private static void CloneVertices(List <Segment> segments, int segIndex, GeneratingModel model, List <int> output, ref int wrapPoint)
{
var input = output.ToArray();
output.Clear();
var seg = segments[segIndex];
bool wrapProcessed = false;
for (int i = 0; i < input.Length; ++i)
{
var rdv = model.rdv[input[i]];
var deg = seg.Rotation0Fraction + seg.RotationStepFraction * i;
if (deg >= 1)
{
if (i != input.Length - 1)
{
continue; //should never happen
}
deg = 0;
}
rdv.Normal = CalculateNormal(segments, segIndex, deg, true);
output.Add(model.AddRDV(rdv));
if (rdv.UV.Y == 0 && wrapPoint != -1)
{
if (wrapProcessed)
{
throw new Exception();
}
var rdv2 = new ModelVertex
{
Position = model.rdv[wrapPoint].Position,
Normal = rdv.Normal,
UV = model.rdv[wrapPoint].UV,
};
wrapPoint = model.AddRDV(rdv2);
wrapProcessed = true;
}
}
if (!wrapProcessed && wrapPoint != -1)
{
throw new Exception();
}
}
public static SingleMaterialModel Generate(List <Segment> segments)
{
if (segments.Count < 2)
{
throw new InvalidOperationException();
}
var totalUDistance = segments.Sum(x => x.UStep);
var currentU = 0f;
GeneratingModel model = new GeneratingModel();
List <int> lastSegment = new List <int>(); //rdv index
List <int> thisSegment = new List <int>();
int lastWrapPoint, thisWrapPoint;
int GetLast(int index)
{
if (index == lastSegment.Count)
{
return(lastWrapPoint);
}
return(lastSegment[index]);
}
int GetThis(int index)
{
if (index == thisSegment.Count)
{
return(thisWrapPoint);
}
return(thisSegment[index]);
}
CreateVertices(segments, 0, currentU / totalUDistance, model, lastSegment, out lastWrapPoint);
for (int i = 1; i < segments.Count; ++i)
{
//Creating new vertices
currentU += segments[i].UStep;
CreateVertices(segments, i, currentU / totalUDistance, model, thisSegment, out thisWrapPoint);
//Clone old vertices
if (!segments[i - 1].ContinuousNormal)
{
CloneVertices(segments, i - 1, model, lastSegment, ref lastWrapPoint);
}
//Check index mapping
bool lastF = segments[i - 1].Rotation0Fraction != 0;
bool thisF = segments[i].Rotation0Fraction != 0;
int lastN = lastSegment.Count - (lastF ? 1 : 0);
int thisN = thisSegment.Count - (thisF ? 1 : 0);
if (lastN != 1 && thisN != 1 && lastN != thisN)
{
throw new ArgumentException("Vertices number mismatch");
}
if (lastN == 1 && thisN == 1)
{
throw new ArgumentException("Invalid segment");
}
if (segments[i].Rotation0Fraction > segments[i].RotationStepFraction)
{
throw new ArgumentException("Invalid rotation");
}
//Create triangles
if (lastN == 1)
{
//TODO make the order same for F and non-F
if (thisF)
{
model.AddTriangle(lastSegment[0], GetThis(0), GetThis(thisSegment.Count - 1));
for (int j = 0; j < thisSegment.Count - 2; ++j)
{
model.AddTriangle(lastSegment[0], GetThis(j + 1), GetThis(j));
}
model.AddTriangle(lastSegment[0], GetThis(thisSegment.Count), GetThis(thisSegment.Count - 2));
}
else
{
for (int j = 0; j < thisSegment.Count; ++j)
{
model.AddTriangle(lastSegment[0], GetThis(j + 1), GetThis(j));
}
}
}
else if (thisN == 1)
{
if (lastF)
{
model.AddTriangle(thisSegment[0], GetLast(lastSegment.Count - 1), GetLast(0));
for (int j = 0; j < lastSegment.Count - 2; ++j)
{
model.AddTriangle(thisSegment[0], GetLast(j), GetLast(j + 1));
}
