WorldWind Source Analysis Series: Image storage Class Imagestore

Image Storage Class Imagestore

The image storage Class Imagestore provides various interfaces for calculating the local image path and remote image URL Access, and is the base class for the Wmsimagestore class and the Nltimagestore class. The class diagram for this class is as follows.

The primary fields, properties, and methods provided by the image storage class base class Imagestore are briefly described below:

Protected string m_datadirectory;//image Data Catalog

protected double m_levelzerotilesizedegrees = 36; Pyramid image of level 0 tile size degree

protected int m_levelcount = 1; Detail Image Layer Series

protected string m_imagefileextension; Source image file name extension

protected string m_cachedirectory; This layer image data buffer subdirectory

protected string M_duplicatetexturepath; Copy Texture Path

protected string M_serverlogo; Image Data Server logo

Public virtual bool isdownloadablelayer//is a downloadable layer

Virtual method Public virtual string Getlocalpath (Quadtile qt) is based on the tile hierarchy, line number, column number, and source image file extension that are included in the four-fork tree tile qt that you want to request m_ Imagefileextension constructs a relative path, and then, judging if the image data directory m_datadirectory is not empty, it joins the relative path to build an absolute path and returns; if the image data directory is empty, the image data Buffer subdirectory is judged m_ Cachedirectory is empty, returns the absolute path constructed by the buffer subdirectory and relative directory, and then uses the valid extension string const string validextensions = ". Bmp.dds.dib.hdr.jpg.jpeg.pfm.png.ppm.tga.gif.tif "; To verify that the file under the buffer subdirectory is a valid file that is supported, and if so, returns its path.

Virtual method protected Virtual string Getdownloadurl (Quadtile qt) returns its URL string based on information about the four-tree tile QT that is requested. A quilt class overload is required to control how the image is downloaded.

Virtual method public virtual void deletelocalcopy (Quadtile qt) deletes a locally buffered tile copy.

The virtual method protected virtual void Convertimage (Texture Texture, string filePath) converts the image to a compressed texture file in DDS format.

Method public Texture LoadFile (quadtile qt) loads the image corresponding to the four-fork tree tile QT to be requested, and returns the texture object.

method void Queuedownload (Quadtile qt, string filePath) converts this request to a Geospatialdownloadrequest request object based on the four-tree tile QT That is requested and the absolute path it is located in. and joins the request object to the download queue.

Nlt image storage Class class Nltimagestore

The NLT image storage Class class Nltimagestore is used to read NLT-style terrain/elevation data stored in the Bil file. Among them, NLT is the acronym for NASA Learning Technologies.

String m_datasetname;//Data set name

String m_serveruri;//The URL string for the request service

public override bool Isdownloadablelayer Property overload parent class with same Name property

The constructor public Nltimagestore (String datasetname,string Serveruri) simply completes the field initialization

protected override string Getdownloadurl (Quadtile Qt) overloads the parent class with the same name virtual method, the specific implementation please consult the source code

WMS image storage Class Wmsimagestore

The WMS image Storage Class Wmsimagestore is used to obtain WMS services that follow the OGC specifications. The main fields, properties, and methods provided are briefly described below:

String m_servergetmapurl;//The URL string describing the WMS service

String M_wmslayername; Layer name for WMS Service

String M_wmslayerstyle; Layer Styles for WMS Services

String M_imageformat; Layer image format for WMS Services

String m_version; Version number of the WMS service

int m_texturesizepixels = 512; The image texture size of the WMS service, measured in the number of pixels included

public override bool Isdownloadablelayer Property overload parent class with same Name property

protected override string Getdownloadurl (WorldWind.Renderable.QuadTile Qt) overloads the parent class with the same name virtual method, the specific implementation please consult the source code

WorldWind Source Analysis Series: Image storage Class Imagestore