matplotlib.backends.backend_cairo
¶
A Cairo backend for matplotlib¶
Author: | Steve Chaplin and others |
---|
This backend depends on cairocffi or pycairo.
-
matplotlib.backends.backend_cairo.
FigureCanvas
¶ alias of
matplotlib.backends.backend_cairo.FigureCanvasCairo
-
class
matplotlib.backends.backend_cairo.
FigureCanvasCairo
(figure=None)[source]¶ Bases:
matplotlib.backend_bases.FigureCanvasBase
-
print_raw
(self, fobj)¶
-
-
class
matplotlib.backends.backend_cairo.
GraphicsContextCairo
(renderer)[source]¶ Bases:
matplotlib.backend_bases.GraphicsContextBase
-
restore
(self)[source]¶ Restore the graphics context from the stack - needed only for backends that save graphics contexts on a stack.
-
set_alpha
(self, alpha)[source]¶ 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.
-
set_capstyle
(self, cs)[source]¶ Set how to draw endpoints of lines.
Parameters: - cs
CapStyle
or {'butt', 'projecting', 'round'}
- cs
-
set_clip_path
(self, path)[source]¶ Set the clip path to a
TransformedPath
or None.
-
set_dashes
(self, offset, dashes)[source]¶ Set the dash style for the gc.
Parameters: - dash_offsetfloat or None
The offset (usually 0).
- dash_listarray-like or None
The on-off sequence as points.
Notes
(None, None)
specifies a solid line.See p. 107 of to PostScript blue book for more info.
-
set_foreground
(self, fg, isRGBA=None)[source]¶ Set the foreground color.
Parameters: - fgcolor
- isRGBAbool
If fg is known to be an
(r, g, b, a)
tuple, isRGBA can be set to True to improve performance.
-
-
class
matplotlib.backends.backend_cairo.
RendererCairo
(dpi)[source]¶ Bases:
matplotlib.backend_bases.RendererBase
-
draw_image
(self, gc, x, y, im)[source]¶ Draw an RGBA image.
Parameters: - gc
GraphicsContextBase
A graphics context with clipping information.
- xscalar
The distance in physical units (i.e., dots or pixels) from the left hand side of the canvas.
- yscalar
The distance in physical units (i.e., dots or pixels) from the bottom side of the canvas.
- im(N, M, 4) array-like of np.uint8
An array of RGBA pixels.
- transform
matplotlib.transforms.Affine2DBase
If and only if the concrete backend is written such that
option_scale_image()
returnsTrue
, an affine transformation (i.e., anAffine2DBase
) may be passed todraw_image()
. The translation vector of the transformation is given in physical units (i.e., dots or pixels). Note that the transformation does not override x and y, and has to be applied before translating the result by x and y (this can be accomplished by adding x and y to the translation vector defined by transform).
- gc
-
draw_markers
(self, gc, marker_path, marker_trans, path, transform, rgbFace=None)[source]¶ Draw a marker at each of path's vertices (excluding control points).
This provides a fallback implementation of draw_markers that makes multiple calls to
draw_path()
. Some backends may want to override this method in order to draw the marker only once and reuse it multiple times.Parameters: - gc
GraphicsContextBase
The graphics context.
- marker_trans
matplotlib.transforms.Transform
An affine transform applied to the marker.
- trans
matplotlib.transforms.Transform
An affine transform applied to the path.
- gc
-
draw_path
(self, gc, path, transform, rgbFace=None)[source]¶ Draw a
Path
instance using the given affine transform.
-
draw_text
(self, gc, x, y, s, prop, angle, ismath=False, mtext=None)[source]¶ Draw the text instance.
Parameters: - gc
GraphicsContextBase
The graphics context.
- xfloat
The x location of the text in display coords.
- yfloat
The y location of the text baseline in display coords.
- sstr
The text string.
- prop
matplotlib.font_manager.FontProperties
The font properties.
- anglefloat
The rotation angle in degrees anti-clockwise.
- mtext
matplotlib.text.Text
The original text object to be rendered.
Notes
Note for backend implementers:
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.
- gc
-
property
fontangles
¶
-
property
fontweights
¶
-
get_text_width_height_descent
(self, s, prop, ismath)[source]¶ Get the width, height, and descent (offset from the bottom to the baseline), in display coords, of the string s with
FontProperties
prop.
-
property
mathtext_parser
¶
-
new_gc
(self)[source]¶ Return an instance of a
GraphicsContextBase
.
-
points_to_pixels
(self, points)[source]¶ Convert points to display units.
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 * dpi/72
Parameters: - pointsfloat or array-like
a float or a numpy array of float
Returns: - Points converted to pixels
-