void tessellation(List <RibbonTrackData> ribbon, ref List <RibbonTrackData> ribbonTess) //镶嵌三角形，形成光滑的条带
{
ribbonTess.Clear();
//ribbonTess.AddRange(ribbon);
// return; //temp code
int count = ribbon.Count - 1;
if (count <= 0)
{
return;
}
for (int i = 0; i < count; ++i)
{
RibbonTrackData t0 = new RibbonTrackData();
if (i == 0)
{
t0.pos = ribbon[i + 1].pos - ribbon[i].pos;
t0.color = ribbon[i + 1].color - ribbon[i].color;
t0.bornTime = ribbon[i + 1].bornTime - ribbon[i].bornTime;
}
else
{
t0.pos = ribbon[i + 1].pos - ribbon[i - 1].pos;
t0.color = ribbon[i + 1].color - ribbon[i - 1].color;
t0.bornTime = ribbon[i + 1].bornTime - ribbon[i - 1].bornTime;
}
RibbonTrackData t1 = new RibbonTrackData();
if (i == (count - 1))
{
t1.pos = ribbon[i + 1].pos - ribbon[i].pos;
t1.color = ribbon[i + 1].color - ribbon[i].color;
t1.bornTime = ribbon[i + 1].bornTime - ribbon[i].bornTime;
}
else
{
t1.pos = ribbon[i + 2].pos - ribbon[i].pos;
t1.color = ribbon[i + 2].color - ribbon[i].color;
t1.bornTime = ribbon[i + 2].bornTime - ribbon[i].bornTime;
}
RibbonTrackData p0 = ribbon[i];
RibbonTrackData p1 = ribbon[i + 1];
//Q(s) = (2s3 - 3s2 + 1)v1 + (-2s3 + 3s2)v2 + (s3 - 2s2 + s)t1 + (s3 - s2)t2.
float step = 1.0f / (Tessellation + 1);
for (int j = 0; j < (Tessellation + 1); ++j)
{
RibbonTrackData p = new RibbonTrackData();
float s = j * step;
float a = (2 * s * s * s - 3 * s * s + 1);
float b = (-2 * s * s * s + 3 * s * s);
float c = (s * s * s - 2 * s * s + s);
float d = (s * s * s - s * s);
p.pos = a * p0.pos + b * p1.pos + c * t0.pos + d * t1.pos;
p.color = (float)a * p0.color + (float)b * p1.color + (float)c * t0.color + (float)d * t1.color;
p.bornTime = (float)a * p0.bornTime + (float)b * p1.bornTime + (float)c * t0.bornTime + (float)d * t1.bornTime;
ribbonTess.Add(p);
}
}
ribbonTess.Add(ribbon[ribbon.Count - 1]);
}
void UpdateRibbonMesh()
{
if (StartRibbon == false || mRibbonStart == null || mRibbonEnd == null)
{
return;
}
RibbonTrackData curRibbonTrackStart = new RibbonTrackData();
curRibbonTrackStart.pos = mRibbonStart.transform.position;
curRibbonTrackStart.bornTime = 0;
curRibbonTrackStart.color = new Color(1, 1, 1, 1);
mRibbonStartTrack.Add(curRibbonTrackStart);
RibbonTrackData curRibbonTrackEnd = new RibbonTrackData();
curRibbonTrackEnd.pos = mRibbonEnd.transform.position;
curRibbonTrackEnd.bornTime = 0;
curRibbonTrackEnd.color = new Color(1, 1, 1, 1);
mRibbonEndTrack.Add(curRibbonTrackEnd);
int numTrackVertex = mRibbonStartTrack.Count;
List <RibbonTrackData> removeStartList = new List <RibbonTrackData>();
List <RibbonTrackData> removeEndList = new List <RibbonTrackData>();
for (int i = 0; i < numTrackVertex; ++i)
{
float alpha = (LifeTime - mRibbonStartTrack[i].bornTime) / LifeTime;
if (alpha < 0)
{
removeStartList.Add(mRibbonStartTrack[i]);
removeEndList.Add(mRibbonEndTrack[i]);
}
if (AlphaBlend)
{
mRibbonStartTrack[i].color = new Color(1, 1, 1, alpha);
mRibbonEndTrack[i].color = new Color(1, 1, 1, alpha);
}
else
{
mRibbonStartTrack[i].color = new Color(alpha, alpha, alpha, 1);
mRibbonEndTrack[i].color = new Color(alpha, alpha, alpha, 1);
}
mRibbonStartTrack[i].bornTime += Time.deltaTime;
mRibbonEndTrack[i].bornTime += Time.deltaTime;
}
for (int j = 0; j < removeStartList.Count; ++j)//销毁到期的点
{
mRibbonStartTrack.Remove(removeStartList[j]);
mRibbonEndTrack.Remove(removeEndList[j]);
}
mRibbonMesh.Clear();
if (mRibbonStartTrack.Count <= 1)//不能构成刀光
{
return;
}
tessellation(mRibbonStartTrack, ref mRibbonStartTrackTess);
tessellation(mRibbonEndTrack, ref mRibbonEndTrackTess);
List <Vector3> vertices = new List <Vector3>();
List <Vector2> uvs = new List <Vector2>();
List <Color> colors = new List <Color>();
List <int> triangles = new List <int>();
List <Vector3> normals = new List <Vector3>();
numTrackVertex = mRibbonStartTrackTess.Count;
if (numTrackVertex <= 1)
{
return;
}
for (int i = 0; i < (numTrackVertex); ++i)
{
float uvx = 1 - ((float)i) / (float)(numTrackVertex - 1);
vertices.Add(mRibbonStartTrackTess[i].pos);
colors.Add(mRibbonStartTrackTess[i].color);
uvs.Add(new Vector2(uvx, 0));
normals.Add(Vector3.up);
vertices.Add(mRibbonEndTrackTess[i].pos);
colors.Add(mRibbonEndTrackTess[i].color);
uvs.Add(new Vector2(uvx, 1));
normals.Add(Vector3.up);
}
for (int i = 0; i < (numTrackVertex - 1); ++i)
{
triangles.Add(2 * i);//三角形1
triangles.Add(2 * i + 1);
triangles.Add(2 * (i + 1));
triangles.Add(2 * i + 1);
triangles.Add(2 * (i + 1));
triangles.Add(2 * (i + 1) + 1);
}
mRibbonMesh.vertices = vertices.ToArray();
mRibbonMesh.colors = colors.ToArray();
mRibbonMesh.uv = uvs.ToArray();
mRibbonMesh.normals = normals.ToArray();
mRibbonMesh.triangles = triangles.ToArray();
mRibbonMesh.RecalculateBounds();
}
