private IVertexOutputData[] ClipPolygon(IVertexOutputData[] polygon)
{
for (int planeIndex = 0; planeIndex < 6; planeIndex++)
{
List <IVertexOutputData> vdatas = new List <IVertexOutputData>();
int vi = planeIndex / 2;
int sign = planeIndex % 2 == 0 ? 1 : -1;
for (int pointIndex = 0; pointIndex < polygon.Length; pointIndex++)
{
int index0 = pointIndex;
int index1 = pointIndex == polygon.Length - 1 ? 0 : pointIndex + 1;
IVertexOutputData v0 = polygon[index0];
IVertexOutputData v1 = polygon[index1];
Vector4 p0 = v0.clip;
Vector4 p1 = v1.clip;
Vector3 n0 = v0.viewNormal;
Vector3 n1 = v1.viewNormal;
float d0 = (p0[vi] + p0.w * sign) * p0.w;
float d1 = (p1[vi] + p1.w * sign) * p1.w;
float ds = d0 * d1;
if (ds < 0)
{
// 边与裁剪面相交
float u = d0 / (d0 - d1);
Vector4 p = p0 + (p1 - p0) * u;
Vector3 n = n0 + (n1 - n0) * u;
if (sign * d0 > 0)
{
vdatas.Add(v0);
}
IVertexOutputData data = new VertexOutputData();
data.clip = p;
data.viewNormal = n;
vdatas.Add(data);
}
else if (MathS.Abs(d0) < Threshold)
{
// p0点在裁剪面上
vdatas.Add(v0);
}
else if (sign * d0 > 0 && sign * d1 >= 0)
{
// 边完全位于裁剪面之内
vdatas.Add(v0);
}
}
polygon = vdatas.ToArray();
}
return(polygon);
}
public Vector4 Process(IVertexOutputData v2f)
{
return(new Vector4(1, 0, 0, 1));
}