COG API Doodles

COGProtoType.scala

class CogLayerReader {
    def read(...): CogLayer
}

class Layer[K: SpatialComponent, V] {
    def extent: Extent
    def layout: GridBounds
    def get(key: K): V
}

class TileLayer[K: SpatialComponent, V]  extends Layer[K, V] {
    def cellSize: CellSize
}

class CogLayer[K: SpatialComponent, V] extends TileLayer[K, GeoTiff[V]] {
    
}

/*
!!! - DO THIS
Layer has a Layout which is specified by LayoutDefinition.
LayoutDefintions may be related by a scheme, made by LayoutScheme.
...
*/
class CogLayer {
    def tileLayer(cellSize: CellSize): TileLayerRDD[K, V]
    def tileLayer(zoom: Int): TileLayerRDD[K, V]
    def tiffs: RDD[(SpatialKey, GeoTiff[V])]
    def layoutScheme: LayoutScheme // ???
    def zoomLevels: Range[Int]
    // case 1: layoutScheme = ZoomedLayoutScheme => zoomLevel is TMS zoom level
    // case 2: layoutScheme = LocalLayoutScheme => zoomLevel is level of detail relative to base

    //scratch
    def baseLayout: LayoutDefinition
    def layouts: Map[Int, LayoutDefinition]
}

class LayoutScheme {
    def extent: Extent
    def baseLayout: TileLayout
}

object User {
    // !!! Cog segment size is always the same size of tile size in base layer

    val population: TileLayerRDD[SpatialKey] = ???

    val writer: CogLayerWriter = ???
    val cog: CogLayer = CogLayer.fromRDD(population, compression = ???, resampleMethod = ???)
    // problems: 
    // 1. how do we control the size of the COG base tile
    //  "I know the optimum file size for my storage medium" => Pixel Size or Byte Size
    //  -- I don't know how much this will be compressed :(
    //  -- But I know the upper bound based on uncompressed image size
    case class Dimension(width: Int, height: Int)
    // ~= 12, 11, 10, 9, 8
    val cog: CogLayer = CogLayer.fromRDD(
        population, 
        compression = ???, 
        resampleMethod = ???, 
        tilesPerTiff = Dimension(16, 16))
    // ^ this is a partial pyramid in a set of Tiffs

    // Oh! I want to pyramid this all the way to the tippy top!
    if (cog.minZoom > 0) {
        val cogMinusOne: CogLayer = cog.pyramidLayer()
        // we know ...
        // - layout of the top pyramid layer
        // - its "zoom"ish number
        // - I guess we saved resampleMethod, compression, tilesPerTiff
    }

    // 2. how do we control the boundaries of GeoTiff files
    //  "I care deeply about the GeoTiffs because they're my actual output" => Layout
    //  Layout here could conflict with 
    val cog: CogLayer = CogLayer.fromRDD(population, compression = ???, resampleMethod = ???, layout = ???)
    // => cut the population to confirm to layout, delegate to above

    writer.write(LayerId("pop", 12), cog)

    val reader: CogLayerReader = ???

    val cogOut = reader.read(LayerId("pop", 12))
    val population12 = cogOut.tileLayer(12)

    val layer: TileLayerRDD[K, V] = Cog2Pyramid(reader).read(LayerId("pop", 12))
}

object User {
    val population: TileLayerRDD[SpatialKey] = ???
    val writer: CogLayerWriter = ???
    writer.write(LayerId("pop", 12), population)

    val reader: CogLayerReader = ???
    val population12 = reader.read(LayerId("pop", 12))
    val population11 = reader.read(LayerId("pop", 11))
    val population10 = reader.read(LayerId("pop", 10))
    
}