built artifacts into assets_zip_dir, and then run:
+
+``` bash
+python scripts/build_scripts/build_package.py --zip_dir=<assets_zip_dir> -–output=<output dir> --apis=<lib1,lib2>
 ```
 
+## Including in Project
+
+We can refer to [Firebase Unity Installation Options](https://firebase.google.com/docs/unity/setup-alternative) to learn how to import the unitypacakge or tgz files that packaged.
+
+## Contributing
+
+We love contributions, but note that we are still working on setting up our
+test infrastructure, so we may choose not to accept pull requests until we have
+a way to validate those changes on GitHub. Please read our
+[contribution guidelines](/CONTRIBUTING.md) to get started.
+
+## License
+
+The contents of this repository is licensed under the
+[Apache License, version 2.0](http://www.apache.org/licenses/LICENSE-2.0).
+
+Your use of Firebase is governed by the
+[Terms of Service for Firebase Services](https://firebase.google.com/terms/).