Class ScyllaTriGrid<TCell>.SynchronizedScyllaTriGrid

Thread-safe wrapper around ScyllaTriGrid<TCell> that serialises all read and write operations using a lock.

Inheritance
object
ScyllaTriGrid<TCell>.SynchronizedScyllaTriGrid
Implements
Inherited Members
Namespace: Scylla.Core.Structures
Assembly: ScyllaCore.dll
Syntax
public sealed class ScyllaTriGrid<TCell>.SynchronizedScyllaTriGrid : IScyllaGrid<TriCoord, TCell>, IScyllaCollection
Remarks

Obtain an instance via AsSynchronized(object) or the builder's Synchronized() option. Width, Height, and Capabilities are cached at construction and read without acquiring the lock.

Individual property reads each acquire their own lock; compound check-then-act sequences are still subject to TOCTOU races and must be externally synchronized using the shared SyncRoot.

Constructors

SynchronizedScyllaTriGrid(ScyllaTriGrid<TCell>, object)

Initializes a new synchronized wrapper around the specified grid.

Declaration
public SynchronizedScyllaTriGrid(ScyllaTriGrid<TCell> inner, object syncRoot)
Parameters
Type Name Description
ScyllaTriGrid<TCell> inner

The grid to wrap. Must not be null.
object syncRoot

The lock object to use. If null, a new private lock is created.

Properties

Capabilities

Gets the feature and capability flags supported by this collection instance.

Declaration
public ScyllaCollectionCapabilities Capabilities { get; }
Property Value
Type Description
ScyllaCollectionCapabilities

A bitfield of ScyllaCollectionCapabilities flags describing which optional operations the concrete instance supports. The value None indicates that only the base contract (Count, IsEmpty, Clear()) is available.
Remarks

Use Capabilities for feature detection in place of type-casting. For example: 

if ((collection.Capabilities & ScyllaCollectionCapabilities.SupportsPeek) != 0)
{
    // safe to call TryPeek through IScyllaCollection<T>
}

Synchronized wrappers cache the capability flags of their inner collection at construction time, so the value returned is stable and does not require synchronization.

See Also

CellCount

Gets the number of populated (logically active) cells in the grid.

Declaration
public int CellCount { get; }
Property Value
Type Description
int

For dense grids, this always equals Count - every cell slot is pre-allocated and considered populated regardless of its stored value. The value is fixed at construction and never changes.

For sparse grids, this equals the number of cells that have been explicitly written via TrySet(TCoord, TCell) and not yet removed. The value may be zero on a freshly created or cleared sparse grid.

See Also
TrySet(TCoord, TCell)

Count

Gets the number of items currently contained in the collection.

Declaration
public int Count { get; }
Property Value
Type Description
int

A non-negative integer representing the current element count. Returns 0 when the collection is empty.
Remarks

On unsynchronized collections, Count is not thread-safe and may return a stale value when accessed concurrently. On synchronized wrappers, reading Count is protected by the internal lock.

Height

Gets the grid height.

Declaration
public int Height { get; }
Property Value
Type Description
int

IsEmpty

Always returns false. A dense grid pre-allocates all cells at construction time and is never logically empty.

Declaration
public bool IsEmpty { get; }
Property Value
Type Description
bool

this[TriCoord]

Gets or sets the cell value at the specified coordinate.

Declaration
public TCell this[TriCoord coord] { get; set; }
Parameters
Type Name Description
TriCoord coord

The triangle coordinate.
Property Value
Type Description
TCell
Exceptions
Type Condition
IndexOutOfRangeException

Thrown when the coordinate is out of bounds.

SyncRoot

Gets the synchronization root object used to externally coordinate multi-step operations with this collection.

Declaration
public object SyncRoot { get; }
Property Value
Type Description
object

A non-null object suitable for use with lock when ThreadSafety is Synchronized. Returns null for unsynchronized collections, which do not own a lock.
Remarks

When this collection is a synchronized wrapper, SyncRoot must be non-null and stable for the entire lifetime of the wrapper. All internal operations on the wrapper must lock on this same object. This allows callers to perform atomic multi-step sequences: 

lock (collection.SyncRoot)
{
    if (!collection.IsEmpty)
        typedCollection.TryRemove(out var item);
}

For unsynchronized collections (SyncRoot == null), callers are responsible for supplying and consistently applying their own external synchronization mechanism. A null SyncRoot does not mean the collection is thread-safe; consult ThreadSafety for the authoritative guarantee.

See Also

ThreadSafety

Gets the thread-safety guarantees provided by this collection instance.

Declaration
public ScyllaCollectionThreadSafety ThreadSafety { get; }
Property Value
Type Description
ScyllaCollectionThreadSafety

A ScyllaCollectionThreadSafety value indicating whether the collection is unsynchronized, synchronized via a lock, or safe for lock-free concurrent access. Most core implementations return Unsynchronized. Synchronized wrappers return Synchronized.
Remarks

Always check this property (or SyncRoot) before assuming a collection is safe for concurrent use. Do not rely solely on the absence of a non-null SyncRoot to infer thread safety; use this property as the authoritative source.

