Bitmap

public Bitmap();

Creates an owned Resource with size (0, 0) and no allocated cells. Call Create/CreateFromImageAlpha before cell operations; Dispose after use.

public Reckfell.Collections.Dictionary Data { get; set; }

Internal Dictionary with size (Vector2I) and data (byte[]) keys. The getter creates a dictionary containing a bit-data snapshot; the setter calls Create(size) then replaces bytes without validating length or padding bits. Use only valid same-runtime representations; malformed contents can make later operations unsafe. Dispose the getter dictionary after use.

public Image ConvertToImage();

Creates a separate same-sized L8 Image without mipmaps. true becomes white, false black; both have opaque alpha. Updates no previously created Image and creates no GPU texture. Requires an allocated mask; Dispose the owned result.

public void Create(Vector2I size);

Replaces dimensions and clears every bit, including existing contents at the same size. Both dimensions must be positive and their product at most Int32.MaxValue. Does not emit Changed.

public void CreateFromImageAlpha(Image image, float threshold = 0.1f);

Replaces the mask with image-sized data. Converts an Image copy to LA8; a bit is true only for alpha/255 > threshold. Leaves the source unchanged; RGB brightness has no effect. Requires a nonempty Image with supported format conversion.

public bool GetBit(int x, int y);

Reads one bit at x/y. Coordinates must lie inside the mask; out-of-range access is diagnosed and returns false, so false alone does not establish valid coordinates.

public bool GetBitv(Vector2I position);

Same read as GetBit with Vector2I coordinates. Neither clamps nor wraps coordinates.

public Vector2I GetSize();

Returns width and height in cells. A new resource before Create has size (0, 0).

public int GetTrueBitCount();

Counts set bits. For a valid representation this equals the occupied-cell count. The implementation counts every storage byte including final-byte padding; arbitrary Data can break that interpretation.

public void GrowMask(int pixels, Rect2I rect);

Positive pixels dilates true regions, negative erodes them, and 0 is a no-op. Reads a circular neighborhood from a snapshot, without cascading growth within one call. Erosion treats space outside rect as false; cells outside rect remain unchanged. Supply rect inside mask bounds and a reasonable radius: large radii are expensive and extreme int values were not accepted by this review.

public Reckfell.Collections.Array<Vector2[]> OpaqueToPolygons(Rect2I rect, float epsilon = 2f);

Extracts true-cell contours in rect intersected with the mask using marching squares, then simplifies with RDP. Vertices are relative to the intersection position rather than the full mask. Empty regions yield an empty array; contours with fewer than three vertices are skipped. For contours of at least 9 vertices, epsilon is clamped to 0…half the smaller region dimension; smaller contours bypass RDP. Creates no collision object automatically.

public void Resize(Vector2I newSize);

Scales the mask with nearest-neighbor sampling: source coordinates truncate xoldWidth/newWidth and yoldHeight/newHeight. Does not append empty rows/columns. Same dimensions are a no-op; use positive dimensions. Zero dimensions are not a safe clearing operation.

public void SetBit(int x, int y, bool bit);

Sets or clears a cell. Coordinates must lie inside the mask; invalid ones are diagnosed without writing. Does not automatically emit Resource.Changed.

public void SetBitRect(Rect2I rect, bool bit);

Fills the intersection of rect and mask bounds with bit. Right/bottom bounds are exclusive; a disjoint rectangle changes nothing. Assigns values rather than toggling bits.

public void SetBitv(Vector2I position, bool bit);

Same mutation as SetBit using Vector2I coordinates. Does not resize the mask.