hpgl_encoder.py revision 30e61e8a619dd1a8eb52ce65ae4528d939831f44
#!/usr/bin/env python
# coding=utf-8
'''
Copyright (C) 2008 Aaron Spike, aaron@ekips.org
Copyright (C) 2013 Sebastian Wüst, sebi@timewaster.de
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
'''
# standard libraries
import math
import string
# local libraries
import bezmisc
import cspsubdiv
import cubicsuperpath
import inkex
import simplestyle
import simpletransform
# TODO: Unittests
class hpglEncoder:
PI = math.pi
TWO_PI = PI * 2
def __init__(self, effect):
''' options:
"resolutionX":float
"resolutionY":float
"pen":int
"orientation":string // "0", "90", "-90", "180"
"mirrorX":bool
"mirrorY":bool
"center":bool
"flat":float
"useOvercut":bool
"overcut":float
"useToolOffset":bool
"toolOffset":float
"precut":bool
"offsetX":float
"offsetY":float
'''
self.doc = effect.document.getroot()
self.options = effect.options
self.divergenceX = 'False'
self.divergenceY = 'False'
self.sizeX = 'False'
self.sizeY = 'False'
self.dryRun = True
self.lastPoint = [0, 0, 0]
self.scaleX = self.options.resolutionX / 90 # inch to pixels
self.scaleY = self.options.resolutionY / 90 # inch to pixels
self.options.offsetX = self.options.offsetX * 3.5433070866 * self.scaleX # mm to dots (plotter coordinate system)
self.options.offsetY = self.options.offsetY * 3.5433070866 * self.scaleY # mm to dots
self.options.overcut = self.options.overcut * 3.5433070866 * ((self.scaleX + self.scaleY) / 2) # mm to dots
self.options.toolOffset = self.options.toolOffset * 3.5433070866 * ((self.scaleX + self.scaleY) / 2) # mm to dots
self.options.flat = ((self.options.resolutionX + self.options.resolutionY) / 2) * self.options.flat / 1000 # scale flatness to resolution
self.toolOffsetFlat = self.options.flat / self.options.toolOffset * 4.5 # scale flatness to offset
self.mirrorX = 1.0
if self.options.mirrorX:
self.mirrorX = -1.0
self.mirrorY = -1.0
if self.options.mirrorY:
self.mirrorY = 1.0
# process viewBox attribute to correct page scaling
viewBox = self.doc.get('viewBox')
self.viewBoxTransformX = 1
self.viewBoxTransformY = 1
if viewBox:
viewBox = string.split(viewBox, ' ')
if viewBox[2] and viewBox[3]:
self.viewBoxTransformX = float(effect.unittouu(self.doc.get('width'))) / float(viewBox[2])
self.viewBoxTransformY = float(effect.unittouu(self.doc.get('height'))) / float(viewBox[3])
def getHpgl(self):
# dryRun to find edges
groupmat = [[self.mirrorX * self.scaleX * self.viewBoxTransformX, 0.0, 0.0], [0.0, self.mirrorY * self.scaleY * self.viewBoxTransformY, 0.0]]
groupmat = simpletransform.composeTransform(groupmat, simpletransform.parseTransform('rotate(' + self.options.orientation + ')'))
self.vData = [['', -1.0, -1.0], ['', -1.0, -1.0], ['', -1.0, -1.0], ['', -1.0, -1.0]]
self.processGroups(self.doc, groupmat)
if self.divergenceX == 'False' or self.divergenceY == 'False' or self.sizeX == 'False' or self.sizeY == 'False':
raise Exception('NO_PATHS')
# live run
self.dryRun = False
if self.options.center:
self.divergenceX += (self.sizeX - self.divergenceX) / 2
self.divergenceY += (self.sizeY - self.divergenceY) / 2
elif self.options.useToolOffset:
self.options.offsetX += self.options.toolOffset
self.options.offsetY += self.options.toolOffset
groupmat = [[self.mirrorX * self.scaleX * self.viewBoxTransformX, 0.0, - self.divergenceX + self.options.offsetX],
[0.0, self.mirrorY * self.scaleY * self.viewBoxTransformY, - self.divergenceY + self.options.offsetY]]
groupmat = simpletransform.composeTransform(groupmat, simpletransform.parseTransform('rotate(' + self.options.orientation + ')'))
self.vData = [['', -1.0, -1.0], ['', -1.0, -1.0], ['', -1.0, -1.0], ['', -1.0, -1.0]]
# store first hpgl commands
self.hpgl = 'IN;SP%d' % self.options.pen
# add precut
if self.options.useToolOffset and self.options.precut:
self.processOffset('PU', 0, 0)
self.processOffset('PD', 0, self.options.toolOffset * 8)
