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"""
An agg http://antigrain.com/ backend
Features that are implemented
* capstyles and join styles
* dashes
* linewidth
* lines, rectangles, ellipses
* clipping to a rectangle
* output to RGBA and PNG
* alpha blending
* DPI scaling properly - everything scales properly (dashes, linewidths, etc)
* draw polygon
* freetype2 w/ ft2font
TODO:
* allow save to file handle
* integrate screen dpi w/ ppi and text
"""
from __future__ import division
import numpy as npy
from matplotlib import verbose, rcParams
from matplotlib.backend_bases import RendererBase,\
FigureManagerBase, FigureCanvasBase
from matplotlib.cbook import is_string_like, maxdict
from matplotlib.figure import Figure
from matplotlib.font_manager import findfont
from matplotlib.ft2font import FT2Font, LOAD_FORCE_AUTOHINT
from matplotlib.mathtext import MathTextParser
from matplotlib.path import Path
from matplotlib.transforms import Bbox, BboxBase
from _backend_agg import RendererAgg as _RendererAgg
from matplotlib import _png
backend_version = 'v2.2'
class RendererAgg(RendererBase):
"""
The renderer handles all the drawing primitives using a graphics
context instance that controls the colors/styles
"""
debug=1
def __init__(self, width, height, dpi):
if __debug__: verbose.report('RendererAgg.__init__', 'debug-annoying')
RendererBase.__init__(self)
self.texd = maxdict(50) # a cache of tex image rasters
self._fontd = maxdict(50)
self.dpi = dpi
self.width = width
self.height = height
if __debug__: verbose.report('RendererAgg.__init__ width=%s, height=%s'%(width, height), 'debug-annoying')
self._renderer = _RendererAgg(int(width), int(height), dpi, debug=False)
if __debug__: verbose.report('RendererAgg.__init__ _RendererAgg done',
'debug-annoying')
#self.draw_path = self._renderer.draw_path # see below
self.draw_markers = self._renderer.draw_markers
self.draw_path_collection = self._renderer.draw_path_collection
self.draw_quad_mesh = self._renderer.draw_quad_mesh
self.draw_image = self._renderer.draw_image
self.copy_from_bbox = self._renderer.copy_from_bbox
self.tostring_rgba_minimized = self._renderer.tostring_rgba_minimized
self.mathtext_parser = MathTextParser('Agg')
self.bbox = Bbox.from_bounds(0, 0, self.width, self.height)
if __debug__: verbose.report('RendererAgg.__init__ done',
'debug-annoying')
def draw_path(self, gc, path, transform, rgbFace=None):
"""
Draw the path
"""
nmax = rcParams['agg.path.chunksize'] # here at least for testing
npts = path.vertices.shape[0]
if (nmax > 100 and npts > nmax and path.should_simplify and
rgbFace is None and gc.get_hatch() is None):
nch = npy.ceil(npts/float(nmax))
chsize = int(npy.ceil(npts/nch))
i0 = npy.arange(0, npts, chsize)
i1 = npy.zeros_like(i0)
i1[:-1] = i0[1:] - 1
i1[-1] = npts
for ii0, ii1 in zip(i0, i1):
v = path.vertices[ii0:ii1,:]
c = path.codes
if c is not None:
c = c[ii0:ii1]
c[0] = Path.MOVETO # move to end of last chunk
p = Path(v, c)
self._renderer.draw_path(gc, p, transform, rgbFace)
else:
self._renderer.draw_path(gc, path, transform, rgbFace)
def draw_mathtext(self, gc, x, y, s, prop, angle):
"""
Draw the math text using matplotlib.mathtext
"""
if __debug__: verbose.report('RendererAgg.draw_mathtext',
'debug-annoying')
ox, oy, width, height, descent, font_image, used_characters = \
self.mathtext_parser.parse(s, self.dpi, prop)
x = int(x) + ox
y = int(y) - oy
self._renderer.draw_text_image(font_image, x, y + 1, angle, gc)
def draw_text(self, gc, x, y, s, prop, angle, ismath):
"""
Render the text
"""
if __debug__: verbose.report('RendererAgg.draw_text', 'debug-annoying')
if ismath:
return self.draw_mathtext(gc, x, y, s, prop, angle)
font = self._get_agg_font(prop)
if font is None: return None
if len(s) == 1 and ord(s) > 127:
font.load_char(ord(s), flags=LOAD_FORCE_AUTOHINT)
else:
# We pass '0' for angle here, since it will be rotated (in raster
# space) in the following call to draw_text_image).
font.set_text(s, 0, flags=LOAD_FORCE_AUTOHINT)
font.draw_glyphs_to_bitmap()
#print x, y, int(x), int(y)
self._renderer.draw_text_image(font.get_image(), int(x), int(y) + 1, angle, gc)
def get_text_width_height_descent(self, s, prop, ismath):
"""
get the width and height in display coords of the string s
with FontPropertry prop
# passing rgb is a little hack to make cacheing in the
# texmanager more efficient. It is not meant to be used
# outside the backend
"""
if ismath=='TeX':
# todo: handle props
size = prop.get_size_in_points()
texmanager = self.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
if ismath:
ox, oy, width, height, descent, fonts, used_characters = \
self.mathtext_parser.parse(s, self.dpi, prop)
return width, height, descent
font = self._get_agg_font(prop)
font.set_text(s, 0.0, flags=LOAD_FORCE_AUTOHINT) # the width and height of unrotated string
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 draw_tex(self, gc, x, y, s, prop, angle):
# todo, handle props, angle, origins
size = prop.get_size_in_points()
texmanager = self.get_texmanager()
key = s, size, self.dpi, angle, texmanager.get_font_config()
im = self.texd.get(key)
if im is None:
Z = texmanager.get_grey(s, size, self.dpi)
Z = npy.array(Z * 255.0, npy.uint8)
self._renderer.draw_text_image(Z, x, y, angle, gc)
def get_canvas_width_height(self):
'return the canvas width and height in display coords'
return self.width, self.height
def _get_agg_font(self, prop):
"""
Get the font for text instance t, cacheing for efficiency
"""
if __debug__: verbose.report('RendererAgg._get_agg_font',
'debug-annoying')
key = hash(prop)
font = self._fontd.get(key)
if font is None:
fname = findfont(prop)
font = self._fontd.get(fname)
if font is None:
font = FT2Font(str(fname))
self._fontd[fname] = font
self._fontd[key] = font
font.clear()
size = prop.get_size_in_points()
font.set_size(size, self.dpi)
return font
def points_to_pixels(self, points):
"""
convert point measures to pixes using dpi and the pixels per
inch of the display
"""
if __debug__: verbose.report('RendererAgg.points_to_pixels',
'debug-annoying')
return points*self.dpi/72.0
def tostring_rgb(self):
if __debug__: verbose.report('RendererAgg.tostring_rgb',
'debug-annoying')
return self._renderer.tostring_rgb()
def tostring_argb(self):
if __debug__: verbose.report('RendererAgg.tostring_argb',
'debug-annoying')
return self._renderer.tostring_argb()
def buffer_rgba(self,x,y):
if __debug__: verbose.report('RendererAgg.buffer_rgba',
'debug-annoying')
return self._renderer.buffer_rgba(x,y)
def clear(self):
self._renderer.clear()
def option_image_nocomposite(self):
# It is generally faster to composite each image directly to
# the Figure, and there's no file size benefit to compositing
# with the Agg backend
return True
def restore_region(self, region, bbox=None, xy=None):
"""
restore the saved region. if bbox (instance of BboxBase, or
its extents) is given, only the region specified by the bbox
will be restored. *xy* (a tuple of two floasts) optionally
specify the new position (of the LLC of the originally region,
not the LLC of the bbox) that the region will be restored.
>>> region = renderer.copy_from_bbox()
>>> x1, y1, x2, y2 = region.get_extents()
>>> renderer.restore_region(region, bbox=(x1+dx, y1, x2, y2),
xy=(x1-dx, y1))
"""
if bbox is not None or xy is not None:
if bbox is None:
x1, y1, x2, y2 = region.get_extents()
elif isinstance(bbox, BboxBase):
x1, y1, x2, y2 = bbox.extents
else:
x1, y1, x2, y2 = bbox
if xy is None:
ox, oy = x1, y1
else:
ox, oy = xy
self._renderer.restore_region2(region, x1, y1, x2, y2, ox, oy)
else:
self._renderer.restore_region(region)
def new_figure_manager(num, *args, **kwargs):
"""
Create a new figure manager instance
"""
if __debug__: verbose.report('backend_agg.new_figure_manager',
'debug-annoying')
FigureClass = kwargs.pop('FigureClass', Figure)
thisFig = FigureClass(*args, **kwargs)
canvas = FigureCanvasAgg(thisFig)
manager = FigureManagerBase(canvas, num)
return manager
class FigureCanvasAgg(FigureCanvasBase):
"""
The canvas the figure renders into. Calls the draw and print fig
methods, creates the renderers, etc...
Public attribute
figure - A Figure instance
"""
def copy_from_bbox(self, bbox):
renderer = self.get_renderer()
return renderer.copy_from_bbox(bbox)
def restore_region(self, region, bbox=None, xy=None):
renderer = self.get_renderer()
return renderer.restore_region(region, bbox, xy)
def draw(self):
"""
Draw the figure using the renderer
"""
if __debug__: verbose.report('FigureCanvasAgg.draw', 'debug-annoying')
self.renderer = self.get_renderer()
self.figure.draw(self.renderer)
def get_renderer(self):
l, b, w, h = self.figure.bbox.bounds
key = w, h, self.figure.dpi
try: self._lastKey, self.renderer
except AttributeError: need_new_renderer = True
else: need_new_renderer = (self._lastKey != key)
if need_new_renderer:
self.renderer = RendererAgg(w, h, self.figure.dpi)
self._lastKey = key
return self.renderer
def tostring_rgb(self):
if __debug__: verbose.report('FigureCanvasAgg.tostring_rgb',
'debug-annoying')
return self.renderer.tostring_rgb()
def tostring_argb(self):
if __debug__: verbose.report('FigureCanvasAgg.tostring_argb',
'debug-annoying')
return self.renderer.tostring_argb()
def buffer_rgba(self,x,y):
if __debug__: verbose.report('FigureCanvasAgg.buffer_rgba',
'debug-annoying')
return self.renderer.buffer_rgba(x,y)
def get_default_filetype(self):
return 'png'
def print_raw(self, filename_or_obj, *args, **kwargs):
FigureCanvasAgg.draw(self)
renderer = self.get_renderer()
original_dpi = renderer.dpi
renderer.dpi = self.figure.dpi
if is_string_like(filename_or_obj):
filename_or_obj = file(filename_or_obj, 'wb')
renderer._renderer.write_rgba(filename_or_obj)
renderer.dpi = original_dpi
print_rgba = print_raw
def print_png(self, filename_or_obj, *args, **kwargs):
FigureCanvasAgg.draw(self)
renderer = self.get_renderer()
original_dpi = renderer.dpi
renderer.dpi = self.figure.dpi
if is_string_like(filename_or_obj):
filename_or_obj = file(filename_or_obj, 'wb')
_png.write_png(renderer._renderer.buffer_rgba(0, 0),
renderer.width, renderer.height,
filename_or_obj, self.figure.dpi)
renderer.dpi = original_dpi
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