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backend_bases.py
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3350 lines (2728 loc) · 108 KB
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"""
Abstract base classes define the primitives that renderers and
graphics contexts must implement to serve as a matplotlib backend
:class:`RendererBase`
An abstract base class to handle drawing/rendering operations.
:class:`FigureCanvasBase`
The abstraction layer that separates the
:class:`matplotlib.figure.Figure` from the backend specific
details like a user interface drawing area
:class:`GraphicsContextBase`
An abstract base class that provides color, line styles, etc...
:class:`Event`
The base class for all of the matplotlib event
handling. Derived classes such as :class:`KeyEvent` and
:class:`MouseEvent` store the meta data like keys and buttons
pressed, x and y locations in pixel and
:class:`~matplotlib.axes.Axes` coordinates.
:class:`ShowBase`
The base class for the Show class of each interactive backend;
the 'show' callable is then set to Show.__call__, inherited from
ShowBase.
:class:`ToolContainerBase`
The base class for the Toolbar class of each interactive backend.
:class:`StatusbarBase`
The base class for the messaging area.
"""
from __future__ import (absolute_import, division, print_function,
unicode_literals)
from contextlib import contextmanager
from matplotlib.externals import six
from matplotlib.externals.six.moves import xrange
import os
import sys
import warnings
import time
import io
import numpy as np
import matplotlib.cbook as cbook
import matplotlib.colors as colors
import matplotlib.transforms as transforms
import matplotlib.widgets as widgets
#import matplotlib.path as path
from matplotlib import rcParams
from matplotlib import is_interactive
from matplotlib import get_backend
from matplotlib._pylab_helpers import Gcf
from matplotlib import lines
from matplotlib.transforms import Bbox, TransformedBbox, Affine2D
import matplotlib.tight_bbox as tight_bbox
import matplotlib.textpath as textpath
from matplotlib.path import Path
from matplotlib.cbook import mplDeprecation, warn_deprecated
import matplotlib.backend_tools as tools
try:
from importlib import import_module
except:
# simple python 2.6 implementation (no relative imports)
def import_module(name):
__import__(name)
return sys.modules[name]
try:
from PIL import Image
_has_pil = True
del Image
except ImportError:
_has_pil = False
_default_filetypes = {
'ps': 'Postscript',
'eps': 'Encapsulated Postscript',
'pdf': 'Portable Document Format',
'pgf': 'PGF code for LaTeX',
'png': 'Portable Network Graphics',
'raw': 'Raw RGBA bitmap',
'rgba': 'Raw RGBA bitmap',
'svg': 'Scalable Vector Graphics',
'svgz': 'Scalable Vector Graphics'
}
_default_backends = {
'ps': 'matplotlib.backends.backend_ps',
'eps': 'matplotlib.backends.backend_ps',
'pdf': 'matplotlib.backends.backend_pdf',
'pgf': 'matplotlib.backends.backend_pgf',
'png': 'matplotlib.backends.backend_agg',
'raw': 'matplotlib.backends.backend_agg',
'rgba': 'matplotlib.backends.backend_agg',
'svg': 'matplotlib.backends.backend_svg',
'svgz': 'matplotlib.backends.backend_svg',
}
def register_backend(format, backend, description=None):
"""
Register a backend for saving to a given file format.
format : str
File extention
backend : module string or canvas class
Backend for handling file output
description : str, optional
Description of the file type. Defaults to an empty string
"""
if description is None:
description = ''
_default_backends[format] = backend
_default_filetypes[format] = description
def get_registered_canvas_class(format):
"""
Return the registered default canvas for given file format.
Handles deferred import of required backend.
"""
if format not in _default_backends:
return None
backend_class = _default_backends[format]
if cbook.is_string_like(backend_class):
backend_class = import_module(backend_class).FigureCanvas
_default_backends[format] = backend_class
return backend_class
class ShowBase(object):
"""
Simple base class to generate a show() callable in backends.
Subclass must override mainloop() method.
"""
def __call__(self, block=None):
"""
Show all figures. If *block* is not None, then
it is a boolean that overrides all other factors
determining whether show blocks by calling mainloop().
The other factors are:
it does not block if run inside ipython's "%pylab" mode
it does not block in interactive mode.
