def _parse_linear_gradient(grad_el, shape_bbox, view_box, upem):
width, height = _get_gradient_units_relative_scale(grad_el, view_box)
x1 = _number_or_percentage(grad_el.attrib.get("x1", "0%"), width)
y1 = _number_or_percentage(grad_el.attrib.get("y1", "0%"), height)
x2 = _number_or_percentage(grad_el.attrib.get("x2", "100%"), width)
y2 = _number_or_percentage(grad_el.attrib.get("y2", "0%"), height)
p0 = Point(x1, y1)
p1 = Point(x2, y2)
# compute the vector n perpendicular to vector v from P1 to P0
v = p0 - p1
n = v.perpendicular()
transform = _get_gradient_transform(grad_el, shape_bbox, view_box, upem)
# apply transformations to points and perpendicular vector
p0 = transform.map_point(p0)
p1 = transform.map_point(p1)
n = transform.map_vector(n)
# P2 is equal to P1 translated by the orthogonal projection of the transformed
# vector v' (from P1' to P0') onto the transformed vector n'; before the
# transform the vector n is perpendicular to v, so the projection of v onto n
# is zero and P2 == P1; if the transform has a skew or a scale that doesn't
# preserve aspect ratio, the projection of v' onto n' is non-zero and P2 != P1
v = p0 - p1
p2 = p1 + v.projection(n)
return {"p0": p0, "p1": p1, "p2": p2}
def cubic_deriv(p0, p1, p2, p3):
# derivative is a quad
return (
Point(3 * (p1[0] - p0[0]), 3 * (p1[1] - p0[1])),
Point(3 * (p2[0] - p1[0]), 3 * (p2[1] - p1[1])),
Point(3 * (p3[0] - p2[0]), 3 * (p3[1] - p2[1])),
)
def _gradient_paint(ttfont: ttLib.TTFont,
ot_paint: otTables.Paint) -> _GradientPaint:
stops = tuple(
ColorStop(
stop.StopOffset,
_color(ttfont, stop.PaletteIndex, stop.Alpha),
) for stop in ot_paint.ColorLine.ColorStop)
extend = Extend((ot_paint.ColorLine.Extend, ))
if ot_paint.Format == PaintLinearGradient.format:
return PaintLinearGradient(
stops=stops,
extend=extend,
p0=Point(ot_paint.x0, ot_paint.y0),
p1=Point(ot_paint.x1, ot_paint.y1),
p2=Point(ot_paint.x2, ot_paint.y2),
)
elif ot_paint.Format == PaintRadialGradient.format:
return PaintRadialGradient(
stops=stops,
extend=extend,
c0=Point(ot_paint.x0, ot_paint.y0),
c1=Point(ot_paint.x1, ot_paint.y1),
r0=ot_paint.r0,
r1=ot_paint.r1,
)
else:
raise ValueError(
f"Expected one of Paint formats {_GRADIENT_PAINT_FORMATS}; "
f"found {ot_paint.Format}")
def _parse_linear_gradient(
config: FontConfig,
grad_el: etree.Element,
shape_bbox: Rect,
view_box: Rect,
glyph_width: int,
shape_opacity: float = 1.0,
):
gradient = SVGLinearGradient.from_element(grad_el, view_box)
p0 = Point(gradient.x1, gradient.y1)
p1 = Point(gradient.x2, gradient.y2)
# Set P2 to P1 rotated 90 degrees counter-clockwise around P0
p2 = p0 + (p1 - p0).perpendicular()
common_args = _common_gradient_parts(grad_el, shape_opacity)
transform = _get_gradient_transform(
config, grad_el, shape_bbox, view_box, glyph_width
)
return PaintLinearGradient( # pytype: disable=wrong-arg-types
