pyx/style.py

   1 # -*- encoding: utf-8 -*-
   2 #
   3 #
   4 # Copyright (C) 2002-2012 Jörg Lehmann <joergl@users.sourceforge.net>
   5 # Copyright (C) 2003-2006 Michael Schindler <m-schindler@users.sourceforge.net>
   6 # Copyright (C) 2002-2012 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 from . import attr, unit
  26
  27 #
  28 # base classes for stroke and fill styles
  29 #
  30
  31 class style:
  32     pass
  33
  34 class strokestyle(style):
  35     pass
  36
  37 class fillstyle(style):
  38     pass
  39
  40 #
  41 # common stroke styles
  42 #
  43
  44
  45 class linecap(attr.exclusiveattr, strokestyle):
  46
  47     """linecap of paths"""
  48
  49     def __init__(self, value=0):
  50         attr.exclusiveattr.__init__(self, linecap)
  51         self.value = value
  52
  53     def processPS(self, file, writer, context, registry):
  54         file.write("%d setlinecap\n" % self.value)
  55
  56     def processPDF(self, file, writer, context, registry):
  57         file.write("%d J\n" % self.value)
  58
  59 linecap.butt = linecap(0)
  60 linecap.round = linecap(1)
  61 linecap.square = linecap(2)
  62 linecap.clear = attr.clearclass(linecap)
  63
  64
  65 class linejoin(attr.exclusiveattr, strokestyle):
  66
  67     """linejoin of paths"""
  68
  69     def __init__(self, value=0):
  70         attr.exclusiveattr.__init__(self, linejoin)
  71         self.value = value
  72
  73     def processPS(self, file, writer, context, registry):
  74         file.write("%d setlinejoin\n" % self.value)
  75
  76     def processPDF(self, file, writer, context, registry):
  77         file.write("%d j\n" % self.value)
  78
  79 linejoin.miter = linejoin(0)
  80 linejoin.round = linejoin(1)
  81 linejoin.bevel = linejoin(2)
  82 linejoin.clear = attr.clearclass(linejoin)
  83
  84
  85 class miterlimit(attr.exclusiveattr, strokestyle):
  86
  87     """miterlimit of paths"""
  88
  89     def __init__(self, value=10.0):
  90         attr.exclusiveattr.__init__(self, miterlimit)
  91         self.value = value
  92
  93     def processPS(self, file, writer, context, registry):
  94         file.write("%f setmiterlimit\n" % self.value)
  95
  96     def processPDF(self, file, writer, context, registry):
  97         file.write("%f M\n" % self.value)
  98
  99 miterlimit.lessthan180deg = miterlimit(1/math.sin(math.pi*180/360))
 100 miterlimit.lessthan90deg = miterlimit(1/math.sin(math.pi*90/360))
 101 miterlimit.lessthan60deg = miterlimit(1/math.sin(math.pi*60/360))
 102 miterlimit.lessthan45deg = miterlimit(1/math.sin(math.pi*45/360))
 103 miterlimit.lessthan11deg = miterlimit(10) # the default, approximately 11.4783 degress
 104 miterlimit.clear = attr.clearclass(miterlimit)
 105
 106
 107 _defaultlinewidth = 0.02 * unit.w_cm
 108 _defaultlinewidth_pt = unit.topt(_defaultlinewidth)
 109
 110 class dash(attr.exclusiveattr, strokestyle):
 111
 112     """dash of paths"""
 113
 114     def __init__(self, pattern=[], offset=0, rellengths=1):
 115         """set pattern with offset.
