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mightyscape-0.92-deprecated/extensions/fablabchemnitz_elliptic_stretch.py
2019-11-14 20:09:28 +01:00

663 lines
23 KiB
Python

#!/usr/bin/env python
# coding=utf-8
# Written by Daniel C. Newman ( dan dot newman at mtbaldy dot us )
# 19 October 2010
# 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 math
import bezmisc
import cspsubdiv
import cubicsuperpath
import inkex
import simplepath
from simpletransform import applyTransformToPath, applyTransformToPoint, composeTransform, parseTransform
N_PAGE_WIDTH = 3200
N_PAGE_HEIGHT = 800
def inverseTransform(tran):
"""
An SVG transform matrix looks like
[ a c e ]
[ b d f ]
[ 0 0 1 ]
And it's inverse is
[ d -c cf - de ]
[ -b a be - af ] * ( ad - bc ) ** -1
[ 0 0 1 ]
And, no reasonable 2d coordinate transform will have
the products ad and bc equal.
SVG represents the transform matrix column by column as
matrix(a b c d e f) while Inkscape extensions store the
transform matrix as
[[a, c, e], [b, d, f]]
To invert the transform stored Inkscape style, we wish to
produce
[[d/D, -c/D, (cf - de)/D], [-b/D, a/D, (be-af)/D]]
where
D = 1 / (ad - bc)
"""
D = tran[0][0] * tran[1][1] - tran[1][0] * tran[0][1]
if D == 0:
return None
return [[tran[1][1] / D, -tran[0][1] / D,
(tran[0][1] * tran[1][2] - tran[1][1] * tran[0][2]) / D],
[-tran[1][0] / D, tran[0][0] / D,
(tran[1][0] * tran[0][2] - tran[0][0] * tran[1][2]) / D]]
def parseLengthWithUnits(a_str):
"""
Parse an SVG value which may or may not have units attached
This version is greatly simplified in that it only allows: no units,
units of px, and units of %. Everything else, it returns None for.
There is a more general routine to consider in scour.py if more
generality is ever needed.
"""
u = 'px'
s = a_str.strip()
if s[-2:] == 'px':
s = s[:-2]
elif s[-1:] == '%':
u = '%'
s = s[:-1]
try:
v = float(s)
except:
return None, None
return v, u
def subdivideCubicPath(sp, flat, i=1):
"""
[ Lifted from eggbot.py with impunity ]
Break up a bezier curve into smaller curves, each of which
is approximately a straight line within a given tolerance
(the "smoothness" defined by [flat]).
This is a modified version of cspsubdiv.cspsubdiv(): rewritten
because recursion-depth errors on complicated line segments
could occur with cspsubdiv.cspsubdiv().
"""
while True:
while True:
if i >= len(sp):
return
p0 = sp[i - 1][1]
p1 = sp[i - 1][2]
p2 = sp[i][0]
p3 = sp[i][1]
b = (p0, p1, p2, p3)
if cspsubdiv.maxdist(b) > flat:
break
i += 1
one, two = bezmisc.beziersplitatt(b, 0.5)
sp[i - 1][2] = one[1]
sp[i][0] = two[2]
p = [one[2], one[3], two[1]]
sp[i:1] = [p]
class Map(inkex.Effect):
def __init__(self):
inkex.Effect.__init__(self)
self.OptionParser.add_option('--smoothness', dest='smoothness',
type='float', default=float(0.2), action='store',
help='Curve smoothing (less for more)')
self.OptionParser.add_option('--maxDy', dest='maxDy',
type='float', default=float(5.0), action='store',
help='Vertical smoothing (less for more)')
self.cx = float(N_PAGE_WIDTH) / 2.0
self.cy = float(N_PAGE_HEIGHT) / 2.0
self.xmin, self.xmax = (1.0E70, -1.0E70)
self.maxDy = float(5)
self.paths = {}
self.transforms = {}
# For handling an SVG viewbox attribute, we will need to know the
# values of the document's <svg> width and height attributes as well
# as establishing a transform from the viewbox to the display.
self.docWidth = float(N_PAGE_WIDTH)
self.docHeight = float(N_PAGE_HEIGHT)
self.docTransform = [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0]]
def getLength(self, name, default):
"""
Get the <svg> attribute with name "name" and default value "default"
Parse the attribute into a value and associated units. Then, accept
no units (''), units of pixels ('px'), and units of percentage ('%').