model.AddTriangle(thisSegment[0], GetLast(lastSegment.Count - 2), GetLast(lastSegment.Count));
}
else
{
for (int j = 0; j < lastSegment.Count; ++j)
{
model.AddTriangle(thisSegment[0], GetLast(j), GetLast(j + 1));
}
}
}
else
{
bool old0new1 = lastF && !thisF;
int normalN = thisN;
if (lastF || thisF)
{
normalN -= 1;
}
for (int j = 0; j < normalN; ++j)
{
var old0 = GetLast(j);
var old1 = GetLast(j + 1);
var new0 = GetThis(j);
var new1 = GetThis(j + 1);
if (old0new1)
{
model.AddTriangle(old0, old1, new1);
model.AddTriangle(old0, new1, new0);
}
else
{
model.AddTriangle(old0, old1, new0);
model.AddTriangle(new0, old1, new1);
}
}
if (lastF && thisF)
{
//ignore old0new1 flag
var old0 = lastSegment[normalN];
var old1 = lastSegment[normalN + 1];
var old1r = lastWrapPoint;
var old2 = lastSegment[0];
var new0 = thisSegment[normalN];
var new1 = thisSegment[normalN + 1];
var new1r = thisWrapPoint;
var new2 = thisSegment[0];
//ignore old0new1 flag
model.AddTriangle(old0, old1r, new1r);
model.AddTriangle(old0, new1r, new0);
model.AddTriangle(old1, old2, new2);
model.AddTriangle(old1, new2, new1);
}
else if (lastF)
{
var old0 = lastSegment[normalN];
var old1 = lastSegment[normalN + 1];
var old1r = lastWrapPoint;
var old2 = lastSegment[0];
var new0 = thisSegment[normalN];
var new2 = thisSegment[0];
var new2r = thisWrapPoint;
model.AddTriangle(old0, old1r, new2r);
model.AddTriangle(old1, old2, new2);
model.AddTriangle(new0, old0, new2r);
}
else if (thisF)
{
var old0 = lastSegment[normalN];
var old2 = lastSegment[0];
var old2r = lastWrapPoint;
var new0 = thisSegment[normalN];
var new1 = thisSegment[normalN + 1];
var new1r = thisWrapPoint;
var new2 = thisSegment[0];
model.AddTriangle(old0, old2r, new0);
model.AddTriangle(old2, new2, new1);
model.AddTriangle(old2r, new1r, new0);
}
}
//Move vertex list
{
var e = lastSegment;
lastSegment = thisSegment;
thisSegment = e;
lastWrapPoint = thisWrapPoint;
}
}
return(model.ToModel());
}
private static void CreateVertices(List <Segment> segments, int segIndex, float u, GeneratingModel model, List <int> output, out int wrapPoint)
{
var seg = segments[segIndex];
output.Clear();
for (int i = 0; seg.Rotation0Fraction + seg.RotationStepFraction * i < 1; ++i)
{
var frac = seg.Rotation0Fraction + seg.RotationStepFraction * i;
var pos = CalculatePosition(seg, frac);
var rdx = model.AddRDV(new ModelVertex
{
Position = pos,
Normal = CalculateNormal(segments, segIndex, frac, false),
UV = new Vector2(u, frac),
});
output.Add(rdx);
}
if (seg.Rotation0Fraction != 0)
{
if (output.Count < 2)
{
throw new ArgumentException("Invalid segment");
}
var pos = (model.rdv[output[0]].Position + model.rdv[output[output.Count - 1]].Position) / 2;
var rdx = model.AddRDV(new ModelVertex
{
Position = pos,
Normal = CalculateNormal(segments, segIndex, 0, false),
UV = new Vector2(u, 0),
});
output.Add(rdx);
}
if (output.Count == 1)
{
wrapPoint = -1;
//Move v to 0.5
var rtv = model.rdv[output[0]];
rtv.UV.Y = 0.5f;
model.rdv[output[0]] = rtv;
}
else
{
var zero = output.Where(ii => model.rdv[ii].UV.Y == 0).First();
var rdx = model.AddRDV(new ModelVertex
{
Position = model.rdv[zero].Position,
Normal = model.rdv[zero].Normal,
UV = new Vector2(u, 1),
});
wrapPoint = rdx;
}
}
