Provider

Overview
API
Example

Provider base class allows you to create simple IOC containers. Ideally your provider should have virtuals methods which return interface types that can be overriding in concrete providers (runtime provider & testing provider). Main goal of this pattern is to decouple dependencies and easy testing.

Implementation#

Simple provider implementation

public class SimpleProvider : Provider<SimpleProvider> {

    public SimpleSettings Settings { get; set; }
    
    public virtual ISimpleComponent CreateComponent() => new SimpleComponent(Settings.Health);

}

Singletons

Can be created by storing the objects in member variables

Initialization#

Providers need to be initialized once before use and this can be done by calling the initialize method.

Provider Initialization

Provider<SimpleProvider>.Initialize(new TestSimpleProvider(), provider => {
    provider.Settings = _settings;
});

Initialize has 2 overloads :-

Initialize(provider, initializer) :-
- provider - it's the concrete instance of your provider, usefull when you are overiding your provider and want to use differnt provider depending upon config
- initializer - it's a callback that is called just after the provider is initialized, you can set singleton member variables here for eager initialization
Initialize(initializer) - same as above just that provider is created according to the generic type, can't use different implementation's of provider in this case

Usage#

Objects can be requested in the following manner.

Provider usage

var component = Provider<TestProvider>.Current.CreateComponent();

Provider pattern used in a voxel engine

Below example shows how a provider is being used in a voxel terrain generation system.#

Voxel Provider

public class VoxelProvider<B> : Provider<VoxelProvider<B>> where B : IBlock {

    public VoxelSettings Settings { get; set; }

    public virtual Chunk<B> CreateChunk(Vector3Int position) => new Chunk<B>(position);

    public virtual ChunkStore<B> ChunkStore(INoiseProfile<B> noiseProfile) => new ChunkStore<B>(noiseProfile, Settings.Chunk);

    public virtual IChunkData<B> ChunkData(B[] blocks) => null;
    
    public virtual INoiseProfile<B> NoiseProfile() => null;

    public virtual ChunkBehaviourPool<B> ChunkPool(Transform transform) => new ChunkBehaviourPool<B>(transform);

    public virtual IMeshBuilder<B> MeshBuilder() => new GreedyMeshBuilder<B>(Settings.Chunk.ChunkSize);
    
    public virtual MeshBuildCoordinator<B> MeshBuildCoordinator(ChunkBehaviourPool<B> chunkBehaviourPool) => new UniTaskMultiThreadedMeshBuildCoordinator<B>(chunkBehaviourPool, Settings.Schedular.BatchSize);

}

This base class is extended by 2 classes :-#

ColoredVoxelProvider - used at runtime for colored voxel terrain generation system
public class ColoredVoxelProvider : VoxelProvider<ColoredBlock> {

public override IMeshBuilder<ColoredBlock> MeshBuilder() => new ColoredGreedyMeshBuilder(Settings.Chunk.ChunkSize);

public override INoiseProfile<ColoredBlock> NoiseProfile() => new ColoredNoiseProfile2D(Settings.NoiseSettings as NoiseSettings2D, Settings.Chunk);

public override IChunkData<ColoredBlock> ChunkData(ColoredBlock[] blocks) {
var data = new ColoredChunkData(blocks, 4, Settings.Chunk.ChunkSize);
data.Compress();

return data;
}

public override MeshBuildCoordinator<ColoredBlock> MeshBuildCoordinator(ChunkBehaviourPool<ColoredBlock> chunkBehaviourPool) => new ColoredMeshBuildCoordinator(chunkBehaviourPool, Settings.Schedular.BatchSize);

}
TestVoxelProvider - used for testing of the voxel terrain generation system
public class TestVoxelProvider : VoxelProvider<TestBlock> {

public override INoiseProfile<TestBlock> NoiseProfile() => new TestNoiseProfile2D(Settings.NoiseSettings as NoiseSettings2D, Settings.Chunk);

}

Finally the provider is initialized in the system.#

protected virtual VoxelProvider<B> Provider() => new VoxelProvider<B>();

private void Awake() {
    VoxelProvider<B>.Initialize(Provider(), provider => {
        provider.Settings = _settings;
    });
}

The Provider() method is overwritten depending upon config and the correct provider is initialized.