def add_ellipse(dwg: svgwrite.Drawing,
container: BaseElement,
center,
beta: float,
rotation,
size: int = 100,
color: str = "blue",
marker_size: int = 20,
width: int = 1,
ell_scale=0.8):
"""
Add ellipse to svg files with two arrows at outline
:return group with arcs of ellipse
:param dwg a Drawing class object
:param container some object of subclass BasElement
:param center of ellipse in pixel (2d tuple)
:param size length of side square what restricted the ellipse
:param beta angle of ellipticity. beta = tg(e)
:param rotation contre clock wise rotation in radian
:param color color of outline and arrow
:param marker_size in pixels. It define side of the square where will be an arrow.
:param width width of the outlines
:param ell_scale coefficient of scale the size of ellipse
"""
# if abs(rotation) < 4*np.finfo(float).eps:
# g = Group(transform=f"translate({center[0]},{center[1]})")
# else:
if abs(beta) < properties.EPS_D:
radii = (0, 0)
ell_point_x = size / 2 # - marker_size // 4
else:
radii = (abs(math.cos(beta)), abs(math.sin(beta)))
radii = np.multiply(radii, size / (2 * max(radii[0], radii[1])))
ell_point_x = radii[0]
# print(radii)
g = Group(
transform=
f"translate({center[0]},{center[1]}) scale(1,-1) rotate({np.rad2deg(rotation)})"
)
arrow_marker: Marker = dwg.marker(refX=marker_size // 2 *
(-1 if beta > 0 else 1),
refY=marker_size // 2,
markerUnits="strokeWidth",
markerWidth=int(0.4 * marker_size),
markerHeight=int(0.3 * marker_size),
orient="auto")
# Marker()
arrow_marker.viewbox(minx=0, miny=0, width=marker_size, height=marker_size)
ms = marker_size
ms_2 = marker_size // 2
str_path = f"M -{ms_2}, 0 L {ms_2} {ms_2} L -{ms_2} {ms}" if beta > 0 else \
f"M {ms_2}, 0 L -{ms_2} {ms_2} L {ms_2} {ms}"
arrow_head: svgwrite.path.Path = arrow_marker.add(dwg.path(d=str_path))
# beta > 0 - right cw beta < 0 - left ccw
arrow_head.fill("none")
arrow_head.stroke(color, 2 * width)
dwg.defs.add(arrow_marker)
radii = np.asarray(radii)
radii = radii * ell_scale
ell_point_x = ell_point_x * ell_scale
# just axes
g.add(
dwg.path(d=f"M 50,50 l -100,0 l 0,-100 l 100,0 l 0,100",
transform=f"rotate({-np.rad2deg(rotation)})"))
point = g.add(dwg.path(d=f"M 0,0 L 5,0 M 0,0 L 0,3")
) # if abs(beta) > properties.EPS_D else None
arc1 = g.add(
dwg.path(
d=f"M {ell_point_x},0 a{radii[0]},{radii[1]} 0 0,0 -{2 * ell_point_x},0"
))
arc2 = g.add(
dwg.path(
d=f"M -{ell_point_x},0 a{radii[0]},{radii[1]} 0 0,0 {2 * ell_point_x},0"
))
arc1.set_markers(
(None, None, arrow_marker
)) # set the end marker. start and middle markers is empty.
arc2.set_markers((None, None, arrow_marker))
g.fill("none")
g.stroke(color)
g.stroke(color, width)
return container.add(g)