p0=p0, p1=p1, p2=p2, **common_args
).apply_transform(transform)
def _parse_radial_gradient(
config: FontConfig,
grad_el: etree.Element,
shape_bbox: Rect,
view_box: Rect,
glyph_width: int,
shape_opacity: float = 1.0,
):
gradient = SVGRadialGradient.from_element(grad_el, view_box)
c0 = Point(gradient.fx, gradient.fy)
r0 = gradient.fr
c1 = Point(gradient.cx, gradient.cy)
r1 = gradient.r
gradient_args = {"c0": c0, "c1": c1, "r0": r0, "r1": r1}
gradient_args.update(_common_gradient_parts(grad_el, shape_opacity))
transform = _get_gradient_transform(
config, grad_el, shape_bbox, view_box, glyph_width
)
return PaintRadialGradient( # pytype: disable=wrong-arg-types
**gradient_args
).apply_transform(transform)
class PaintLinearGradient(Paint):
format: ClassVar[int] = 2
extend: Extend = Extend.PAD
stops: Tuple[ColorStop, ...] = tuple()
p0: Point = Point()
p1: Point = Point()
p2: Point = None # if undefined, default to p1
def __post_init__(self):
# use object.__setattr__ as the dataclass is frozen
if self.p2 is None:
object.__setattr__(self, "p2", self.p1)
def colors(self):
for stop in self.stops:
yield stop.color
def to_ufo_paint(self, colors):
return {
"format": self.format,
"colorLine": _ufoColorLine(self, colors),
"p0": self.p0,
"p1": self.p1,
"p2": self.p2,
}
class PaintRadialGradient(Paint):
format: ClassVar[int] = 3
extend: Extend = Extend.PAD
stops: Tuple[ColorStop] = tuple()
c0: Point = Point()
c1: Point = Point()
r0: float = 0.0
r1: float = 0.0
affine2x2: Optional[Tuple[float, float, float, float]] = None
def colors(self):
for stop in self.stops:
yield stop.color
def to_ufo_paint(self, colors):
result = {
"format": self.format,
"colorLine": _ufoColorLine(self, colors),
"c0": self.c0,
"c1": self.c1,
"r0": self.r0,
"r1": self.r1,
}
if self.affine2x2:
result["transform"] = self.affine2x2
return result
def _parse_radial_gradient(grad_el, shape_bbox, view_box, upem):
width, height = _get_gradient_units_relative_scale(grad_el, view_box)
cx = _number_or_percentage(grad_el.attrib.get("cx", "50%"), width)
cy = _number_or_percentage(grad_el.attrib.get("cy", "50%"), height)
r = _number_or_percentage(grad_el.attrib.get("r", "50%"), width)
raw_fx = grad_el.attrib.get("fx")
fx = _number_or_percentage(raw_fx, width) if raw_fx is not None else cx
raw_fy = grad_el.attrib.get("fy")
fy = _number_or_percentage(raw_fy, height) if raw_fy is not None else cy
fr = _number_or_percentage(grad_el.attrib.get("fr", "0%"), width)
c0 = Point(fx, fy)
r0 = fr
c1 = Point(cx, cy)
r1 = r
transform = _get_gradient_transform(grad_el, shape_bbox, view_box, upem)
# The optional Affine2x2 matrix of COLRv1.RadialGradient is used to transform
# the circles into ellipses "around their centres": i.e. centres coordinates
# are _not_ transformed by it. Thus we apply the full transform to them.
c0 = transform.map_point(c0)
c1 = transform.map_point(c1)
