RasterTile.h

#pragma once
 
#include "../Extent.h"
 
#include <atomic>
 
namespace Cogs
{
  struct TileFlags
  {
    enum ETileFlags : uint32_t
    {
      None = 0,
      Requested = 1,
      OutOfBounds = 1 << 1,
      Invalidated = 1 << 2,
    };
  };
 
  struct RasterTileIdentifier
  {
    RasterTileIdentifier getSouthwestChild() const { return { level + 1, x * 2, y * 2 }; }
    RasterTileIdentifier getSoutheastChild() const { return { level + 1, x * 2 + 1, y * 2 }; }
    RasterTileIdentifier getNorthwestChild() const { return { level + 1, x * 2, y * 2 + 1 }; }
    RasterTileIdentifier getNortheastChild() const { return { level + 1, x * 2 + 1, y * 2 + 1 }; }
 
    size_t getHashCode() const
    {
      size_t result = level;
      result = result * 16777619 + x;
      result = result * 16777619 + y;
      return result;
    }
 
    int level;
    int x;
    int y;
  };
 
  struct RasterTile
  {
    int getWidth() const { return extent.getWidth(); }
    int getHeight() const { return extent.getHeight(); }
 
    bool isSet(TileFlags::ETileFlags flag) const { return (flags & flag) == flag; }
 
    bool isOOB() const { return isSet(TileFlags::OutOfBounds); }
    bool isRequested() const { return isSet(TileFlags::Requested); }
    bool isInvalidated() const { return isSet(TileFlags::Invalidated); }
    bool isResident() const { return data && !isInvalidated(); }
 
    void invalidate() { generation++; flags |= TileFlags::Invalidated; }
    void setValid() { flags &= ~TileFlags::Invalidated; unsetRequested(); }
 
    void setRequested() { flags |= TileFlags::Requested; }
    void unsetRequested() { flags &= ~TileFlags::Requested; }
 
    RasterTileIdentifier identifier;
    Extent extent;
 
    struct RasterTileData * data = nullptr;
    
    std::atomic<size_t> generation = 1;
    std::atomic<uint32_t> usage = 0;
    std::atomic<uint32_t> flags = TileFlags::None;
  };
 
  struct TileLoadRequest
  {
    RasterTile * tile;
  };
 
  struct TileLoadResponse
  {
    RasterTile * tile;
    int rasterLevel;
  };
 
  struct RasterTileRegion
  {
    RasterTile * tile;
    Extent extent;
  };
}