def set_source_rgb(self,
colour: Union[ColorType, List[ColorType]],
ctx: cairocffi.Context = None):
# If an alternate context is not provided then we draw to the
# drawer's default context
if ctx is None:
ctx = self.ctx
if isinstance(colour, list):
if len(colour) == 0:
# defaults to black
ctx.set_source_rgba(*utils.rgb("#000000"))
elif len(colour) == 1:
ctx.set_source_rgba(*utils.rgb(colour[0]))
else:
linear = cairocffi.LinearGradient(0.0, 0.0, 0.0, self.height)
step_size = 1.0 / (len(colour) - 1)
step = 0.0
for c in colour:
rgb_col = utils.rgb(c)
if len(rgb_col) < 4:
rgb_col[3] = 1
linear.add_color_stop_rgba(step, *rgb_col)
step += step_size
ctx.set_source(linear)
else:
ctx.set_source_rgba(*utils.rgb(colour))
def coloured_bezier(ctx: cairo.Context, p0, p1, p2, p3, colors, width, detail=100, fade=None):
p0 = np.array(p0)
p1 = np.array(p1)
p2 = np.array(p2)
p3 = np.array(p3)
bez, bezd = cubic_bezier(p0, p1, p2, p3, numpoints=detail)
bezd = normalize(bezd, norm='l2', axis=1)
frac_sum = -.5
for color, frac in colors:
(r, g, b, a) = color
if fade is None:
ctx.set_source_rgba(r, g, b, a)
else:
ctx.set_source(fade_pattern(p0[0], p0[1], p3[0], p3[1], r, g, b, a, fade))
ctx.set_line_width(frac*width)
frac_sum += frac/2
ctx.move_to(bez[0][0] - width * frac_sum * bezd[0][1], bez[0][1] + width * frac_sum * bezd[0][0])
for i in range(0, bez.shape[0] - 3, 3):
ctx.curve_to(bez[i + 1][0] - width * frac_sum * bezd[i + 1][1], bez[i + 1][1] + width * frac_sum * bezd[i + 1][0],
bez[i + 2][0] - width * frac_sum * bezd[i + 2][1], bez[i + 2][1] + width * frac_sum * bezd[i + 2][0],
bez[i + 3][0] - width * frac_sum * bezd[i + 3][1], bez[i + 3][1] + width * frac_sum * bezd[i + 3][0])
# for i in range(0, bez.shape[0] - 3, 2):
# ctx.move_to(bez[i][0] - width * frac_sum * bezd[i][1], bez[i][1] + width * frac_sum * bezd[i][0])
# ctx.curve_to(bez[i + 1][0] - width * frac_sum * bezd[i + 1][1], bez[i + 1][1] + width * frac_sum * bezd[i + 1][0],
# bez[i + 2][0] - width * frac_sum * bezd[i + 2][1], bez[i + 2][1] + width * frac_sum * bezd[i + 2][0],
# bez[i + 3][0] - width * frac_sum * bezd[i + 3][1], bez[i + 3][1] + width * frac_sum * bezd[i + 3][0])
ctx.stroke()
frac_sum += frac/2
