LIVE / pydiffvg /shape.py
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import torch
import svgpathtools
import math
class Circle:
def __init__(self, radius, center, stroke_width = torch.tensor(1.0), id = ''):
self.radius = radius
self.center = center
self.stroke_width = stroke_width
self.id = id
class Ellipse:
def __init__(self, radius, center, stroke_width = torch.tensor(1.0), id = ''):
self.radius = radius
self.center = center
self.stroke_width = stroke_width
self.id = id
class Path:
def __init__(self,
num_control_points,
points,
is_closed,
stroke_width = torch.tensor(1.0),
id = '',
use_distance_approx = False):
self.num_control_points = num_control_points
self.points = points
self.is_closed = is_closed
self.stroke_width = stroke_width
self.id = id
self.use_distance_approx = use_distance_approx
class Polygon:
def __init__(self, points, is_closed, stroke_width = torch.tensor(1.0), id = ''):
self.points = points
self.is_closed = is_closed
self.stroke_width = stroke_width
self.id = id
class Rect:
def __init__(self, p_min, p_max, stroke_width = torch.tensor(1.0), id = ''):
self.p_min = p_min
self.p_max = p_max
self.stroke_width = stroke_width
self.id = id
class ShapeGroup:
def __init__(self,
shape_ids,
fill_color,
use_even_odd_rule = True,
stroke_color = None,
shape_to_canvas = torch.eye(3),
id = ''):
self.shape_ids = shape_ids
self.fill_color = fill_color
self.use_even_odd_rule = use_even_odd_rule
self.stroke_color = stroke_color
self.shape_to_canvas = shape_to_canvas
self.id = id
def from_svg_path(path_str, shape_to_canvas = torch.eye(3), force_close = False):
path = svgpathtools.parse_path(path_str)
if len(path) == 0:
return []
ret_paths = []
subpaths = path.continuous_subpaths()
for subpath in subpaths:
if subpath.isclosed():
if len(subpath) > 1 and isinstance(subpath[-1], svgpathtools.Line) and subpath[-1].length() < 1e-5:
subpath.remove(subpath[-1])
subpath[-1].end = subpath[0].start # Force closing the path
subpath.end = subpath[-1].end
assert(subpath.isclosed())
else:
beg = subpath[0].start
end = subpath[-1].end
if abs(end - beg) < 1e-5:
subpath[-1].end = beg # Force closing the path
subpath.end = subpath[-1].end
assert(subpath.isclosed())
elif force_close:
subpath.append(svgpathtools.Line(end, beg))
subpath.end = subpath[-1].end
assert(subpath.isclosed())
num_control_points = []
points = []
for i, e in enumerate(subpath):
if i == 0:
points.append((e.start.real, e.start.imag))
else:
# Must begin from the end of previous segment
assert(e.start.real == points[-1][0])
assert(e.start.imag == points[-1][1])
if isinstance(e, svgpathtools.Line):
num_control_points.append(0)
elif isinstance(e, svgpathtools.QuadraticBezier):
num_control_points.append(1)
points.append((e.control.real, e.control.imag))
elif isinstance(e, svgpathtools.CubicBezier):
num_control_points.append(2)
points.append((e.control1.real, e.control1.imag))
points.append((e.control2.real, e.control2.imag))
elif isinstance(e, svgpathtools.Arc):
# Convert to Cubic curves
# https://www.joecridge.me/content/pdf/bezier-arcs.pdf
start = e.theta * math.pi / 180.0
stop = (e.theta + e.delta) * math.pi / 180.0
sign = 1.0
if stop < start:
sign = -1.0
epsilon = 0.00001
debug = abs(e.delta) >= 90.0
while (sign * (stop - start) > epsilon):
arc_to_draw = stop - start
if arc_to_draw > 0.0:
arc_to_draw = min(arc_to_draw, 0.5 * math.pi)
else:
arc_to_draw = max(arc_to_draw, -0.5 * math.pi)
alpha = arc_to_draw / 2.0
cos_alpha = math.cos(alpha)
sin_alpha = math.sin(alpha)
cot_alpha = 1.0 / math.tan(alpha)
phi = start + alpha
cos_phi = math.cos(phi)
sin_phi = math.sin(phi)
lambda_ = (4.0 - cos_alpha) / 3.0
mu = sin_alpha + (cos_alpha - lambda_) * cot_alpha
last = sign * (stop - (start + arc_to_draw)) <= epsilon
num_control_points.append(2)
rx = e.radius.real
ry = e.radius.imag
cx = e.center.real
cy = e.center.imag
rot = e.phi * math.pi / 180.0
cos_rot = math.cos(rot)
sin_rot = math.sin(rot)
x = lambda_ * cos_phi + mu * sin_phi
y = lambda_ * sin_phi - mu * cos_phi
xx = x * cos_rot - y * sin_rot
yy = x * sin_rot + y * cos_rot
points.append((cx + rx * xx, cy + ry * yy))
x = lambda_ * cos_phi - mu * sin_phi
y = lambda_ * sin_phi + mu * cos_phi
xx = x * cos_rot - y * sin_rot
yy = x * sin_rot + y * cos_rot
points.append((cx + rx * xx, cy + ry * yy))
if not last:
points.append((cx + rx * math.cos(rot + start + arc_to_draw),
cy + ry * math.sin(rot + start + arc_to_draw)))
start += arc_to_draw
first = False
if i != len(subpath) - 1:
points.append((e.end.real, e.end.imag))
else:
if subpath.isclosed():
# Must end at the beginning of first segment
assert(e.end.real == points[0][0])
assert(e.end.imag == points[0][1])
else:
points.append((e.end.real, e.end.imag))
points = torch.tensor(points)
points = torch.cat((points, torch.ones([points.shape[0], 1])), dim = 1) @ torch.transpose(shape_to_canvas, 0, 1)
points = points / points[:, 2:3]
points = points[:, :2].contiguous()
ret_paths.append(Path(torch.tensor(num_control_points), points, subpath.isclosed()))
return ret_paths