Function _draw_rasterized

lib/matplotlib/axes/_base.py:5059–5119

A helper function for rasterizing the list of artists. The bookkeeping to track if we are or are not in rasterizing mode with the mixed-mode backends is relatively complicated and is now handled in the matplotlib.artist.allow_rasterization decorator. This helper defines the ab

(figure, artists, renderer)

def _draw_rasterized(figure, artists, renderer):
    """
    A helper function for rasterizing the list of artists.

    The bookkeeping to track if we are or are not in rasterizing mode
    with the mixed-mode backends is relatively complicated and is now
    handled in the matplotlib.artist.allow_rasterization decorator.

    This helper defines the absolute minimum methods and attributes on a
    shim class to be compatible with that decorator and then uses it to
    rasterize the list of artists.

    This is maybe too-clever, but allows us to reuse the same code that is
    used on normal artists to participate in the "are we rasterizing"
    accounting.

    Please do not use this outside of the "rasterize below a given zorder"
    functionality of Axes.

    Parameters
    ----------
    figure : matplotlib.figure.Figure
        The figure all of the artists belong to (not checked).  We need this
        because we can at the figure level suppress composition and insert each
        rasterized artist as its own image.

    artists : List[matplotlib.artist.Artist]
        The list of Artists to be rasterized.  These are assumed to all
        be in the same Figure.

    renderer : matplotlib.backendbases.RendererBase
        The currently active renderer

    Returns
    -------
    None

    """
    class _MinimalArtist:
        def get_rasterized(self):
            return True

        def get_agg_filter(self):
            return None

        def __init__(self, figure, artists):
            self.figure = figure
            self.artists = artists

        def get_figure(self, root=False):
            if root:
                return self.figure.get_figure(root=True)
            else:
                return self.figure

        @martist.allow_rasterization
        def draw(self, renderer):
            for a in self.artists: