fixes in collinear line filtering in contour scanner

This commit is contained in:
Mario Voigt 2021-07-08 12:52:31 +02:00
parent e12b2500cc
commit 5d90d4f2ed
2 changed files with 157 additions and 41 deletions

View File

@ -11,9 +11,10 @@
<param name="break_apart" type="bool" gui-text="Break apart input" gui-description="Break apart input paths into sub paths. Modifies original paths: converts to absolute paths and might create additional new path elements.">false</param>
<param name="handle_groups" type="bool" gui-text="Handle groups" gui-description="Also looks for paths in groups which are in the current selection. Note: The generated results have a different structure (less granularity due to grouping and conversion of absolute paths to relative paths) than directly selected paths. The colorization for non-intersected paths will be different too.">false</param>
<param name="flattenbezier" type="bool" gui-text="Quantization (flatten bezier curves to polylines)" gui-description="Convert bezier curves to polylines.">true</param>
<param name="flatness" type="float" min="0.001" max="99999.000" precision="3" gui-text="Flatness (tolerance)" gui-description="Minimum flatness = 0.001. The smaller the value the more fine segments you will get (quantization). Large values might destroy the line continuity.">0.100</param>
<param name="flatness" type="float" min="0.001" max="99999.000" precision="3" gui-text="Flatness (tolerance)" gui-description="Minimum flatness = 0.001. The smaller the value the more fine segments you will get (quantization). Large values might destroy the line continuity (default: 0.1).">0.100</param>
<param name="decimals" type="int" min="0" max="16" gui-text="Decimals" gui-description="Accuracy for sub split lines / lines trimmed by shapely (default: 3)">3</param>
<param name="snap_tolerance" type="float" min="0.01" max="10.0" gui-text="Snap tolerance" gui-description="Snap tolerance for intersection points on paths (default: 0.1)">0.1</param>
<param name="collinear_filter_epsilon" type="float" min="0.000000001" max="1.0" precision="9" gui-text="Epsilon for collinear line filter" gui-description="default: 0.01">0.01</param>
<label appearance="header">General style</label>
<param name="strokewidth" min="0.0" max="10000.0" precision="3" gui-text="Stroke width (px)" gui-description="Applies For sub split lines and trimmed lines" type="float">1.0</param>
<param name="dotsize_intersections" type="int" min="0" max="10000" gui-text="Intersection dot size (px)" gui-description="For self-intersecting and global intersection points">30</param>

View File

@ -6,8 +6,7 @@ Extension for InkScape 1.0+
- ToDo:
- add more comments
- add more debug output
- add documentation at online page
- fix filtering duplicate lines if perfect vertical > write a function process_set_y()
- add documentation about used algorithms at online page
- add statistics about type counts and path lengths (before/after sub splitting/trimming)
- add options:
- replace trimmed paths by bezier paths (calculating lengths and required t parameter)
@ -54,7 +53,7 @@ Extension for InkScape 1.0+
Author: Mario Voigt / FabLab Chemnitz
Mail: mario.voigt@stadtfabrikanten.org
Date: 09.08.2020 (extension originally called "Contour Scanner")
Last patch: 24.06.2021
Last patch: 08.07.2021
License: GNU GPL v3
'''
@ -80,10 +79,9 @@ idPrefixTrimming = "trimmed"
intersectedVerb = "intersected"
collinearVerb = "collinear"
EPS_M = 0.01
class ContourScannerAndTrimmer(inkex.EffectExtension):
def break_contours(self, element, breakelements = None):
'''
this does the same as "CTRL + SHIFT + K"
@ -336,8 +334,8 @@ class ContourScannerAndTrimmer(inkex.EffectExtension):
# if slopes all match the working set's slope, we're collinear
# if not, these segments are parallel but not collinear and should be left alone
expected_slope = working_set[i]['slope']
if (abs(self.slope(working_set[i]['p1'], working_set[j]['p0']) - expected_slope) > EPS_M) \
or (abs(self.slope(working_set[i]['p0'], working_set[j]['p1']) - expected_slope) > EPS_M):
if (abs(self.slope(working_set[i]['p1'], working_set[j]['p0']) - expected_slope) > self.options.collinear_filter_epsilon) \
or (abs(self.slope(working_set[i]['p0'], working_set[j]['p1']) - expected_slope) > self.options.collinear_filter_epsilon):
continue
# the only remaining permissible configuration: collinear segments with a gap between them
@ -369,14 +367,63 @@ class ContourScannerAndTrimmer(inkex.EffectExtension):
return (True, working_set)
def process_set_y(self, working_set):
if len(working_set) < 2:
return (True, working_set)
# sort working set top to bottom
working_set.sort(key=lambda y: -y['p0'][1])
for i in range(0, len(working_set)):
for j in range(i + 1, len(working_set)):
# the only remaining permissible configuration: collinear segments with a gap between them
# e.g.
# |
# |
#
# |
# |
# |
#
# otherwise we combine segments and flag the set as requiring more processing
s0y0 = working_set[i]['p0'][1]
s0y1 = working_set[i]['p1'][1]
s1y0 = working_set[j]['p0'][1]
s1y1 = working_set[j]['p1'][1]
if not (s0y0 < s0y1 and s0y1 < s1y0 and s1y0 < s1y1):
# make a duplicate set, omitting segments i and j
new_set = [y for (k, y) in enumerate(working_set) if k not in (i, j)]
# add a segment representing i and j's furthest points
pts = [ working_set[i]['p0'], working_set[i]['p1'], working_set[j]['p0'], working_set[j]['p1'] ]
pts.sort(key=lambda y: y[1])
new_set.append({
'p0': pts[0],
'p1': pts[-1],
'slope': self.slope(pts[0], pts[-1]),
'id': working_set[i]['id'],
'originalPathId': working_set[i]['originalPathId'],
'composed_transform': working_set[i]['composed_transform']
})
return (False, new_set)
return (True, working_set)
def filter_collinear(self, lineArray):
'''
''' Another sweep line algorithm to scan collinear lines
Loop through a set of lines and find + fiter all overlapping segments / duplicate segments
finally returns a set of merged-like lines and a set of original items which should be dropped.
Based on the style of the algorithm we have no good influence on the z-index of the items because
it is scanned by slope and point coordinates. That's why we have a more special
'remove_trim_duplicates()' function for trimmed duplicates!
'''
'''
filter for regular input lines and special vertical lines
'''
input_set = []
input_ids = []
@ -408,13 +455,14 @@ class ContourScannerAndTrimmer(inkex.EffectExtension):
#s['d'] = line.attrib['d']
input_set.append(s)
working_set = []
output_set = []
input_set.sort(key=lambda x: x['slope'])
#input_set.append(False) # used to clear out lingering contents of working_set_x on last iteration
input_set_new = []
#loop through input_set to filter out the vertical lines because we need to handle them separately
vertical_set = []
vertical_ids = []
for i in range(0, len(input_set)):
if input_set[i]['slope'] == sys.float_info.max:
vertical_set.append(input_set[i])
@ -422,41 +470,97 @@ class ContourScannerAndTrimmer(inkex.EffectExtension):
input_set_new.append(input_set[i])
input_set = input_set_new #overwrite the input_set with the filtered one
input_set.append(False) # used to clear out lingering contents of working_set on last iteration
current_slope = input_set[0]['slope']
for input in input_set:
# bin sets of input_set by slope (within a tolerance)
dm = input and abs(input['slope'] - current_slope) or 0
if input and dm < EPS_M:
working_set.append(input) #we put all lines to working set which have similar slopes
if input['id'] != '': input_ids.append(input['id'])
else: # slope discontinuity, process accumulated set
while True:
(done, working_set) = self.process_set_x(working_set)
if done:
output_set.extend(working_set)
break
input_set.append(False) # used to clear out lingering contents of working_set_x on last iteration