"""
managers = Gcf.get_all_fig_managers()
if not managers:
return
for manager in managers:
manager.show()
if block is not None:
if block:
self.mainloop()
return
else:
return
# Hack: determine at runtime whether we are
# inside ipython in pylab mode.
from matplotlib import pyplot
try:
ipython_pylab = not pyplot.show._needmain
# IPython versions >= 0.10 tack the _needmain
# attribute onto pyplot.show, and always set
# it to False, when in %pylab mode.
ipython_pylab = ipython_pylab and get_backend() != 'WebAgg'
# TODO: The above is a hack to get the WebAgg backend
# working with ipython's `%pylab` mode until proper
# integration is implemented.
except AttributeError:
ipython_pylab = False
# Leave the following as a separate step in case we
# want to control this behavior with an rcParam.
if ipython_pylab:
return
if not is_interactive() or get_backend() == 'WebAgg':
self.mainloop()
def mainloop(self):
pass
class RendererBase(object):
"""An abstract base class to handle drawing/rendering operations.
The following methods must be implemented in the backend for full
functionality (though just implementing :meth:`draw_path` alone would
give a highly capable backend):
* :meth:`draw_path`
* :meth:`draw_image`
* :meth:`draw_gouraud_triangle`
The following methods *should* be implemented in the backend for
optimization reasons:
* :meth:`draw_text`
* :meth:`draw_markers`
* :meth:`draw_path_collection`
* :meth:`draw_quad_mesh`
"""
def __init__(self):
self._texmanager = None
self._text2path = textpath.TextToPath()
def open_group(self, s, gid=None):
"""
Open a grouping element with label *s*. If *gid* is given, use
*gid* as the id of the group. Is only currently used by
:mod:`~matplotlib.backends.backend_svg`.
"""
pass
def close_group(self, s):
"""
Close a grouping element with label *s*
Is only currently used by :mod:`~matplotlib.backends.backend_svg`
"""
pass
def draw_path(self, gc, path, transform, rgbFace=None):
"""
Draws a :class:`~matplotlib.path.Path` instance using the
given affine transform.
"""
raise NotImplementedError
def draw_markers(self, gc, marker_path, marker_trans, path,
trans, rgbFace=None):
"""
Draws a marker at each of the vertices in path. This includes
all vertices, including control points on curves. To avoid
that behavior, those vertices should be removed before calling
this function.
*gc*
the :class:`GraphicsContextBase` instance
*marker_trans*
is an affine transform applied to the marker.
*trans*
is an affine transform applied to the path.
This provides a fallback implementation of draw_markers that
makes multiple calls to :meth:`draw_path`. Some backends may
want to override this method in order to draw the marker only
once and reuse it multiple times.
"""
for vertices, codes in path.iter_segments(trans, simplify=False):
if len(vertices):
x, y = vertices[-2:]
self.draw_path(gc, marker_path,
marker_trans +
transforms.Affine2D().translate(x, y),
rgbFace)
def draw_path_collection(self, gc, master_transform, paths, all_transforms,
offsets, offsetTrans, facecolors, edgecolors,
linewidths, linestyles, antialiaseds, urls,
offset_position):
"""
Draws a collection of paths selecting drawing properties from
the lists *facecolors*, *edgecolors*, *linewidths*,
*linestyles* and *antialiaseds*. *offsets* is a list of
offsets to apply to each of the paths. The offsets in
*offsets* are first transformed by *offsetTrans* before being
applied. *offset_position* may be either "screen" or "data"
depending on the space that the offsets are in.
This provides a fallback implementation of
:meth:`draw_path_collection` that makes multiple calls to
:meth:`draw_path`. Some backends may want to override this in
order to render each set of path data only once, and then
reference that path multiple times with the different offsets,
colors, styles etc. The generator methods
:meth:`_iter_collection_raw_paths` and
:meth:`_iter_collection` are provided to help with (and
standardize) the implementation across backends. It is highly
recommended to use those generators, so that changes to the
behavior of :meth:`draw_path_collection` can be made globally.
"""
path_ids = []
for path, transform in self._iter_collection_raw_paths(
master_transform, paths, all_transforms):
path_ids.append((path, transforms.Affine2D(transform)))
for xo, yo, path_id, gc0, rgbFace in self._iter_collection(
gc, master_transform, all_transforms, path_ids, offsets,
offsetTrans, facecolors, edgecolors, linewidths, linestyles,
antialiaseds, urls, offset_position):
path, transform = path_id
transform = transforms.Affine2D(
transform.get_matrix()).translate(xo, yo)
self.draw_path(gc0, path, transform, rgbFace)
def draw_quad_mesh(self, gc, master_transform, meshWidth, meshHeight,
coordinates, offsets, offsetTrans, facecolors,
antialiased, edgecolors):
"""
This provides a fallback implementation of
:meth:`draw_quad_mesh` that generates paths and then calls
:meth:`draw_path_collection`.