"""
s = self.document.getroot().get(name)
if s:
v, u = parseLengthWithUnits(s)
if not v:
# Couldn't parse the value
return None
elif (u == '') or (u == 'px'):
return v
elif u == '%':
return float(default) * v / 100.0
else:
# Unsupported units
return None
else:
# No width specified; assume the default value
return float(default)
def getDocProps(self):
"""
Get the document's height and width attributes from the <svg> tag.
Use a default value in case the property is not present or is
expressed in units of percentages.
"""
self.docHeight = self.getLength('height', N_PAGE_HEIGHT)
self.docWidth = self.getLength('width', N_PAGE_WIDTH)
if (self.docHeight is None) or (self.docWidth is None):
return False
else:
return True
def handleViewBox(self):
"""
Set up the document-wide transform in the event that the document has an SVG viewbox
"""
if self.getDocProps():
viewbox = self.document.getroot().get('viewBox')
if viewbox:
vinfo = viewbox.strip().replace(',', ' ').split(' ')
if (vinfo[2] != 0) and (vinfo[3] != 0):
sx = self.docWidth / float(vinfo[2])
sy = self.docHeight / float(vinfo[3])
self.docTransform = parseTransform('scale({0:f},{1:f})'.format(sx, sy))
def getPathVertices(self, path, node=None, transform=None, find_bbox=False):
"""
Decompose the path data from an SVG element into individual
subpaths, each subpath consisting of absolute move to and line
to coordinates. Place these coordinates into a list of polygon
vertices.
"""
if (not path) or (len(path) == 0):
# Nothing to do
return None
# parsePath() may raise an exception. This is okay
sp = simplepath.parsePath(path)
if (not sp) or (len(sp) == 0):
# Path must have been devoid of any real content
return None
# Get a cubic super path
p = cubicsuperpath.CubicSuperPath(sp)
if (not p) or (len(p) == 0):
# Probably never happens, but...
return None
if transform:
applyTransformToPath(transform, p)
# Now traverse the cubic super path
subpath_list = []
subpath_vertices = []
for sp in p:
if len(subpath_vertices):
subpath_list.append(subpath_vertices)
subpath_vertices = []
last_csp = None
subdivideCubicPath(sp, float(self.options.smoothness))
for csp in sp:
if (last_csp is not None) and (math.fabs(csp[1][1] - last_csp[1]) > self.options.maxDy):
dy = (csp[1][1] - last_csp[1])
dx = (csp[1][0] - last_csp[0])
nsteps = math.ceil(math.fabs(dy / self.options.maxDy))
for n in range(1, int(1 + nsteps)):
s = n / nsteps
subpath_vertices.append([last_csp[0] + s * dx, last_csp[1] + s * dy])
else:
# Add this vertex to the list of vertices
subpath_vertices.append(csp[1])
last_csp = csp[1]
if find_bbox:
if last_csp[0] < self.xmin:
self.xmin = last_csp[0]
elif last_csp[0] > self.xmax:
self.xmax = last_csp[0]
# Handle final subpath
if len(subpath_vertices):
subpath_list.append(subpath_vertices)
if len(subpath_list) > 0:
self.paths[node] = subpath_list
self.transforms[node] = transform
def mapPathVertices(self, node):
steps2rads = math.pi / float(1600)
transform = self.transforms[node]
if transform is None:
inv_transform = None
else:
inv_transform = inverseTransform(transform)
new_path = ''
for subpath in self.paths[node]:
last_point = subpath[0]
last_point[0] = self.cx + (last_point[0] - self.cx) / math.cos((last_point[1] - self.cy) * steps2rads)
if inv_transform is not None:
applyTransformToPoint(inv_transform, last_point)
new_path += ' M {0:f},{1:f}'.format(last_point[0], last_point[1])
for point in subpath[1:]:
x = self.cx + (point[0] - self.cx) / math.cos((point[1] - self.cy) * steps2rads)
pt = [x, point[1]]
if inv_transform is not None:
applyTransformToPoint(inv_transform, pt)
new_path += ' l {0:f},{1:f}'.format(pt[0] - last_point[0], pt[1] - last_point[1])
last_point = pt
self.paths[node] = new_path
def recursivelyTraverseSvg(self, a_node_list, mat_current=None, parent_visibility='visible', find_bbox=False):
"""
[ This too is largely lifted from eggbot.py ]
Recursively walk the SVG document, building polygon vertex lists
for each graphical element we support.