if input: # begin new working set
working_set = [input]
current_slope = input['slope']
if input['id'] != '': input_ids.append(input['id'])
'''
process x lines (all lines except vertical ones)
'''
working_set_x = []
working_x_ids = []
output_set_x = []
output_x_ids = []
if len(input_set) > 0:
current_slope = input_set[0]['slope']
for input in input_set:
# bin sets of input_set by slope (within a tolerance)
dm = input and abs(input['slope'] - current_slope) or 0
if input and dm < self.options.collinear_filter_epsilon:
working_set_x.append(input) #we put all lines to working set which have similar slopes
if input['id'] != '': input_ids.append(input['id'])
else: # slope discontinuity, process accumulated set
while True:
(done, working_set_x) = self.process_set_x(working_set_x)
if done:
output_set_x.extend(working_set_x)
break
if input: # begin new working set
working_set_x = [input]
current_slope = input['slope']
if input['id'] != '': input_ids.append(input['id'])
for output_x in output_set_x:
output_x_ids.append(output_x['id'])
for working_x in working_set_x:
working_x_ids.append(working_x['id'])
else:
if self.options.show_debug is True:
self.msg("Scanning: no non-vertical input lines found. That might be okay or not ...")
'''
process vertical lines
'''
working_set_y = []
working_y_ids = []
output_set_y = []
output_y_ids = []
if len(vertical_set) > 0:
vertical_set.sort(key=lambda x: x['p0'][0]) #sort verticals by their x coordinate
vertical_set.append(False) # used to clear out lingering contents of working_set_y on last iteration
current_x = vertical_set[0]['p0'][0]
for vertical in vertical_set:
if vertical and current_x == vertical['p0'][0]:
working_set_y.append(vertical) #we put all lines to working set which have same x coordinate
if vertical['id'] != '': vertical_ids.append(vertical['id'])
else: # x coord discontinuity, process accumulated set
while True:
(done, working_set_y) = self.process_set_y(working_set_y)
if done:
output_set_y.extend(working_set_y)
break
if vertical: # begin new working set
working_set_y = [vertical]
current_x = vertical['p0'][0]
if vertical['id'] != '': vertical_ids.append(vertical['id'])
else:
if self.options.show_debug is True:
self.msg("Scanning: no vertical lines found. That might be okay or not ...")
for output_y in output_set_y:
output_y_ids.append(output_y['id'])
for working_y in working_set_y:
working_y_ids.append(working_y['id'])
output_set = output_set_x
output_set.extend(output_set_y)
output_ids = []
for output in output_set:
#self.msg(output)
output_ids.append(output['id'])
working_ids = []
for working in working_set:
working_ids.append(working['id'])
#we finally build a list which contains all overlapping elements we want to drop
dropped_ids = []
for input_id in input_ids: #if the input_id id is not in the output ids we are going to drop it
if input_id not in output_ids:
dropped_ids.append(input_id)
dropped_ids.append(input_id)
for vertical_id in vertical_ids: #if the input_id id is not in the output ids we are going to drop it
if vertical_id not in output_ids:
dropped_ids.append(vertical_id)
if self.options.show_debug is True:
#self.msg("input_set:{}".format(input_set))
@ -464,11 +568,21 @@ class ContourScannerAndTrimmer(inkex.EffectExtension):
for input_id in input_ids:
self.msg(input_id)
self.msg("*"*24)
#self.msg("working_set:{}".format(working_set))
self.msg("working_ids [{}]:".format(len(working_ids)))
for working_id in working_ids:
self.msg(working_id)
#self.msg("working_set_x:{}".format(working_set_x))
self.msg("working_x_ids [{}]:".format(len(working_x_ids)))
for working_x_id in working_x_ids:
self.msg(working_x_id)
self.msg("*"*24)
#self.msg("output_set_x:{}".format(output_set_x))
self.msg("output_x_ids [{}]:".format(len(output_x_ids)))
for output_x_id in output_x_ids:
self.msg(output_x_id)
self.msg("*"*24)
#self.msg("output_set_y:{}".format(output_set_y))
self.msg("output_y_ids [{}]:".format(len(output_y_ids)))
for output_y_id in output_y_ids:
self.msg(output_y_id)
self.msg("*"*24)
#self.msg("output_set:{}".format(output_set))
self.msg("output_ids [{}]:".format(len(output_ids)))
for output_id in output_ids:
@ -478,7 +592,7 @@ class ContourScannerAndTrimmer(inkex.EffectExtension):
for dropped_id in dropped_ids:
self.msg(dropped_id)
self.msg("*"*24)
return output_set, dropped_ids
@ -613,6 +727,7 @@ class ContourScannerAndTrimmer(inkex.EffectExtension):
pars.add_argument("--flatness", type=float, default=0.1, help="Minimum flatness = 0.001. The smaller the value the more fine segments you will get (quantization). Large values might destroy the line continuity.")
pars.add_argument("--decimals", type=int, default=3, help="Accuracy for sub split lines / lines trimmed by shapely")
pars.add_argument("--snap_tolerance", type=float, default=0.1, help="Snap tolerance for intersection points")
pars.add_argument("--collinear_filter_epsilon", type=float, default=0.01, help="Epsilon for collinear line filter")
#Settings - General Style
pars.add_argument("--strokewidth", type=float, default=1.0, help="Stroke width (px)")
pars.add_argument("--dotsize_intersections", type=int, default=30, help="Dot size (px) for self-intersecting and global intersection points")