"""
from matplotlib.collections import QuadMesh
paths = QuadMesh.convert_mesh_to_paths(
meshWidth, meshHeight, coordinates)
if edgecolors is None:
edgecolors = facecolors
linewidths = np.array([gc.get_linewidth()], np.float_)
return self.draw_path_collection(
gc, master_transform, paths, [], offsets, offsetTrans, facecolors,
edgecolors, linewidths, [], [antialiased], [None], 'screen')
def draw_gouraud_triangle(self, gc, points, colors, transform):
"""
Draw a Gouraud-shaded triangle.
*points* is a 3x2 array of (x, y) points for the triangle.
*colors* is a 3x4 array of RGBA colors for each point of the
triangle.
*transform* is an affine transform to apply to the points.
"""
raise NotImplementedError
def draw_gouraud_triangles(self, gc, triangles_array, colors_array,
transform):
"""
Draws a series of Gouraud triangles.
*points* is a Nx3x2 array of (x, y) points for the trianglex.
*colors* is a Nx3x4 array of RGBA colors for each point of the
triangles.
*transform* is an affine transform to apply to the points.
"""
transform = transform.frozen()
for tri, col in zip(triangles_array, colors_array):
self.draw_gouraud_triangle(gc, tri, col, transform)
def _iter_collection_raw_paths(self, master_transform, paths,
all_transforms):
"""
This is a helper method (along with :meth:`_iter_collection`) to make
it easier to write a space-efficent :meth:`draw_path_collection`
implementation in a backend.
This method yields all of the base path/transform
combinations, given a master transform, a list of paths and
list of transforms.
The arguments should be exactly what is passed in to
:meth:`draw_path_collection`.
The backend should take each yielded path and transform and
create an object that can be referenced (reused) later.
"""
Npaths = len(paths)
Ntransforms = len(all_transforms)
N = max(Npaths, Ntransforms)
if Npaths == 0:
return
transform = transforms.IdentityTransform()
for i in xrange(N):
path = paths[i % Npaths]
if Ntransforms:
transform = Affine2D(all_transforms[i % Ntransforms])
yield path, transform + master_transform
def _iter_collection_uses_per_path(self, paths, all_transforms,
offsets, facecolors, edgecolors):
"""
Compute how many times each raw path object returned by
_iter_collection_raw_paths would be used when calling
_iter_collection. This is intended for the backend to decide
on the tradeoff between using the paths in-line and storing
them once and reusing. Rounds up in case the number of uses
is not the same for every path.
"""
Npaths = len(paths)
if Npaths == 0 or (len(facecolors) == 0 and len(edgecolors) == 0):
return 0
Npath_ids = max(Npaths, len(all_transforms))
N = max(Npath_ids, len(offsets))
return (N + Npath_ids - 1) // Npath_ids
def _iter_collection(self, gc, master_transform, all_transforms,
path_ids, offsets, offsetTrans, facecolors,
edgecolors, linewidths, linestyles,
antialiaseds, urls, offset_position):
"""
This is a helper method (along with
:meth:`_iter_collection_raw_paths`) to make it easier to write
a space-efficent :meth:`draw_path_collection` implementation in a
backend.
This method yields all of the path, offset and graphics
context combinations to draw the path collection. The caller
should already have looped over the results of
:meth:`_iter_collection_raw_paths` to draw this collection.
The arguments should be the same as that passed into
:meth:`draw_path_collection`, with the exception of
*path_ids*, which is a list of arbitrary objects that the
backend will use to reference one of the paths created in the
:meth:`_iter_collection_raw_paths` stage.
Each yielded result is of the form::
xo, yo, path_id, gc, rgbFace
where *xo*, *yo* is an offset; *path_id* is one of the elements of
*path_ids*; *gc* is a graphics context and *rgbFace* is a color to
use for filling the path.
