def fromFoci(cls, f1, f2, f3):
"""Create an ellipse from foci.
f1 and f2 are foci
f3 is the axis_b
/----f3----\
/ \
| f1 f2 |
\ /
\----------/
"""
if not isinstance(f1, (QgsPoint, CADPoint)) \
or not isinstance(f2,
(QgsPoint, CADPoint)) \
or not isinstance(f3,
(QgsPoint, CADPoint)):
raise AttributeError
f1 = CADPoint(f1)
f2 = CADPoint(f2)
f3 = CADPoint(f3)
dist_f1f2 = f1.distance(f2)
dist_f1f3 = f1.distance(f3)
dist_f2f3 = f2.distance(f3)
dist_tot = dist_f1f3 + dist_f2f3
angle_exist = f1.getAngleOfLineBetweenTwoPoints(f2)
center_f1f2 = f1.midpoint(f2)
axis_a = dist_tot / 2.0
axis_b = math.sqrt((dist_tot / 2.0)**2.0 - (dist_f1f2 / 2.0)**2.0)
return cls(center_f1f2, axis_a, axis_b, angle_exist)
def by2Corners(cls, p1, p2, nbEdges=5):
"""CADRegularPolygon by 2 corners (AB):
A----B
/ \
/ \
\ /
\------/
"""
if not isinstance(p1, (QgsPoint, CADPoint)) or \
not isinstance(p2, (QgsPoint, CADPoint)) or \
not isinstance(nbEdges, (long, int)):
raise AttributeError
else:
p1 = CADPoint(p1)
p2 = CADPoint(p2)
angle_exist = p1.getAngleOfLineBetweenTwoPoints(p2)
pm = p1.midpoint(p2)
length = p1.distance(pm)
angle = (180.0 - (360.0 / nbEdges)) / 2.0
hypo = length / math.cos(math.radians(angle))
pc = p1.pointProjected(hypo, angle_exist + angle)
return cls(pc, p1, nbEdges)
return None
def by2Points(cls, p1, p2):
"""Create a CADCircle with 2 points (from diameter : AB)
/------\
| |
A B
| |
\------/
"""
if not all(isinstance(p, (QgsPoint, CADPoint)) for p in [p1, p2]):
raise AttributeError
p1 = CADPoint(p1)
p2 = CADPoint(p2)
center = p1.midpoint(p2)
radius = p1.distance(center)
return cls(center, radius)
def byExtent(cls, p1, p2):
"""Create an ellipse by extent
/----------\ p2
/ \
| |
\ /
p1 \----------/
"""
if not isinstance(p1, (QgsPoint, CADPoint)) \
or not isinstance(p2,
(QgsPoint, CADPoint)):
raise AttributeError
p1 = CADPoint(p1)
p2 = CADPoint(p2)
pc = p1.midpoint(p2)
xOffset = (abs(p2.x - p1.x)) / 2.0
yOffset = (abs(p2.y - p1.y)) / 2.0
return cls(pc, xOffset, yOffset)
def byCenterPointAngle(cls, ptCenter, ptStart, inAngle, direction=1):
"""Create a CADCirclurArc with by Center C a point A and angle
A C
|
\------/Angle
"""
if not all([isinstance(p, (CADPoint, QgsPoint))
for p in [ptCenter, ptStart]]) or \
not isinstance(inAngle, (int, long, float)) or \
not isinstance(direction, (int, long)):
raise AttributeError
ptCenter = CADPoint(ptCenter)
ptStart = CADPoint(ptStart)
angle = ptCenter.getAngleOfLineBetweenTwoPoints(ptStart)
dist = ptCenter.distance(ptStart)
if inAngle < 0:
inAngle += 360
ptAngle = 0
if direction == 1:
ptAngle = angle - (360 - inAngle)
elif direction == -1:
ptAngle = angle + inAngle
ptEnd = ptCenter.pointProjected(dist, ptAngle)
ptAngle_arc = ptCenter.getAngleOfLineBetweenTwoPoints(
ptStart.midpoint(ptEnd))
if direction == 1:
if inAngle < 180:
ptAngle_arc = ptAngle_arc + 180
if direction == -1:
if inAngle > 180:
ptAngle_arc = ptAngle_arc - 180
ptArc = ptCenter.pointProjected(dist, ptAngle_arc)
return cls(ptStart, ptEnd, ptArc)