private Arc(Circle circle, Coordinate p1, Coordinate p2, bool isClockwise)
{
this.p1 = p1;
this.p2 = p2;
clockwise = isClockwise;
p1Angle = circle.GetAngle(p1);
if (p1.Equals2D(p2))
{
p2Angle = TWO_PI + p1Angle;
}
else
{
p2Angle = circle.GetAngle(p2);
}
DetermineArcAngle();
}
private double arcAngle; // angle in radians
internal Arc(Circle circle, Coordinate p1, Coordinate midPt, Coordinate p2)
{
this.circle = circle;
this.p1 = p1;
this.p2 = p2;
p1Angle = circle.GetAngle(p1);
// See if this arc covers the whole circle
if (p1.Equals2D(p2))
{
p2Angle = TWO_PI + p1Angle;
arcAngle = TWO_PI;
}
else
{
p2Angle = circle.GetAngle(p2);
double midPtAngle = circle.GetAngle(midPt);
// determine the direction
double ccDegrees = SubtractAngles(p1Angle,
midPtAngle)
+ SubtractAngles(midPtAngle, p2Angle);
if (ccDegrees < TWO_PI)
{
clockwise = false;
arcAngle = ccDegrees;
}
else
{
clockwise = true;
arcAngle = TWO_PI - ccDegrees;
}
}
}
/**
* Given a circle defined by the 3 points, creates a linearized
* interpolation of the circle starting and ending on the first coordinate.
* This method uses a tolerence value of 1/100 of the length of the radius.
*
* @param x1
* x coordinate of point 1
* @param y1
* y coordinate of point 1
* @param x2
* x coordinate of point 2
* @param y2
* y coordinate of point 2
* @param x3
* x coordinate of point 3
* @param y3
* y coordinate of point 3
* @return an ordered list of Coordinates representing a series of chords
* approximating the arc.
*/
public static Coordinate[] LinearizeCircle(
double x1, double y1,
double x2, double y2,
double x3, double y3)
{
Coordinate p1 = new Coordinate(x1, y1);
Coordinate p2 = new Coordinate(x2, y2);
Coordinate p3 = new Coordinate(x3, y3);
Circle c = new Circle(p1, p2, p3);
double tolerence = 0.01 * c.Radius;
return c.LinearizeArc(p1, p2, p1, tolerence);
}
public bool Equals(Circle obj)
{
if (ReferenceEquals(null, obj))
{
return false;
}
if (ReferenceEquals(this, obj))
{
return true;
}
if (obj.radius != radius)
{
return false;
}
if (center != null
? !center.Equals2D(obj.center)
: obj.center != null)
{
return false;
}
return true;
}
/**
* Linearizes arcs and circles.
*
* @param arcOrdinates
* arc or circle coordinates
* @param dim
* coordinate dimension
* @param lrs
* whether this is an lrs geometry
* @param entireCirlce
* whether the whole arc should be linearized
* @return linearized interpolation of arcs or circle
*/
private Coordinate[] Linearize(double[] arcOrdinates, int dim, bool lrs, bool entireCirlce)
{
Coordinate[] linearizedCoords = new Coordinate[0];
// CoordDim is the dimension that includes only non-measure (X,Y,Z)
// ordinates in its value
int coordDim = lrs ? dim - 1 : dim;
// this only works with 2-Dimensional geometries, since we use
// JGeometry linearization;
if (coordDim != 2)
{
throw new ArgumentException("Can only linearize 2D arc segments, but geometry is " + dim + "D.");
}
int numOrd = dim;
while (numOrd < arcOrdinates.Length)
{
numOrd = numOrd - dim;
double x1 = arcOrdinates[numOrd++];
double y1 = arcOrdinates[numOrd++];
double m1 = lrs ? arcOrdinates[numOrd++] : Double.NaN;
double x2 = arcOrdinates[numOrd++];
double y2 = arcOrdinates[numOrd++];
double m2 = lrs ? arcOrdinates[numOrd++] : Double.NaN;
double x3 = arcOrdinates[numOrd++];
double y3 = arcOrdinates[numOrd++];
double m3 = lrs ? arcOrdinates[numOrd++] : Double.NaN;
Coordinate[] coords;
if (entireCirlce)
{
coords = Circle.LinearizeCircle(x1, y1, x2, y2, x3, y3);
}
else
{
coords = Circle.LinearizeArc(x1, y1, x2, y2, x3, y3);
}
// if this is an LRS geometry, fill the measure values into
// the linearized array
if (lrs)
{
Coordinate[] mcoord = new Coordinate[coords.Length];
int lastIndex = coords.Length - 1;
mcoord[0] = MCoordinate.Create2dWithMeasure(x1, y1, m1);
mcoord[lastIndex] = MCoordinate.Create2dWithMeasure(x3, y3, m3);
// convert the middle coordinates to MCoordinate
for (int i = 1; i < lastIndex; i++)
{
mcoord[i] = MCoordinate.ConvertCoordinate(coords[i]);
// if we happen to split on the middle measure, then
// assign it
if (mcoord[i].X == x2 && mcoord[i].Y == y2)
{
((MCoordinate)mcoord[i]).M = m2;
}
}
coords = mcoord;
}
// if this is not the first arcsegment, the first linearized
// point is already in linearizedArc, so disregard this.
int resultBegin = 1;
if (linearizedCoords.Length == 0)
{
resultBegin = 0;
}
int destPos = linearizedCoords.Length;
Coordinate[] tmpCoords = new Coordinate[linearizedCoords.Length + coords.Length - resultBegin];
Array.Copy(linearizedCoords, 0, tmpCoords, 0, linearizedCoords.Length);
Array.Copy(coords, resultBegin, tmpCoords, destPos, coords.Length - resultBegin);
linearizedCoords = tmpCoords;
}
return(linearizedCoords);
}
