# coyote: CGKML_GROUNDOVERLAY__DEFINE

- coyote/Graphics
- coyote/FileIO
- [Source code]

Description

      This program implements the KML GroundOverlay element. For
      reference, see  the `Google KML Reference Documentation <https://developers.google.com/kml/documentation/kmlreference#groundoverlay>`.
      A GroundOverlay element draws an image overlay draped onto the terrain
      of a Google Earth display.

Categories

      Graphics, FileIO

Examples

      See the `cgKML_File` object for examples of how to create a KML file.

Author

      FANNING SOFTWARE CONSULTING::
         David W. Fanning
         1645 Sheely Drive
         Fort Collins, CO 80526 USA
         Phone: 970-221-0438
         E-mail: david@idlcoyote.com
         Coyote's Guide to IDL Programming: http://www.idlcoyote.com

History

      Change History::
         Written, 28 October 2012 by David W. Fanning.

Copyright

      Copyright (c) 2012, Fanning Software Consulting, Inc.
      e purpose of this method is to establish an abstract KML GroundOverlay class. For reference, see
      tps://developers.google.com/kml/documentation/kmlreference?hl=fr#groundoverlay.

Keywords

      altitude: in, optional, type=double
          Specifies the distance above the earth's surface, in meters, and is interpreted
          according to the altitude mode
      altmode: in, optional, type=string, default='clampToGround'
          The altitude mode. Possible values are "clampToGround", which ignores the `Altitude`
          value and drapes the overlay over the terrain. The other possible mode is "absolute",
          which sets the altitude of the overlay relative to sea level, regardless of the
          actual elevation of the terrain beneath the element. For example, if you set the
          altitude of an overlay to 10 meters with an absolute altitude mode, the overlay will
          appear to be at ground level if the terrain beneath is also 10 meters above sea level.
          If the terrain is 3 meters above sea level, the overlay will appear elevated above the
          terrain by 7 meters.
      latlonbox: in, optional, type=fltarr
          A four-element float array that specifies the top, bottom, right, and left sides
          of a bounding box that the ground overlay is aligned to. The elements of the array
          also correspond to [north, south, east, west] coordinates, which should be specified
          in decimal degrees. North/South coordinates are in the range -90 to +90, and East/West
          coordinates are in the range -180 to 180.
      latlonquad: in, optional, type=fltarr
          An 8-element array describing the four corners of a quadrilateral defining the overlay area.
          Exactly four coordinate pairs have to be provided, each consisting of floating point values
          for longitude and latitude. The coordinates must be specified in counter-clockwise order
          with the first coordinate corresponding to the lower-left corner of the overlayed image.
          The shape described by these corners must be convex.
      rotation: in, optional, type=float, default=0.0
           Specifies a rotation of the overlay about its center, in degrees. Values can be ±180.
           The default is 0 (north). Rotations are specified in a counterclockwise direction.
           Used only with the `LatLonBox` array.
      _ref_extra: out, optional
          Any keywords for the superclass objects are allowed.
      e purpose of this method is to destroy anything we created that may leak
      mory or need to be released from use.
      e cgKML_GroundOverlay class definition module. It is a container object
      d represents part of the KML file hierarchy.

Params

      class: out, optional, type=structure
          The class definition returned as a structure variable. Occassionally useful.