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Fix arc bounding box calculation

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This commit is contained in:
Jan Petykiewicz 2018-10-28 13:32:04 -07:00
parent 64cb1ced34
commit b295c318a9
1 changed files with 10 additions and 12 deletions
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22
masque/shapes/arc.py
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@ -237,33 +237,31 @@ class Arc(Shape):
# Cutoff angles # Cutoff angles
xpt = (-self.rotation) % (2 * pi) + a0_offset xpt = (-self.rotation) % (2 * pi) + a0_offset
ypt = self.rotation % (2 * pi) + a0_offset ypt = (pi/2 - self.rotation) % (2 * pi) + a0_offset
xnt = (xpt - pi) % (2 * pi) + a0_offset xnt = (xpt - pi) % (2 * pi) + a0_offset
ynt = (ypt - pi) % (2 * pi) + a0_offset ynt = (ypt - pi) % (2 * pi) + a0_offset
# Points along coordinate axes # Points along coordinate axes
xs = rx * sin_r rx2_inv = 1 / (rx * rx)
yc = ry * cos_r ry2_inv = 1 / (ry * ry)
sin_ax = yc / (yc * yc + xs * xs) xr = numpy.abs(cos_r * cos_r * rx2_inv + sin_r * sin_r * ry2_inv) ** -0.5
cos_ax = xs / (yc * yc + xs * xs) yr = numpy.abs(-sin_r * -sin_r * rx2_inv + cos_r * cos_r * ry2_inv) ** -0.5
xr = rx * cos_r * cos_ax - ry * sin_r * sin_ax
yr = ry * sin_r * cos_ax + ry * cos_r * sin_ax
# Arc endpoints # Arc endpoints
xn, xp = sorted(rx * cos_r * cos_a - ry * sin_r * sin_a) xn, xp = sorted(rx * cos_r * cos_a - ry * sin_r * sin_a)
yn, yp = sorted(rx * sin_r * cos_a + ry * cos_r * sin_a) yn, yp = sorted(rx * sin_r * cos_a + ry * cos_r * sin_a)
# If # If our arc subtends a coordinate axis, use the extremum along that axis
if a0 < xpt < a1: if a0 < xpt < a1 or a0 < xpt + 2 * pi < a1:
xp = xr xp = xr
if a0 < xnt < a1: if a0 < xnt < a1 or a0 < xnt + 2 * pi < a1:
xn = -xr xn = -xr
if a0 < ypt < a1: if a0 < ypt < a1 or a0 < ypt + 2 * pi < a1:
yp = yr yp = yr
if a0 < ynt < a1: if a0 < ynt < a1 or a0 < ynt + 2 * pi < a1:
yn = -yr yn = -yr
mins.append([xn, yn]) mins.append([xn, yn])