faces/charting/renderer.py

   1 ############################################################################
   2 #   Copyright (C) 2005 by Reithinger GmbH
   3 #   mreithinger@web.de
   4 #
   5 #   This file is part of faces.
   6 #
   7 #   faces is free software; you can redistribute it and/or modify
   8 #   it under the terms of the GNU General Public License as published by
   9 #   the Free Software Foundation; either version 2 of the License, or
  10 #   (at your option) any later version.
  11 #
  12 #   faces is distributed in the hope that it will be useful,
  13 #   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 #   GNU General Public License for more details.
  16 #
  17 #   You should have received a copy of the GNU General Public License
  18 #   along with this program; if not, write to the
  19 #   Free Software Foundation, Inc.,
  20 #   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 ############################################################################
  22
  23 """
  24 Patched Renderers of matplotlib
  25 """
  26
  27 import matplotlib.numerix as numerix
  28 import matplotlib.transforms as mtrans
  29 import matplotlib.backends.backend_agg as agg
  30 import math
  31
  32
  33 class PatchedRendererAgg(agg.RendererAgg):
  34     def __init__(self, *args, **kwargs):
  35         agg.RendererAgg.__init__(self, *args, **kwargs)
  36         self.old_draw_lines = self.draw_lines
  37         self.draw_lines = self.patched_draw_lines
  38         self.dumy_trans = mtrans.identity_transform()
  39
  40
  41     def patched_draw_lines(self, gc, xs, ys, trans=None):
  42         self.old_draw_lines(gc, xs, ys, trans or self.dumy_trans)
  43
  44
  45     def draw_line(self, gc, x1, y1, x2, y2):
  46         """
  47         x and y are equal length arrays, draw lines connecting each
  48         point in x, y
  49         """
  50         x = numerix.array([x1,x2], typecode=numerix.Float)
  51         y = numerix.array([y1,y2], typecode=numerix.Float)
  52         self.patched_draw_lines(gc, x, y)
  53
  54
  55     def draw_text(self, gc, x, y, s, prop, angle, ismath):
  56         if ismath:
  57             return self.draw_mathtext(gc, x, y, s, prop, angle)
  58
  59         font = self._get_agg_font(prop)
  60         if font is None: return None
  61         if len(s)==1 and ord(s)>127:
  62             font.load_char(ord(s))
  63         else:
  64             font.set_text(s, angle)
  65         font.draw_glyphs_to_bitmap()
  66
  67         decent = font.get_descent() / 64.0
  68         #print x, y, int(x), int(y)
  69
  70         self._renderer.draw_text(font, int(x), int(y + decent), gc)
  71
  72
  73 class PatchedFigureCanvasAgg(agg.FigureCanvasAgg):
  74     def get_renderer(self):
  75         l,b,w,h = self.figure.bbox.get_bounds()
  76         key = w, h, self.figure.dpi.get()
  77         try: self._lastKey, self.renderer
  78         except AttributeError: need_new_renderer = True
  79         else:  need_new_renderer = (self._lastKey != key)
  80
  81         if need_new_renderer:
  82             self.renderer = PatchedRendererAgg(w, h, self.figure.dpi)
  83             self._lastKey = key
  84
  85         return self.renderer
  86
  87
  88 class SpeedupGraphicsContext(agg.GraphicsContextBase):
  89     def set_alpha(self, alpha):
  90         # workaround for alpha bug in agg (needed for WidgetAxes.speed_up)
  91         # If normal alpha would be set, the object is to light by factor alpha
  92         # in speed_up cache.
  93         agg.GraphicsContextBase.set_alpha(self, math.sqrt(alpha))
  94
  95
  96 class SpeedupRenderer(PatchedRendererAgg):
  97     def new_gc(self):
  98         """
  99         Return an instance of a GraphicsContextBase
 100         """
 101         return SpeedupGraphicsContext()