Documentation

Interface: Globe

Globe

Globe is an interface to handle all WebGL objects through a Context. Globe is able :
  • to draw layers,
  • to render layers,
  • to dispose layers and WebGL objects,
  • to transform (longitude,latitude) from/to pixel coordinates
The pixel coordinates are expressed in the canvas frame, i.e. (0,0) corresponds to the lower-left corner of the pixel. The geo-position coordinates(longitude,latitude) are expressed in decimal degree in their defined coordinate reference system. In Mizar, it exists two kinds of globes :
Sky Provides two grids to handle data according to their coordinate reference system : Equatorial, Galactic. Then the globe renders the two grids in the same time.
Planet Provides only one grid to handle data in the reference frame of the planet
In addition to the classes, a factory is available to help for creating globe. Once the globe is created, the client can handle it by the use of its interface.
See:

Methods

isSky()

Checks if the globe is a sky or a planet
Returns:
True when the globe is a sky otherwise false
Type
boolean

getType()

Returns the type of globe.
Returns:
type of globe
Type
GLOBE

setBaseImagery(layer)

Registers the layer as a background raster and attach it to the globe.
When a raster layer is already set, this layer is replaced by the new one.
Parameters:
Name Type Description
layer AbstractRasterLayer raster layer to use

getBaseImagery()

Returns the background raster as a layer.
Returns:
the raster layer
Type
AbstractRasterLayer

setBaseElevation()

Registers the elevation layer and attach it to the globe.
When an elevation layer is already set, this layer is replaced by the new one
Returns:
the layer used
Type
WMSElevationLayer | WCSElevationLayer

getBaseElevation()

Returns the elevation layer.
Returns:
the layer used
Type
WMSElevationLayer | WCSElevationLayer

addLayer(layer)

Registers a new layer to globe to be visualized on the globe.
When the layer is added, an internal ID is generated to the layer based on an autoincrement value. Once the layer is added, the globe is rendered. According to the visible attribute of the layer, the layer is automatically shown on the globe. The layer can be mainly a raster or a set of vectors.
In the vector case, the data is located in the url attribute of the layer object. In addition to the URL, a callback attribute can be applied to the data.
Parameters:
Name Type Description
layer Layer the layer to add
Fires:

removeLayer(layer)

Removes a layer. The layer is set to unvisible. Then it is detached to the globe. The globe is rendered to remove the layer from the globe.
Parameters:
Name Type Description
layer Layer the layer to remove
Fires:

addAnimation(anim)

Adds an animation to be played later on.
Parameters:
Name Type Description
anim Animation the animation to add

removeAnimation(anim)

Removes an animation.
Parameters:
Name Type Description
anim Animation the animation to remove

getElevation(lon, lat)

Returns the elevation in meters at a geo position at the defined coordinate reference system.
Parameters:
Name Type Description
lon float the longitude in degree
lat float the latitude in degree
Returns:
the elevation in meter at the position [lon,lat]
Type
float

getViewportGeoBound(transformCallback)

Returns the viewport geo bound.
Parameters:
Name Type Description
transformCallback Callback transforming the frustum/globe intersection coordinates if needed
Returns:
the geo bound of the viewport
Type
GeoBound

getLonLatFromPixel(x, y)

Returns the geo position [longitude, latitude] in degree from a pixel.
The pixel is expressed in the canvas frame, i.e. (0,0) corresponds to the lower-left corner of the pixel. The geo position is expressed in the defined coordinate reference system.
Parameters:
Name Type Description
x int the pixel x coordinate
y int the pixel y coordinate
Returns:
an array of two numbers [lon,lat] or null if the pixel is not on the globe
Type
Array.<float> | null

getPixelFromLonLat(lon, lat)

Returns the pixel coordinates from geo position [longitude, latitude] in degree in the defined coordinate reference system.
The pixel is expressed in the canvas frame, i.e. (0,0) corresponds to the lower-left corner of the pixel
Parameters:
Name Type Description
lon float the longitude in decimal degree
lat float the latitude in decimal degree
Returns:
an array of two numbers [x,y] or null if the pixel is not on the globe
Type
Array.<int> | null

setCoordinateSystem(coordinateSystem)

Sets the coordinate reference system
Parameters:
Name Type Description
coordinateSystem Crs the coordinate reference system

getCoordinateSystem()

Returns the coordinate reference system.
Returns:
the coordinate reference system
Type
Crs

getRenderStats()

Displays some rendering statistics.
Returns:
the statistics
Type
string

getRenderContext()

Returns the rendering context.
Returns:
the rendering context
Type
RenderContext

setRenderContext(context)

Sets the rendering context.
Parameters:
Name Type Description
context RenderContext the rendering context

getTileManager()

Returns the tile manager.
Returns:
Tile manager
Type
TileManager

dispose()

Cleans up every reference to gl objects and unloads all tiles

destroy()

Destroys the globe. The globe is destroyed by :
  • cleaning up every reference to gl objects and unloads all tiles
  • Removing the renderer from all the tiles

refresh()

Refreshes rendering, must be called when canvas size is modified.

isEnabled()

Checks if the globe rendering is enabled.
Returns:
True when the globe rendering is enabled whereas False
Type
boolean

enable()

Enables the globe. This is used to enable the sky when we use the sphere to map the data. In this way, we see the globe and the sky in the same time.

disable()

Disables the globe. This method is only overloaded by the sky to make disable the sky when the planet is projected on a map.