pyx/color.py

   1 #!/usr/bin/env python
   2 # -*- coding: ISO-8859-1 -*-
   3 #
   4 #
   5 # Copyright (C) 2002-2004, 2006 Jörg Lehmann <joergl@users.sourceforge.net>
   6 # Copyright (C) 2003-2006 Michael Schindler <m-schindler@users.sourceforge.net>
   7 # Copyright (C) 2002-2004 André Wobst <wobsta@users.sourceforge.net>
   8 #
   9 # This file is part of PyX (http://pyx.sourceforge.net/).
  10 #
  11 # PyX is free software; you can redistribute it and/or modify
  12 # it under the terms of the GNU General Public License as published by
  13 # the Free Software Foundation; either version 2 of the License, or
  14 # (at your option) any later version.
  15 #
  16 # PyX is distributed in the hope that it will be useful,
  17 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 # GNU General Public License for more details.
  20 #
  21 # You should have received a copy of the GNU General Public License
  22 # along with PyX; if not, write to the Free Software
  23 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  24
  25 import colorsys, math
  26 import attr, style, pdfwriter
  27
  28 # device-dependend (nonlinear) functions for color conversion
  29 # UCRx : [0,1] -> [-1, 1] UnderColorRemoval (removes black from c, y, m)
  30 # BG   : [0,1] -> [0, 1]  BlackGeneration (generate the black from the nominal k-value)
  31 # as long as we have no further knowledge we define them linearly with constants 1
  32 def _UCRc(x): return x
  33 def _UCRm(x): return x
  34 def _UCRy(x): return x
  35 def _BG(x): return x
  36
  37 def set(UCRc=None, UCRm=None, UCRy=None, BG=None):
  38     global _UCRc
  39     global _UCRm
  40     global _UCRy
  41     global _BG
  42
  43     if UCRc is not None:
  44         _UCRc = UCRc
  45     if UCRm is not None:
  46         _UCRm = UCRm
  47     if UCRy is not None:
  48         _UCRy = UCRy
  49     if BG is not None:
  50         _BG = BG
  51
  52
  53 class color(attr.exclusiveattr, style.strokestyle, style.fillstyle):
  54
  55     """base class for all colors"""
  56
  57     def __init__(self):
  58         attr.exclusiveattr.__init__(self, color)
  59
  60
  61 clear = attr.clearclass(color)
  62
  63
  64 class grey(color):
  65
  66     """grey tones"""
  67
  68     def __init__(self, gray):
  69         color.__init__(self)
  70         if gray<0 or gray>1: raise ValueError
  71         self.color = {"gray": gray}
  72
  73     def processPS(self, file, writer, context, registry, bbox):
  74         file.write("%(gray)g setgray\n" % self.color)
  75
  76     def processPDF(self, file, writer, context, registry, bbox):
  77         if context.strokeattr:
  78             file.write("%(gray)f G\n" % self.color)
  79         if context.fillattr:
  80             file.write("%(gray)f g\n" % self.color)
  81
  82     def cmyk(self):
  83         return cmyk(0, 0, 0, 1 - self.color["gray"])
  84
  85     def grey(self):
  86         return self
  87     gray = grey
  88
  89     def hsb(self):
  90         return hsb(0, 0, self.color["gray"])
  91
  92     def rgb(self):
  93         return rgb(self.color["gray"], self.color["gray"], self.color["gray"])
  94
  95 grey.black = grey(0.0)
  96 grey.white = grey(1.0)
  97 gray = grey
  98
  99
 100 class rgb(color):
 101
 102     """rgb colors"""
 103
 104     def __init__(self, r=0.0, g=0.0, b=0.0):
 105         color.__init__(self)
 106         if r<0 or r>1 or g<0 or g>1 or b<0 or b>1: raise ValueError
 107         self.color = {"r": r, "g": g, "b": b}
 108
 109     def processPS(self, file, writer, context, registry, bbox):
 110         file.write("%(r)g %(g)g %(b)g setrgbcolor\n" % self.color)