"""
Ntransforms = len(all_transforms)
Npaths = len(path_ids)
Noffsets = len(offsets)
N = max(Npaths, Noffsets)
Nfacecolors = len(facecolors)
Nedgecolors = len(edgecolors)
Nlinewidths = len(linewidths)
Nlinestyles = len(linestyles)
Naa = len(antialiaseds)
Nurls = len(urls)
if (Nfacecolors == 0 and Nedgecolors == 0) or Npaths == 0:
return
if Noffsets:
toffsets = offsetTrans.transform(offsets)
gc0 = self.new_gc()
gc0.copy_properties(gc)
if Nfacecolors == 0:
rgbFace = None
if Nedgecolors == 0:
gc0.set_linewidth(0.0)
xo, yo = 0, 0
for i in xrange(N):
path_id = path_ids[i % Npaths]
if Noffsets:
xo, yo = toffsets[i % Noffsets]
if offset_position == 'data':
if Ntransforms:
transform = (
Affine2D(all_transforms[i % Ntransforms]) +
master_transform)
else:
transform = master_transform
xo, yo = transform.transform_point((xo, yo))
xp, yp = transform.transform_point((0, 0))
xo = -(xp - xo)
yo = -(yp - yo)
if not (np.isfinite(xo) and np.isfinite(yo)):
continue
if Nfacecolors:
rgbFace = facecolors[i % Nfacecolors]
if Nedgecolors:
if Nlinewidths:
gc0.set_linewidth(linewidths[i % Nlinewidths])
if Nlinestyles:
gc0.set_dashes(*linestyles[i % Nlinestyles])
fg = edgecolors[i % Nedgecolors]
if len(fg) == 4:
if fg[3] == 0.0:
gc0.set_linewidth(0)
else:
gc0.set_foreground(fg)
else:
gc0.set_foreground(fg)
if rgbFace is not None and len(rgbFace) == 4:
if rgbFace[3] == 0:
rgbFace = None
gc0.set_antialiased(antialiaseds[i % Naa])
if Nurls:
gc0.set_url(urls[i % Nurls])
yield xo, yo, path_id, gc0, rgbFace
gc0.restore()
def get_image_magnification(self):
"""
Get the factor by which to magnify images passed to :meth:`draw_image`.
Allows a backend to have images at a different resolution to other
artists.
"""
return 1.0
def draw_image(self, gc, x, y, im, trans=None):
"""
Draw the image instance into the current axes;
*gc*
a GraphicsContext containing clipping information
*x*
is the distance in pixels from the left hand side of the canvas.
*y*
the distance from the origin. That is, if origin is
upper, y is the distance from top. If origin is lower, y
is the distance from bottom
*im*
An NxMx4 array of RGBA pixels (of dtype uint8).
*trans*
If the concrete backend is written such that
`option_scale_image` returns `True`, an affine
transformation may also be passed to `draw_image`. The
backend should apply the transformation to the image
before applying the translation of `x` and `y`.
"""
raise NotImplementedError
def option_image_nocomposite(self):
"""
override this method for renderers that do not necessarily always
want to rescale and composite raster images. (like SVG, PDF, or PS)
"""
return False
def option_scale_image(self):
"""
override this method for renderers that support arbitrary
scaling of image (most of the vector backend).
"""
return False
def draw_tex(self, gc, x, y, s, prop, angle, ismath='TeX!', mtext=None):
"""
"""
self._draw_text_as_path(gc, x, y, s, prop, angle, ismath="TeX")
def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
"""
Draw the text instance
*gc*
the :class:`GraphicsContextBase` instance
*x*
the x location of the text in display coords
*y*
the y location of the text baseline in display coords
*s*
the text string
*prop*
a :class:`matplotlib.font_manager.FontProperties` instance
*angle*
the rotation angle in degrees
*mtext*
a :class:`matplotlib.text.Text` instance
**backend implementers note**
When you are trying to determine if you have gotten your bounding box
right (which is what enables the text layout/alignment to work
properly), it helps to change the line in text.py::
if 0: bbox_artist(self, renderer)
to if 1, and then the actual bounding box will be plotted along with
your text.
"""
self._draw_text_as_path(gc, x, y, s, prop, angle, ismath)
def _get_text_path_transform(self, x, y, s, prop, angle, ismath):
"""
return the text path and transform
*prop*
font property
*s*
text to be converted
*usetex*
If True, use matplotlib usetex mode.
*ismath*
If True, use mathtext parser. If "TeX", use *usetex* mode.
"""
text2path = self._text2path
fontsize = self.points_to_pixels(prop.get_size_in_points())
if ismath == "TeX":
verts, codes = text2path.get_text_path(prop, s, ismath=False,
usetex=True)
else:
verts, codes = text2path.get_text_path(prop, s, ismath=ismath,
usetex=False)
path = Path(verts, codes)
angle = angle / 180. * 3.141592
if self.flipy():
transform = Affine2D().scale(fontsize / text2path.FONT_SCALE,
fontsize / text2path.FONT_SCALE)
transform = transform.rotate(angle).translate(x, self.height - y)
else:
transform = Affine2D().scale(fontsize / text2path.FONT_SCALE,
fontsize / text2path.FONT_SCALE)
transform = transform.rotate(angle).translate(x, y)
return path, transform
def _draw_text_as_path(self, gc, x, y, s, prop, angle, ismath):
"""
draw the text by converting them to paths using textpath module.