# As for the circle radii (which are affected by Affine2x2), we only scale them
# by the maximum of the (absolute) scale or skew.
# Then in Affine2x2 we only store a "fraction" of the original transform, i.e.
# multiplied by the inverse of the scale that we've already applied to the radii.
# Especially when gradientUnits="objectBoundingBox", where circle positions and
# radii are expressed using small floats in the range [0..1], this pre-scaling
# helps reducing the inevitable rounding errors that arise from storing these
# values as integers in COLRv1 tables.
s = max(abs(v) for v in transform[:4])
rscale = Affine2D(s, 0, 0, s, 0, 0)
r0 = rscale.map_vector((r0, 0)).x
r1 = rscale.map_vector((r1, 0)).x
affine2x2 = Affine2D.product(rscale.inverse(), transform)
gradient = {
"c0": c0,
"c1": c1,
"r0": r0,
"r1": r1,
"affine2x2":
(affine2x2[:4] if affine2x2 != Affine2D.identity() else None),
}
# TODO handle degenerate cases, fallback to solid, w/e
return gradient
class PaintLinearGradient(Paint):
format: ClassVar[int] = int(ot.PaintFormat.PaintLinearGradient)
extend: Extend = Extend.PAD
stops: Tuple[ColorStop, ...] = tuple()
p0: Point = Point()
p1: Point = Point()
p2: Point = None # if normal undefined, default to P1 rotated 90° cc'wise
def __post_init__(self):
if self.p2 is None:
p0, p1 = Point(*self.p0), Point(*self.p1)
# use object.__setattr__ as the dataclass is frozen
object.__setattr__(self, "p2", p0 + (p1 - p0).perpendicular())
def colors(self):
for stop in self.stops:
yield stop.color
def to_ufo_paint(self, colors):
return {
"Format": self.format,
"ColorLine": _ufoColorLine(self, colors),
"x0": self.p0[0],
"y0": self.p0[1],
"x1": self.p1[0],
"y1": self.p1[1],
"x2": self.p2[0],
"y2": self.p2[1],
}
def check_overflows(self) -> "PaintLinearGradient":
for i in range(3):
attr_name = f"p{i}"
value = getattr(self, attr_name)
for j in range(2):
if not (MIN_INT16 <= value[j] <= MAX_INT16):
raise OverflowError(
f"{self.__class__.__name__}.{attr_name}[{j}] ({value[j]}) is "
f"out of bounds: [{MIN_INT16}...{MAX_INT16}]"
)
return self
def apply_transform(self, transform: Affine2D) -> Paint:
return dataclasses.replace(
self,
p0=transform.map_point(self.p0),
p1=transform.map_point(self.p1),
p2=transform.map_point(self.p2),
).check_overflows()
def transformed(transform: Affine2D, target: Paint) -> Paint:
if transform == Affine2D.identity():
return target
sx, b, c, sy, dx, dy = transform
# Int16 translation?
if (dx, dy) != (0, 0) and Affine2D.identity().translate(dx, dy) == transform:
if int16_safe(dx, dy):
return PaintTranslate(paint=target, dx=dx, dy=dy)
# Scale?
# If all we have are scale and translation this is pure scaling
# If b,c are present this is some sort of rotation or skew
if (sx, sy) != (1, 1) and (b, c) == (0, 0) and f2dot14_safe(sx, sy):
if (dx, dy) == (0, 0):
if almost_equal(sx, sy):
return PaintScaleUniform(paint=target, scale=sx)
else:
return PaintScale(paint=target, scaleX=sx, scaleY=sy)
else:
# translated scaling is the same as scale around a non-origin center
# If you trace through translate, scale, translate you get:
# dx = (1 - sx) * cx
# cx = dx / (1 - sx) # undefined if sx == 1; if so dx should == 0
# so, as long as (1==sx) == (0 == dx) we're good
if (1 == sx) == (0 == dx) and (1 == sy) == (0 == dy):
cx = 0
if sx != 1:
cx = dx / (1 - sx)
cy = 0
if sy != 1:
cy = dy / (1 - sy)
if int16_safe(cx, cy):
if almost_equal(sx, sy):
return PaintScaleUniformAroundCenter(
paint=target, scale=sx, center=Point(cx, cy)
)
else:
return PaintScaleAroundCenter(
paint=target, scaleX=sx, scaleY=sy, center=Point(cx, cy)
)
# TODO optimize rotations
# TODO optimize, skew, rotate around center
return PaintTransform(paint=target, transform=tuple(transform))
class PaintScaleAroundCenter(Paint):
format: ClassVar[int] = int(ot.PaintFormat.PaintScaleAroundCenter)
paint: Paint
scaleX: float = 1.0
scaleY: float = 1.0
center: Point = Point()
def colors(self):
yield from self.paint.colors()
def to_ufo_paint(self, colors):
paint = {
"Format": self.format,
"Paint": self.paint.to_ufo_paint(colors),
"scaleX": self.scaleX,
"scaleY": self.scaleY,
"centerX": self.center[0],
"centerY": self.center[1],
}
return paint
def children(self) -> Iterable[Paint]:
return (self.paint,)
def gettransform(self) -> Affine2D:
return (
Affine2D.identity()
.translate(self.center[0], self.center[1])
.scale(self.scaleX, self.scaleY)
.translate(-self.center[0], -self.center[1])
)
class PaintRotateAroundCenter(Paint):
format: ClassVar[int] = int(ot.PaintFormat.PaintRotateAroundCenter)
paint: Paint
angle: float = 0.0
center: Point = Point()
def colors(self):
yield from self.paint.colors()
def to_ufo_paint(self, colors):
paint = {
"Format": self.format,
"Paint": self.paint.to_ufo_paint(colors),
"angle": self.angle,
"centerX": self.center[0],
"centerY": self.center[1],
}
return paint
def children(self) -> Iterable[Paint]:
return (self.paint,)
def gettransform(self) -> Affine2D:
return Affine2D.identity().rotate(
radians(self.angle), self.center[0], self.center[1]
)
class PaintSkewAroundCenter(Paint):
format: ClassVar[int] = int(ot.PaintFormat.PaintSkewAroundCenter)
paint: Paint
xSkewAngle: float = 0.0
ySkewAngle: float = 0.0
center: Point = Point()
def colors(self):
yield from self.paint.colors()
def to_ufo_paint(self, colors):
paint = {
"Format": self.format,
"Paint": self.paint.to_ufo_paint(colors),
"xSkewAngle": self.xSkewAngle,
"ySkewAngle": self.ySkewAngle,
"centerX": self.center[0],
"centerY": self.center[1],
}
return paint
def children(self) -> Iterable[Paint]:
return (self.paint,)
def gettransform(self) -> Affine2D:
return (
Affine2D.identity()
.translate(self.center[0], self.center[1])
.skew(-radians(self.xSkewAngle), radians(self.ySkewAngle))
.translate(-self.center[0], -self.center[1])
)
def arc_to_cubic_callback(subpath_start, curr_pos, cmd, args, *_):
del subpath_start
if cmd not in {"a", "A"}:
# no work to do
return ((cmd, args), )
(rx, ry, x_rotation, large, sweep, end_x, end_y) = args
if cmd == "a":
end_x += curr_pos.x
end_y += curr_pos.y
end_pt = Point(end_x, end_y)
result = []
for p1, p2, target in arc_to_cubic(curr_pos, rx, ry, x_rotation,
large, sweep, end_pt):
x, y = target
if p1 is not None:
assert p2 is not None
x1, y1 = p1
x2, y2 = p2
result.append(("C", (x1, y1, x2, y2, x, y)))
else:
result.append(("L", (x, y)))
return tuple(result)
def _arc_to_cubic(arc: EllipticalArc) -> Iterator[Tuple[Point, Point, Point]]:
arc = arc.correct_out_of_range_radii()
arc_params = arc.end_to_center_parametrization()
point_transform = (
Affine2D.identity()
.translate(arc_params.center_point.x, arc_params.center_point.y)
.rotate(radians(arc.rotation))
.scale(arc.rx, arc.ry)
)