 111
 112     def processPDF(self, file, writer, context, registry, bbox):
 113         if context.strokeattr:
 114             file.write("%(r)f %(g)f %(b)f RG\n" % self.color)
 115         if context.fillattr:
 116             file.write("%(r)f %(g)f %(b)f rg\n" % self.color)
 117
 118     def cmyk(self):
 119         # conversion to cmy
 120         c, m, y = 1 - self.color["r"], 1 - self.color["g"], 1 - self.color["b"]
 121         # conversion from cmy to cmyk with device-dependent functions
 122         k = min([c, m, y])
 123         return cmyk(min(1, max(0, c - _UCRc(k))),
 124                     min(1, max(0, m - _UCRm(k))),
 125                     min(1, max(0, y - _UCRy(k))),
 126                     _BG(k))
 127
 128     def grey(self):
 129         return grey(0.3*self.color["r"] + 0.59*self.color["g"] + 0.11*self.color["b"])
 130     gray = grey
 131
 132     def hsb(self):
 133
 134         values = self.color.values()
 135         values.sort()
 136         z, y, x = values
 137         r, g, b = self.color["r"], self.color["g"], self.color["b"]
 138         try:
 139             if r == x and g == z:
 140                 return hsb((5 + (x-b)/(x-z)) / 6.0, (x - z) / x, x)
 141             elif r == x and g > z:
 142                 return hsb((1 - (x-g)/(x-z)) / 6.0, (x - z) / x, x)
 143             elif g == x and b == z:
 144                 return hsb((1 + (x-r)/(x-z)) / 6.0, (x - z) / x, x)
 145             elif g == x and b > z:
 146                 return hsb((3 - (x-b)/(x-z)) / 6.0, (x - z) / x, x)
 147             elif b == x and r == z:
 148                 return hsb((3 + (x-g)/(x-z)) / 6.0, (x - z) / x, x)
 149             elif b == x and r > z:
 150                 return hsb((5 - (x-r)/(x-z)) / 6.0, (x - z) / x, x)
 151             else:
 152                 raise ValueError
 153         except ZeroDivisionError:
 154             return hsb(0, 0, x)
 155
 156     def rgb(self):
 157         return self
 158
 159 rgb.red   = rgb(1 ,0, 0)
 160 rgb.green = rgb(0 ,1, 0)
 161 rgb.blue  = rgb(0 ,0, 1)
 162 rgb.white = rgb(1 ,1, 1)
 163 rgb.black = rgb(0 ,0, 0)
 164
 165
 166 class hsb(color):
 167
 168     """hsb colors"""
 169
 170     def __init__(self, h=0.0, s=0.0, b=0.0):
 171         color.__init__(self)
 172         if h<0 or h>1 or s<0 or s>1 or b<0 or b>1: raise ValueError
 173         self.color = {"h": h, "s": s, "b": b}
 174
 175     def processPS(self, file, writer, context, registry, bbox):
 176         file.write("%(h)g %(s)g %(b)g sethsbcolor\n" % self.color)
 177
 178     def processPDF(self, file, writer, context, registry, bbox):
 179         r, g, b = colorsys.hsv_to_rgb(self.color["h"], self.color["s"], self.color["b"])
 180         rgb(r, g, b).processPDF(file, writer, context, registry, bbox)
 181
 182     def cmyk(self):
 183         return self.rgb().cmyk()
 184
 185     def grey(self):
 186         return self.rgb().grey()
 187     gray = grey
 188
 189     def hsb(self):
 190         return self
 191
 192     def rgb(self):
 193         h, s, b = self.color["h"], self.color["s"], self.color["b"]
 194         i = int(6*h)
 195         f = 6*h - i
 196         m, n, k = 1 - s, 1 - s*f, 1 - s*(1-f)
 197         if i == 1:
 198             return rgb(b*n, b, b*m)
 199         elif i == 2:
 200             return rgb(b*m, b, b*k)
 201         elif i == 3:
 202             return rgb(b*m, b*n, b)
 203         elif i == 4:
 204             return rgb(b*k, b*m, b)
 205         elif i == 5:
 206             return rgb(b, b*m, b*n)
 207         else:
 208             return rgb(b, b*k, b*m)
