private static Path GeneratePathPolygon(LLObject.ObjectData prim, int sides, float startOff, float endScale,
float twistScale)
{
Path path = new Path();
path.Points = new List<PathPoint>();
float revolutions = prim.PathRevolutions;
float skew = prim.PathSkew;
float skewMag = (float)Math.Abs(skew);
float holeX = prim.PathScaleX * (1f - skewMag);
float holeY = prim.PathScaleY;
// Calculate taper begin/end for x,y (Negative means taper the beginning)
float taperXBegin = 1f;
float taperXEnd = 1f - prim.PathTaperX;
float taperYBegin = 1f;
float taperYEnd = 1f - prim.PathTaperY;
if (taperXEnd > 1f)
{
// Flip tapering
taperXBegin = 2f - taperXEnd;
taperXEnd = 1f;
}
if (taperYEnd > 1f)
{
// Flip tapering
taperYBegin = 2f - taperYEnd;
taperYEnd = 1f;
}
// For spheres, the radius is usually zero
float radiusStart = 0.5f;
if (sides < 8)
radiusStart = TABLE_SCALE[sides];
// Scale the radius to take the hole size into account
radiusStart *= 1f - holeY;
// Now check the radius offset to calculate the start,end radius. (Negative means
// decrease the start radius instead)
float radiusEnd = radiusStart;
float radiusOffset = prim.PathRadiusOffset;
if (radiusOffset < 0f)
radiusStart *= 1f + radiusOffset;
else
radiusEnd *= 1f - radiusOffset;
// Is the path NOT a closed loop?
path.Open =
((prim.PathEnd * endScale - prim.PathBegin < 1f) ||
(skewMag > 0.001f) ||
(Math.Abs(taperXEnd - taperXBegin) > 0.001d) ||
(Math.Abs(taperYEnd - taperYBegin) > 0.001d) ||
(Math.Abs(radiusEnd - radiusStart) > 0.001d));
float ang, c, s;
Quaternion twist = Quaternion.Identity;
Quaternion qang = Quaternion.Identity;
PathPoint point;
Vector3 pathAxis = new Vector3(1f, 0f, 0f);
float twistBegin = prim.PathTwistBegin * twistScale;
float twistEnd = prim.PathTwist * twistScale;
// We run through this once before the main loop, to make sure
// the path begins at the correct cut
float step = 1f / sides;
float t = prim.PathBegin;
ang = 2f * F_PI * revolutions * t;
s = (float)Math.Sin(ang) * MathHelper.Lerp(radiusStart, radiusEnd, t);
c = (float)Math.Cos(ang) * MathHelper.Lerp(radiusStart, radiusEnd, t);
point = new PathPoint();
point.Position = new Vector3(
0 + MathHelper.Lerp(0, prim.PathShearX, s) +
0 + MathHelper.Lerp(-skew, skew, t) * 0.5f,
c + MathHelper.Lerp(0, prim.PathShearY, s),
s);
point.Scale.X = holeX * MathHelper.Lerp(taperXBegin, taperXEnd, t);
point.Scale.Y = holeY * MathHelper.Lerp(taperYBegin, taperYEnd, t);
point.TexT = t;
// Twist rotates the path along the x,y plane
twist = Quaternion.CreateFromAxisAngle(MathHelper.Lerp(twistBegin, twistEnd, t) * 2f * F_PI - F_PI, 0f, 0f, 1f);
// Rotate the point around the circle's center
qang = Quaternion.CreateFromAxisAngle(pathAxis, ang);
point.Rotation = twist * qang;
path.Points.Add(point);
t += step;
// Snap to a quantized parameter, so that cut does not
// affect most sample points
t = ((int)(t * sides)) / (float)sides;
// Run through the non-cut dependent points
point = new PathPoint();
while (t < prim.PathEnd)
{
ang = 2f * F_PI * revolutions * t;
c = (float)Math.Cos(ang) * MathHelper.Lerp(radiusStart, radiusEnd, t);
s = (float)Math.Sin(ang) * MathHelper.Lerp(radiusStart, radiusEnd, t);
point.Position = new Vector3(
0 + MathHelper.Lerp(0, prim.PathShearX, s) +
0 + MathHelper.Lerp(-skew, skew, t) * 0.5f,
c + MathHelper.Lerp(0, prim.PathShearY, s),
s);
point.Scale.X = holeX * MathHelper.Lerp(taperXBegin, taperXEnd, t);
point.Scale.Y = holeY * MathHelper.Lerp(taperYBegin, taperYEnd, t);
point.TexT = t;
// Twist rotates the path along the x,y plane
twist = Quaternion.CreateFromAxisAngle(MathHelper.Lerp(twistBegin, twistEnd, t) * 2f * F_PI - F_PI, 0f, 0f, 1f);
// Rotate the point around the circle's center
qang = Quaternion.CreateFromAxisAngle(pathAxis, ang);
point.Rotation = twist * qang;
path.Points.Add(point);
t += step;
}
// Make one final pass for the end cut
t = prim.PathEnd;
point = new PathPoint();
ang = 2f * F_PI * revolutions * t;
c = (float)Math.Cos(ang) * MathHelper.Lerp(radiusStart, radiusEnd, t);
s = (float)Math.Sin(ang) * MathHelper.Lerp(radiusStart, radiusEnd, t);
point.Position = new Vector3(
MathHelper.Lerp(0, prim.PathShearX, s) + MathHelper.Lerp(-skew, skew, t) * 0.5f,
c + MathHelper.Lerp(0, prim.PathShearY, s),
s);
point.Scale.X = holeX * MathHelper.Lerp(taperXBegin, taperXEnd, t);
point.Scale.Y = holeY * MathHelper.Lerp(taperYBegin, taperYEnd, t);
point.TexT = t;
// Twist rotates the path along the x,y plane
twist = Quaternion.CreateFromAxisAngle(MathHelper.Lerp(twistBegin, twistEnd, t) * 2f * F_PI - F_PI, 0f, 0f, 1f);
qang = Quaternion.CreateFromAxisAngle(pathAxis, ang);
point.Rotation = twist * qang;
path.Points.Add(point);
return path;
}
private static Path GeneratePath(LLObject.ObjectData prim, float detail)
{
Path path;
path.Open = true;
int np = 2; // Hardcode for line
float step;
switch (prim.PathCurve)
{
default:
case LLObject.PathCurve.Line:
{
// Take the begin/end twist into account for detail
np = (int)Math.Floor(Math.Abs(prim.PathTwistBegin - prim.PathTwist) * 3.5f * (detail - 0.5f)) + 2;
path.Points = new List<PathPoint>(np);
step = 1f / (np - 1);
Vector2 startScale = prim.PathBeginScale;
Vector2 endScale = prim.PathEndScale;
for (int i = 0; i < np; i++)
{
PathPoint point = new PathPoint();
float t = MathHelper.Lerp(prim.PathBegin, prim.PathEnd, (float)i * step);
point.Position = new Vector3(
MathHelper.Lerp(0, prim.PathShearX, t),
MathHelper.Lerp(0, prim.PathShearY, t),
t - 0.5f);
point.Rotation = Quaternion.CreateFromAxisAngle(MathHelper.Lerp(F_PI * prim.PathTwistBegin, F_PI * prim.PathTwist, t), 0f, 0f, 1f);
point.Scale.X = MathHelper.Lerp(startScale.X, endScale.X, t);
point.Scale.Y = MathHelper.Lerp(startScale.Y, endScale.Y, t);
point.TexT = t;
path.Points.Add(point);
}
}
break;
case LLObject.PathCurve.Circle:
{
// Increase the detail as the revolutions and twist increase
float twistMag = Math.Abs(prim.PathTwistBegin - prim.PathTwist);
int sides = (int)Math.Floor(
Math.Floor(MIN_DETAIL_FACES * detail + twistMag * 3.5f * (detail - 0.5f))
* prim.PathRevolutions);
// FIXME: Sculpty support
//if (is_sculpted)
// sides = sculpt_sides(detail);
path = GeneratePathPolygon(prim, sides);
}
break;
case LLObject.PathCurve.Circle2:
{
if (prim.PathEnd - prim.PathBegin >= 0.99f && prim.PathScaleX >= 0.99f)
path.Open = false;
path = GeneratePathPolygon(prim, (int)Math.Floor(MIN_DETAIL_FACES * detail));
float t = 0f;
float tStep = 1f / path.Points.Count;
float toggle = 0.5f;
for (int i = 0; i < path.Points.Count; i++)
{
PathPoint point = path.Points[i];
point.Position.X = toggle;
path.Points[i] = point;
if (toggle == 0.5f)
toggle = -0.5f;
else
toggle = 0.5f;
t += tStep;
}
}
break;
case LLObject.PathCurve.Test:
throw new NotImplementedException("PathCurve.Test is not supported");
}
if (prim.PathTwist != prim.PathTwistBegin)
path.Open = true;
return path;
}