def _draw_arc(self, inner_radius, outer_radius, startangle, endangle,
color, border=None, colour=None, **kwargs):
""" draw_arc(self, inner_radius, outer_radius, startangle, endangle, color)
-> Group
o inner_radius Float distance of inside of arc from drawing center
o outer_radius Float distance of outside of arc from drawing center
o startangle Float angle subtended by start of arc at drawing center
(in radians)
o endangle Float angle subtended by end of arc at drawing center
(in radians)
o color colors.Color object for arc (overridden by backwards
compatible argument with UK spelling, colour).
Returns a closed path object describing an arced box corresponding to
the passed values. For very small angles, a simple four sided
polygon is used.
"""
#Let the UK spelling (colour) override the USA spelling (color)
if colour is not None:
color = colour
if border is None:
border = color
if color is None:
color = colour
if color == colors.white and border is None: # Force black border on
strokecolor = colors.black # white boxes with
elif border is None: # undefined border, else
strokecolor = color # use fill colour
elif border is not None:
strokecolor = border
if abs(float(endangle - startangle))>.01:
# Wide arc, must use full curves
p = ArcPath(strokeColor=strokecolor,
fillColor=color,
strokewidth=0)
#Note reportlab counts angles anti-clockwise from the horizontal
#(as in mathematics, e.g. complex numbers and polar coordinates)
#but we use clockwise from the vertical. Also reportlab uses
#degrees, but we use radians.
p.addArc(self.xcenter, self.ycenter, inner_radius,
90 - (endangle * 180 / pi), 90 - (startangle * 180 / pi),
moveTo=True)
p.addArc(self.xcenter, self.ycenter, outer_radius,
90 - (endangle * 180 / pi), 90 - (startangle * 180 / pi),
reverse=True)
p.closePath()
return p
else:
#Cheat and just use a four sided polygon.
# Calculate trig values for angle and coordinates
startcos, startsin = cos(startangle), sin(startangle)
endcos, endsin = cos(endangle), sin(endangle)
x0,y0 = self.xcenter, self.ycenter # origin of the circle
x1,y1 = (x0+inner_radius*startsin, y0+inner_radius*startcos)
x2,y2 = (x0+inner_radius*endsin, y0+inner_radius*endcos)
x3,y3 = (x0+outer_radius*endsin, y0+outer_radius*endcos)
x4,y4 = (x0+outer_radius*startsin, y0+outer_radius*startcos)
return draw_polygon([(x1,y1),(x2,y2),(x3,y3),(x4,y4)], color, border)
def _draw_arc_arrow(self, inner_radius, outer_radius, startangle, endangle,
color, border=None,
shaft_height_ratio=0.4, head_length_ratio=0.5, orientation='right',
colour=None, **kwargs):
"""Draw an arrow along an arc."""
#Let the UK spelling (colour) override the USA spelling (color)
if colour is not None:
color = colour
if border is None:
border = color
if color is None:
color = colour
if color == colors.white and border is None: # Force black border on
strokecolor = colors.black # white boxes with
elif border is None: # undefined border, else
strokecolor = color # use fill colour
elif border is not None:
strokecolor = border
#if orientation == 'right':
# startangle, endangle = min(startangle, endangle), max(startangle, endangle)
#elif orientation == 'left':
# startangle, endangle = max(startangle, endangle), min(startangle, endangle)
#else :
startangle, endangle = min(startangle, endangle), max(startangle, endangle)
if orientation <> "left" and orientation <> "right" :
raise ValueError("Invalid orientation %s, should be 'left' or 'right'" \
% repr(orientation))
angle = float(endangle - startangle) # angle subtended by arc
middle_radius = 0.5*(inner_radius+outer_radius)
boxheight = outer_radius - inner_radius
shaft_height = boxheight*shaft_height_ratio
shaft_inner_radius = middle_radius - 0.5*shaft_height
shaft_outer_radius = middle_radius + 0.5*shaft_height
headangle_delta = min(abs(asin(boxheight/middle_radius)*head_length_ratio), abs(angle))
if angle < 0 :
headangle_delta *= -1 #reverse it
if orientation=="right" :
headangle = endangle-headangle_delta
else :
headangle = startangle+headangle_delta
if startangle <= endangle :
headangle = max(min(headangle, endangle), startangle)
else :
headangle = max(min(headangle, startangle), endangle)
assert startangle <= headangle <= endangle \
or endangle <= headangle <= startangle
# Calculate trig values for angle and coordinates
startcos, startsin = cos(startangle), sin(startangle)
headcos, headsin = cos(headangle), sin(headangle)
endcos, endsin = cos(endangle), sin(endangle)
x0,y0 = self.xcenter, self.ycenter # origin of the circle
if abs(headangle_delta) >= abs(angle) :
#Cheat and just use a triangle.
if orientation=="right" :
x1,y1 = (x0+inner_radius*startsin, y0+inner_radius*startcos)
x2,y2 = (x0+outer_radius*startsin, y0+outer_radius*startcos)
x3,y3 = (x0+middle_radius*endsin, y0+middle_radius*endcos)
else :
x1,y1 = (x0+inner_radius*endsin, y0+inner_radius*endcos)
x2,y2 = (x0+outer_radius*endsin, y0+outer_radius*endcos)
x3,y3 = (x0+middle_radius*startsin, y0+middle_radius*startcos)
return draw_polygon([(x1,y1),(x2,y2),(x3,y3)], color, border)
elif orientation=="right" :
p = ArcPath(strokeColor=strokecolor,
fillColor=color,
#default is mitre/miter which can stick out too much:
strokeLineJoin=1, #1=round
strokewidth=0)
#Note reportlab counts angles anti-clockwise from the horizontal
#(as in mathematics, e.g. complex numbers and polar coordinates)
#but we use clockwise from the vertical. Also reportlab uses
#degrees, but we use radians.
p.addArc(self.xcenter, self.ycenter, shaft_inner_radius,
90 - (headangle * 180 / pi), 90 - (startangle * 180 / pi),
moveTo=True)
p.addArc(self.xcenter, self.ycenter, shaft_outer_radius,
90 - (headangle * 180 / pi), 90 - (startangle * 180 / pi),
reverse=True)
p.lineTo(x0+outer_radius*headsin, y0+outer_radius*headcos)
p.lineTo(x0+middle_radius*endsin, y0+middle_radius*endcos)
p.lineTo(x0+inner_radius*headsin, y0+inner_radius*headcos)
p.closePath()
return p
else :
p = ArcPath(strokeColor=strokecolor,
fillColor=color,
#default is mitre/miter which can stick out too much:
strokeLineJoin=1, #1=round
strokewidth=0)
#Note reportlab counts angles anti-clockwise from the horizontal
#(as in mathematics, e.g. complex numbers and polar coordinates)
#but we use clockwise from the vertical. Also reportlab uses
#degrees, but we use radians.
p.addArc(self.xcenter, self.ycenter, shaft_inner_radius,
90 - (endangle * 180 / pi), 90 - (headangle * 180 / pi),
moveTo=True, reverse=True)
p.addArc(self.xcenter, self.ycenter, shaft_outer_radius,
90 - (endangle * 180 / pi), 90 - (headangle * 180 / pi),
reverse=False)
p.lineTo(x0+outer_radius*headsin, y0+outer_radius*headcos)
p.lineTo(x0+middle_radius*startsin, y0+middle_radius*startcos)
p.lineTo(x0+inner_radius*headsin, y0+inner_radius*headcos)
p.closePath()
return p