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@ue-too/board / RotateByHandlerFunction

Type Alias: RotateByHandlerFunction() ​

RotateByHandlerFunction = (delta, camera, config) => number

Defined in: packages/board/src/camera/camera-rig/rotation-handler.ts:137

Handler function type for relative "rotate by" camera operations.

Parameters ​

delta ​

number

Rotation angle change in radians (positive = counter-clockwise)

camera ​

BoardCamera

Current camera instance

config ​

RotationHandlerConfig

Rotation behavior configuration

Returns ​

number

Transformed rotation delta (after applying restrictions and clamping)

Remarks ​

Rotate-by handlers process relative rotation change requests. They form a pipeline that can apply restrictions, clamping, and other transformations to the delta.

Handler pipeline pattern:

  • Each handler receives the rotation delta, camera state, and config
  • Returns a potentially modified delta
  • Handlers can be chained using createHandlerChain

Common transformations:

  • Angular boundary clamping (prevent exceeding min/max angles)
  • Rotation locking (return zero delta)
  • Delta dampening or snapping

Rotation angles are in radians where:

  • 0 = North (no rotation)
  • Positive values = Counter-clockwise rotation
  • Negative values = Clockwise rotation

Example ​

typescript
const myRotateByHandler: RotateByHandlerFunction = (delta, camera, config) => {
  // Custom logic: snap to 45-degree increments
  const totalRotation = camera.rotation + delta;
  const snapped = Math.round(totalRotation / (Math.PI / 4)) * (Math.PI / 4);
  return snapped - camera.rotation;
};

See ​