*prop*
font property
*s*
text to be converted
*usetex*
If True, use matplotlib usetex mode.
*ismath*
If True, use mathtext parser. If "TeX", use *usetex* mode.
"""
path, transform = self._get_text_path_transform(
x, y, s, prop, angle, ismath)
color = gc.get_rgb()
gc.set_linewidth(0.0)
self.draw_path(gc, path, transform, rgbFace=color)
def get_text_width_height_descent(self, s, prop, ismath):
"""
get the width and height, and the offset from the bottom to the
baseline (descent), in display coords of the string s with
:class:`~matplotlib.font_manager.FontProperties` prop
"""
if ismath == 'TeX':
# todo: handle props
size = prop.get_size_in_points()
texmanager = self._text2path.get_texmanager()
fontsize = prop.get_size_in_points()
w, h, d = texmanager.get_text_width_height_descent(s, fontsize,
renderer=self)
return w, h, d
dpi = self.points_to_pixels(72)
if ismath:
dims = self._text2path.mathtext_parser.parse(s, dpi, prop)
return dims[0:3] # return width, height, descent
flags = self._text2path._get_hinting_flag()
font = self._text2path._get_font(prop)
size = prop.get_size_in_points()
font.set_size(size, dpi)
# the width and height of unrotated string
font.set_text(s, 0.0, flags=flags)
w, h = font.get_width_height()
d = font.get_descent()
w /= 64.0 # convert from subpixels
h /= 64.0
d /= 64.0
return w, h, d
def flipy(self):
"""
Return true if y small numbers are top for renderer Is used
for drawing text (:mod:`matplotlib.text`) and images
(:mod:`matplotlib.image`) only
"""
return True
def get_canvas_width_height(self):
'return the canvas width and height in display coords'
return 1, 1
def get_texmanager(self):
"""
return the :class:`matplotlib.texmanager.TexManager` instance
"""
if self._texmanager is None:
from matplotlib.texmanager import TexManager
self._texmanager = TexManager()
return self._texmanager
def new_gc(self):
"""
Return an instance of a :class:`GraphicsContextBase`
"""
return GraphicsContextBase()
def points_to_pixels(self, points):
"""
Convert points to display units
*points*
a float or a numpy array of float
return points converted to pixels
You need to override this function (unless your backend
doesn't have a dpi, e.g., postscript or svg). Some imaging
systems assume some value for pixels per inch::
points to pixels = points * pixels_per_inch/72.0 * dpi/72.0
"""
return points
def strip_math(self, s):
return cbook.strip_math(s)
def start_rasterizing(self):
"""
Used in MixedModeRenderer. Switch to the raster renderer.
"""
pass
def stop_rasterizing(self):
"""
Used in MixedModeRenderer. Switch back to the vector renderer
and draw the contents of the raster renderer as an image on
the vector renderer.
"""
pass
def start_filter(self):
"""
Used in AggRenderer. Switch to a temporary renderer for image
filtering effects.
"""
pass
def stop_filter(self, filter_func):
"""
Used in AggRenderer. Switch back to the original renderer.
The contents of the temporary renderer is processed with the
*filter_func* and is drawn on the original renderer as an
image.
"""
pass
class GraphicsContextBase(object):
"""
An abstract base class that provides color, line styles, etc...