# start conversion
self.processGroups(self.doc, groupmat)
# shift an empty node in in order to process last node in cache
self.processOffset('PU', 0, 0)
# add return to zero point
self.hpgl += ';PU0,0;'
return self.hpgl
def processGroups(self, doc, groupmat):
# flatten groups to avoid recursion
paths = []
for node in doc:
if (node.tag == inkex.addNS('g', 'svg') and self.isGroupVisible(node)) or node.tag == inkex.addNS('path', 'svg'):
paths.append([node.tag, node, self.mergeTransform(node, groupmat)])
doc = ''
hasGroups = True
while hasGroups:
hasGroups = False
for i, elm in enumerate(paths):
if paths[i][0] == inkex.addNS('g', 'svg') and self.isGroupVisible(paths[i][1]):
hasGroups = True
for path in paths[i][1]:
if (path.tag == inkex.addNS('g', 'svg') and self.isGroupVisible(path)) or path.tag == inkex.addNS('path', 'svg'):
paths.append([path.tag, path, self.mergeTransform(path, paths[i][2])])
paths[i][0] = ''
for node in paths:
if node[0] == inkex.addNS('path', 'svg'):
self.processPath(node[1], node[2])
def mergeTransform(self, doc, matrix):
# get and merge two matrixes into one
trans = doc.get('transform')
if trans:
return simpletransform.composeTransform(matrix, simpletransform.parseTransform(trans))
else:
return matrix
def isGroupVisible(self, group):
style = group.get('style')
if style:
style = simplestyle.parseStyle(style)
if 'display' in style and style['display'] == 'none':
return False
return True
def processPath(self, node, mat):
# process path
paths = node.get('d')
if paths:
# parse and transform path
paths = cubicsuperpath.parsePath(paths)
simpletransform.applyTransformToPath(mat, paths)
cspsubdiv.cspsubdiv(paths, self.options.flat)
# path to HPGL commands
oldPosX = 0.0
oldPosY = 0.0
# TODO: Plot smallest parts first to avid plotter dragging parts of foil around (on text)
for singlePath in paths:
cmd = 'PU'
for singlePathPoint in singlePath:
posX, posY = singlePathPoint[1]
# check if point is repeating, if so, ignore
if int(round(posX)) != int(round(oldPosX)) or int(round(posY)) != int(round(oldPosY)):
self.processOffset(cmd, posX, posY)
cmd = 'PD'
oldPosX = posX
oldPosY = posY
# perform overcut
if self.options.useOvercut and not self.dryRun:
# check if last and first points are the same, otherwise the path is not closed and no overcut can be performed
if int(round(oldPosX)) == int(round(singlePath[0][1][0])) and int(round(oldPosY)) == int(round(singlePath[0][1][1])):
overcutLength = 0
for singlePathPoint in singlePath:
posX, posY = singlePathPoint[1]
# check if point is repeating, if so, ignore
if int(round(posX)) != int(round(oldPosX)) or int(round(posY)) != int(round(oldPosY)):
overcutLength += self.getLength(oldPosX, oldPosY, posX, posY)
if overcutLength >= self.options.overcut:
newLength = self.changeLength(oldPosX, oldPosY, posX, posY, - (overcutLength - self.options.overcut))
self.processOffset(cmd, newLength[0], newLength[1])
break
else:
self.processOffset(cmd, posX, posY)
oldPosX = posX
oldPosY = posY
def getLength(self, x1, y1, x2, y2, absolute=True):
# calc absoulute or relative length between two points
length = math.sqrt((x2 - x1) ** 2.0 + (y2 - y1) ** 2.0)
if absolute:
length = math.fabs(length)
return length
def changeLength(self, x1, y1, x2, y2, offset):
# change length of line
if offset < 0:
offset = max( - self.getLength(x1, y1, x2, y2), offset)
x = x2 + (x2 - x1) / self.getLength(x1, y1, x2, y2, False) * offset
y = y2 + (y2 - y1) / self.getLength(x1, y1, x2, y2, False) * offset
return [x, y]
def getAlpha(self, x1, y1, x2, y2, x3, y3):
# get alpha of point 2
temp1 = (x1 - x2) ** 2 + (y1 - y2) ** 2 + (x3 - x2) ** 2 + (y3 - y2) ** 2 - (x1 - x3) ** 2 - (y1 - y3) ** 2
temp2 = 2 * math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) * math.sqrt((x3 - x2) ** 2 + (y3 - y2) ** 2)
return math.acos(max(min(temp1 / temp2, 1.0), -1.0))
def processOffset(self, cmd, posX, posY):
# calculate offset correction (or dont)
if not self.options.useToolOffset or self.dryRun:
