Source code for cartopy.mpl.slippy_image_artist
# (C) British Crown Copyright 2014 - 2018, Met Office
#
# This file is part of cartopy.
#
# cartopy is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License as published by the
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# GNU Lesser General Public License for more details.
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"""
Define the SlippyImageArtist class, which interfaces with
:class:`cartopy.io.RasterSource` instances at draw time, for interactive
dragging and zooming of raster data.
"""
from __future__ import (absolute_import, division, print_function)
from matplotlib.image import AxesImage
import matplotlib.artist
[docs]class SlippyImageArtist(AxesImage):
"""
A subclass of :class:`~matplotlib.image.AxesImage` which provides an
interface for getting a raster from the given object with interactive
slippy map type functionality.
Kwargs are passed to the AxesImage constructor.
"""
def __init__(self, ax, raster_source, **kwargs):
self.raster_source = raster_source
super(SlippyImageArtist, self).__init__(ax, **kwargs)
self.set_clip_path(ax.outline_patch)
@matplotlib.artist.allow_rasterization
def draw(self, renderer, *args, **kwargs):
if not self.get_visible():
return
ax = self.axes
window_extent = ax.get_window_extent()
[x1, y1], [x2, y2] = ax.viewLim.get_points()
located_images = self.raster_source.fetch_raster(
ax.projection, extent=[x1, x2, y1, y2],
target_resolution=(window_extent.width, window_extent.height))
for img, extent in located_images:
self.set_array(img)
with ax.hold_limits():
self.set_extent(extent)
super(SlippyImageArtist, self).draw(renderer, *args, **kwargs)