def GetTangentPoint(self,x,y,outx,outy):
"""
Get the tangent from an axternal point
args:
x,y is a point near the circle
xout,yout is a point far from the circle
return:
a tuple(x,y,x1,xy) that define the tangent line
"""
firstPoint=Point(x,y)
fromPoint=Point(outx,outy)
twoPointDistance=self.center.dist(fromPoint)
if(twoPointDistance<self.radius):
return None,None
originPoint=Point(0.0,0.0)
tanMod=math.sqrt(pow(twoPointDistance,2)-pow(self.radius,2))
tgAngle=math.asin(self.radius/twoPointDistance)
#Compute the x versor
xPoint=Point(1.0,0.0)
xVector=Vector(originPoint,xPoint)
twoPointVector=Vector(fromPoint,self.center)
rightAngle=twoPointVector.ang(xVector)
cx,cy=self.center.getCoords()
if(outy>cy): # stupid situation
rightAngle=-rightAngle
posAngle=rightAngle+tgAngle
negAngle=rightAngle-tgAngle
# Compute the Positive Tangent
xCord=math.cos(posAngle)
yCord=math.sin(posAngle)
dirPoint=Point(xCord,yCord) # Versor that point at the tangentPoint
ver=Vector(originPoint,dirPoint)
ver.mult(tanMod)
tangVectorPoint=ver.Point()
posPoint=Point(tangVectorPoint+(outx,outy))
# Compute the Negative Tangent
xCord=math.cos(negAngle)
yCord=math.sin(negAngle)
dirPoint=Point(xCord,yCord)#Versor that point at the tangentPoint
ver=Vector(originPoint,dirPoint)
ver.mult(tanMod)
tangVectorPoint=ver.point()
negPoint=Point(tangVectorPoint+(outx,outy))
if(firstPoint.dist(posPoint)<firstPoint.dist(negPoint)):
return posPoint.getCoords()
else:
return negPoint.getCoords()
def GetTangentPoint(self, x, y, outx, outy):
"""
Get the tangent from an axternal point
args:
x,y is a point near the circle
xout,yout is a point far from the circle
return:
a tuple(x,y,x1,xy) that define the tangent line
"""
firstPoint = Point(x, y)
fromPoint = Point(outx, outy)
twoPointDistance = self.center.dist(fromPoint)
if (twoPointDistance < self.radius):
return None, None
originPoint = Point(0.0, 0.0)
tanMod = math.sqrt(pow(twoPointDistance, 2) - pow(self.radius, 2))
tgAngle = math.asin(self.radius / twoPointDistance)
#Compute the x versor
xPoint = Point(1.0, 0.0)
xVector = Vector(originPoint, xPoint)
twoPointVector = Vector(fromPoint, self.center)
rightAngle = twoPointVector.ang(xVector)
cx, cy = self.center.getCoords()
if (outy > cy): # stupid situation
rightAngle = -rightAngle
posAngle = rightAngle + tgAngle
negAngle = rightAngle - tgAngle
# Compute the Positive Tangent
xCord = math.cos(posAngle)
yCord = math.sin(posAngle)
dirPoint = Point(xCord, yCord) # Versor that point at the tangentPoint
ver = Vector(originPoint, dirPoint)
ver.mult(tanMod)
tangVectorPoint = ver.Point()
posPoint = Point(tangVectorPoint + (outx, outy))
# Compute the Negative Tangent
xCord = math.cos(negAngle)
yCord = math.sin(negAngle)
dirPoint = Point(xCord, yCord) #Versor that point at the tangentPoint
ver = Vector(originPoint, dirPoint)
ver.mult(tanMod)
tangVectorPoint = ver.point()
negPoint = Point(tangVectorPoint + (outx, outy))
if (firstPoint.dist(posPoint) < firstPoint.dist(negPoint)):
return posPoint.getCoords()
else:
return negPoint.getCoords()
