Layers and Chunks

You implement pairs of layers and chunks, e.g. ExampleLayer and ExampleChunk. A layer contains chunks of the corresponding type.

Layer and chunk classes

A layer class must inherit from ChunkBasedDataLayer and a chunk class must inherit from LayerChunk. Both of those base classes must be used with generic type parameters of the layer and chunk themselves, e.g. <ExampleLayer, ExampleChunk>.

Here is a simplified example. See the Script Templates page for more complete templates or the Getting Started page for a simple working example.

public class ExampleChunk : LayerChunk<ExampleLayer, ExampleChunk> {
    // Data for this chunk goes here.
 
    public override void Create(int level, bool destroy) {
        // Generate or destroy data here.
    }
}
 
public class ExampleLayer : ChunkBasedDataLayer<ExampleLayer, ExampleChunk> {
    // Specify the world space dimensions of the chunks.
    public override int chunkW { get { return 256; } }
    public override int chunkH { get { return 256; } }
 
    public ExampleLayer() {
        // Dependencies on other layers are set up here.
    }
 
    // APIs for requesting data from this layer go here.
}

Each layer stores a RollingGrid of corresponding chunks. This is automatically handled by the layer base class, though you can optionally specify the size of the grid in the base class constructor.

Chunk size

Chunks are always rectangular and all chunks in a given layer have the same world space size. This size is specified in the layer by overriding the two properties chunkW and chunkH.

The size is specified in integers, meaning the smallest possible size is one unit, but apart from that, chunks can have any size.

// Specify the world space dimensions of the chunks.
public override int chunkW { get { return 256; } }
public override int chunkH { get { return 256; } }

There is also a convenience property chunkSize of type Point which combines the width and height.

Chunk lifetime

A chunk is generated (invoking its generation code) when it’s depended on, and it's destroyed (recycled) when it’s no longer depended on.

// Chunk Create method where the generation happens.
public override void Create(int level, bool destroy) {
    if (destroy) {
        // Destroy data for this chunk here.
    }
    else {
        // Create data for this chunk here.
    }
}

The following pages will cover how to setup layer dependencies that allow chunks to request data from other layers, as well as the concept of internal layer levels, which is a special and optional concept where a single class can implement multiple layers at once.