share/extensions/render_alphabetsoup.py

   1 #!/usr/bin/env python
   2 '''
   3 Copyright (C) 2001-2002 Matt Chisholm matt@theory.org
   4 Copyright (C) 2008 Joel Holdsworth joel@airwebreathe.org.uk
   5     for AP
   6
   7 This program 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 This program 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 Free Software
  19 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20 '''
  21
  22 import copy
  23 import inkex
  24 import simplestyle
  25 import math
  26 import cmath
  27 import string
  28 import random
  29 import render_alphabetsoup_config
  30 import bezmisc
  31 import simplepath
  32 import os
  33 import sys
  34
  35 syntax   = render_alphabetsoup_config.syntax
  36 alphabet = render_alphabetsoup_config.alphabet
  37 units   = render_alphabetsoup_config.units
  38 font     = render_alphabetsoup_config.font
  39
  40 # Loads a super-path from a given SVG file
  41 def loadPath( svgPath ):
  42         extensionDir = os.path.normpath(os.path.join(os.getcwd(),os.path.dirname(sys.argv[0])))
  43         tree = inkex.etree.parse( extensionDir + "/" + svgPath )
  44         root = tree.getroot()
  45         pathElement = root.find('{http://www.w3.org/2000/svg}path')
  46         if pathElement == None:
  47                 return None, 0, 0
  48         d = pathElement.get("d")
  49         width = float(root.get("width"))
  50         height = float(root.get("height"))
  51         return simplepath.parsePath(d), width, height # Currently we only support a single path
  52
  53 def combinePaths( pathA, pathB ):
  54         if pathA == None and pathB == None:
  55                 return None
  56         elif pathA == None:
  57                 return pathB
  58         elif pathB == None:
  59                 return pathA
  60         else:
  61                 return pathA + pathB
  62
  63 def flipLeftRight( sp, width ):
  64         for cmd,params in sp:
  65                 defs = simplepath.pathdefs[cmd]
  66                 for i in range(defs[1]):
  67                         if defs[3][i] == 'x':
  68                                 params[i] = width - params[i]
  69
  70 def flipTopBottom( sp, height ):
  71         for cmd,params in sp:
  72                 defs = simplepath.pathdefs[cmd]
  73                 for i in range(defs[1]):
  74                         if defs[3][i] == 'y':
  75                                 params[i] = height - params[i]
  76
  77 def solveQuadratic(a, b, c):
  78         det = b*b - 4.0*a*c
  79         if det >= 0: # real roots
  80                 sdet = math.sqrt(det)
  81         else: # complex roots
  82                 sdet = cmath.sqrt(det)
  83         return (-b + sdet) / (2*a), (-b - sdet) / (2*a)
  84
  85 def cbrt(x):
  86         if x >= 0:
  87                 return x**(1.0/3.0)
  88         else:
  89                 return -((-x)**(1.0/3.0))
  90
  91 def findRealRoots(a,b,c,d):
  92         if a != 0:
  93                 a, b, c, d = 1, b/float(a), c/float(a), d/float(a)      # Divide through by a
  94                 t = b / 3.0
  95                 p, q = c - 3 * t**2, d - c * t + 2 * t**3
  96                 u, v = solveQuadratic(1, q, -(p/3.0)**3)
  97                 if type(u) == type(0j):                 # Complex Cubic Root
  98                         r = math.sqrt(u.real**2 + u.imag**2)
  99                         w = math.atan2(u.imag, u.real)
 100                         y1 = 2 * cbrt(r) * math.cos(w / 3.0)
 101                 else:           # Complex Real Root
 102                         y1 = cbrt(u) + cbrt(v)
 103
 104                 y2, y3 = solveQuadratic(1, y1, p + y1**2)
 105
 106                 if type(y2) == type(0j):        # Are y2 and y3 complex?
