static int SliceCubicBézierSegments(IApiDraw api, Vertex PT, double n1, double n2, Tuple <Point, LineObj> Tu1, Tuple <Point, LineObj> Tu2, int recursion)
{
// Tu1 may be null and cause Exception
// Tu2 may be null and cause Exception
// infinity recursion ?
if (recursion > MAX_RECURSION)
{
Point P = Tu2.Item1;
if (api != null)
{
api.lineTo(Tu2.Item1);
}
return(1);
}
// process segment
Point CP = Tu1.Item2.GetLineCross(Tu2.Item2);
// a controlpoint is considered misplaced if its distance
// from one of the anchor is greater than the distance
// between the two anchors.
Point PO = Tu1.Item1 - Tu2.Item1; // point
double DN = PO.Pow(); // double
double D0 = Tu1.Item1.To(CP); // double
double D1 = Tu1.Item1.To(Tu2.Item1); // double
double D2 = Tu2.Item1.To(CP); // double
if (CP == null || D1 > D0 || D2 > D0)
{
int total = 0; // total for this subsegment starts at 0
double umid = (n1 + n2) / 2D; // if misplaced control-point, slice segment more
Vertex PM = PT.CloneAt(Convert.ToInt64(umid));
Tuple <Point, LineObj> tumid = PM.CubicTangent();
// sub segment count
total += SliceCubicBézierSegments(api, PT, n1, umid, Tu1, tumid, recursion + 1);
total += SliceCubicBézierSegments(api, PT, umid, n2, tumid, Tu2, recursion + 1);
return(total);
}
else
{
// draw curve
if (api != null)
{
api.curveTo(CP.X, CP.Y, Tu2.Item1.X, Tu2.Item1.Y);
}
return(1);
}
}
int DrawCubicBézier(IApiDraw api, Vertex pt)
{
Tuple <Point, LineObj> curt = null; // Tangent Object (LineObj)?
Tuple <Point, LineObj> next; // Tangent Object (LineObj)?
int total = 0; // int or long
int nSegment = numSegments < 2 ? 4 : this.numSegments;
double tstep = 1 / nSegment;
curt = new Tuple <Point, LineObj>(pt.p0, LineObj.GetLine(pt.p0, pt.p1));
if (api != null)
{
api.moveTo(pt.p0);
}
for (int i = 1; i < nSegment; i++)
{
next = pt.CubicTangent(Convert.ToInt32(i * tstep)); // next tangent
total += SliceCubicBézierSegments(api, pt, (i - 1) * tstep, i * tstep, curt, next, 0); // current segment
if (total > numSegments)
{
}
curt = next;
}
return(total);
}
int DrawCubicBézier(IApiDraw api, Vertex pt)
{
Tuple<Point,LineObj> curt = null; // Tangent Object (LineObj)?
Tuple<Point,LineObj> next; // Tangent Object (LineObj)?
int total = 0; // int or long
int nSegment = numSegments < 2 ? 4 : this.numSegments;
double tstep = 1 / nSegment;
curt = new Tuple<Point,LineObj>(pt.p0,LineObj.GetLine(pt.p0,pt.p1));
if (api!=null) api.moveTo(pt.p0);
for (int i=1; i < nSegment; i++)
{
next = pt.CubicTangent(Convert.ToInt32(i * tstep)); // next tangent
total += SliceCubicBézierSegments( api, pt, (i - 1) * tstep, i * tstep, curt, next, 0); // current segment
if (total > numSegments) {} curt = next;
}
return total;
}
