LevelDescription

A LevelDescription object contains information about the number of map tiles on the horizontal and vertical axes, and the width and height in virtual pixels of the map image created in memory, for a given map zoom level.

When a LevelDescription object is returned in an EnvinsaResponse JSON object, the LevelDescription object is always located in a JSON field named levelDescription.

Fields

A LevelDescription object contains the following fields:

Field Name Type Description
tileAcross Integer The number of map tiles on the horizontal axis in this zoom level.
tileDown Integer The number of map tiles on the vertical axis in this zoom level.
virtualImageHeight Integer The height of the map image created in memory, measured in the virtual pixel space of the entire map image. (See note below.)
virtualImageWidth Integer The width of the map image created in memory, measured in the virtual pixel space of the entire map image. (See note below.)
Note: Do not confuse coordinates in the virtual pixel space of the entire map image with normal screen pixel coordinates. Normal screen pixel coordinates always start with (0, 0) at the top left corner of the screen, regardless of what section of the entire map image is currently displayed in the screen. In contrast, the virtual pixel space of the map image is constant at any particular zoom level, regardless of what part of the map is currently displayed in the screen. So, for example, if a map image is set to zoom level 3, the map image is composed of 4 tiles across and 4 tiles down. If each tile has dimensions of 512 by 256 pixels, then the dimensions of the entire map image are 2048 by 1024 pixels. This is referred to as the virtual pixel space of the map image, because only a subsection of the entire image may be displayed in the screen at any one time.

Example

{
    "tileAcross": 2,
    "tileDown": 2,
    "virtualImageHeight": 512,
    "virtualImageWidth": 512
}