--- /dev/null
+#!/usr/bin/env python
+"""
+simplepath.py
+functions for digesting paths into a simple list structure
+
+Copyright (C) 2005 Aaron Spike, aaron@ekips.org
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+"""
+import re, math
+
+def lexPath(d):
+ """
+ returns and iterator that breaks path data
+ identifies command and parameter tokens
+ """
+ offset = 0
+ length = len(d)
+ delim = re.compile(r'[ \t\r\n,]+')
+ command = re.compile(r'[MLHVCSQTAZmlhvcsqtaz]')
+ parameter = re.compile(r'(([-+]?[0-9]+(\.[0-9]*)?|[-+]?\.[0-9]+)([eE][-+]?[0-9]+)?)')
+ while 1:
+ m = delim.match(d, offset)
+ if m:
+ offset = m.end()
+ if offset >= length:
+ break
+ m = command.match(d, offset)
+ if m:
+ yield [d[offset:m.end()], True]
+ offset = m.end()
+ continue
+ m = parameter.match(d, offset)
+ if m:
+ yield [d[offset:m.end()], False]
+ offset = m.end()
+ continue
+ #TODO: create new exception
+ raise Exception, 'Invalid path data!'
+'''
+pathdefs = {commandfamily:
+ [
+ implicitnext,
+ #params,
+ [casts,cast,cast],
+ [coord type,x,y,0]
+ ]}
+'''
+pathdefs = {
+ 'M':['L', 2, [float, float], ['x','y']],
+ 'L':['L', 2, [float, float], ['x','y']],
+ 'H':['H', 1, [float], ['x']],
+ 'V':['V', 1, [float], ['y']],
+ 'C':['C', 6, [float, float, float, float, float, float], ['x','y','x','y','x','y']],
+ 'S':['S', 4, [float, float, float, float], ['x','y','x','y']],
+ 'Q':['Q', 4, [float, float, float, float], ['x','y','x','y']],
+ 'T':['T', 2, [float, float], ['x','y']],
+ 'A':['A', 7, [float, float, float, int, int, float, float], ['r','r','a',0,'s','x','y']],
+ 'Z':['L', 0, [], []]
+ }
+def parsePath(d):
+ """
+ Parse SVG path and return an array of segments.
+ Removes all shorthand notation.
+ Converts coordinates to absolute.
+ """
+ retval = []
+ lexer = lexPath(d)
+
+ pen = (0.0,0.0)
+ subPathStart = pen
+ lastControl = pen
+ lastCommand = ''
+
+ while 1:
+ try:
+ token, isCommand = lexer.next()
+ except StopIteration:
+ break
+ params = []
+ needParam = True
+ if isCommand:
+ if not lastCommand and token.upper() != 'M':
+ raise Exception, 'Invalid path, must begin with moveto.'
+ else:
+ command = token
+ else:
+ #command was omited
+ #use last command's implicit next command
+ needParam = False
+ if lastCommand:
+ if lastCommand.isupper():
+ command = pathdefs[lastCommand][0]
+ else:
+ command = pathdefs[lastCommand.upper()][0].lower()
+ else:
+ raise Exception, 'Invalid path, no initial command.'
+ numParams = pathdefs[command.upper()][1]
+ while numParams > 0:
+ if needParam:
+ try:
+ token, isCommand = lexer.next()
+ if isCommand:
+ raise Exception, 'Invalid number of parameters'
+ except StopIteration:
+ raise Exception, 'Unexpected end of path'
+ cast = pathdefs[command.upper()][2][-numParams]
+ param = cast(token)
+ if command.islower():
+ if pathdefs[command.upper()][3][-numParams]=='x':
+ param += pen[0]
+ elif pathdefs[command.upper()][3][-numParams]=='y':
+ param += pen[1]
+ params.append(param)
+ needParam = True
+ numParams -= 1
+ #segment is now absolute so
+ outputCommand = command.upper()
+
+ #Flesh out shortcut notation
+ if outputCommand in ('H','V'):
+ if outputCommand == 'H':
+ params.append(pen[1])
+ if outputCommand == 'V':
+ params.insert(0,pen[0])
+ outputCommand = 'L'
+ if outputCommand in ('S','T'):
+ params.insert(0,pen[1]+(pen[1]-lastControl[1]))
+ params.insert(0,pen[0]+(pen[0]-lastControl[0]))
+ if outputCommand == 'S':
+ outputCommand = 'C'
+ if outputCommand == 'T':
+ outputCommand = 'Q'
+
+ #current values become "last" values
+ if outputCommand == 'M':
+ subPathStart = tuple(params[0:2])
+ pen = subPathStart
+ if outputCommand == 'Z':
+ pen = subPathStart
+ else:
+ pen = tuple(params[-2:])
+
+ if outputCommand in ('Q','C'):
+ lastControl = tuple(params[-4:-2])
+ else:
+ lastControl = pen
+ lastCommand = command
+
+ retval.append([outputCommand,params])
+ return retval
+
+def formatPath(a):
+ """Format SVG path data from an array"""
+ return "".join([cmd + " ".join([str(p) for p in params]) for cmd, params in a])
+
+def translatePath(p, x, y):
+ for cmd,params in p:
+ defs = pathdefs[cmd]
+ for i in range(defs[1]):
+ if defs[3][i] == 'x':
+ params[i] += x
+ elif defs[3][i] == 'y':
+ params[i] += y
+
+def scalePath(p, x, y):
+ for cmd,params in p:
+ defs = pathdefs[cmd]
+ for i in range(defs[1]):
+ if defs[3][i] == 'x':
+ params[i] *= x
+ elif defs[3][i] == 'y':
+ params[i] *= y
+ elif defs[3][i] == 'r': # radius parameter
+ params[i] *= x
+ elif defs[3][i] == 's': # sweep-flag parameter
+ if x*y < 0:
+ params[i] = 1 - params[i]
+ elif defs[3][i] == 'a': # x-axis-rotation angle
+ if y < 0:
+ params[i] = - params[i]
+
+def rotatePath(p, a, cx = 0, cy = 0):
+ if a == 0:
+ return p
+ for cmd,params in p:
+ defs = pathdefs[cmd]
+ for i in range(defs[1]):
+ if defs[3][i] == 'x':
+ x = params[i] - cx
+ y = params[i + 1] - cy
+ r = math.sqrt((x**2) + (y**2))
+ if r != 0:
+ theta = math.atan2(y, x) + a
+ params[i] = (r * math.cos(theta)) + cx
+ params[i + 1] = (r * math.sin(theta)) + cy
+
+
+# vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 encoding=utf-8 textwidth=99
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff