opensim/OpenSim/Region/Physics/Meshing/Extruder.cs

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using OpenSim.Region.Physics.Manager;

namespace OpenSim.Region.Physics.Meshing
{
    internal class Extruder
    {
        public float startParameter;
        public float stopParameter;
        public PhysicsVector size;

        public float taperTopFactorX = 1f;
        public float taperTopFactorY = 1f;
        public float taperBotFactorX = 1f;
        public float taperBotFactorY = 1f;

        public float pushX = 0f;
        public float pushY = 0f;

        // twist amount in radians.  NOT DEGREES.
        public float twistTop = 0;
        public float twistBot = 0;
        public float twistMid = 0;

        public Mesh Extrude(Mesh m)
        {
            startParameter = float.MinValue;
            stopParameter = float.MaxValue;
            // Currently only works for iSteps=1;
            Mesh result = new Mesh();

            Mesh workingPlus = m.Clone();
            Mesh workingMiddle = m.Clone();
            Mesh workingMinus = m.Clone();

            Quaternion tt = new Quaternion();
            Vertex v2 = new Vertex(0, 0, 0);

            foreach (Vertex v in workingPlus.vertices)
            {
                if (v == null)
                    continue;

                // This is the top
                // Set the Z + .5 to match the rest of the scale of the mesh
                // Scale it by Size, and Taper the scaling
                v.Z = +.5f;
                v.X *= (size.X * taperTopFactorX);
                v.Y *= (size.Y * taperTopFactorY);
                v.Z *= size.Z;
                
                //Push the top of the object over by the Top Shear amount
                v.X += pushX * size.X;
                v.Y += pushY * size.X;

                if (twistTop != 0)
                {
                    // twist and shout
                    tt = new Quaternion(new Vertex(0, 0, 1), twistTop);
                    v2 = v * tt;
                    v.X = v2.X;
                    v.Y = v2.Y;
                    v.Z = v2.Z;
                }
            }

            foreach (Vertex v in workingMiddle.vertices)
            {
                if (v == null)
                    continue;

                // This is the top
                // Set the Z + .5 to match the rest of the scale of the mesh
                // Scale it by Size, and Taper the scaling
                v.Z *= size.Z;
                v.X *= (size.X * ((taperTopFactorX + taperBotFactorX) /2));
                v.Y *= (size.Y * ((taperTopFactorY + taperBotFactorY) / 2));

                v.X += (pushX / 2) * size.X;
                v.Y += (pushY / 2) * size.X;
                //Push the top of the object over by the Top Shear amount
                if (twistMid != 0)
                {
                    // twist and shout
                    tt = new Quaternion(new Vertex(0, 0, 1), twistMid);
                    v2 = v * tt;
                    v.X = v2.X;
                    v.Y = v2.Y;
                    v.Z = v2.Z;
                }
              
            }
            foreach (Vertex v in workingMinus.vertices)
            {
                if (v == null)
                    continue;

                // This is the bottom
                v.Z = -.5f;
                v.X *= (size.X * taperBotFactorX);
                v.Y *= (size.Y * taperBotFactorY);
                v.Z *= size.Z;

                if (twistBot != 0)
                {
                    // twist and shout
                    tt = new Quaternion(new Vertex(0, 0, 1), twistBot);
                    v2 = v * tt;
                    v.X = v2.X;
                    v.Y = v2.Y;
                    v.Z = v2.Z;
                }
            }

            foreach (Triangle t in workingMinus.triangles)
            {
                t.invertNormal();
            }

            result.Append(workingMinus);

            result.Append(workingMiddle);


            int iLastNull = 0;

            for (int i = 0; i < workingMiddle.vertices.Count; i++)
            {
                int iNext = (i + 1);

                if (workingMiddle.vertices[i] == null) // Can't make a simplex here
                {
                    iLastNull = i + 1;
                    continue;
                }

                if (i == workingMiddle.vertices.Count - 1) // End of list
                {
                    iNext = iLastNull;
                }

                if (workingMiddle.vertices[iNext] == null) // Null means wrap to begin of last segment
                {
                    iNext = iLastNull;
                }

                Triangle tSide;
                tSide = new Triangle(workingMiddle.vertices[i], workingMinus.vertices[i], workingMiddle.vertices[iNext]);
                result.Add(tSide);

                tSide =
                    new Triangle(workingMiddle.vertices[iNext], workingMinus.vertices[i], workingMinus.vertices[iNext]);
                result.Add(tSide);
            }
            //foreach (Triangle t in workingPlus.triangles)
            //{
                //t.invertNormal();
           // }
            result.Append(workingPlus);

            iLastNull = 0;
            for (int i = 0; i < workingPlus.vertices.Count; i++)
            {
                int iNext = (i + 1);

                if (workingPlus.vertices[i] == null) // Can't make a simplex here
                {
                    iLastNull = i + 1;
                    continue;
                }

                if (i == workingPlus.vertices.Count - 1) // End of list
                {
                    iNext = iLastNull;
                }

                if (workingPlus.vertices[iNext] == null) // Null means wrap to begin of last segment
                {
                    iNext = iLastNull;
                }

                Triangle tSide;
                tSide = new Triangle(workingPlus.vertices[i], workingMiddle.vertices[i], workingPlus.vertices[iNext]);
                result.Add(tSide);

                tSide =
                    new Triangle(workingPlus.vertices[iNext], workingMiddle.vertices[i], workingMiddle.vertices[iNext]);
                result.Add(tSide);
            }
            if (twistMid != 0)
            {
                foreach (Vertex v in result.vertices)
                {
                    // twist and shout
                    if (v != null)
                    {
                        tt = new Quaternion(new Vertex(0, 0, -1), twistMid*2);
                        v2 = v * tt;
                        v.X = v2.X;
                        v.Y = v2.Y;
                        v.Z = v2.Z;
                    }
                }
            }
            return result;
        }
    }
}