"""
def __init__(self):
self._alpha = 1.0
self._forced_alpha = False # if True, _alpha overrides A from RGBA
self._antialiased = 1 # use 0,1 not True, False for extension code
self._capstyle = 'butt'
self._cliprect = None
self._clippath = None
self._dashes = None, None
self._joinstyle = 'round'
self._linestyle = 'solid'
self._linewidth = 1
self._rgb = (0.0, 0.0, 0.0, 1.0)
self._hatch = None
self._hatch_linewidth = rcParams['hatch.linewidth']
self._url = None
self._gid = None
self._snap = None
self._sketch = None
def copy_properties(self, gc):
'Copy properties from gc to self'
self._alpha = gc._alpha
self._forced_alpha = gc._forced_alpha
self._antialiased = gc._antialiased
self._capstyle = gc._capstyle
self._cliprect = gc._cliprect
self._clippath = gc._clippath
self._dashes = gc._dashes
self._joinstyle = gc._joinstyle
self._linestyle = gc._linestyle
self._linewidth = gc._linewidth
self._rgb = gc._rgb
self._hatch = gc._hatch
self._url = gc._url
self._gid = gc._gid
self._snap = gc._snap
self._sketch = gc._sketch
def restore(self):
"""
Restore the graphics context from the stack - needed only
for backends that save graphics contexts on a stack
"""
pass
def get_alpha(self):
"""
Return the alpha value used for blending - not supported on
all backends
"""
return self._alpha
def get_antialiased(self):
"Return true if the object should try to do antialiased rendering"
return self._antialiased
def get_capstyle(self):
"""
Return the capstyle as a string in ('butt', 'round', 'projecting')
"""
return self._capstyle
def get_clip_rectangle(self):
"""
Return the clip rectangle as a :class:`~matplotlib.transforms.Bbox`
instance
"""
return self._cliprect
def get_clip_path(self):
"""
Return the clip path in the form (path, transform), where path
is a :class:`~matplotlib.path.Path` instance, and transform is
an affine transform to apply to the path before clipping.
"""
if self._clippath is not None:
return self._clippath.get_transformed_path_and_affine()
return None, None
def get_dashes(self):
"""
Return the dash information as an offset dashlist tuple.
The dash list is a even size list that gives the ink on, ink
off in pixels.
See p107 of to PostScript `BLUEBOOK
<http://www-cdf.fnal.gov/offline/PostScript/BLUEBOOK.PDF>`_
for more info.
Default value is None
"""
if rcParams['_internal.classic_mode']:
return self._dashes
else:
scale = max(1.0, self.get_linewidth())
offset, dashes = self._dashes
if offset is not None:
offset = offset * scale
if dashes is not None:
dashes = [x * scale for x in dashes]
return offset, dashes
def get_forced_alpha(self):
"""
Return whether the value given by get_alpha() should be used to
override any other alpha-channel values.
"""
return self._forced_alpha
def get_joinstyle(self):
"""
Return the line join style as one of ('miter', 'round', 'bevel')
"""
return self._joinstyle
def get_linestyle(self, style):
"""
Return the linestyle: one of ('solid', 'dashed', 'dashdot',
'dotted').
"""
return self._linestyle
def get_linewidth(self):
"""
Return the line width in points as a scalar
"""
return self._linewidth
def get_rgb(self):
"""
returns a tuple of three or four floats from 0-1.
"""
return self._rgb
def get_url(self):
"""
returns a url if one is set, None otherwise
"""
return self._url
def get_gid(self):
"""
Return the object identifier if one is set, None otherwise.
"""
return self._gid
def get_snap(self):
"""
returns the snap setting which may be:
* True: snap vertices to the nearest pixel center
* False: leave vertices as-is
* None: (auto) If the path contains only rectilinear line
segments, round to the nearest pixel center
"""
return self._snap
def set_alpha(self, alpha):
"""
Set the alpha value used for blending - not supported on all backends.
If ``alpha=None`` (the default), the alpha components of the
foreground and fill colors will be used to set their respective
transparencies (where applicable); otherwise, ``alpha`` will override
them.
"""
if alpha is not None:
self._alpha = alpha
self._forced_alpha = True
else:
self._alpha = 1.0
self._forced_alpha = False
self.set_foreground(self._rgb, isRGBA=True)
def set_antialiased(self, b):
"""
True if object should be drawn with antialiased rendering
"""
# use 0, 1 to make life easier on extension code trying to read the gc
if b:
self._antialiased = 1
else:
self._antialiased = 0
def set_capstyle(self, cs):
"""
Set the capstyle as a string in ('butt', 'round', 'projecting')
"""
if cs in ('butt', 'round', 'projecting'):
self._capstyle = cs
else:
raise ValueError('Unrecognized cap style. Found %s' % cs)
def set_clip_rectangle(self, rectangle):
"""
Set the clip rectangle with sequence (left, bottom, width, height)
"""
self._cliprect = rectangle
def set_clip_path(self, path):
"""
Set the clip path and transformation. Path should be a
:class:`~matplotlib.transforms.TransformedPath` instance.
"""
if path is not None and not isinstance(path,
transforms.TransformedPath):
msg = ("Path should be a matplotlib.transforms.TransformedPath"
"instance.")
raise ValueError(msg)
self._clippath = path
def set_dashes(self, dash_offset, dash_list):
"""
Set the dash style for the gc.
*dash_offset*