Rendered SVG elements:
<circle>, <ellipse>, <line>, <path>, <polygon>, <polyline>, <rect>
Supported SVG elements:
<group>, <use>
Ignored SVG elements:
<defs>, <eggbot>, <metadata>, <namedview>, <pattern>,
processing directives
All other SVG elements trigger an error (including <text>)
"""
if mat_current is None:
mat_current = [[1.0, 0.0, 0.0], [0.0, 1.0, 0.0]]
for node in a_node_list:
# Ignore invisible nodes
v = node.get('visibility', parent_visibility)
if v == 'inherit':
v = parent_visibility
if v == 'hidden' or v == 'collapse':
pass
# First apply the current matrix transform to this node's transform
mat_new = composeTransform(mat_current, parseTransform(node.get("transform")))
if node.tag in [inkex.addNS('g', 'svg'), 'g']:
self.recursivelyTraverseSvg(node, mat_new, v, find_bbox)
elif node.tag in [inkex.addNS('use', 'svg'), 'use']:
# A <use> element refers to another SVG element via an xlink:href="#blah"
# attribute. We will handle the element by doing an XPath search through
# the document, looking for the element with the matching id="blah"
# attribute. We then recursively process that element after applying
# any necessary (x,y) translation.
#
# Notes:
# 1. We ignore the height and width attributes as they do not apply to
# path-like elements, and
# 2. Even if the use element has visibility="hidden", SVG still calls
# for processing the referenced element. The referenced element is
# hidden only if its visibility is "inherit" or "hidden".
refid = node.get(inkex.addNS('href', 'xlink'))
# [1:] to ignore leading '#' in reference
path = '//*[@id="{0}"]'.format(refid[1:])
refnode = node.xpath(path)
if refnode:
x = float(node.get('x', '0'))
y = float(node.get('y', '0'))
# Note: the transform has already been applied
if (x != 0) or (y != 0):
mat_new2 = composeTransform(mat_new, parseTransform('translate({0:f},{1:f})'.format(x, y)))
else:
mat_new2 = mat_new
v = node.get('visibility', v)
self.recursivelyTraverseSvg(refnode, mat_new2, v, find_bbox)
elif node.tag == inkex.addNS('path', 'svg'):
path_data = node.get('d')
if path_data:
self.getPathVertices(path_data, node, mat_new, find_bbox)
elif node.tag in [inkex.addNS('rect', 'svg'), 'rect']:
# Manually transform
#
# <rect x="X" y="Y" width="W" height="H"/>
#
# into
#
# <path d="MX,Y lW,0 l0,H l-W,0 z"/>
#
# I.e., explicitly draw three sides of the rectangle and the
# fourth side implicitly
# Create a path with the outline of the rectangle
x = float(node.get('x'))
y = float(node.get('y'))
w = float(node.get('width', '0'))
h = float(node.get('height', '0'))
a = [['M ', [x, y]],
[' l ', [w, 0]],
[' l ', [0, h]],
[' l ', [-w, 0]],
[' Z', []],
