public MeshEdge(int index, Vector2i e)
{
mIndex = index;
mPointIndex = e;
mSharedFaces = new HashSet <int>();
}
public MeshEdge(int index, int start, int end)
{
mIndex = index;
mPointIndex = new Vector2i(start, end);
mSharedFaces = new HashSet <int>();
}
private void Initialize(List <Vector3> vertices, List <int> faces)
{
for (int i = 0; i < vertices.Count; ++i)
{
mVertexes.Add(new MeshVertex(i, vertices[i]));
}
int count = faces.Count / 3;
for (int i = 0; i < count; ++i)
{
int p1 = faces[i * 3 + 0];
int p2 = faces[i * 3 + 1];
int p3 = faces[i * 3 + 2];
Vector2i e1 = new Vector2i(p1, p2);
Vector2i e2 = new Vector2i(p2, p3);
Vector2i e3 = new Vector2i(p3, p1);
int i1 = mEdges.FindIndex((MeshEdge e) => { return(e.mPointIndex == e1); });
int i2 = mEdges.FindIndex((MeshEdge e) => { return(e.mPointIndex == e2); });
int i3 = mEdges.FindIndex((MeshEdge e) => { return(e.mPointIndex == e3); });
int index = mEdges.Count;
if (i1 == -1)
{
i1 = index++;
mEdges.Add(new MeshEdge(i1, e1));
}
if (i2 == -1)
{
i2 = index++;
mEdges.Add(new MeshEdge(i2, e2));
}
if (i3 == -1)
{
i3 = index++;
mEdges.Add(new MeshEdge(i3, e3));
}
mVertexes[p1].AddSharedEdges(i1);
mVertexes[p2].AddSharedEdges(i2);
mVertexes[p3].AddSharedEdges(i3);
mVertexes[p1].AddSharedFaces(i);
mVertexes[p2].AddSharedEdges(i);
mVertexes[p3].AddSharedEdges(i);
mVertexes[p1].AddNeiborPoint(p2);
mVertexes[p1].AddNeiborPoint(p3);
mVertexes[p2].AddNeiborPoint(p3);
mVertexes[p2].AddNeiborPoint(p1);
mVertexes[p3].AddNeiborPoint(p1);
mVertexes[p3].AddNeiborPoint(p2);
mEdges[i1].AddSharedFaces(i);
mEdges[i2].AddSharedFaces(i);
mEdges[i3].AddSharedFaces(i);
MeshFace face = new MeshFace(i, p1, p2, p3, i1, i2, i3);
mFaces.Add(face);
}
for (int i = 0; i < mFaces.Count; ++i)
{
foreach (int pi in mFaces[i].mPointIndex)
{
mFaces[i].AddNeiborFaceByPoint(mVertexes[pi].mSharedFaces);
}
foreach (int ei in mFaces[i].mEdgeIndex)
{
mFaces[i].AddNeiborFaceByEdge(mEdges[ei].mSharedFaces);
}
}
}
public static List <Vector2i> Scan(List <Vector2i> poly)
{
List <Vector2i> results = new List <Vector2i>();
Vector2i max = new Vector2i(int.MinValue, int.MinValue);
Vector2i min = new Vector2i(int.MaxValue, int.MaxValue);
foreach (Vector2i v in poly)
{
max = Vector2i.Max(v, max);
min = Vector2i.Min(v, min);
}
List <Vector2i> trans = poly.Select(t => { return(t - min); }).ToList();
int height = max[1] - min[1];
List <ScanEdge> scanLines = new List <ScanEdge>();
int count = trans.Count;
int count1 = count - 1;
for (int i = 0; i < count; ++i)
{
Vector2i ps = trans[i];
int post = (i + 1) % count;
Vector2i pe = trans[post];
if (ps[1] == pe[1]) // 水平 去掉
{
Vector2i hori = Vector2i.GetVector2i(ps[0], pe[0]);
for (int hi = hori[0]; hi <= hori[1]; ++hi)
{
results.Add(new Vector2i(hi, ps[1]));
}
continue;
}
int pre = (i + count1) % count;
Vector2i pss = trans[pre];
int ppost = (post + 1) % count;
Vector2i pee = trans[ppost];
double dx = (ps[0] - pe[0]) * 1.0f / (ps[1] - pe[1]);
bool yiG0 = ps[1] < pe[1];
double startX = yiG0 ? ps[0] : pe[0];
int ymin = yiG0 ? ps[1] : pe[1];
int ymax = yiG0 ? pe[1] : ps[1];
if (pe[1] > ps[1])
{
if (pee[1] >= pe[1])
{
ymax -= 1;
}
}
else
{
if (pss[1] >= ps[1])
{
ymax -= 1;
}
}
ScanEdge ep = new ScanEdge();
ep.mMinY = ymin;
ep.mMaxY = ymax;
ep.mStartX = startX;
ep.mDx = dx;
scanLines.Add(ep);
}
for (int i = 0; i < height; ++i)
{
List <ScanEdge> tmp = scanLines.FindAll(delegate(ScanEdge line) { return(line.Include(i)); });
tmp.Sort((e1, e2) =>
{
//此处可以不考虑 斜率。 x相等时，不用考虑谁在前谁在后
return(e1.mStartX.CompareTo(e2.mStartX));
});
if (tmp.Count % 2 != 0)
{
throw new Exception("必须是偶数");
}
for (int idx = 0; idx < tmp.Count; idx += 2)
{
int next = idx + 1;
int x1 = (int)tmp[idx].mStartX;
int x2 = (int)tmp[next].mStartX;
if (x1 > x2)
{
continue;
}
for (int xi = x1; xi <= x2; ++xi)
{
results.Add(new Vector2i(xi, i));
}
tmp[idx].Increase();
tmp[next].Increase();
}
scanLines.RemoveAll((t) => t.mMaxY == i);
}
results = results.Select(t => { return(t + min); }).ToList();
return(results);
}
public void SharedFace(int f1, int f2)
{
mSharedTriangles = Vector2i.GetVector2i(f1, f2);
}
public SharedEdge(int index, int i, int j, int other)
{
mEdgeVertexIndex = Vector2i.GetVector2i(i, j);
mFaceIndex = index;
mOtherVertex = other;
}