 209
 210
 211 class cmyk(color):
 212
 213     """cmyk colors"""
 214
 215     def __init__(self, c=0.0, m=0.0, y=0.0, k=0.0):
 216         color.__init__(self)
 217         if c<0 or c>1 or m<0 or m>1 or y<0 or y>1 or k<0 or k>1: raise ValueError
 218         self.color = {"c": c, "m": m, "y": y, "k": k}
 219
 220     def processPS(self, file, writer, context, registry, bbox):
 221         file.write("%(c)g %(m)g %(y)g %(k)g setcmykcolor\n" % self.color)
 222
 223     def processPDF(self, file, writer, context, registry, bbox):
 224         if context.strokeattr:
 225             file.write("%(c)f %(m)f %(y)f %(k)f K\n" % self.color)
 226         if context.fillattr:
 227             file.write("%(c)f %(m)f %(y)f %(k)f k\n" % self.color)
 228
 229     def cmyk(self):
 230         return self
 231
 232     def grey(self):
 233         return grey(1 - min([1, 0.3*self.color["c"] + 0.59*self.color["m"] +
 234                                 0.11*self.color["y"] + self.color["k"]]))
 235     gray = grey
 236
 237     def hsb(self):
 238         return self.rgb().hsb()
 239
 240     def rgb(self):
 241         # conversion to cmy:
 242         c = min(1, self.color["c"] + self.color["k"])
 243         m = min(1, self.color["m"] + self.color["k"])
 244         y = min(1, self.color["y"] + self.color["k"])
 245         # conversion from cmy to rgb:
 246         return rgb(1 - c, 1 - m, 1 - y)
 247
 248 cmyk.GreenYellow    = cmyk(0.15, 0, 0.69, 0)
 249 cmyk.Yellow         = cmyk(0, 0, 1, 0)
 250 cmyk.Goldenrod      = cmyk(0, 0.10, 0.84, 0)
 251 cmyk.Dandelion      = cmyk(0, 0.29, 0.84, 0)
 252 cmyk.Apricot        = cmyk(0, 0.32, 0.52, 0)
 253 cmyk.Peach          = cmyk(0, 0.50, 0.70, 0)
 254 cmyk.Melon          = cmyk(0, 0.46, 0.50, 0)
 255 cmyk.YellowOrange   = cmyk(0, 0.42, 1, 0)
 256 cmyk.Orange         = cmyk(0, 0.61, 0.87, 0)
 257 cmyk.BurntOrange    = cmyk(0, 0.51, 1, 0)
 258 cmyk.Bittersweet    = cmyk(0, 0.75, 1, 0.24)
 259 cmyk.RedOrange      = cmyk(0, 0.77, 0.87, 0)
 260 cmyk.Mahogany       = cmyk(0, 0.85, 0.87, 0.35)
 261 cmyk.Maroon         = cmyk(0, 0.87, 0.68, 0.32)
 262 cmyk.BrickRed       = cmyk(0, 0.89, 0.94, 0.28)
 263 cmyk.Red            = cmyk(0, 1, 1, 0)
 264 cmyk.OrangeRed      = cmyk(0, 1, 0.50, 0)
 265 cmyk.RubineRed      = cmyk(0, 1, 0.13, 0)
 266 cmyk.WildStrawberry = cmyk(0, 0.96, 0.39, 0)
 267 cmyk.Salmon         = cmyk(0, 0.53, 0.38, 0)
 268 cmyk.CarnationPink  = cmyk(0, 0.63, 0, 0)
 269 cmyk.Magenta        = cmyk(0, 1, 0, 0)
 270 cmyk.VioletRed      = cmyk(0, 0.81, 0, 0)
 271 cmyk.Rhodamine      = cmyk(0, 0.82, 0, 0)
 272 cmyk.Mulberry       = cmyk(0.34, 0.90, 0, 0.02)
 273 cmyk.RedViolet      = cmyk(0.07, 0.90, 0, 0.34)
 274 cmyk.Fuchsia        = cmyk(0.47, 0.91, 0, 0.08)
 275 cmyk.Lavender       = cmyk(0, 0.48, 0, 0)
 276 cmyk.Thistle        = cmyk(0.12, 0.59, 0, 0)
 277 cmyk.Orchid         = cmyk(0.32, 0.64, 0, 0)
 278 cmyk.DarkOrchid     = cmyk(0.40, 0.80, 0.20, 0)
 279 cmyk.Purple         = cmyk(0.45, 0.86, 0, 0)
 280 cmyk.Plum           = cmyk(0.50, 1, 0, 0)
 281 cmyk.Violet         = cmyk(0.79, 0.88, 0, 0)
 282 cmyk.RoyalPurple    = cmyk(0.75, 0.90, 0, 0)
 283 cmyk.BlueViolet     = cmyk(0.86, 0.91, 0, 0.04)
 284 cmyk.Periwinkle     = cmyk(0.57, 0.55, 0, 0)
 285 cmyk.CadetBlue      = cmyk(0.62, 0.57, 0.23, 0)
 286 cmyk.CornflowerBlue = cmyk(0.65, 0.13, 0, 0)
 287 cmyk.MidnightBlue   = cmyk(0.98, 0.13, 0, 0.43)
 288 cmyk.NavyBlue       = cmyk(0.94, 0.54, 0, 0)
 289 cmyk.RoyalBlue      = cmyk(1, 0.50, 0, 0)
 290 cmyk.Blue           = cmyk(1, 1, 0, 0)
 291 cmyk.Cerulean       = cmyk(0.94, 0.11, 0, 0)
 292 cmyk.Cyan           = cmyk(1, 0, 0, 0)