# Some results of atan2 on some platform implementations are not exact
# enough. So that we get more cubic curves than expected here. Adding 0.001f
# reduces the count of sgements to the correct count.
num_segments = int(ceil(fabs(arc_params.theta_arc / (PI_OVER_TWO + 0.001))))
for i in range(num_segments):
start_theta = arc_params.theta1 + i * arc_params.theta_arc / num_segments
end_theta = arc_params.theta1 + (i + 1) * arc_params.theta_arc / num_segments
t = (4 / 3) * tan(0.25 * (end_theta - start_theta))
if not isfinite(t):
return
sin_start_theta = sin(start_theta)
cos_start_theta = cos(start_theta)
sin_end_theta = sin(end_theta)
cos_end_theta = cos(end_theta)
point1 = Point(
cos_start_theta - t * sin_start_theta, sin_start_theta + t * cos_start_theta
)
end_point = Point(cos_end_theta, sin_end_theta)
point2 = end_point + Vector(t * sin_end_theta, -t * cos_end_theta)
point1 = point_transform.map_point(point1)
point2 = point_transform.map_point(point2)
# by definition, the last bezier's end point == the arc end point
# by directly taking the end point we avoid floating point imprecision
if i == num_segments - 1:
end_point = arc.end_point
else:
end_point = point_transform.map_point(end_point)
yield point1, point2, end_point
def test_point_subtraction_and_addition():
p0 = Point(1, 3)
p1 = Point(-2, 4)
v = p1 - p0
assert isinstance(v, Vector)
assert v.x == -3
assert v.y == 1
p2 = p1 - v
assert isinstance(p2, Point)
assert p2 == p0
p3 = p0 + v
assert isinstance(p3, Point)
assert p3 == p1
def cubic_tangent(t, p0, p1, p2, p3) -> Vector:
# Returns the unit vector defining the cubic bezier curve's direction at t
if t == 0.0:
tangent = Point(*p1) - Point(*p0)
elif t == 1.0:
tangent = Point(*p3) - Point(*p2)
else:
tangent = Vector(*cubic_deriv_pos(t, p0, p1, p2, p3))
tangent = tangent.unit()
if tangent is not None:
return tangent
return Vector()
def _cubic_callback(subpath_start, curr_xy, cmd, args, prev_xy, prev_cmd,
prev_args):
if cmd.upper() == "M":
return ((cmd, args), )
# Convert to cubic if needed
if cmd.upper() == "Z":
# a line back to subpath start ... unless we are there already
if curr_xy == subpath_start:
return ()
cmd = "L"
args = subpath_start
if cmd == "L":
# line from curr_xy to args
assert len(args) == 2
end_xy = args
# cubic ctl points 1/3rd and 2/3rds along
cmd = "C"
args = (
*line_pos(0.33, curr_xy, end_xy),
*line_pos(0.66, curr_xy, end_xy),
*end_xy,
)
if cmd == "Q":
assert len(args) == 4
cmd = "C"
p0 = Point(*curr_xy)
p1 = Point(*args[0:2])
p2 = Point(*args[2:4])
args = (*(p0 + 2 / 3 * (p1 - p0)), *(p2 + 2 / 3 * (p1 - p2)), *p2)
if cmd != "C":
raise ValueError(f"How do you cubic {cmd}, {args}")
assert len(args) == 6
return (("C", args), )
def arc_to_cubic(
start_point: Tuple[float, float],
rx: float,
ry: float,
rotation: float,
large: int,
sweep: int,
end_point: Tuple[float, float],
) -> Iterator[Tuple[Optional[Point], Optional[Point], Point]]:
"""Convert arc to cubic(s).
start/end point are (x,y) tuples with absolute coordinates.
See https://skia.org/user/api/SkPath_Reference#SkPath_arcTo_4
Note in particular:
SVG sweep-flag value is opposite the integer value of sweep;
SVG sweep-flag uses 1 for clockwise, while kCW_Direction cast to int is zero.
Yields 3-tuples of Points for each Cubic bezier, i.e. two off-curve points and
one on-curve end point.
If either rx or ry is 0, the arc is treated as a straight line joining the end
points, and a (None, None, arc.end_point) tuple is yielded.
Yields empty iterator if arc has zero length.
"""
if not isinstance(start_point, Point):
start_point = Point(*start_point)
if not isinstance(end_point, Point):
end_point = Point(*end_point)
arc = EllipticalArc(start_point, rx, ry, rotation, large, sweep, end_point)
if arc.is_zero_length():
return
elif arc.is_straight_line():
yield None, None, arc.end_point
else:
yield from _arc_to_cubic(arc)
def _is_almost_line(curve, flatness=1.0):