]
self.getPathVertices(simplepath.formatPath(a), node, mat_new, find_bbox)
elif node.tag in [inkex.addNS('line', 'svg'), 'line']:
# Convert
#
# <line x1="X1" y1="Y1" x2="X2" y2="Y2/>
#
# to
#
# <path d="MX1,Y1 LX2,Y2"/>
x1 = float(node.get('x1'))
y1 = float(node.get('y1'))
x2 = float(node.get('x2'))
y2 = float(node.get('y2'))
a = [['M ', [x1, y1]],
[' L ', [x2, y2]],
]
self.getPathVertices(simplepath.formatPath(a), node, mat_new, find_bbox)
elif node.tag in [inkex.addNS('polyline', 'svg'), 'polyline']:
# Convert
#
# <polyline points="x1,y1 x2,y2 x3,y3 [...]"/>
#
# to
#
# <path d="Mx1,y1 Lx2,y2 Lx3,y3 [...]"/>
#
# Note: we ignore polylines with no points
pl = node.get('points', '').strip()
pa = pl.split()
d = "".join(["M " + pa[i] if i == 0 else " L " + pa[i] for i in range(0, len(pa))])
self.getPathVertices(d, node, mat_new, find_bbox)
elif node.tag in [inkex.addNS('polygon', 'svg'), 'polygon']:
# Convert
#
# <polygon points="x1,y1 x2,y2 x3,y3 [...]"/>
#
# to
#
# <path d="Mx1,y1 Lx2,y2 Lx3,y3 [...] Z"/>
#
# Note: we ignore polygons with no points
pl = node.get('points', '').strip()
pa = pl.split()
d = "".join(["M " + pa[i] if i == 0 else " L " + pa[i] for i in range(len(pa))])
d += " Z"
self.getPathVertices(d, node, mat_new, find_bbox)
elif node.tag in [inkex.addNS('ellipse', 'svg'), 'ellipse',
inkex.addNS('circle', 'svg'), 'circle']:
# Convert circles and ellipses to a path with two 180 degree arcs.
# In general (an ellipse), we convert
#
# <ellipse rx="RX" ry="RY" cx="X" cy="Y"/>
#
# to
#
# <path d="MX1,CY A RX,RY 0 1 0 X2,CY A RX,RY 0 1 0 X1,CY"/>
#
# where
#
# X1 = CX - RX
# X2 = CX + RX
#
# Note: ellipses or circles with a radius attribute of value 0 are ignored
if node.tag in [inkex.addNS('ellipse', 'svg'), 'ellipse']:
rx = float(node.get('rx', '0'))
ry = float(node.get('ry', '0'))
else:
rx = float(node.get('r', '0'))
ry = rx
cx = float(node.get('cx', '0'))
cy = float(node.get('cy', '0'))
x1 = cx - rx
x2 = cx + rx
d = 'M {x1:f},{cy:f} ' \
'A {rx:f},{ry:f} ' \
'0 1 0 {x2:f},{cy:f} ' \
'A {rx:f},{ry:f} ' \
'0 1 0 {x1:f},{cy:f}'.format(x1=x1,
x2=x2,
rx=rx,
ry=ry,
cy=cy)
self.getPathVertices(d, node, mat_new, find_bbox)
elif node.tag in [inkex.addNS('pattern', 'svg'), 'pattern']:
pass
elif node.tag in [inkex.addNS('metadata', 'svg'), 'metadata']:
pass
elif node.tag in [inkex.addNS('defs', 'svg'), 'defs']:
pass
elif node.tag in [inkex.addNS('namedview', 'sodipodi'), 'namedview']:
pass
elif node.tag in [inkex.addNS('eggbot', 'svg'), 'eggbot']:
pass
elif node.tag in [inkex.addNS('text', 'svg'), 'text']:
inkex.errormsg('Warning: unable to draw text, please convert it to a path first.')
