lace_ground.py

#!/usr/bin/env python

# Copyright (c) 2017, Veronika Irvine
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 
# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import sys
import os
from math import sin,cos,radians, ceil
from lxml import etree
from random import random

import inkex

__author__ = 'Veronika Irvine'
__credits__ = ['Ben Connors', 'Veronika Irvine', 'Mark Shafer']
__license__ = 'Simplified BSD'

class LaceGround(inkex.Effect):
    """
    Create a ground for lace from a text file descriptor 
    using specified angle and spacing
    """

    def unitToUu(self,param):
        """ Convert units.
        Converts a number in some units into the units used internally by 
        Inkscape.
        
        param is a string representing a number with units attached. An 
            example would be '3.8mm'. Any units supported by Inkscape
            are supported by this function.
        
        This wrapper function catches changes made to the location
        of the function between Inkscape versions.
        """
        try:
            return self.svg.unittouu(param)
        except:
            return inkex.unittouu(param)

    def loadFile(self):
        # Ensure that file exists and has the proper extension
        if not self.options.file:
            inkex.errormsg('You must specify a template file.')
            exit()
        self.options.file = self.options.file.strip()
        if self.options.file == '':
            inkex.errormsg('You must specify a template file.')
            exit()
        if not os.path.isfile(self.options.file):
            inkex.errormsg('You have not specified a valid path for the template file.\n\nYour entry: '+self.options.file)
            exit()
        extension = os.path.splitext(self.options.file)[1]
        if extension != '.txt':
            inkex.errormsg('The file name must end with .txt.\n\nYour entry: '+self.options.file)
            exit()
            
        data = []
        rowCount = 0
        colCount = 0
        with open(self.options.file,'r') as f:
            first = True
            for line in f:
                if first:
                    # first line of file gives row count and column count
                    first = False
                    line = line.strip()
                    temp = line.split('\t')
                    type = temp[0]
                    rowCount = int(temp[1])
                    colCount = int(temp[-1])
                    
                else:
                    line = line.strip()
                    line = line.lstrip('[')
                    line = line.rstrip(']')
                    rowData = line.split(']\t[')
                    data.append([])
                    for cell in rowData:
                        cell = cell.strip()
                        data[-1].append([float(num) for num in cell.split(',')])
                        
        return {'type':type, 'rowCount':rowCount, 'colCount':colCount, 'data':data}

    def line(self, x1, y1, x2, y2):
        """
        Draw a line from point at (x1, y1) to point at (x2, y2).
        Style of line is hard coded and specified by 's'.
        """
        # define the motions
        path = 'M %s,%s L %s,%s' %(x1,y1,x2,y2)
        
        # define the stroke style
        s = {'stroke-linejoin': 'miter', 
            'stroke-width': self.options.linewidth,
            'stroke-opacity': '1.0', 
            'fill-opacity': '1.0',
            'stroke': self.options.linecolor, 
            'stroke-linecap': 'butt',
            'stroke-linejoin': 'miter',
            'fill': 'none'
        }
        
        # create attributes from style and path
        attribs = {'style':str(inkex.Style(s)), 'd':path}
        
        # insert path object into current layer
        etree.SubElement(self.svg.get_current_layer(), inkex.addNS('path', 'svg'), attribs)

    def jitter(self, nodeJitter, x, y):
        if self.options.xrand == 0 and self.options.yrand == 0:
            return [x,y]
        id = "%.3f" % x +",%.3f" % y
        value = nodeJitter.get(id)
        if not value:
            jitx = x + self.options.xrand*(2.0*random()-1.0)*self.options.spacing/100
            jity = y + self.options.yrand*(2.0*random()-1.0)*self.options.spacing/100
            value = [jitx,jity]
            nodeJitter[id] = value
        return value

    def draw(self, data, rowCount, colCount):
        a = self.options.spacing
        theta = self.options.angle
        deltaX = a*sin(theta) 
        deltaY = a*cos(theta)
        maxRows = ceil(self.options.height / deltaY)
        maxCols = ceil(self.options.width  / deltaX)
        
        x = 0.0
        y = 0.0
        repeatY = 0
        repeatX = 0

        # Random jitter of nodes
        nodeJitter = {}

        while repeatY * rowCount < maxRows:
            x = 0.0
            repeatX = 0
            
            while repeatX * colCount < maxCols:
                
                for row in data:
                    for coords in row:
                        x1 = x + coords[0]*deltaX
                        y1 = y + coords[1]*deltaY
                        x2 = x + coords[2]*deltaX
                        y2 = y + coords[3]*deltaY
                        x3 = x + coords[4]*deltaX
                        y3 = y + coords[5]*deltaY
                        x1,y1 = self.jitter(nodeJitter,x1,y1)
                        x2,y2 = self.jitter(nodeJitter,x2,y2)
                        x3,y3 = self.jitter(nodeJitter,x3,y3)

                        self.line(x1,y1,x2,y2)
                        self.line(x1,y1,x3,y3)
                    
                repeatX += 1
                x += deltaX * colCount

            repeatY += 1
            y += deltaY * rowCount
        
    def __init__(self):
        """
        Constructor.
        Defines the '--centerx' option of the script.
        """
        # Call the base class constructor.
        inkex.Effect.__init__(self)

        # file
        self.arg_parser.add_argument('-f', '--file',
                                     type=str,
                                     dest='file',
                                     help='File containing lace ground description')
        # Grid description
        self.arg_parser.add_argument('--angle',
                                     type=float,
                                     dest='angle')
        self.arg_parser.add_argument('--distance',
                                     type=float,
                                     dest='spacing')
        self.arg_parser.add_argument('--pinunits',
                                     type=str,
                                     dest='pinunits')
        self.arg_parser.add_argument('--width',
                                     type=float,
                                     dest='width')
        self.arg_parser.add_argument('--patchunits',
                                     type=str,
                                     dest='patchunits')
        self.arg_parser.add_argument('--height',
                                     type=float,
                                     dest='height')
        self.arg_parser.add_argument('--linewidth',
                                     type=float,
                                     dest='linewidth')
        self.arg_parser.add_argument('--lineunits',
                                     type=str,
                                     dest='lineunits')
        self.arg_parser.add_argument('--linecolor',
                                     type=inkex.Color,
                                     dest='linecolor')
        self.arg_parser.add_argument('--xrand',
                                      type=int,
                                      dest='xrand')
        self.arg_parser.add_argument('--yrand',
                                      type=int,
                                      dest='yrand')

    def effect(self):
        """
        Effect behaviour.
        Overrides base class' method and draws something.
        """
        result = self.loadFile()
        
        # Convert input to universal units
        self.options.width = self.unitToUu(str(self.options.width)+self.options.patchunits)
        self.options.height = self.unitToUu(str(self.options.height)+self.options.patchunits)
        self.options.linewidth = self.unitToUu(str(self.options.linewidth)+self.options.lineunits)
        self.options.spacing = self.unitToUu(str(self.options.spacing)+self.options.pinunits)
        
        # Users expect spacing to be the vertical distance between footside pins 
        # (vertical distance between every other row) but in the script we use it 
        # as the diagonal distance between grid points
        # therefore convert spacing based on the angle chosen
        self.options.angle = radians(self.options.angle)
        self.options.spacing = self.options.spacing/(2.0*cos(self.options.angle))
        
        # Draw a ground based on file description and user inputs
        self.options.linecolor = self.options.linecolor.to_rgb()
        # For now, assume style is Checker but could change in future
        self.draw(result['data'],result['rowCount'],result['colCount'])

# Create effect instance and apply it.
effect = LaceGround()
effect.run()