 107                         return [y1 - t]
 108                 return [y1 - t, y2 - t, y3 - t]
 109         elif b != 0:
 110                 det=c*c - 4.0*b*d
 111                 if det >= 0:
 112                         return [(-c + math.sqrt(det))/(2.0*b),(-c - math.sqrt(det))/(2.0*b)]
 113         elif c != 0:
 114                 return [-d/c]
 115         return []
 116
 117 def getPathBoundingBox( sp ):
 118
 119         box = None
 120         last = None
 121         lostctrl = None
 122
 123         for cmd,params in sp:
 124
 125                 segmentBox = None
 126
 127                 if cmd == 'M':
 128                         # A move cannot contribute to the bounding box
 129                         last = params[:]
 130                         lastctrl = params[:]
 131                 elif cmd == 'L':
 132                         if last:
 133                                 segmentBox = (min(params[0], last[0]), max(params[0], last[0]), min(params[1], last[1]), max(params[1], last[1]))
 134                         last = params[:]
 135                         lastctrl = params[:]
 136                 elif cmd == 'C':
 137                         if last:
 138                                 segmentBox = (min(params[4], last[0]), max(params[4], last[0]), min(params[5], last[1]), max(params[5], last[1]))
 139
 140                                 bx0, by0 = last[:]
 141                                 bx1, by1, bx2, by2, bx3, by3 = params[:]
 142
 143                                 # Compute the x limits
 144                                 a = (-bx0 + 3*bx1 - 3*bx2 + bx3)*3
 145                                 b = (3*bx0 - 6*bx1  + 3*bx2)*2
 146                                 c = (-3*bx0 + 3*bx1)
 147                                 ts = findRealRoots(0, a, b, c)
 148                                 for t in ts:
 149                                         if t >= 0 and t <= 1:
 150                                                 x = (-bx0 + 3*bx1 - 3*bx2 + bx3)*(t**3) + \
 151                                                         (3*bx0 - 6*bx1 + 3*bx2)*(t**2) + \
 152                                                         (-3*bx0 + 3*bx1)*t + \
 153                                                         bx0
 154                                                 segmentBox = (min(segmentBox[0], x), max(segmentBox[1], x), segmentBox[2], segmentBox[3])
 155
 156                                 # Compute the y limits
 157                                 a = (-by0 + 3*by1 - 3*by2 + by3)*3
 158                                 b = (3*by0 - 6*by1  + 3*by2)*2
 159                                 c = (-3*by0 + 3*by1)
 160                                 ts = findRealRoots(0, a, b, c)
 161                                 for t in ts:
 162                                         if t >= 0 and t <= 1:
 163                                                 y = (-by0 + 3*by1 - 3*by2 + by3)*(t**3) + \
 164                                                         (3*by0 - 6*by1 + 3*by2)*(t**2) + \
 165                                                         (-3*by0 + 3*by1)*t + \
 166                                                         by0
 167                                                 segmentBox = (segmentBox[0], segmentBox[1], min(segmentBox[2], y), max(segmentBox[3], y))
 168
 169                         last = params[-2:]
 170                         lastctrl = params[2:4]
 171
 172                 elif cmd == 'Q':
 173                         # Provisional
 174                         if last:
 175                                 segmentBox = (min(params[0], last[0]), max(params[0], last[0]), min(params[1], last[1]), max(params[1], last[1]))
 176                         last = params[-2:]
 177                         lastctrl = params[2:4]
 178
 179                 elif cmd == 'A':
 180                         # Provisional
 181                         if last:
 182                                 segmentBox = (min(params[0], last[0]), max(params[0], last[0]), min(params[1], last[1]), max(params[1], last[1]))
 183                         last = params[-2:]
 184                         lastctrl = params[2:4]
 185
 186                 if segmentBox:
 187                         if box:
 188                                 box = (min(segmentBox[0],box[0]), max(segmentBox[1],box[1]), min(segmentBox[2],box[2]), max(segmentBox[3],box[3]))
 189                         else:
 190                                 box = segmentBox
 191         return box
 192
 193 def mxfm( image, width, height, stack ):                                                                # returns possibly transformed image
 194         tbimage = image
 195         if ( stack[0] == "-" ):                                                   # top-bottom flip
 196                 flipTopBottom(tbimage, height)
 197                 stack.pop( 0 )
 198
 199         lrimage = tbimage
 200         if ( stack[0] == "|" ):                                                   # left-right flip