pass
elif not isinstance(node.tag, basestring):
pass
else:
inkex.errormsg('Warning: unable to draw object <{0}>, please convert it to a path first.'.format(node.tag))
pass
def recursivelyReplaceSvg(self, nodes, parent_visibility='visible'):
for i in range(len(nodes)):
node = nodes[i]
# Ignore invisible nodes
v = node.get('visibility', parent_visibility)
if v == 'inherit':
v = parent_visibility
if v == 'hidden' or v == 'collapse':
pass
if node.tag in [inkex.addNS('g', 'svg'), 'g']:
self.recursivelyReplaceSvg(node, parent_visibility=v)
elif node.tag == inkex.addNS('path', 'svg'):
if node in self.paths:
# Change the path data to be the new path
node.set('d', self.paths[node][1:])
del self.paths[node]
elif node.tag in [inkex.addNS('use', 'svg'), 'use',
inkex.addNS('rect', 'svg'), 'rect',
inkex.addNS('line', 'svg'), 'line',
inkex.addNS('polyline', 'svg'), 'polyline',
inkex.addNS('polygon', 'svg'), 'polygon',
inkex.addNS('ellipse', 'svg'), 'ellipse',
inkex.addNS('circle', 'svg'), 'circle']:
# Replace this element with a <path> element
if node in self.paths:
# Create a new <path> element
# We simply copy all of the attributes from
# the old element to this new element even though
# some of the attributes are no longer relevant
new_node = inkex.etree.Element(inkex.addNS('path', 'svg'), node.attrib)
new_node.set('d', self.paths[node][1:])
# Now replace the old element with this element
nodes[i] = new_node
# And dispose of the old data and element
del self.paths[node]
del node
else:
pass
def recursivelyGetEnclosingTransform(self, node):
"""
Determine the cumulative transform which node inherits from
its chain of ancestors.
"""
node = node.getparent()
if node is not None:
parent_transform = self.recursivelyGetEnclosingTransform(node)
node_transform = node.get('transform', None)
if node_transform is None:
return parent_transform
else:
tr = parseTransform(node_transform)
if parent_transform is None:
return tr
else:
return composeTransform(parent_transform, tr)
else:
return self.docTransform
def effect(self):
# Viewbox handling
self.handleViewBox()
# Locate the center of the document by obtaining its dimensions
if (self.docHeight is None) or (self.docWidth is None):
inkex.errormsg('Document has inappropriate width or height units')
return
self.cy = self.docHeight / 2.0
self.cx = self.docWidth / 2.0
# First traverse the document (or selected items), reducing
# everything to line segments. If working on a selection,
# then determine the selection's bounding box in the process.
# (Actually, we just need to know it's extrema on the x-axis.)
if self.options.ids:
# Traverse the selected objects
for id_ in self.options.ids:
transform = self.recursivelyGetEnclosingTransform(self.selected[id_])
self.recursivelyTraverseSvg([self.selected[id_]], transform, find_bbox=True)
# Use as the vertical centerline the midpoint between
# the bounding box's extremal X coordinates
self.cx = 0.5 * (self.xmin + self.xmax)
else:
# Traverse the entire document building new, transformed paths
self.recursivelyTraverseSvg(self.document.getroot(), self.docTransform)
# Now that we know the x-axis extrema, we can remap the data
# Had we know the x-axis extrema in advance (i.e., operating
# on the entire document), then we could have done the mapping
# at the same time we "rendered" everything to line segments.
for key in self.paths:
self.mapPathVertices(key)
# And now replace the old paths with the new paths
# WE DO NOT compute and replace the paths in the same pass!
# So doing can cause multiple transformations of cloned paths
self.recursivelyReplaceSvg(self.document.getroot(), self.docTransform) # TODO The arguments here don't look right.
if __name__ == '__main__':
e = Map()
e.affect()