 293 cmyk.ProcessBlue    = cmyk(0.96, 0, 0, 0)
 294 cmyk.SkyBlue        = cmyk(0.62, 0, 0.12, 0)
 295 cmyk.Turquoise      = cmyk(0.85, 0, 0.20, 0)
 296 cmyk.TealBlue       = cmyk(0.86, 0, 0.34, 0.02)
 297 cmyk.Aquamarine     = cmyk(0.82, 0, 0.30, 0)
 298 cmyk.BlueGreen      = cmyk(0.85, 0, 0.33, 0)
 299 cmyk.Emerald        = cmyk(1, 0, 0.50, 0)
 300 cmyk.JungleGreen    = cmyk(0.99, 0, 0.52, 0)
 301 cmyk.SeaGreen       = cmyk(0.69, 0, 0.50, 0)
 302 cmyk.Green          = cmyk(1, 0, 1, 0)
 303 cmyk.ForestGreen    = cmyk(0.91, 0, 0.88, 0.12)
 304 cmyk.PineGreen      = cmyk(0.92, 0, 0.59, 0.25)
 305 cmyk.LimeGreen      = cmyk(0.50, 0, 1, 0)
 306 cmyk.YellowGreen    = cmyk(0.44, 0, 0.74, 0)
 307 cmyk.SpringGreen    = cmyk(0.26, 0, 0.76, 0)
 308 cmyk.OliveGreen     = cmyk(0.64, 0, 0.95, 0.40)
 309 cmyk.RawSienna      = cmyk(0, 0.72, 1, 0.45)
 310 cmyk.Sepia          = cmyk(0, 0.83, 1, 0.70)
 311 cmyk.Brown          = cmyk(0, 0.81, 1, 0.60)
 312 cmyk.Tan            = cmyk(0.14, 0.42, 0.56, 0)
 313 cmyk.Gray           = cmyk(0, 0, 0, 0.50)
 314 cmyk.Grey           = cmyk.Gray
 315 cmyk.Black          = cmyk(0, 0, 0, 1)
 316 cmyk.White          = cmyk(0, 0, 0, 0)
 317 cmyk.white          = cmyk.White
 318 cmyk.black          = cmyk.Black
 319
 320
 321 class palette(color, attr.changeattr):
 322
 323     """base class for all palettes
 324
 325     A palette is a collection of colors with a single parameter ranging from 0 to 1
 326     to address them"""
 327
 328     def __init__(self):
 329         color.__init__(self)
 330
 331     def getcolor(self, param):
 332         """return color corresponding to param"""
 333         pass
 334
 335     def select(self, index, n_indices):
 336         """return a color corresponding to an index out of n_indices"""
 337         if n_indices == 1:
 338             param = 0
 339         else:
 340             param = index / (n_indices - 1.0)
 341         return self.getcolor(param)
 342
 343     def processPS(self, file, writer, context, registry, bbox):
 344         self.getcolor(0).processPS(file, writer, context)
 345
 346     def processPDF(self, file, writer, context, registry, bbox):
 347         self.getcolor(0).processPDF(file, writer, context)
 348
 349
 350 class linearpalette(palette):
 351
 352     """linearpalette is a collection of two colors for a linear transition between them"""
 353
 354     def __init__(self, mincolor, maxcolor):
 355         palette.__init__(self)
 356         if mincolor.__class__ != maxcolor.__class__:
 357             raise ValueError
 358         self.colorclass = mincolor.__class__
 359         self.mincolor = mincolor
 360         self.maxcolor = maxcolor
 361
 362     def getcolor(self, param):
 363         colordict = {}
 364         for key in self.mincolor.color.keys():
 365             colordict[key] = param * self.maxcolor.color[key] + (1 - param) * self.mincolor.color[key]
 366         return self.colorclass(**colordict)
 367
 368
 369 class functionpalette(palette):
 370
 371     """functionpalette is a collection of colors for an arbitray non-linear transition between them
 372
 373     parameters:
 374     functions: a dictionary for the color values
 375     type:      a string indicating the color class
 376     """
 377
 378     def __init__(self, functions, type):
 379         palette.__init__(self)
 380         if type == "cmyk":
 381             self.colorclass = cmyk
 382         elif type == "rgb":
 383             self.colorclass = rgb
 384         elif type == "hsb":
 385             self.colorclass = hsb
 386         elif type == "grey" or type == "gray":
