TLCommentAnchor

Where a comment thread is anchored on the canvas. Modeled as a discriminated union so new anchor kinds can be added without breaking existing threads:

• shape — pinned to a shape. x/y are normalized (0–1) within the shape's bounds, so the pin keeps its spot as the shape moves, resizes, and rotates. isPrecise mirrors arrow bindings: when false (the default) the pin sits at a consumer-defined spot instead, top-right out of the box, and x/y are the remembered precise position - point — pinned to a fixed point on the page, in page coordinates - region — pinned to a rectangular area of the page, in page coordinates - page — a page-level thread with no spatial anchor

type TLCommentAnchor =
  | {
      pinX?: number;
      h: number;
      pinY?: number;
      type: "region";
      w: number;
      x: number;
      y: number;
    }
  | {
      isPrecise: boolean;
      shapeId: TLShapeId;
      type: "shape";
      x: number;
      y: number;
    }
  | {
      type: "page";
    }
  | {
      type: "point";
      x: number;
      y: number;
    };