self.storePoint(cmd, posX, posY)
else:
# insert data into cache
self.vData.pop(0)
self.vData.insert(3, [cmd, posX, posY])
# decide if enough data is availabe
if self.vData[2][1] != -1.0:
if self.vData[1][1] == -1.0:
self.storePoint(self.vData[2][0], self.vData[2][1], self.vData[2][2])
else:
# perform tool offset correction (It's a *tad* complicated, if you want to understand it draw the data as lines on paper)
if self.vData[2][0] == 'PD': # If the 3rd entry in the cache is a pen down command make the line longer by the tool offset
pointThree = self.changeLength(self.vData[1][1], self.vData[1][2], self.vData[2][1], self.vData[2][2], self.options.toolOffset)
self.storePoint('PD', pointThree[0], pointThree[1])
elif self.vData[0][1] != -1.0:
# Elif the 1st entry in the cache is filled with data and the 3rd entry is a pen up command shift
# the 3rd entry by the current tool offset position according to the 2nd command
pointThree = self.changeLength(self.vData[0][1], self.vData[0][2], self.vData[1][1], self.vData[1][2], self.options.toolOffset)
pointThree[0] = self.vData[2][1] - (self.vData[1][1] - pointThree[0])
pointThree[1] = self.vData[2][2] - (self.vData[1][2] - pointThree[1])
self.storePoint('PU', pointThree[0], pointThree[1])
else:
# Else just write the 3rd entry
pointThree = [self.vData[2][1], self.vData[2][2]]
self.storePoint('PU', pointThree[0], pointThree[1])
if self.vData[3][0] == 'PD':
# If the 4th entry in the cache is a pen down command guide tool to next line with a circle between the prolonged 3rd and 4th entry
if self.getLength(self.vData[2][1], self.vData[2][2], self.vData[3][1], self.vData[3][2]) >= self.options.toolOffset:
pointFour = self.changeLength(self.vData[3][1], self.vData[3][2], self.vData[2][1], self.vData[2][2], - self.options.toolOffset)
else:
pointFour = self.changeLength(self.vData[2][1], self.vData[2][2], self.vData[3][1], self.vData[3][2],
(self.options.toolOffset - self.getLength(self.vData[2][1], self.vData[2][2], self.vData[3][1], self.vData[3][2])))
# get angle start and angle vector
angleStart = math.atan2(pointThree[1] - self.vData[2][2], pointThree[0] - self.vData[2][1])
angleVector = math.atan2(pointFour[1] - self.vData[2][2], pointFour[0] - self.vData[2][1]) - angleStart
# switch direction when arc is bigger than 180°
if angleVector > self.PI:
angleVector -= self.TWO_PI
elif angleVector < - self.PI:
angleVector += self.TWO_PI
# draw arc
if angleVector >= 0:
angle = angleStart + self.toolOffsetFlat
while angle < angleStart + angleVector:
self.storePoint('PD', self.vData[2][1] + math.cos(angle) * self.options.toolOffset, self.vData[2][2] + math.sin(angle) * self.options.toolOffset)
angle += self.toolOffsetFlat
else:
angle = angleStart - self.toolOffsetFlat
while angle > angleStart + angleVector:
self.storePoint('PD', self.vData[2][1] + math.cos(angle) * self.options.toolOffset, self.vData[2][2] + math.sin(angle) * self.options.toolOffset)
angle -= self.toolOffsetFlat
self.storePoint('PD', pointFour[0], pointFour[1])
def storePoint(self, command, x, y):
x = int(round(x))
y = int(round(y))
# skip when no change in movement
if self.lastPoint[0] == command and self.lastPoint[1] == x and self.lastPoint[2] == y:
return
if self.dryRun:
# find edges
if self.divergenceX == 'False' or x < self.divergenceX:
self.divergenceX = x
if self.divergenceY == 'False' or y < self.divergenceY:
self.divergenceY = y
if self.sizeX == 'False' or x > self.sizeX:
self.sizeX = x
if self.sizeY == 'False' or y > self.sizeY:
self.sizeY = y
else:
# store point
if not self.options.center:
# only positive values are allowed (usually)
if x < 0:
x = 0
if y < 0:
y = 0
# do not repeat command
if command == 'PD' and self.lastPoint[0] == 'PD':
self.hpgl += ',%d,%d' % (x, y)
else:
self.hpgl += ';%s%d,%d' % (command, x, y)
self.lastPoint = [command, x, y]
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