# Returns True if the bezier curve is equivalent to a line.
# A 'flat' bezier curve is one such that the sum of the distances between
# consecutive control points equals the distance from start to end points.
# That's because if a control point isn't on the line from start to end then
# the length would exceed the direct path start => end.
# The 'flatness' factor of 1.0 means exactly flat, anything greater than 1.0
# proportionately means flat "enough". Less than 1.0 means never flat (i.e.
# keep all flat curves as curves, FWIW).
points = [Point(*p) for p in curve]
length = 0
for i in range(len(curve) - 1):
length += (points[i + 1] - points[i]).norm()
max_length = (points[-1] - points[0]).norm()
return length <= flatness * max_length
def _next_pos(curr_pos, cmd, cmd_args):
# update current position
x_coord_idxs, y_coord_idxs = svg_meta.cmd_coords(cmd)
new_x, new_y = curr_pos
if cmd.isupper():
if x_coord_idxs:
new_x = 0
if y_coord_idxs:
new_y = 0
if x_coord_idxs:
new_x += cmd_args[x_coord_idxs[-1]]
if y_coord_idxs:
new_y += cmd_args[y_coord_idxs[-1]]
return Point(new_x, new_y)
def expand_shorthand_callback(_, curr_pos, cmd, args, prev_pos,
prev_cmd, prev_args):
short_to_long = {"S": "C", "T": "Q"}
if not cmd.upper() in short_to_long:
return ((cmd, args), )
if cmd.islower():
cmd, args = _relative_to_absolute(curr_pos, cmd, args)
# if there is no prev, or a bad prev, control point coincident current
new_cp = (curr_pos.x, curr_pos.y)
if prev_cmd:
if prev_cmd.islower():
prev_cmd, prev_args = _relative_to_absolute(
prev_pos, prev_cmd, prev_args)
if prev_cmd in short_to_long.values():
# reflect 2nd-last x,y pair over curr_pos and make it our first arg
prev_cp = Point(prev_args[-4], prev_args[-3])
new_cp = (2 * curr_pos.x - prev_cp.x,
2 * curr_pos.y - prev_cp.y)
return ((short_to_long[cmd], new_cp + args), )
def walk(self, callback):
"""Walk path and call callback to build potentially new commands.
https://www.w3.org/TR/SVG11/paths.html
def callback(subpath_start, curr_xy, cmd, args, prev_xy, prev_cmd, prev_args)
prev_* None if there was no previous
returns sequence of (new_cmd, new_args) that replace cmd, args
"""
curr_pos = Point()
subpath_start_pos = curr_pos # where a z will take you
new_cmds = []
# iteration gives us exploded commands
for idx, (cmd, args) in enumerate(self):
svg_meta.check_cmd(cmd, args)
if idx == 0 and cmd == "m":
cmd = "M"
prev = (None, None, None)
if new_cmds:
prev = new_cmds[-1]
for (new_cmd, new_cmd_args) in callback(subpath_start_pos,
curr_pos, cmd, args,
*prev):
if new_cmd.lower() != "z":
next_pos = _next_pos(curr_pos, new_cmd, new_cmd_args)
else:
next_pos = subpath_start_pos
prev_pos, curr_pos = curr_pos, next_pos
if new_cmd.upper() == "M":
subpath_start_pos = curr_pos
new_cmds.append((prev_pos, new_cmd, new_cmd_args))
self.d = ""
for _, cmd, args in new_cmds:
self._add_cmd(cmd, *args)
def _colr_v1_glyph_to_svg(ttfont: ttLib.TTFont, view_box: Rect,
glyph: otTables.BaseGlyphRecord) -> etree.Element:
glyph_set = ttfont.getGlyphSet()
svg_root = _svg_root(view_box)
defs = svg_root[0]
for glyph_layer in glyph.LayerV1List.LayerV1Record:
svg_path = etree.SubElement(svg_root, "path")
# TODO care about variations, such as for alpha
paint = glyph_layer.Paint
if paint.Format == _PAINT_SOLID:
_solid_paint(svg_path, ttfont, paint.Color.PaletteIndex,
paint.Color.Alpha.value)
elif paint.Format == _PAINT_LINEAR_GRADIENT:
_linear_gradient_paint(
defs,
svg_path,
ttfont,
view_box,
stops=[
_ColorStop(
stop.StopOffset.value,
stop.Color.PaletteIndex,
stop.Color.Alpha.value,
) for stop in paint.ColorLine.ColorStop
],
extend=Extend((paint.ColorLine.Extend.value, )),
