import math

from StringIO import StringIO

import inkex

class hpglDecoder:

def __init__(self, hpglString, options):

''' options:

self.hpglString = hpglString

self.options = options

self.scaleX = options.resolutionX / 90.0 # dots/inch to dots/pixels

self.scaleY = options.resolutionY / 90.0 # dots/inch to dots/pixels

self.warning = ''

self.textMovements = _("Movements")

self.textPenNumber = _("Pen #")

def getSvg(self):

# prepare document

self.doc = inkex.etree.parse(StringIO('<svg xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd" width="%s" height="%s"></svg>' %

(self.options.docWidth, self.options.docHeight)))

actualLayer = 0

self.layers = {}

if self.options.showMovements:

self.layers[0] = inkex.etree.SubElement(self.doc.getroot(), 'g', {inkex.addNS('groupmode', 'inkscape'): 'layer', inkex.addNS('label', 'inkscape'): self.textMovements})

# parse paths

hpglData = self.hpglString.split(';')

if len(hpglData) < 3:

raise Exception('NO_HPGL_DATA')

oldCoordinates = (0.0, self.options.docHeight)

path = ''

for i, command in enumerate(hpglData):

if command.strip() != '':

if command[:2] == 'IN' or command[:2] == 'FS' or command[:2] == 'VS':

# if Initialize, force or speed command, ignore

pass

elif command[:2] == 'SP':

# if Select Pen command

actualLayer = command[2:]

self.createLayer(actualLayer)

elif command[:2] == 'PU':

# if Pen Up command

if ' L ' in path:

self.addPathToLayer(path, actualLayer)

if self.options.showMovements and oldCoordinates != self.getParameters(command[2:]):

path = 'M %f,%f' % oldCoordinates

path += ' L %f,%f' % self.getParameters(command[2:])

self.addPathToLayer(path, 0)

path = 'M %f,%f' % self.getParameters(command[2:])

oldCoordinates = self.getParameters(command[2:])

elif command[:2] == 'PD':

# if Pen Down command

parameterString = command[2:]

if parameterString.strip() != '':

parameterString = parameterString.replace(';', '').strip()

parameter = parameterString.split(',')

for i, param in enumerate(parameter):

if i % 2 == 0:

parameter[i] = str(float(param) / self.scaleX)

else:

parameter[i] = str(self.options.docHeight - (float(param) / self.scaleY))

parameterString = ','.join(parameter)

path += ' L %s' % parameterString

oldCoordinates = (float(parameter[-2]), float(parameter[-1]))

else:

self.warning = 'UNKNOWN_COMMANDS'

if ' L ' in path:

self.addPathToLayer(path, actualLayer)

return (self.doc, self.warning)

def createLayer(self, layerNumber):

try:

self.layers[layerNumber]

except KeyError:

self.layers[layerNumber] = inkex.etree.SubElement(self.doc.getroot(), 'g',

{inkex.addNS('groupmode', 'inkscape'): 'layer', inkex.addNS('label', 'inkscape'): self.textPenNumber + layerNumber})

def addPathToLayer(self, path, layerNumber):

lineColor = '000000'

if layerNumber == 0:

lineColor = 'ff0000'

inkex.etree.SubElement(self.layers[layerNumber], 'path', {'d': path, 'style': 'stroke:#' + lineColor + '; stroke-width:0.4; fill:none;'})

def getParameters(self, parameterString):

# process coordinates

if parameterString.strip() == '':

return []

# remove command delimiter

parameterString = parameterString.replace(';', '').strip()

# split parameter

parameter = parameterString.split(',')

# convert to svg coordinate system and return

return (float(parameter[0]) / self.scaleX, self.options.docHeight - (float(parameter[1]) / self.scaleY))