public SplineObject GenerateCircle(double rad)
{
const double TANG = 0.415;
double sn, cs;
int i, sub = 4;
SplineObject op = SplineObject.Alloc(sub * 2, SPLINETYPE.SPLINETYPE_BEZIER);
if (null == op || null == op.MakeVariableTag(C4dApi.Tsegment, 2))
{
C4dApi.blDelete_cs(op);
return(null);
}
op.GetDataInstance().SetBool(C4dApi.SPLINEOBJECT_CLOSED, true);
Segment seg = new Segment();
seg.closed = true;
seg.cnt = sub;
op.SetSegmentAt(0, seg);
op.SetSegmentAt(1, seg);
for (i = 0; i < sub; i++)
{
double angle = 2.0 * Math.PI * (double)i / (double)sub;
sn = Math.Sin(angle);
cs = Math.Cos(angle);
double3 vOuter = new double3(cs * rad, sn * rad, 0.0);
double3 vOuterTangentL = new double3(sn * rad * TANG, -cs * rad * TANG, 0.0);
double3 vOuterTangentR = -vOuterTangentL;
double3 vInner = vOuter * 0.5;
double3 vInnerTangentL = vOuterTangentL * 0.5;
double3 vInnerTangentR = -vInnerTangentL;
op.SetPointAt(i, vOuter);
Tangent outerTangent = new Tangent();
outerTangent.vl = vOuterTangentL;
outerTangent.vr = vOuterTangentR;
op.SetTangentAt(i, outerTangent);
op.SetPointAt(i + sub, vInner);
Tangent innerTangent = new Tangent();
innerTangent.vl = vInnerTangentL;
innerTangent.vr = vInnerTangentR;
op.SetTangentAt(i + sub, innerTangent);
}
op.Message(C4dApi.MSG_UPDATE);
return(op);
}
static void OrientObject(SplineObject op, int plane, bool reverse)
{
// double3 padr = op.GetPointW();
// Tangent hadr = op.GetTangentW(), h;
int nPoints = op.GetPointCount();
int i;
bool bTangents = op.GetTangentCount() != 0;
if (plane >= 1)
{
switch (plane)
{
case 1: // ZY
for (i = 0; i < nPoints; i++)
{
double3 v = op.GetPointAt(i);
op.SetPointAt(i, new double3(-v.z, v.y, v.x));
if (!bTangents)
{
continue;
}
Tangent t = op.GetTangentAt(i);
Tangent t2 = new Tangent();
t2.vl = new double3(-t.vl.z, t.vl.y, t.vl.x);
t2.vr = new double3(-t.vr.z, t.vr.y, t.vr.x);
op.SetTangentAt(i, t2);
}
break;
case 2: // XZ
for (i = 0; i < nPoints; i++)
{
double3 v = op.GetPointAt(i);
op.SetPointAt(i, new double3(v.x, -v.z, v.y));
if (!bTangents)
{
continue;
}
Tangent t = op.GetTangentAt(i);
Tangent t2 = new Tangent();
t2.vl = new double3(t.vl.x, -t.vl.z, t.vl.y);
t2.vr = new double3(t.vr.x, -t.vr.z, t.vr.y);
op.SetTangentAt(i, t2);
}
break;
}
}
if (reverse)
{
double3 p;
int to = nPoints / 2;
if ((nPoints % 2) != 0)
{
to++;
}
for (i = 0; i < to; i++)
{
p = op.GetPointAt(i);
op.SetPointAt(i, op.GetPointAt(nPoints - 1 - i));
op.SetPointAt(nPoints - 1 - i, p);
if (!bTangents)
{
continue;
}
Tangent h1 = op.GetTangentAt(i);
Tangent h2 = op.GetTangentAt(nPoints - 1 - i);
Tangent hTmp1 = new Tangent();
Tangent hTmp2 = new Tangent();
hTmp1.vl = new double3(h2.vr);
hTmp1.vr = new double3(h2.vl);
hTmp2.vl = new double3(h1.vr);
hTmp2.vr = new double3(h1.vl);
op.SetTangentAt(i, hTmp1);
op.SetTangentAt(nPoints - 1 - i, hTmp2);
}
}
op.Message(C4dApi.MSG_UPDATE);
}