def draw_polygon(ctx: Context, polygon: Polygon):
if hasattr(polygon.exterior, 'coords'):
start = True
ctx.new_path()
for x, y in polygon.exterior.coords:
if start:
ctx.move_to(x, y)
else:
ctx.line_to(x, y)
start = False
for interior in polygon.interiors:
ctx.new_sub_path()
start = True
for x, y in interior.coords:
if start:
ctx.move_to(x, y)
else:
ctx.line_to(x, y)
start = False
ctx.close_path()
ctx.close_path()
def draw_rounded_rectangle(ctx: Context, rectangle: Rectangle, radius: float):
"""
Draw rectangles with rounded (circular arc) corners.
:param ctx: Cairo render context.
:param rectangle: Extent of the rectangle.
:param radius: Radius of the corners.
"""
from math import pi
a, c = rectangle.position(Anchor.TOP_LEFT)
b, d = rectangle.position(Anchor.BOTTOM_RIGHT)
ctx.arc(a + radius, c + radius, radius, 2 * (pi / 2), 3 * (pi / 2))
ctx.arc(b - radius, c + radius, radius, 3 * (pi / 2), 4 * (pi / 2))
ctx.arc(b - radius, d - radius, radius, 0 * (pi / 2), 1 * (pi / 2)) # ;o)
ctx.arc(a + radius, d - radius, radius, 1 * (pi / 2), 2 * (pi / 2))
ctx.close_path()
def draw_rect(self, g: Graphics, area: Bounds, radius: float) -> None:
(x, y, w, h) = area.tuple
if w == 0 or h == 0:
return
degrees = pi / 180.0
g.new_sub_path()
g.arc(x + w - radius, y + radius, radius, -90 * degrees, 0)
g.arc(x + w - radius, y + h - radius, radius, 0, 90 * degrees)
g.arc(x + radius, y + h - radius, radius, 90 * degrees, 180 * degrees)
g.arc(x + radius, y + radius, radius, 180 * degrees, 270 * degrees)
g.close_path()
def rounded_rectangle(ctx: cairo.Context, x, y, w, h, rx, ry):
# https://www.cairographics.org/cookbook/roundedrectangles/
arc_to_bezier = 0.55228475
if rx > w - rx:
rx = w / 2
if ry > h - ry:
ry = h / 2
c1 = arc_to_bezier * rx
c2 = arc_to_bezier * ry
ctx.new_path()
ctx.move_to(x + rx, y)
ctx.rel_line_to(w - 2 * rx, 0.0)
ctx.rel_curve_to(c1, 0.0, rx, c2, rx, ry)
ctx.rel_line_to(0, h - 2 * ry)
ctx.rel_curve_to(0.0, c2, c1 - rx, ry, -rx, ry)
ctx.rel_line_to(-w + 2 * rx, 0)
ctx.rel_curve_to(-c1, 0, -rx, -c2, -rx, -ry)
ctx.rel_line_to(0, -h + 2 * ry)
ctx.rel_curve_to(0.0, -c2, rx - c1, -ry, rx, -ry)
ctx.close_path()