 116
 117         If rellengths is True, interpret all dash lengths relative to current linewidth.
 118         """
 119         attr.exclusiveattr.__init__(self, dash)
 120         self.pattern = pattern
 121         self.offset = offset
 122         self.rellengths = rellengths
 123
 124     def processPS(self, file, writer, context, registry):
 125         if self.rellengths:
 126             patternstring = " ".join(["%f" % (element * context.linewidth_pt/_defaultlinewidth_pt) for element in self.pattern])
 127         else:
 128             patternstring = " ".join(["%f" % element for element in self.pattern])
 129         file.write("[%s] %d setdash\n" % (patternstring, self.offset))
 130
 131     def processPDF(self, file, writer, context, registry):
 132         if self.rellengths:
 133             patternstring = " ".join(["%f" % (element * context.linewidth_pt/_defaultlinewidth_pt) for element in self.pattern])
 134         else:
 135             patternstring = " ".join(["%f" % element for element in self.pattern])
 136         file.write("[%s] %d d\n" % (patternstring, self.offset))
 137
 138 dash.clear = attr.clearclass(dash)
 139
 140
 141 class linestyle(attr.exclusiveattr, strokestyle):
 142
 143     """linestyle (linecap together with dash) of paths"""
 144
 145     def __init__(self, c=linecap.butt, d=dash([])):
 146         # XXX better, but at the moment not supported by attr.exlusiveattr would be:
 147         # XXX   attr.exclusiveattr.__init__(self, [linestyle, linecap, dash])
 148         attr.exclusiveattr.__init__(self, linestyle)
 149         self.c = c
 150         self.d = d
 151
 152     def processPS(self, file, writer, context, registry):
 153         self.c.processPS(file, writer, context, registry)
 154         self.d.processPS(file, writer, context, registry)
 155
 156     def processPDF(self, file, writer, context, registry):
 157         self.c.processPDF(file, writer, context, registry)
 158         self.d.processPDF(file, writer, context, registry)
 159
 160 linestyle.solid = linestyle(linecap.butt, dash([]))
 161 linestyle.dashed = linestyle(linecap.butt, dash([2]))
 162 linestyle.dotted = linestyle(linecap.round, dash([0, 2]))
 163 linestyle.dashdotted = linestyle(linecap.round, dash([0, 2, 2, 2]))
 164 linestyle.clear = attr.clearclass(linestyle)
 165
 166
 167 class linewidth(attr.sortbeforeexclusiveattr, strokestyle):
 168
 169     """linewidth of paths"""
 170
 171     def __init__(self, width):
 172         attr.sortbeforeexclusiveattr.__init__(self, linewidth, [dash, linestyle])
 173         self.width = width
 174
 175     def processPS(self, file, writer, context, registry):
 176         file.write("%f setlinewidth\n" % unit.topt(self.width))
 177         context.linewidth_pt = unit.topt(self.width)
 178
 179     def processPDF(self, file, writer, context, registry):
 180         file.write("%f w\n" % unit.topt(self.width))
 181         context.linewidth_pt = unit.topt(self.width)
 182
 183 linewidth.THIN = linewidth(_defaultlinewidth/math.sqrt(32))
 184 linewidth.THIn = linewidth(_defaultlinewidth/math.sqrt(16))
 185 linewidth.THin = linewidth(_defaultlinewidth/math.sqrt(8))
 186 linewidth.Thin = linewidth(_defaultlinewidth/math.sqrt(4))
 187 linewidth.thin = linewidth(_defaultlinewidth/math.sqrt(2))
 188 linewidth.normal = linewidth(_defaultlinewidth)
 189 linewidth.thick = linewidth(_defaultlinewidth*math.sqrt(2))
 190 linewidth.Thick = linewidth(_defaultlinewidth*math.sqrt(4))
 191 linewidth.THick = linewidth(_defaultlinewidth*math.sqrt(8))
 192 linewidth.THIck = linewidth(_defaultlinewidth*math.sqrt(16))
 193 linewidth.THICk = linewidth(_defaultlinewidth*math.sqrt(32))
 194 linewidth.THICK = linewidth(_defaultlinewidth*math.sqrt(64))
 195 linewidth.clear = attr.clearclass(linewidth)
 196
 197
 198 class fillrule(attr.exclusiveattr, fillstyle):
 199
 200     """defines the fill rule to be used"""
 201
 202     def __init__(self, even_odd):
 203         attr.exclusiveattr.__init__(self, fillrule)
 204         self.even_odd = even_odd
 205
 206     def processPS(self, file, writer, context, registry):
 207         context.fillrule = self.even_odd
 208
 209     def processPDF(self, file, writer, context, registry):
 210         context.fillrule = self.even_odd
 211
 212 fillrule.nonzero_winding = fillrule(0)
 213 fillrule.even_odd = fillrule(1)
 214 fillrule.clear = attr.clearclass(fillrule)