 201                 flipLeftRight(tbimage, width)
 202                 stack.pop( 0 )
 203         return lrimage
 204
 205 def comparerule( rule, nodes ):                                           # compare node list to nodes in rule
 206         for i in range( 0, len(nodes)):                                   # range( a, b ) = (a, a+1, a+2 ... b-2, b-1)
 207                 if (nodes[i] == rule[i][0]):
 208                         pass
 209                 else: return 0
 210         return 1
 211
 212 def findrule( state, nodes ):                                                   # find the rule which generated this subtree
 213         ruleset = syntax[state][1]
 214         nodelen = len(nodes)
 215         for rule in ruleset:
 216                 rulelen = len(rule)
 217                 if ((rulelen == nodelen) and (comparerule( rule, nodes ))):
 218                         return rule
 219         return
 220
 221 def generate( state ):                                                             # generate a random tree (in stack form)
 222         stack  = [ state ]
 223         if ( len(syntax[state]) == 1 ):                                         # if this is a stop symbol
 224                 return stack
 225         else:
 226                 stack.append( "[" )
 227                 path = random.randint(0, (len(syntax[state][1])-1)) # choose randomly from next states
 228                 for symbol in syntax[state][1][path]:                   # recurse down each non-terminal
 229                         if ( symbol != 0 ):                                               # 0 denotes end of list ###
 230                                 substack = generate( symbol[0] )                 # get subtree
 231                                 for elt in substack:
 232                                         stack.append( elt )
 233                                 if (symbol[3]):stack.append( "-" )         # top-bottom flip
 234                                 if (symbol[4]):stack.append( "|" )         # left-right flip
 235                         #else:
 236                                 #inkex.debug("found end of list in generate( state =", state, ")") # this should be deprecated/never happen
 237                 stack.append("]")
 238                 return stack
 239
 240 def draw( stack ):                                                                         # draw a character based on a tree stack
 241         state = stack.pop(0)
 242         #print state,
 243
 244         image, width, height = loadPath( font+syntax[state][0] )                  # load the image
 245         if (stack[0] != "["):                                                           # terminal stack element
 246                 if (len(syntax[state]) == 1):                                     # this state is a terminal node
 247                         return image, width, height
 248                 else:
 249                         substack = generate( state )                             # generate random substack
 250                         return draw( substack )                                   # draw random substack
 251         else:
 252                 #inkex.debug("[")
 253                 stack.pop(0)
 254                 images = []                                                               # list of daughter images
 255                 nodes  = []                                                               # list of daughter names
 256                 while (stack[0] != "]"):                                         # for all nodes in stack
 257                         newstate = stack[0]                                       # the new state
 258                         newimage, width, height = draw( stack )                          # draw the daughter state
 259                         if (newimage):
 260                                 tfimage = mxfm( newimage, width, height, stack )        # maybe transform daughter state
 261                                 images.append( [tfimage, width, height] )                        # list of daughter images
 262                                 nodes.append( newstate )                         # list of daughter nodes
 263                         else:
 264                                 #inkex.debug(("recurse on",newstate,"failed")) # this should never happen
 265                                 return None, 0, 0
 266                 rule = findrule( state, nodes )                   # find the rule for this subtree
 267
 268                 for i in range( 0, len(images)):
 269                         currimg, width, height = images[i]
 270
 271                         if currimg:
 272                                 #box = getPathBoundingBox(currimg)
 273                                 dx = rule[i][1]*units
 274                                 dy = rule[i][2]*units
 275                                 #newbox = ((box[0]+dx),(box[1]+dy),(box[2]+dx),(box[3]+dy))
 276                                 simplepath.translatePath(currimg, dx, dy)