See Also

Width

Gets the grid width.

Declaration
public int Width { get; }
Property Value
Type Description
int

Methods

Clear()

Removes all items from the collection and resets it to an empty state.

Declaration
public void Clear()
Remarks

Implementations that store reference-type elements should null out internal slots after clearing to avoid retaining object references and preventing garbage collection. After Clear returns, Count must be 0 and IsEmpty must be true.

On synchronized wrappers this operation is protected by the collection's internal lock. On unsynchronized collections, callers are responsible for external coordination.

Contains(TriCoord)

Determines whether the specified coordinate is addressable and populated in this grid.

Declaration
public bool Contains(TriCoord coord)
Parameters
Type Name Description
TriCoord coord

The coordinate to test.
Returns
Type Description
bool

For dense grids, returns true when coord maps to a valid index within the grid's pre-allocated array - that is, when the coordinate is geometrically within the grid's dimensions, regardless of the stored value.

For sparse grids, returns true only when coord has been explicitly written via TrySet(TCoord, TCell) and not since removed. An in-bounds coordinate that has never been written returns false.

Remarks

This method is equivalent to checking whether TryGet(TCoord, out TCell) would return true for the same coordinate. Use it when you only need the existence check and do not need the value.

See Also
TryGet(TCoord, out TCell)
TrySet(TCoord, TCell)

Fill(TCell)

Fills all cells with the specified value.

Declaration
public void Fill(TCell value)
Parameters
Type Name Description
TCell value

The value to fill with.

GetNeighborsNonAlloc(TriCoord, Span<TriCoord>)

Writes the in-bounds edge-sharing neighbors of the specified coordinate into the buffer.

Declaration
public int GetNeighborsNonAlloc(TriCoord coord, Span<TriCoord> buffer)
Parameters
Type Name Description
TriCoord coord

The triangle coordinate to find neighbors for.
Span<TriCoord> buffer

A span of at least 3 elements to receive neighbor coordinates.
Returns
Type Description
int

The number of in-bounds neighbors written (up to 3).

GridToWorld(TriCoord)

Converts a triangle coordinate to world-space position using the grid's layout.

Declaration
public Vector2 GridToWorld(TriCoord coord)
Parameters
Type Name Description
TriCoord coord

The triangle coordinate.
Returns
Type Description
Vector2

The world-space center of the triangle.

IsInBounds(TriCoord)

Determines whether the specified coordinate is within the grid bounds and has a valid triangle sum.

Declaration
public bool IsInBounds(TriCoord coord)
Parameters
Type Name Description
TriCoord coord

The triangle coordinate.
Returns
Type Description
bool

True if the coordinate is valid and within bounds.

TryGet(TriCoord, out TCell)

Attempts to retrieve the value stored at the specified coordinate without throwing on failure.

Declaration
public bool TryGet(TriCoord coord, out TCell value)
Parameters
Type Name Description
TriCoord coord

The grid coordinate to look up.
TCell value

When this method returns true, contains the cell value at coord. When this method returns false, contains default(TCell). This parameter is passed uninitialized and is always written before this method returns.
Returns
Type Description
bool

true if coord is within the grid's valid range and a value was successfully read; false if the coordinate is out of bounds (dense grids) or has not been explicitly written (sparse grids).
Remarks

Prefer this method over direct indexer access when the coordinate's validity is not guaranteed, as it avoids the cost of exception handling on out-of-bounds access. For dense grids, "within bounds" means the coordinate maps to a valid flat-array index. For sparse grids, "within bounds" additionally requires that the cell has been set.

See Also
TrySet(TCoord, TCell)
Contains(TCoord)

TrySet(TriCoord, TCell)

Attempts to store a value at the specified coordinate without throwing on failure.

Declaration
public bool TrySet(TriCoord coord, TCell value)
Parameters
Type Name Description
TriCoord coord

The grid coordinate to write to.
TCell value

The value to store at coord.
Returns
Type Description
bool

true if the coordinate is valid and the value was successfully stored; false if the coordinate is out of bounds and no change was made.
Remarks

For dense grids, this writes to the pre-allocated cell at coord and returns false if the coordinate falls outside the grid's dimensions.

For sparse grids, this inserts or updates the entry at coord and returns false only when the grid is bounded and coord falls outside the defined bounds. On unbounded sparse grids this method always returns true.

A successful call increments CellCount on sparse grids when coord is newly written for the first time.

See Also
TryGet(TCoord, out TCell)
Contains(TCoord)

WorldToGrid(Vector2)

Converts a world-space position to a triangle coordinate using the grid's layout.

Declaration
public TriCoord WorldToGrid(Vector2 worldPos)
Parameters
Type Name Description
Vector2 worldPos

The world-space position.
Returns
Type Description
TriCoord

The nearest triangle coordinate.

Implements

Extension Methods