Draws a curve specified by a sequence of points. The curve may be
piecewise linear, like a polygon, or a Bezier curve.
Poly(d, mode, loop, attribute=value)
d required list of tuples representing points
and possibly control points
mode default="L" "lines", "bezier", "velocity",
"foreback", "smooth", or an abbreviation
loop default=False if True, connect the first and last
point, closing the loop
attribute=value pairs keyword list SVG attributes
The format of the tuples in d depends on the mode.
"lines"/"L" d=[(x,y), (x,y), ...]
piecewise-linear segments joining the (x,y) points
"bezier"/"B" d=[(x, y, c1x, c1y, c2x, c2y), ...]
Bezier curve with two control points (control points
preceed (x,y), as in SVG paths). If (c1x,c1y) and
(c2x,c2y) both equal (x,y), you get a linear
interpolation ("lines")
"velocity"/"V" d=[(x, y, vx, vy), ...]
curve that passes through (x,y) with velocity (vx,vy)
(one unit of arclength per unit time); in other words,
(vx,vy) is the tangent vector at (x,y). If (vx,vy) is
(0,0), you get a linear interpolation ("lines").
"foreback"/"F" d=[(x, y, bx, by, fx, fy), ...]
like "velocity" except that there is a left derivative
(bx,by) and a right derivative (fx,fy). If (bx,by)
equals (fx,fy) (with no minus sign), you get a
"velocity" curve
"smooth"/"S" d=[(x,y), (x,y), ...]
a "velocity" interpolation with (vx,vy)[i] equal to
((x,y)[i+1] - (x,y)[i-1])/2: the minimal derivative
Definition at line 1679 of file svgfig.py.