 277                                 image = combinePaths( image, currimg )
 278
 279                 stack.pop( 0 )
 280                 return image, width, height
 281
 282 def draw_crop_scale( stack, zoom ):                                                     # draw, crop and scale letter image
 283         image, width, height = draw(stack)
 284         bbox = getPathBoundingBox(image)
 285         simplepath.translatePath(image, -bbox[0], 0)
 286         simplepath.scalePath(image, zoom/units, zoom/units)
 287         return image, bbox[1] - bbox[0], bbox[3] - bbox[2]
 288
 289 def randomize_input_string( str, zoom ):                                           # generate list of images based on input string
 290         imagelist = []
 291
 292         for i in range(0,len(str)):
 293                 char = str[i]
 294                 #if ( re.match("[a-zA-Z0-9?]", char)):
 295                 if ( alphabet.has_key(char)):
 296                         if ((i > 0) and (char == str[i-1])):             # if this letter matches previous letter
 297                                 imagelist.append(imagelist[len(stack)-1])# make them the same image
 298                         else:                                                                           # generate image for letter
 299                                 stack = string.split( alphabet[char][random.randint(0,(len(alphabet[char])-1))] , "." )
 300                                 #stack = string.split( alphabet[char][random.randint(0,(len(alphabet[char])-2))] , "." )
 301                                 imagelist.append( draw_crop_scale( stack, zoom ))
 302                 elif( char == " "):                                                       # add a " " space to the image list
 303                         imagelist.append( " " )
 304                 else:                                                                                   # this character is not in config.alphabet, skip it
 305                         print "bad character", char
 306         return imagelist
 307
 308 def optikern( image, width, zoom ):                                   # optical kerning algorithm
 309         left  = []
 310         right = []
 311
 312         for i in range( 0, 36 ):
 313                 y = 0.5 * (i + 0.5) * zoom
 314                 xmin = None
 315                 xmax = None
 316
 317                 for cmd,params in image:
 318
 319                         segmentBox = None
 320
 321                         if cmd == 'M':
 322                                 # A move cannot contribute to the bounding box
 323                                 last = params[:]
 324                                 lastctrl = params[:]
 325                         elif cmd == 'L':
 326                                 if (y >= last[1] and y <= params[1]) or (y >= params[1] and y <= last[1]):
 327                                         if params[0] == last[0]:
 328                                                 x = params[0]
 329                                         else:
 330                                                 a = (params[1] - last[1]) / (params[0] - last[0])
 331                                                 b = last[1] - a * last[0]
 332                                                 if a != 0:
 333                                                         x = (y - b) / a
 334                                                 else: x = None
 335
 336                                         if x:
 337                                                 if xmin == None or x < xmin: xmin = x
 338                                                 if xmax == None or x > xmax: xmax = x
 339
 340                                 last = params[:]
 341                                 lastctrl = params[:]
 342                         elif cmd == 'C':
 343                                 if last:
 344                                         bx0, by0 = last[:]
 345                                         bx1, by1, bx2, by2, bx3, by3 = params[:]
 346
 347                                         d = by0 - y
 348                                         c = -3*by0 + 3*by1
 349                                         b = 3*by0 - 6*by1 + 3*by2
 350                                         a = -by0 + 3*by1 - 3*by2 + by3
 351
 352                                         ts = findRealRoots(a, b, c, d)
 353
 354                                         for t in ts:
 355                                                 if t >= 0 and t <= 1:
 356                                                         x = (-bx0 + 3*bx1 - 3*bx2 + bx3)*(t**3) + \
 357                                                                 (3*bx0 - 6*bx1 + 3*bx2)*(t**2) + \
 358                                                                 (-3*bx0 + 3*bx1)*t + \
 359                                                                 bx0
 360                                                         if xmin == None or x < xmin: xmin = x
