Interface GeoIdentityTransform

Geo Identity Transform

interface GeoIdentityTransform {
    angle(): number;
    angle(angle): GeoIdentityTransform;
    clipExtent(): [[number, number], [number, number]];
    clipExtent(extent): GeoIdentityTransform;
    fitExtent(extent, object): GeoIdentityTransform;
    fitSize(size, object): GeoIdentityTransform;
    invert(point): [number, number];
    postclip(): ((stream) => GeoStream);
    postclip(postclip): GeoIdentityTransform;
    reflectX(): boolean;
    reflectX(reflect): GeoIdentityTransform;
    reflectY(): boolean;
    reflectY(reflect): GeoIdentityTransform;
    scale(): number;
    scale(scale): GeoIdentityTransform;
    stream(stream): GeoStream;
    translate(): [number, number];
    translate(point): GeoIdentityTransform;
    (point): [number, number];
}

Hierarchy

  • Returns a new array [x, y] (typically in pixels) representing the projected point of the given point. The point must be specified as a two-element array [longitude, latitude] in degrees. May return null if the specified point has no defined projected position, such as when the point is outside the clipping bounds of the projection.

    Parameters

    • point: [number, number]

      A point specified as a two-dimensional array [longitude, latitude] in degrees.

    Returns [number, number]

Methods

  • Returns the projection’s current angle, which defaults to 0°.

    Returns number

  • Sets the projection’s post-projection planar rotation angle to the specified angle in degrees and returns the projection.

    Parameters

    • angle: number

      The new rotation angle of the projection.

    Returns GeoIdentityTransform

  • Returns the current viewport clip extent which defaults to null.

    Returns [[number, number], [number, number]]

  • Sets the projection’s viewport clip extent to the specified bounds in pixels and returns the projection. The extent bounds are specified as an array [[x₀, y₀], [x₁, y₁]], where x₀ is the left-side of the viewport, y₀ is the top, x₁ is the right and y₁ is the bottom. If extent is null, no viewport clipping is performed.

    Parameters

    • extent: [[number, number], [number, number]]

    Returns GeoIdentityTransform

  • Returns a new array [longitude, latitude] in degrees representing the unprojected point of the given projected point. May return null if the specified point has no defined projected position, such as when the point is outside the clipping bounds of the projection.

    Parameters

    • point: [number, number]

      The projected point, specified as a two-element array [x, y] (typically in pixels).

    Returns [number, number]

  • Returns the current cartesian clipping function. Post-clipping occurs on the plane, when a projection is bounded to a certain extent such as a rectangle.

    Returns ((stream) => GeoStream)

      • (stream): GeoStream
      • Returns the current cartesian clipping function. Post-clipping occurs on the plane, when a projection is bounded to a certain extent such as a rectangle.

        Parameters

        Returns GeoStream

  • Sets the projection’s cartesian clipping to the specified function and returns the projection.

    Parameters

    • postclip: ((stream) => GeoStream)

      A cartesian clipping function. Clipping functions are implemented as transformations of a projection stream. Post-clipping operates on planar coordinates, in pixels.

    Returns GeoIdentityTransform

  • Returns true if x-reflection is enabled, which defaults to false.

    Returns boolean

  • Sets whether or not the x-dimension is reflected (negated) in the output.

    Parameters

    • reflect: boolean

      true = reflect x-dimension, false = do not reflect x-dimension.

    Returns GeoIdentityTransform

  • Returns true if y-reflection is enabled, which defaults to false.

    Returns boolean

  • Sets whether or not the y-dimension is reflected (negated) in the output.

    This is especially useful for transforming from standard spatial reference systems, which treat positive y as pointing up, to display coordinate systems such as Canvas and SVG, which treat positive y as pointing down.

    Parameters

    • reflect: boolean

      true = reflect y-dimension, false = do not reflect y-dimension.

    Returns GeoIdentityTransform

  • Returns the current scale factor.

    The scale factor corresponds linearly to the distance between projected points; however, absolute scale factors are not equivalent across projections.

    Returns number

  • Sets the projection’s scale factor to the specified value and returns the projection. The scale factor corresponds linearly to the distance between projected points; however, absolute scale factors are not equivalent across projections.

    Parameters

    • scale: number

      Scale factor to be used for the projection.

    Returns GeoIdentityTransform

  • Returns a projection stream for the specified output stream. Any input geometry is projected before being streamed to the output stream. A typical projection involves several geometry transformations: the input geometry is first converted to radians, rotated on three axes, clipped to the small circle or cut along the antimeridian, and lastly projected to the plane with adaptive resampling, scale and translation.

    Parameters

    Returns GeoStream

  • Returns the current translation offset. The translation offset determines the pixel coordinates of the projection’s center.

    Returns [number, number]

  • Sets the projection’s translation offset to the specified two-element array [tx, ty] and returns the projection. The translation offset determines the pixel coordinates of the projection’s center.

    Parameters

    • point: [number, number]

      A two-element array [tx, ty] specifying the translation offset.

    Returns GeoIdentityTransform