cpython/Lib/turtle.py

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Python
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1998-12-05 00:42:46 +08:00
# LogoMation-like turtle graphics
from math import * # Also for export
import Tkinter
Tk = Tkinter
Error = Exception
class RawPen:
def __init__(self, canvas):
self._canvas = canvas
self._items = []
self._tracing = 1
self.degrees()
self.reset()
def degrees(self, fullcircle=360.0):
self._fullcircle = fullcircle
self._invradian = pi / (fullcircle * 0.5)
def radians(self):
self.degrees(2.0*pi)
def reset(self):
canvas = self._canvas
width = canvas.winfo_width()
height = canvas.winfo_height()
if width <= 1:
width = canvas['width']
if height <= 1:
height = canvas['height']
self._origin = float(width)/2.0, float(height)/2.0
self._position = self._origin
self._angle = 0.0
self._drawing = 1
self._width = 1
self._color = "black"
self._filling = 0
self._path = []
self._tofill = []
self.clear()
canvas._root().tkraise()
def clear(self):
self.fill(0)
canvas = self._canvas
items = self._items
self._items = []
for item in items:
canvas.delete(item)
def tracer(self, flag):
self._tracing = flag
def forward(self, distance):
x0, y0 = start = self._position
x1 = x0 + distance * cos(self._angle*self._invradian)
y1 = y0 - distance * sin(self._angle*self._invradian)
self._goto(x1, y1)
def backward(self, distance):
self.forward(-distance)
def left(self, angle):
self._angle = (self._angle + angle) % self._fullcircle
def right(self, angle):
self.left(-angle)
def up(self):
self._drawing = 0
def down(self):
self._drawing = 1
def width(self, width):
self._width = float(width)
def color(self, *args):
if not args:
raise Error, "no color arguments"
if len(args) == 1:
color = args[0]
if type(color) == type(""):
# Test the color first
try:
id = self._canvas.create_line(0, 0, 0, 0, fill=color)
except Tk.TclError:
raise Error, "bad color string: %s" % `color`
self._color = color
return
try:
r, g, b = color
except:
raise Error, "bad color sequence: %s" % `color`
else:
try:
r, g, b = args
except:
raise Error, "bad color arguments: %s" % `args`
assert 0 <= r <= 1
assert 0 <= g <= 1
assert 0 <= b <= 1
x = 255.0
y = 0.5
self._color = "#%02x%02x%02x" % (int(r*x+y), int(g*x+y), int(b*x+y))
def write(self, arg, move=0):
x, y = start = self._position
x = x-1 # correction -- calibrated for Windows
item = self._canvas.create_text(x, y,
text=str(arg), anchor="sw",
fill=self._color)
self._items.append(item)
if move:
x0, y0, x1, y1 = self._canvas.bbox(item)
self._goto(x1, y1)
def fill(self, flag):
if self._filling:
path = tuple(self._path)
smooth = self._filling < 0
if len(path) > 2:
item = self._canvas._create('polygon', path,
{'fill': self._color,
'smooth': smooth})
self._items.append(item)
self._canvas.lower(item)
if self._tofill:
for item in self._tofill:
self._canvas.itemconfigure(item, fill=self._color)
self._items.append(item)
self._path = []
self._tofill = []
self._filling = flag
if flag:
self._path.append(self._position)
def circle(self, radius, extent=None):
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 - 90.0
else:
start = self._angle + 90.0
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)
def goto(self, *args):
if len(args) == 1:
try:
x, y = args[0]
except:
raise Error, "bad point argument: %s" % `args[0]`
else:
try:
x, y = args
except:
raise Error, "bad coordinates: %s" % `args[0]`
x0, y0 = self._origin
self._goto(x0+x, y0-y)
def _goto(self, x1, y1):
x0, y0 = start = self._position
self._position = map(float, (x1, y1))
if self._filling:
self._path.append(self._position)
if self._drawing:
if self._tracing:
dx = float(x1 - x0)
dy = float(y1 - y0)
distance = hypot(dx, dy)
nhops = int(distance)
item = self._canvas.create_line(x0, y0, x0, y0,
width=self._width,
arrow="last",
capstyle="round",
fill=self._color)
try:
for i in range(1, 1+nhops):
x, y = x0 + dx*i/nhops, y0 + dy*i/nhops
self._canvas.coords(item, x0, y0, x, y)
self._canvas.update()
self._canvas.after(10)
self._canvas.itemconfigure(item, arrow="none")
except Tk.TclError:
# Probably the window was closed!
return
else:
item = self._canvas.create_line(x0, y0, x1, y1,
width=self._width,
capstyle="round",
fill=self._color)
self._items.append(item)
_root = None
_canvas = None
_pen = None
class Pen(RawPen):
def __init__(self):
global _root, _canvas
if _root is None:
_root = Tk.Tk()
_root.wm_protocol("WM_DELETE_WINDOW", self._destroy)
if _canvas is None:
# XXX Should have scroll bars
_canvas = Tk.Canvas(_root, background="white")
_canvas.pack(expand=1, fill="both")
RawPen.__init__(self, _canvas)
def _destroy(self):
global _root, _canvas, _pen
root = self._canvas._root()
if root is _root:
_pen = None
_root = None
_canvas = None
root.destroy()
def _getpen():
global _pen
pen = _pen
if not pen:
_pen = pen = Pen()
return pen
def degrees(): _getpen().degrees()
def radians(): _getpen().radians()
def reset(): _getpen().reset()
def clear(): _getpen().clear()
def tracer(flag): _getpen().tracer(flag)
def forward(distance): _getpen().forward(distance)
def backward(distance): _getpen().backward(distance)
def left(angle): _getpen().left(angle)
def right(angle): _getpen().right(angle)
def up(): _getpen().up()
def down(): _getpen().down()
def width(width): _getpen().width(width)
def color(*args): apply(_getpen().color, args)
def write(arg, move=0): _getpen().write(arg, move)
def fill(flag): _getpen().fill(flag)
def circle(radius, extent=None): _getpen().circle(radius, extent)
def goto(*args): apply(_getpen().goto, args)
def demo():
reset()
tracer(1)
up()
backward(100)
down()
# draw 3 squares; the last filled
width(3)
for i in range(3):
if i == 2:
fill(1)
for j in range(4):
forward(20)
left(90)
if i == 2:
color("maroon")
fill(0)
up()
forward(30)
down()
width(1)
color("black")
# move out of the way
tracer(0)
up()
right(90)
forward(100)
right(90)
forward(100)
right(180)
down()
# some text
write("startstart", 1)
write("start", 1)
color("red")
# staircase
for i in range(5):
forward(20)
left(90)
forward(20)
right(90)
# filled staircase
fill(1)
for i in range(5):
forward(20)
left(90)
forward(20)
right(90)
fill(0)
# more text
write("end")
if __name__ == '__main__':
_root.mainloop()
if __name__ == '__main__':
demo()