 387             self.colorclass = grey
 388         else:
 389             raise ValueError
 390         self.functions = functions
 391
 392     def getcolor(self, param):
 393         colordict = {}
 394         for key in self.functions.keys():
 395             colordict[key] = self.functions[key](param)
 396         return self.colorclass(**colordict)
 397
 398
 399 palette.Gray           = linearpalette(gray.white, gray.black)
 400 palette.Grey           = palette.Gray
 401 palette.ReverseGray    = linearpalette(gray.black, gray.white)
 402 palette.ReverseGrey    = palette.ReverseGray
 403 palette.BlackYellow    = functionpalette(functions={#(compare this with reversegray above)
 404     "r":(lambda x: 2*x*(1-x)**5 + 3.5*x**2*(1-x)**3 + 2.1*x*x*(1-x)**2 + 3.0*x**3*(1-x)**2 + x**0.5*(1-(1-x)**2)),
 405     "g":(lambda x: 1.5*x**2*(1-x)**3 - 0.8*x**3*(1-x)**2 + 2.0*x**4*(1-x) + x**4),
 406     "b":(lambda x: 5*x*(1-x)**5 - 0.5*x**2*(1-x)**3 + 0.3*x*x*(1-x)**2 + 5*x**3*(1-x)**2 + 0.5*x**6)},
 407     type="rgb")
 408 palette.RedGreen       = linearpalette(rgb.red, rgb.green)
 409 palette.RedBlue        = linearpalette(rgb.red, rgb.blue)
 410 palette.GreenRed       = linearpalette(rgb.green, rgb.red)
 411 palette.GreenBlue      = linearpalette(rgb.green, rgb.blue)
 412 palette.BlueRed        = linearpalette(rgb.blue, rgb.red)
 413 palette.BlueGreen      = linearpalette(rgb.blue, rgb.green)
 414 palette.RedBlack       = linearpalette(rgb.red, rgb.black)
 415 palette.BlackRed       = linearpalette(rgb.black, rgb.red)
 416 palette.RedWhite       = linearpalette(rgb.red, rgb.white)
 417 palette.WhiteRed       = linearpalette(rgb.white, rgb.red)
 418 palette.GreenBlack     = linearpalette(rgb.green, rgb.black)
 419 palette.BlackGreen     = linearpalette(rgb.black, rgb.green)
 420 palette.GreenWhite     = linearpalette(rgb.green, rgb.white)
 421 palette.WhiteGreen     = linearpalette(rgb.white, rgb.green)
 422 palette.BlueBlack      = linearpalette(rgb.blue, rgb.black)
 423 palette.BlackBlue      = linearpalette(rgb.black, rgb.blue)
 424 palette.BlueWhite      = linearpalette(rgb.blue, rgb.white)
 425 palette.WhiteBlue      = linearpalette(rgb.white, rgb.blue)
 426 palette.Rainbow        = linearpalette(hsb(0, 1, 1), hsb(2.0/3.0, 1, 1))
 427 palette.ReverseRainbow = linearpalette(hsb(2.0/3.0, 1, 1), hsb(0, 1, 1))
 428 palette.Hue            = linearpalette(hsb(0, 1, 1), hsb(1, 1, 1))
 429 palette.ReverseHue     = linearpalette(hsb(1, 1, 1), hsb(0, 1, 1))
 430
 431
 432 class PDFextgstate(pdfwriter.PDFobject):
 433
 434     def __init__(self, name, extgstate, registry):
 435         pdfwriter.PDFobject.__init__(self, "extgstate", name)
 436         registry.addresource("ExtGState", name, self)
 437         self.name = name
 438         self.extgstate = extgstate
 439
 440     def write(self, file, writer, registry):
 441         file.write("%s\n" % self.extgstate)
 442
 443
 444 class transparency(attr.exclusiveattr, style.strokestyle, style.fillstyle):
 445
 446     def __init__(self, value):
 447         value = 1-value
 448         attr.exclusiveattr.__init__(self, transparency)
 449         self.name = "Transparency-%f" % value
 450         self.extgstate = "<< /Type /ExtGState /CA %f /ca %f >>" % (value, value)
 451
 452     def processPS(self, file, writer, context, registry, bbox):
 453         raise NotImplementedError("transparency not available in PostScript")
 454
 455     def processPDF(self, file, writer, context, registry, bbox):
 456         registry.add(PDFextgstate(self.name, self.extgstate, registry))
 457         file.write("/%s gs\n" % self.name)
 458