 361                                                         if xmax == None or x > xmax: xmax = x
 362
 363                                 last = params[-2:]
 364                                 lastctrl = params[2:4]
 365
 366                         elif cmd == 'Q':
 367                                 # Quadratic beziers are ignored
 368                                 last = params[-2:]
 369                                 lastctrl = params[2:4]
 370
 371                         elif cmd == 'A':
 372                                 # Arcs are ignored
 373                                 last = params[-2:]
 374                                 lastctrl = params[2:4]
 375
 376
 377                 if xmin != None and xmax != None:
 378                         left.append( xmin )                        # distance from left edge of region to left edge of bbox
 379                         right.append( width - xmax )               # distance from right edge of region to right edge of bbox
 380                 else:
 381                         left.append(  width )
 382                         right.append( width )
 383
 384         return (left, right)
 385
 386 def layoutstring( imagelist, zoom ):                                     # layout string of letter-images using optical kerning
 387         kernlist  = []
 388         length = zoom
 389         for entry in imagelist:
 390                 if (entry == " "):                                                         # leaving room for " " space characters
 391                         length = length + (zoom * render_alphabetsoup_config.space)
 392                 else:
 393                         image, width, height = entry
 394                         length = length + width + zoom   # add letter length to overall length
 395                         kernlist.append( optikern(image, width, zoom) )            # append kerning data for this image
 396
 397         workspace = None
 398
 399         position = zoom
 400         for i in range(0, len(kernlist)):
 401                 while(imagelist[i] == " "):
 402                         position = position + (zoom * render_alphabetsoup_config.space )
 403                         imagelist.pop(i)
 404                 image, width, height = imagelist[i]
 405
 406                 # set the kerning
 407                 if i == 0: kern = 0                                               # for first image, kerning is zero
 408                 else:
 409                         kerncompare = []                                                         # kerning comparison array
 410                         for j in range( 0, len(kernlist[i][0])):
 411                                 kerncompare.append( kernlist[i][0][j]+kernlist[i-1][1][j] )
 412                         kern = min( kerncompare )
 413
 414                 position = position - kern                                         # move position back by kern amount
 415                 thisimage = copy.deepcopy(image)
 416                 simplepath.translatePath(thisimage, position, 0)
 417                 workspace = combinePaths(workspace, thisimage)
 418                 position = position + width + zoom      # advance position by letter width
 419
 420         return workspace
 421
 422 class AlphabetSoup(inkex.Effect):
 423         def __init__(self):
 424                 inkex.Effect.__init__(self)
 425                 self.OptionParser.add_option("-t", "--text",
 426                                                 action="store", type="string",
 427                                                 dest="text", default="Inkscape",
 428                                                 help="The text for alphabet soup")
 429                 self.OptionParser.add_option("-z", "--zoom",
 430                                                 action="store", type="float",
 431                                                 dest="zoom", default="8.0",
 432                                                 help="The zoom on the output graphics")
 433                 self.OptionParser.add_option("-s", "--seed",
 434                                                 action="store", type="int",
 435                                                 dest="seed", default="0",
 436                                                 help="The random seed for the soup")
 437
 438         def effect(self):
 439                 zoom = self.options.zoom
 440                 random.seed(self.options.seed)
 441
 442                 imagelist = randomize_input_string(self.options.text, zoom)
 443                 image = layoutstring( imagelist, zoom )
 444
 445                 if image:
 446                         s = { 'stroke': 'none', 'fill': '#000000' }
 447
 448                         new = inkex.etree.Element(inkex.addNS('path','svg'))
 449                         new.set('style', simplestyle.formatStyle(s))
 450
 451                         new.set('d', simplepath.formatPath(image))
 452                         self.current_layer.append(new)
 453
 454 e = AlphabetSoup()
 455 e.affect()
 456