pyx/style.py

   1 # -*- encoding: utf-8 -*-
   2 #
   3 #
   4 # Copyright (C) 2002-2011 Jörg Lehmann <joergl@users.sourceforge.net>
   5 # Copyright (C) 2003-2006 Michael Schindler <m-schindler@users.sourceforge.net>
   6 # Copyright (C) 2002-2011 André Wobst <wobsta@users.sourceforge.net>
   7 #
   8 # This file is part of PyX (http://pyx.sourceforge.net/).
   9 #
  10 # PyX is free software; you can redistribute it and/or modify
  11 # it under the terms of the GNU General Public License as published by
  12 # the Free Software Foundation; either version 2 of the License, or
  13 # (at your option) any later version.
  14 #
  15 # PyX is distributed in the hope that it will be useful,
  16 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 # GNU General Public License for more details.
  19 #
  20 # You should have received a copy of the GNU General Public License
  21 # along with PyX; if not, write to the Free Software
  22 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  23
  24 import math
  25 import attr, unit, canvasitem
  26 import bbox as bboxmodule
  27
  28 #
  29 # base classes for stroke and fill styles
  30 #
  31
  32 class strokestyle(canvasitem.canvasitem):
  33     def bbox(self):
  34         # TODO: see TODO in bbox method of canvasitem
  35         return bboxmodule.empty()
  36
  37 class fillstyle(canvasitem.canvasitem):
  38     def bbox(self):
  39         # TODO: see TODO in bbox method of canvasitem
  40         return bboxmodule.empty()
  41
  42 #
  43 # common stroke styles
  44 #
  45
  46
  47 class linecap(attr.exclusiveattr, strokestyle):
  48
  49     """linecap of paths"""
  50
  51     def __init__(self, value=0):
  52         attr.exclusiveattr.__init__(self, linecap)
  53         self.value = value
  54
  55     def processPS(self, file, writer, context, registry, bbox):
  56         file.write("%d setlinecap\n" % self.value)
  57
  58     def processPDF(self, file, writer, context, registry, bbox):
  59         file.write("%d J\n" % self.value)
  60
  61 linecap.butt = linecap(0)
  62 linecap.round = linecap(1)
  63 linecap.square = linecap(2)
  64 linecap.clear = attr.clearclass(linecap)
  65
  66
  67 class linejoin(attr.exclusiveattr, strokestyle):
  68
  69     """linejoin of paths"""
  70
  71     def __init__(self, value=0):
  72         attr.exclusiveattr.__init__(self, linejoin)
  73         self.value = value
  74
  75     def processPS(self, file, writer, context, registry, bbox):
  76         file.write("%d setlinejoin\n" % self.value)
  77
  78     def processPDF(self, file, writer, context, registry, bbox):
  79         file.write("%d j\n" % self.value)
  80
  81 linejoin.miter = linejoin(0)
  82 linejoin.round = linejoin(1)
  83 linejoin.bevel = linejoin(2)
  84 linejoin.clear = attr.clearclass(linejoin)
  85
  86
  87 class miterlimit(attr.exclusiveattr, strokestyle):
  88
  89     """miterlimit of paths"""
  90
  91     def __init__(self, value=10.0):
  92         attr.exclusiveattr.__init__(self, miterlimit)
  93         self.value = value
  94
  95     def processPS(self, file, writer, context, registry, bbox):
  96         file.write("%f setmiterlimit\n" % self.value)
  97
  98     def processPDF(self, file, writer, context, registry, bbox):
  99         file.write("%f M\n" % self.value)
 100
 101 miterlimit.lessthan180deg = miterlimit(1/math.sin(math.pi*180/360))
 102 miterlimit.lessthan90deg = miterlimit(1/math.sin(math.pi*90/360))
 103 miterlimit.lessthan60deg = miterlimit(1/math.sin(math.pi*60/360))
 104 miterlimit.lessthan45deg = miterlimit(1/math.sin(math.pi*45/360))
 105 miterlimit.lessthan11deg = miterlimit(10) # the default, approximately 11.4783 degress
 106 miterlimit.clear = attr.clearclass(miterlimit)
 107
 108
 109 _defaultlinewidth = 0.02 * unit.w_cm
 110 _defaultlinewidth_pt = unit.topt(_defaultlinewidth)
 111
 112 class dash(attr.exclusiveattr, strokestyle):
 113
 114     """dash of paths"""
 115
 116     def __init__(self, pattern=[], offset=0, rellengths=1):
 117         """set pattern with offset.
