Define the cartopy raster fetching interface.

A RasterSource instance is able to supply images and associated extents (as a sequence of LocatedImage instances) through its fetch_raster() method.

As a result, further interfacing classes, such as cartopy.mpl.slippy_image_artist.SlippyImageArtist, can then make use of the interface for functionality such as interactive image retrieval with pan and zoom functionality.




fetch_raster(projection, extent, ...)

Return a sequence of images with extents given some constraining information.


Raise an error if this raster source cannot provide images in the specified projection.