p0=Point(paint.x0.value, paint.y0.value),
p1=Point(paint.x1.value, paint.y1.value),
p2=Point(paint.x2.value, paint.y2.value),
)
elif paint.Format == _PAINT_RADIAL_GRADIENT:
_radial_gradient_paint(
defs,
svg_path,
ttfont,
view_box,
stops=[
_ColorStop(
stop.StopOffset.value,
stop.Color.PaletteIndex,
stop.Color.Alpha.value,
) for stop in paint.ColorLine.ColorStop
],
extend=Extend((paint.ColorLine.Extend.value, )),
c0=Point(paint.x0.value, paint.y0.value),
c1=Point(paint.x1.value, paint.y1.value),
r0=paint.r0.value,
r1=paint.r1.value,
transform=(Affine2D.identity()
if not paint.Transform else Affine2D(
paint.Transform.xx.value,
paint.Transform.xy.value,
paint.Transform.yx.value,
paint.Transform.yy.value,
0,
0,
)),
)
_draw_svg_path(svg_path, view_box, ttfont, glyph_layer.LayerGlyph,
glyph_set)
return svg_root
def test_add_vec(self):
assert Vector(1, 2) + Vector(2, 3) == Vector(3, 5)
assert Vector(1, 2) + Point(2, 3) == Point(3, 5)
assert Point(2, 3) + Vector(1, 2) == Point(3, 5)
def _mid_point(p1, p2):
x1, y1 = p1
x2, y2 = p2
return Point(x1, y1) + (Point(x2, y2) - Point(x1, y1)) * 0.5
def map_point(self, pt: Tuple[float, float]) -> Point:
"""Return Point (x, y) multiplied by Affine2D."""
x, y = pt
return Point(self.a * x + self.c * y + self.e,
self.b * x + self.d * y + self.f)
class PaintRadialGradient(Paint):
format: ClassVar[int] = int(ot.PaintFormat.PaintRadialGradient)
extend: Extend = Extend.PAD
stops: Tuple[ColorStop, ...] = tuple()
c0: Point = Point()
c1: Point = Point()
r0: float = 0.0
r1: float = 0.0
def colors(self):
for stop in self.stops:
yield stop.color
def to_ufo_paint(self, colors):
paint = {
"Format": self.format,
"ColorLine": _ufoColorLine(self, colors),
"x0": self.c0[0],
"y0": self.c0[1],
"r0": self.r0,
"x1": self.c1[0],
"y1": self.c1[1],
"r1": self.r1,
}
return paint
def check_overflows(self) -> "PaintRadialGradient":
int_bounds = {
"c": (MIN_INT16, MAX_INT16),
"r": (MIN_UINT16, MAX_UINT16),
}
attrs = []
for prefix in ("c", "r"):
for i in range(2):
attr_name = f"{prefix}{i}"
value = getattr(self, attr_name)
if prefix == "c":
attrs.extend((f"{attr_name}[{j}]", value[j]) for j in range(2))
else:
attrs.append((f"{attr_name}", value))
for attr_name, value in attrs:
min_value, max_value = int_bounds[attr_name[0]]
if not (min_value <= value <= max_value):
raise OverflowError(
f"{self.__class__.__name__}.{attr_name} ({value}) is "
f"out of bounds: [{min_value}...{max_value}]"
)
return self
def apply_transform(self, transform: Affine2D) -> Paint:
# if gradientUnits="objectBoundingBox" and the bbox is not square, or there's some
# gradientTransform, we may end up with a transformation that does not keep the
# aspect ratio of the gradient circles and turns them into ellipses, but CORLv1
# PaintRadialGradient by itself can only define circles. Thus we only apply the
# uniform scale and translate components of the original transform to the circles,
# then encode any remaining non-uniform transformation as a COLRv1 transform
# that wraps the PaintRadialGradient (see further below).
uniform_transform, remaining_transform = _decompose_uniform_transform(transform)
c0 = uniform_transform.map_point(self.c0)
c1 = uniform_transform.map_point(self.c1)
sx, _ = uniform_transform.getscale()
r0 = self.r0 * sx
r1 = self.r1 * sx
# TODO handle degenerate cases, fallback to solid, w/e
return transformed(
remaining_transform,
dataclasses.replace(self, c0=c0, c1=c1, r0=r0, r1=r1).check_overflows(),
)
def __post_init__(self):
if self.p2 is None:
p0, p1 = Point(*self.p0), Point(*self.p1)
# use object.__setattr__ as the dataclass is frozen
object.__setattr__(self, "p2", p0 + (p1 - p0).perpendicular())
