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Reimplement turtle.circle using a polyline, to allow correct

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filling of arcs. Also fixes #1514693.
This commit is contained in:
Martin v. Löwis 2006-07-03 10:05:30 +00:00
parent bd39c03c9f
commit 4c4300de4e
2 changed files with 17 additions and 48 deletions
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62
Lib/lib-tk/turtle.py
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@ -344,7 +344,7 @@ class RawPen:
"""
self.fill(0)
def circle(self, radius, extent=None):
def circle(self, radius, extent = None):
""" Draw a circle with given radius.
The center is radius units left of the turtle; extent
determines which part of the circle is drawn. If not given,
@ -360,53 +360,19 @@ class RawPen:
>>> turtle.circle(120, 180) # half a circle
"""
if extent is None:
extent = self._fullcircle
x0, y0 = self._position
xc = x0 - radius * sin(self._angle * self._invradian)
yc = y0 - radius * cos(self._angle * self._invradian)
if radius >= 0.0:
start = self._angle - (self._fullcircle / 4.0)
else:
start = self._angle + (self._fullcircle / 4.0)
extent = -extent
if self._filling:
if abs(extent) >= self._fullcircle:
item = self._canvas.create_oval(xc-radius, yc-radius,
xc+radius, yc+radius,
width=self._width,
outline="")
self._tofill.append(item)
item = self._canvas.create_arc(xc-radius, yc-radius,
xc+radius, yc+radius,
style="chord",
start=start,
extent=extent,
width=self._width,
outline="")
self._tofill.append(item)
if self._drawing:
if abs(extent) >= self._fullcircle:
item = self._canvas.create_oval(xc-radius, yc-radius,
xc+radius, yc+radius,
width=self._width,
outline=self._color)
self._items.append(item)
item = self._canvas.create_arc(xc-radius, yc-radius,
xc+radius, yc+radius,
style="arc",
start=start,
extent=extent,
width=self._width,
outline=self._color)
self._items.append(item)
angle = start + extent
x1 = xc + abs(radius) * cos(angle * self._invradian)
y1 = yc - abs(radius) * sin(angle * self._invradian)
self._angle = (self._angle + extent) % self._fullcircle
self._position = x1, y1
if self._filling:
self._path.append(self._position)
self._draw_turtle()
extent = self._fullcircle
frac = abs(extent)/self._fullcircle
steps = 1+int(min(11+abs(radius)/6.0, 59.0)*frac)
w = 1.0 * extent / steps
w2 = 0.5 * w
l = 2.0 * radius * sin(w2*self._invradian)
if radius < 0:
l, w, w2 = -l, -w, -w2
self.left(w2)
for i in range(steps):
self.forward(l)
self.left(w)
self.right(w2)
def heading(self):
""" Return the turtle's current heading.