Loom Network SDK for Unity

This repo contains the SDK code and a Unity 2017.4 project that provides examples.

The SDK currently supports the following Unity targets:

• Desktop Win/macOS/Linux
• Android
• iOS
• WebGL

Requirements

• Unity 2017.4 or later.
• Build Settings -> Player Settings -> Configuration set as follows:
  • Scripting Runtime Version: Experimental (.NET 4.6 Equivalent)
  • API Compatibility Level: .NET 4.6

Overview

LoomChainClient provides the means to communicate with a Loom DAppChain from a Unity game, while the Contract class provides a more convenient abstraction that streamlines invoking methods on a specific smart contract running on a DAppChain.

If you haven't done so already now would be a good time to read through the Unity SDK Quickstart.

Adding new transaction types

Create a new .proto file in the Assets\Protobuf directory, refer to Google Protocol Buffers for syntax details etc. You'll need to download the protoc compiler to generate C# classes from the .proto files.

The relevant command will look something like this:

protoc \
  -I<install path>/protoc-3.5.1/include \
  -I<project path>/Assets/Protobuf \
  --csharp_out=<project path>/Assets/Protobuf \
  <project path>/Assets/Protobuf/sample.proto

Samples

The sample authSample scene expects a local Loom DAppChain node to be running on localhost, if you decide to change the default host/ports the node runs on you'll need to update the host/ports in authSample.cs to match.

When you run the sample scene you will see three buttons that are hooked up to call the corresponding methods in Assets/authSample.cs, these must be pressed in the correct order:

1. Press the Sign In button to generate a new random identity, once you've signed up/in you should see the text above the button change to Signed in as ....
2. Once the textbox indicates you're signed in you can press the Call SetMsg button to call the SetMsg method in the BluePrint smart contract, this method will store a key/value in the smart contract state. If the method executes without error the textbox should change to Smart contract method finished executing.. You can press the Call SetMsg button again to make another call. Each call to the smart contract actually requires a new transaction to be generated, signed, and then validated by the DAppChain.
3. Press the Call SetMsgEcho button to call the SetMsgEcho method in the BluePrint smart contract, similarly to SetMsg this method will store a key/value in the smart contract, and return the key/value it stored.
4. You can press the Call GetMsg button to send a simple query to the BluePrint contract.

Building the SDK

BuildScripts folder contains scripts for building loom-unity-sdk.unitypackage for Windows and macOS. Scripts use the UNITY_PATH environment variable to determine the Unity executable path, if it is set; alternatively, the path can be passed as an argument. As a fallback, standard Unity installation directory might be used. The package is built to Assets\~NonVersioned\loom-unity-sdk.unitypackage.

Dependencies

Here are some notes on the dependencies used and how to update them.

Chaos.NaCl

Download the latest Chaos.NaCl package from NuGet, open as a ZIP archive, use the lib\net40\Chaos.NaCl.dll assembly.

Google Protocol Buffers

Download the latest Google.Protobuf package from NuGet, open as a ZIP archive, use the lib\net45\Google.Protobuf.dll assembly.

Websocket-Sharp

Clone https://github.com/sta/websocket-sharp, build the Release configuration, the output assembly is bin\Release\websocket-sharp.dll.

Nethereum

Download the latest net461dllsAOT.zip release artifact from https://github.com/Nethereum/Nethereum/releases. Only those assemblies are used by the SDK:

Nethereum.ABI.dll
Nethereum.Contracts.dll
Nethereum.Hex.dll
Nethereum.JsonRpc.Client.dll
Nethereum.Model.dll
Nethereum.RLP.dll
Nethereum.RPC.dll
Nethereum.Util.dll
BouncyCastle.Crypto.dll
Common.Logging.Core.dll
Newtonsoft.Json.dll

Dependecy Namespace Prefixing

The SDK contains quite a bit of dependencies, so there is a high chance that a Unity project will contain another version of a dependency for other purposes. Since Unity doesn't have any dependency management for third-party SDKs yet, all dependencies have Loom. prefix added to their namespaces. To do this, AssemblyNamespaceChanger tool is used. The relevant version is already present n the repo.

1. Acquire/build all dependency assemblies.
2. Copy them into the BuildScripts\PrefixDependencies\Original folder.
3. Run the BuildScripts\PrefixDependencies\prefix-dependencies.cmd script. It will prefix the assemblies and put them into the BuildScripts\PrefixDependencies\Processed folder.
4. Copy the prefixed assemblies from BuildScripts\PrefixDependencies\Processed to UnityProject\Assets\LoomSDK\Plugins.