 118
 119         If rellengths is True, interpret all dash lengths relative to current linewidth.
 120         """
 121         attr.exclusiveattr.__init__(self, dash)
 122         self.pattern = pattern
 123         self.offset = offset
 124         self.rellengths = rellengths
 125
 126     def processPS(self, file, writer, context, registry, bbox):
 127         if self.rellengths:
 128             patternstring = " ".join(["%f" % (element * context.linewidth_pt/_defaultlinewidth_pt) for element in self.pattern])
 129         else:
 130             patternstring = " ".join(["%f" % element for element in self.pattern])
 131         file.write("[%s] %d setdash\n" % (patternstring, self.offset))
 132
 133     def processPDF(self, file, writer, context, registry, bbox):
 134         if self.rellengths:
 135             patternstring = " ".join(["%f" % (element * context.linewidth_pt/_defaultlinewidth_pt) for element in self.pattern])
 136         else:
 137             patternstring = " ".join(["%f" % element for element in self.pattern])
 138         file.write("[%s] %d d\n" % (patternstring, self.offset))
 139
 140 dash.clear = attr.clearclass(dash)
 141
 142
 143 class linestyle(attr.exclusiveattr, strokestyle):
 144
 145     """linestyle (linecap together with dash) of paths"""
 146
 147     def __init__(self, c=linecap.butt, d=dash([])):
 148         # XXX better, but at the moment not supported by attr.exlusiveattr would be:
 149         # XXX   attr.exclusiveattr.__init__(self, [linestyle, linecap, dash])
 150         attr.exclusiveattr.__init__(self, linestyle)
 151         self.c = c
 152         self.d = d
 153
 154     def processPS(self, file, writer, context, registry, bbox):
 155         self.c.processPS(file, writer, context, registry, bbox)
 156         self.d.processPS(file, writer, context, registry, bbox)
 157
 158     def processPDF(self, file, writer, context, registry, bbox):
 159         self.c.processPDF(file, writer, context, registry, bbox)
 160         self.d.processPDF(file, writer, context, registry, bbox)
 161
 162 linestyle.solid = linestyle(linecap.butt, dash([]))
 163 linestyle.dashed = linestyle(linecap.butt, dash([2]))
 164 linestyle.dotted = linestyle(linecap.round, dash([0, 2]))
 165 linestyle.dashdotted = linestyle(linecap.round, dash([0, 2, 2, 2]))
 166 linestyle.clear = attr.clearclass(linestyle)
 167
 168
 169 class linewidth(attr.sortbeforeexclusiveattr, strokestyle):
 170
 171     """linewidth of paths"""
 172
 173     def __init__(self, width):
 174         attr.sortbeforeexclusiveattr.__init__(self, linewidth, [dash, linestyle])
 175         self.width = width
 176
 177     def processPS(self, file, writer, context, registry, bbox):
 178         file.write("%f setlinewidth\n" % unit.topt(self.width))
 179         context.linewidth_pt = unit.topt(self.width)
 180
 181     def processPDF(self, file, writer, context, registry, bbox):
 182         file.write("%f w\n" % unit.topt(self.width))
 183         context.linewidth_pt = unit.topt(self.width)
 184
 185 linewidth.THIN = linewidth(_defaultlinewidth/math.sqrt(32))
 186 linewidth.THIn = linewidth(_defaultlinewidth/math.sqrt(16))
 187 linewidth.THin = linewidth(_defaultlinewidth/math.sqrt(8))
 188 linewidth.Thin = linewidth(_defaultlinewidth/math.sqrt(4))
 189 linewidth.thin = linewidth(_defaultlinewidth/math.sqrt(2))
 190 linewidth.normal = linewidth(_defaultlinewidth)
 191 linewidth.thick = linewidth(_defaultlinewidth*math.sqrt(2))
 192 linewidth.Thick = linewidth(_defaultlinewidth*math.sqrt(4))
 193 linewidth.THick = linewidth(_defaultlinewidth*math.sqrt(8))
 194 linewidth.THIck = linewidth(_defaultlinewidth*math.sqrt(16))
 195 linewidth.THICk = linewidth(_defaultlinewidth*math.sqrt(32))
 196 linewidth.THICK = linewidth(_defaultlinewidth*math.sqrt(64))
 197 linewidth.clear = attr.clearclass(linewidth)
 198
 199
 200 class fillrule(attr.exclusiveattr):
 201
 202     """defines the fill rule to be used"""
 203
 204     def __init__(self, even_odd):
 205         attr.exclusiveattr.__init__(self, fillrule)
 206         self.even_odd = even_odd
 207
 208     def processPS(self, file, writer, context, registry, bbox):
 209         pass
 210
 211     def processPDF(self, file, writer, context, registry, bbox):
 212         pass
 213
 214 fillrule.nonzero_winding = fillrule(0)
 215 fillrule.even_odd = fillrule(1)
 216 fillrule.clear = attr.clearclass(fillrule)