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     def processSVGattrs(self, attrs, writer, context, registry):
  60         attrs["stroke-linecap"] = {0: "butt", 1: "round", 2: "square"}[self.value]
  61
  62
  63 linecap.butt = linecap(0)
  64 linecap.round = linecap(1)
  65 linecap.square = linecap(2)
  66 linecap.clear = attr.clearclass(linecap)
  67
  68
  69 class linejoin(attr.exclusiveattr, strokestyle):
  70
  71     """linejoin of paths"""
  72
  73     def __init__(self, value=0):
  74         attr.exclusiveattr.__init__(self, linejoin)
  75         self.value = value
  76
  77     def processPS(self, file, writer, context, registry):
  78         file.write("%d setlinejoin\n" % self.value)
  79
  80     def processPDF(self, file, writer, context, registry):
  81         file.write("%d j\n" % self.value)
  82
  83     def processSVGattrs(self, attrs, writer, context, registry):
  84         attrs["stroke-linejoin"] = {0: "miter", 1: "round", 2: "bevel"}[self.value]
  85
  86 linejoin.miter = linejoin(0)
  87 linejoin.round = linejoin(1)
  88 linejoin.bevel = linejoin(2)
  89 linejoin.clear = attr.clearclass(linejoin)
  90
  91
  92 class miterlimit(attr.exclusiveattr, strokestyle):
  93
  94     """miterlimit of paths"""
  95
  96     def __init__(self, value=10.0):
  97         attr.exclusiveattr.__init__(self, miterlimit)
  98         self.value = value
  99
 100     def processPS(self, file, writer, context, registry):
 101         file.write("%f setmiterlimit\n" % self.value)
 102
 103     def processPDF(self, file, writer, context, registry):
 104         file.write("%f M\n" % self.value)
 105
 106     def processSVGattrs(self, attrs, writer, context, registry):
 107         attrs["stroke-miterlimit"] = "%f" % self.value
 108
 109 miterlimit.lessthan180deg = miterlimit(1/math.sin(math.pi*180/360))
 110 miterlimit.lessthan90deg = miterlimit(1/math.sin(math.pi*90/360))
 111 miterlimit.lessthan60deg = miterlimit(1/math.sin(math.pi*60/360))
 112 miterlimit.lessthan45deg = miterlimit(1/math.sin(math.pi*45/360))
 113 miterlimit.lessthan11deg = miterlimit(10) # the default, approximately 11.4783 degress
 114 miterlimit.clear = attr.clearclass(miterlimit)
 115
 116
 117 _defaultlinewidth = 0.02 * unit.w_cm
 118 _defaultlinewidth_pt = unit.topt(_defaultlinewidth)
 119
 120 class dash(attr.exclusiveattr, strokestyle):
 121
 122     """dash of paths"""
 123
 124     def __init__(self, pattern=[], offset=0, rellengths=1):
 125         """set pattern with offset.
 126
 127         If rellengths is True, interpret all dash lengths relative to current linewidth.
 128         """
 129         attr.exclusiveattr.__init__(self, dash)
 130         self.pattern = pattern
 131         self.offset = offset
 132         self.rellengths = rellengths
 133
 134     def processPS(self, file, writer, context, registry):
 135         if self.rellengths:
 136             patternstring = " ".join(["%f" % (element * context.linewidth_pt/_defaultlinewidth_pt) for element in self.pattern])
 137         else:
 138             patternstring = " ".join(["%f" % element for element in self.pattern])
 139         file.write("[%s] %f setdash\n" % (patternstring, self.offset))
 140
 141     def processPDF(self, file, writer, context, registry):
 142         if self.rellengths:
 143             patternstring = " ".join(["%f" % (element * context.linewidth_pt/_defaultlinewidth_pt) for element in self.pattern])
 144         else:
 145             patternstring = " ".join(["%f" % element for element in self.pattern])
 146         file.write("[%s] %f d\n" % (patternstring, self.offset))
 147
 148     def processSVGattrs(self, attrs, writer, context, registry):
 149         if self.rellengths:
 150             patternstring = " ".join(["%f" % (element * context.linewidth_pt/_defaultlinewidth_pt) for element in self.pattern])
 151         else:
 152             patternstring = " ".join(["%f" % element for element in self.pattern])
 153         if patternstring:
 154             attrs["stroke-dasharray"] = patternstring
 155             attrs["stroke-dashoffset"] = "%f" % self.offset
 156         else:
 157             attrs["stroke-dasharray"] = "none"
 158
 159 dash.clear = attr.clearclass(dash)
 160
 161
 162 class linestyle(attr.exclusiveattr, strokestyle):
 163
 164     """linestyle (linecap together with dash) of paths"""
 165
 166     def __init__(self, c=linecap.butt, d=dash([])):
 167         # XXX better, but at the moment not supported by attr.exlusiveattr would be:
 168         # XXX   attr.exclusiveattr.__init__(self, [linestyle, linecap, dash])
 169         attr.exclusiveattr.__init__(self, linestyle)
 170         self.c = c
 171         self.d = d
 172
 173     def processPS(self, file, writer, context, registry):
 174         self.c.processPS(file, writer, context, registry)
 175         self.d.processPS(file, writer, context, registry)
 176
 177     def processPDF(self, file, writer, context, registry):
 178         self.c.processPDF(file, writer, context, registry)
 179         self.d.processPDF(file, writer, context, registry)
 180
 181     def processSVGattrs(self, attrs, writer, context, registry):
 182         self.c.processSVGattrs(attrs, writer, context, registry)
 183         self.d.processSVGattrs(attrs, writer, context, registry)
 184
 185 linestyle.solid = linestyle(linecap.butt, dash([]))
 186 linestyle.dashed = linestyle(linecap.butt, dash([2]))
 187 linestyle.dotted = linestyle(linecap.round, dash([0, 2]))
 188 linestyle.dashdotted = linestyle(linecap.round, dash([0, 2, 2, 2]))
 189 linestyle.clear = attr.clearclass(linestyle)
 190
 191
 192 class linewidth(attr.sortbeforeexclusiveattr, strokestyle):
 193
 194     """linewidth of paths"""
 195
 196     def __init__(self, width):
 197         attr.sortbeforeexclusiveattr.__init__(self, linewidth, [dash, linestyle])
 198         self.width = width
 199
 200     def processPS(self, file, writer, context, registry):
 201         context.linewidth_pt = unit.topt(self.width)
 202         file.write("%f setlinewidth\n" % context.linewidth_pt)
 203
 204     def processPDF(self, file, writer, context, registry):
 205         context.linewidth_pt = unit.topt(self.width)
 206         file.write("%f w\n" % context.linewidth_pt)
 207
 208     def processSVGattrs(self, attrs, writer, context, registry):
 209         context.linewidth_pt = unit.topt(self.width)
 210         attrs["stroke-width"] = "%f" % context.linewidth_pt
 211
 212 linewidth.THIN = linewidth(_defaultlinewidth/math.sqrt(32))
 213 linewidth.THIn = linewidth(_defaultlinewidth/math.sqrt(16))
 214 linewidth.THin = linewidth(_defaultlinewidth/math.sqrt(8))
 215 linewidth.Thin = linewidth(_defaultlinewidth/math.sqrt(4))
 216 linewidth.thin = linewidth(_defaultlinewidth/math.sqrt(2))
 217 linewidth.normal = linewidth(_defaultlinewidth)
 218 linewidth.thick = linewidth(_defaultlinewidth*math.sqrt(2))
 219 linewidth.Thick = linewidth(_defaultlinewidth*math.sqrt(4))
 220 linewidth.THick = linewidth(_defaultlinewidth*math.sqrt(8))
 221 linewidth.THIck = linewidth(_defaultlinewidth*math.sqrt(16))
 222 linewidth.THICk = linewidth(_defaultlinewidth*math.sqrt(32))
 223 linewidth.THICK = linewidth(_defaultlinewidth*math.sqrt(64))
 224 linewidth.clear = attr.clearclass(linewidth)
 225
 226
 227 class fillrule(attr.exclusiveattr, fillstyle):
 228
 229     """defines the fill rule to be used"""
 230
 231     def __init__(self, even_odd):
 232         attr.exclusiveattr.__init__(self, fillrule)
 233         self.even_odd = even_odd
 234
 235     def processPS(self, file, writer, context, registry):
 236         context.fillrule = self.even_odd
 237
 238     def processPDF(self, file, writer, context, registry):
 239         context.fillrule = self.even_odd
 240
 241     def processSVGattrs(self, attrs, writer, context, registry):
 242         attrs["fill-rule"] = {0: "nonzero", 1: "evenodd"}[self.even_odd]
 243
 244 fillrule.nonzero_winding = fillrule(0)
 245 fillrule.even_odd = fillrule(1)
 246 fillrule.clear = attr.clearclass(fillrule)