Move RoboFab-specific code to a "robofab" module
This commit is contained in:
jamesgk
parent
815c435fc9
commit
45364ed045
@ -1,193 +0,0 @@
|
||||
# Copyright 2015 Google Inc. All Rights Reserved.
|
||||
#
|
||||
# Licensed under the Apache License, Version 2.0 (the "License");
|
||||
# you may not use this file except in compliance with the License.
|
||||
# You may obtain a copy of the License at
|
||||
#
|
||||
# http://www.apache.org/licenses/LICENSE-2.0
|
||||
#
|
||||
# Unless required by applicable law or agreed to in writing, software
|
||||
# distributed under the License is distributed on an "AS IS" BASIS,
|
||||
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
# See the License for the specific language governing permissions and
|
||||
# limitations under the License.
|
||||
|
||||
|
||||
"""Converts cubic bezier curves to quadratic splines.
|
||||
|
||||
Conversion is performed such that the quadratic splines keep the same end-curve
|
||||
tangents as the original cubics. The approach is iterative, increasing the
|
||||
number of segments for a spline until the error gets below a bound.
|
||||
|
||||
If necessary, respective curves from multiple fonts will be converted at once to
|
||||
ensure that the resulting splines are interpolation-compatible.
|
||||
"""
|
||||
|
||||
|
||||
from robofab.objects.objectsRF import RSegment
|
||||
from cu2qu.geometry import Point, curve_to_quadratic, curves_to_quadratic
|
||||
|
||||
|
||||
_zip = zip
|
||||
def zip(*args):
|
||||
"""Ensure each argument to zip has the same length."""
|
||||
|
||||
if len(set(len(a) for a in args)) != 1:
|
||||
msg = 'Args to zip in cu2qu.py should have equal lengths: '
|
||||
raise ValueError(msg + ' '.join(str(a) for a in args))
|
||||
return _zip(*args)
|
||||
|
||||
|
||||
def fonts_to_quadratic(*fonts, **kwargs):
|
||||
"""Convert the curves of a collection of fonts to quadratic.
|
||||
|
||||
If compatibility is required, all curves will be converted to quadratic
|
||||
at once. Otherwise the glyphs will be converted one font at a time,
|
||||
which should be slightly more optimized.
|
||||
"""
|
||||
|
||||
max_n = kwargs.get('max_n', 10)
|
||||
max_err = kwargs.get('max_err', 5)
|
||||
|
||||
report = {}
|
||||
for glyph in FontCollection(fonts):
|
||||
glyph_to_quadratic(glyph, max_n, max_err, report)
|
||||
|
||||
spline_lengths = report.keys()
|
||||
spline_lengths.sort()
|
||||
return (
|
||||
'New spline lengths:\n' +
|
||||
'\n'.join('%s: %d' % (l, report[l]) for l in spline_lengths))
|
||||
|
||||
|
||||
def glyph_to_quadratic(glyph, max_n, max_err, report):
|
||||
"""Convert a glyph's curves to quadratic, in place."""
|
||||
|
||||
for contour in glyph:
|
||||
segments = []
|
||||
for i in range(len(contour)):
|
||||
segment = contour[i]
|
||||
if segment.type == 'curve':
|
||||
segments.append(segment_to_quadratic(
|
||||
contour, i, max_n, max_err, report))
|
||||
else:
|
||||
segments.append(segment)
|
||||
replace_segments(contour, segments)
|
||||
|
||||
|
||||
def segment_to_quadratic(contour, segment_id, max_n, max_err, report):
|
||||
"""Return a quadratic approximation of a cubic segment."""
|
||||
|
||||
segment = contour[segment_id]
|
||||
if segment.type != 'curve':
|
||||
raise TypeError('Segment type not curve')
|
||||
|
||||
# assumes that a curve type will always be proceeded by another point on the
|
||||
# same contour
|
||||
prev_segment = contour[segment_id - 1]
|
||||
points = points_to_quadratic(prev_segment.points[-1], segment.points[0],
|
||||
segment.points[1], segment.points[2],
|
||||
max_n, max_err)
|
||||
|
||||
if isinstance(points[0][0], float): # just one spline
|
||||
n = str(len(points))
|
||||
points = points[1:]
|
||||
|
||||
else: # collection of splines
|
||||
n = str(len(points[0]))
|
||||
points = [p[1:] for p in points]
|
||||
|
||||
report[n] = report.get(n, 0) + 1
|
||||
return as_quadratic(segment, points)
|
||||
|
||||
|
||||
def points_to_quadratic(p0, p1, p2, p3, max_n, max_err):
|
||||
"""Return a quadratic spline approximating the cubic bezier defined by these
|
||||
points (or collections of points).
|
||||
"""
|
||||
|
||||
if hasattr(p0, 'x'):
|
||||
curve = [Point([i.x, i.y]) for i in [p0, p1, p2, p3]]
|
||||
return curve_to_quadratic(curve, max_n, max_err)
|
||||
|
||||
curves = [[Point([i.x, i.y]) for i in p] for p in zip(p0, p1, p2, p3)]
|
||||
return curves_to_quadratic(curves, max_n, max_err)
|
||||
|
||||
|
||||
def replace_segments(contour, segments):
|
||||
"""Replace the segments of a given contour."""
|
||||
|
||||
try:
|
||||
contour.replace_segments(segments)
|
||||
return
|
||||
except AttributeError:
|
||||
pass
|
||||
|
||||
while len(contour):
|
||||
contour.removeSegment(0)
|
||||
for s in segments:
|
||||
contour.appendSegment(s.type, [(p.x, p.y) for p in s.points], s.smooth)
|
||||
|
||||
|
||||
def as_quadratic(segment, points):
|
||||
"""Return a new segment with given points and type qcurve."""
|
||||
|
||||
try:
|
||||
return segment.as_quadratic(points)
|
||||
except AttributeError:
|
||||
return RSegment(
|
||||
'qcurve', [[int(round(i)) for i in p] for p in points], segment.smooth)
|
||||
|
||||
|
||||
class FontCollection:
|
||||
"""A collection of fonts, or font components from different fonts.
|
||||
|
||||
Behaves like a single instance of the component, allowing access into
|
||||
multiple fonts simultaneously for purposes of ensuring interpolation
|
||||
compatibility.
|
||||
"""
|
||||
|
||||
def __init__(self, fonts):
|
||||
self.init(fonts, GlyphCollection)
|
||||
|
||||
def __getitem__(self, key):
|
||||
return self.children[key]
|
||||
|
||||
def __len__(self):
|
||||
return len(self.children)
|
||||
|
||||
def __str__(self):
|
||||
return str(self.instances)
|
||||
|
||||
def init(self, instances, child_collection_type, get_children=None):
|
||||
self.instances = instances
|
||||
children_by_instance = map(get_children, self.instances)
|
||||
self.children = map(child_collection_type, zip(*children_by_instance))
|
||||
|
||||
|
||||
class GlyphCollection(FontCollection):
|
||||
def __init__(self, glyphs):
|
||||
self.init(glyphs, ContourCollection)
|
||||
self.name = glyphs[0].name
|
||||
|
||||
|
||||
class ContourCollection(FontCollection):
|
||||
def __init__(self, contours):
|
||||
self.init(contours, SegmentCollection)
|
||||
|
||||
def replace_segments(self, segment_collections):
|
||||
segments_by_contour = zip(*[s.instances for s in segment_collections])
|
||||
for contour, segments in zip(self.instances, segments_by_contour):
|
||||
replace_segments(contour, segments)
|
||||
|
||||
|
||||
class SegmentCollection(FontCollection):
|
||||
def __init__(self, segments):
|
||||
self.init(segments, None, lambda s: s.points)
|
||||
self.points = self.children
|
||||
self.type = segments[0].type
|
||||
|
||||
def as_quadratic(self, new_points=None):
|
||||
points = new_points or self.children
|
||||
return SegmentCollection([
|
||||
as_quadratic(s, pts) for s, pts in zip(self.instances, points)])
|
||||
193
Lib/cu2qu/robofab.py
Normal file
193
Lib/cu2qu/robofab.py
Normal file
@ -0,0 +1,193 @@
|
||||
# Copyright 2015 Google Inc. All Rights Reserved.
|
||||
#
|
||||
# Licensed under the Apache License, Version 2.0 (the "License");
|
||||
# you may not use this file except in compliance with the License.
|
||||
# You may obtain a copy of the License at
|
||||
#
|
||||
# http://www.apache.org/licenses/LICENSE-2.0
|
||||
#
|
||||
# Unless required by applicable law or agreed to in writing, software
|
||||
# distributed under the License is distributed on an "AS IS" BASIS,
|
||||
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
# See the License for the specific language governing permissions and
|
||||
# limitations under the License.
|
||||
|
||||
|
||||
"""Converts cubic bezier curves to quadratic splines.
|
||||
|
||||
Conversion is performed such that the quadratic splines keep the same end-curve
|
||||
tangents as the original cubics. The approach is iterative, increasing the
|
||||
number of segments for a spline until the error gets below a bound.
|
||||
|
||||
If necessary, respective curves from multiple fonts will be converted at once to
|
||||
ensure that the resulting splines are interpolation-compatible.
|
||||
"""
|
||||
|
||||
|
||||
from robofab.objects.objectsRF import RSegment
|
||||
from cu2qu.geometry import Point, curve_to_quadratic, curves_to_quadratic
|
||||
|
||||
|
||||
_zip = zip
|
||||
def zip(*args):
|
||||
"""Ensure each argument to zip has the same length."""
|
||||
|
||||
if len(set(len(a) for a in args)) != 1:
|
||||
msg = 'Args to zip in cu2qu.py should have equal lengths: '
|
||||
raise ValueError(msg + ' '.join(str(a) for a in args))
|
||||
return _zip(*args)
|
||||
|
||||
|
||||
def fonts_to_quadratic(*fonts, **kwargs):
|
||||
"""Convert the curves of a collection of fonts to quadratic.
|
||||
|
||||
If compatibility is required, all curves will be converted to quadratic
|
||||
at once. Otherwise the glyphs will be converted one font at a time,
|
||||
which should be slightly more optimized.
|
||||
"""
|
||||
|
||||
max_n = kwargs.get('max_n', 10)
|
||||
max_err = kwargs.get('max_err', 5)
|
||||
|
||||
report = {}
|
||||
for glyph in FontCollection(fonts):
|
||||
glyph_to_quadratic(glyph, max_n, max_err, report)
|
||||
|
||||
spline_lengths = report.keys()
|
||||
spline_lengths.sort()
|
||||
return (
|
||||
'New spline lengths:\n' +
|
||||
'\n'.join('%s: %d' % (l, report[l]) for l in spline_lengths))
|
||||
|
||||
|
||||
def glyph_to_quadratic(glyph, max_n, max_err, report):
|
||||
"""Convert a glyph's curves to quadratic, in place."""
|
||||
|
||||
for contour in glyph:
|
||||
segments = []
|
||||
for i in range(len(contour)):
|
||||
segment = contour[i]
|
||||
if segment.type == 'curve':
|
||||
segments.append(segment_to_quadratic(
|
||||
contour, i, max_n, max_err, report))
|
||||
else:
|
||||
segments.append(segment)
|
||||
replace_segments(contour, segments)
|
||||
|
||||
|
||||
def segment_to_quadratic(contour, segment_id, max_n, max_err, report):
|
||||
"""Return a quadratic approximation of a cubic segment."""
|
||||
|
||||
segment = contour[segment_id]
|
||||
if segment.type != 'curve':
|
||||
raise TypeError('Segment type not curve')
|
||||
|
||||
# assumes that a curve type will always be proceeded by another point on the
|
||||
# same contour
|
||||
prev_segment = contour[segment_id - 1]
|
||||
points = points_to_quadratic(prev_segment.points[-1], segment.points[0],
|
||||
segment.points[1], segment.points[2],
|
||||
max_n, max_err)
|
||||
|
||||
if isinstance(points[0][0], float): # just one spline
|
||||
n = str(len(points))
|
||||
points = points[1:]
|
||||
|
||||
else: # collection of splines
|
||||
n = str(len(points[0]))
|
||||
points = [p[1:] for p in points]
|
||||
|
||||
report[n] = report.get(n, 0) + 1
|
||||
return as_quadratic(segment, points)
|
||||
|
||||
|
||||
def points_to_quadratic(p0, p1, p2, p3, max_n, max_err):
|
||||
"""Return a quadratic spline approximating the cubic bezier defined by these
|
||||
points (or collections of points).
|
||||
"""
|
||||
|
||||
if hasattr(p0, 'x'):
|
||||
curve = [Point([i.x, i.y]) for i in [p0, p1, p2, p3]]
|
||||
return curve_to_quadratic(curve, max_n, max_err)
|
||||
|
||||
curves = [[Point([i.x, i.y]) for i in p] for p in zip(p0, p1, p2, p3)]
|
||||
return curves_to_quadratic(curves, max_n, max_err)
|
||||
|
||||
|
||||
def replace_segments(contour, segments):
|
||||
"""Replace the segments of a given contour."""
|
||||
|
||||
try:
|
||||
contour.replace_segments(segments)
|
||||
return
|
||||
except AttributeError:
|
||||
pass
|
||||
|
||||
while len(contour):
|
||||
contour.removeSegment(0)
|
||||
for s in segments:
|
||||
contour.appendSegment(s.type, [(p.x, p.y) for p in s.points], s.smooth)
|
||||
|
||||
|
||||
def as_quadratic(segment, points):
|
||||
"""Return a new segment with given points and type qcurve."""
|
||||
|
||||
try:
|
||||
return segment.as_quadratic(points)
|
||||
except AttributeError:
|
||||
return RSegment(
|
||||
'qcurve', [[int(round(i)) for i in p] for p in points], segment.smooth)
|
||||
|
||||
|
||||
class FontCollection:
|
||||
"""A collection of fonts, or font components from different fonts.
|
||||
|
||||
Behaves like a single instance of the component, allowing access into
|
||||
multiple fonts simultaneously for purposes of ensuring interpolation
|
||||
compatibility.
|
||||
"""
|
||||
|
||||
def __init__(self, fonts):
|
||||
self.init(fonts, GlyphCollection)
|
||||
|
||||
def __getitem__(self, key):
|
||||
return self.children[key]
|
||||
|
||||
def __len__(self):
|
||||
return len(self.children)
|
||||
|
||||
def __str__(self):
|
||||
return str(self.instances)
|
||||
|
||||
def init(self, instances, child_collection_type, get_children=None):
|
||||
self.instances = instances
|
||||
children_by_instance = map(get_children, self.instances)
|
||||
self.children = map(child_collection_type, zip(*children_by_instance))
|
||||
|
||||
|
||||
class GlyphCollection(FontCollection):
|
||||
def __init__(self, glyphs):
|
||||
self.init(glyphs, ContourCollection)
|
||||
self.name = glyphs[0].name
|
||||
|
||||
|
||||
class ContourCollection(FontCollection):
|
||||
def __init__(self, contours):
|
||||
self.init(contours, SegmentCollection)
|
||||
|
||||
def replace_segments(self, segment_collections):
|
||||
segments_by_contour = zip(*[s.instances for s in segment_collections])
|
||||
for contour, segments in zip(self.instances, segments_by_contour):
|
||||
replace_segments(contour, segments)
|
||||
|
||||
|
||||
class SegmentCollection(FontCollection):
|
||||
def __init__(self, segments):
|
||||
self.init(segments, None, lambda s: s.points)
|
||||
self.points = self.children
|
||||
self.type = segments[0].type
|
||||
|
||||
def as_quadratic(self, new_points=None):
|
||||
points = new_points or self.children
|
||||
return SegmentCollection([
|
||||
as_quadratic(s, pts) for s, pts in zip(self.instances, points)])
|
||||
Loading…
x
Reference in New Issue
Block a user