//添加一个顶点
public void AddV(Vector3 v, VertexInfo vInfo)
{
LstVertecies.Add(v);
LstVertexInfo.Add(vInfo);
}
public bool Init(GiftWrap gw)
{
if (gw.ExceptionOccur())
{
return(false);
}
Reset(); //重置为初始状态
Centroid = gw.Centroid; //质心置为初始化gw的质心
//分情况考虑构造CConvexPolytope
if (gw.HullType == GiftWrap.HULL_TYPE.HULL_3D) //3D Hull的情况
{
int[] map = new int[gw.LstVertex.Count]; //构造一个映射表
int count = 0;
//添加有效顶点&构造映射表
int i;
for (i = 0; i < gw.LstVertex.Count; i++)
{
map[i] = -1;
if (gw.LstExtremeVertex[i])
{
//当前点有效，用其初始化v，并将其插入到顶点列表
Vector3 v = gw.LstVertex[i];
LstVertecies.Add(v);
LstVertexInfo.Add(new VertexInfo());
map[i] = count++;
}
}
//构造面片
//添加三角形面片
for (i = 0; i < gw.LstFaces.Count; i++)
{
Face f = gw.LstFaces[i];
if (!f.InPolygon) //不属于任何多边形，添加
{
Vector3 v1 = gw.LstVertex[f.v1];
Vector3 v2 = gw.LstVertex[f.v2];
Vector3 v3 = gw.LstVertex[f.v3];
Patch pat = new Patch(this);
pat.Set(v1, v2, v3); //几何信息
//依次向Neighbors中添加元素
VPNeighbor vpn = new VPNeighbor();
List <VPNeighbor> lstNeighbor = pat.LstNeighbors;
vpn.Vid = map[f.v1]; //这里必须作一个映射
lstNeighbor.Add(vpn);
vpn = new VPNeighbor();
vpn.Vid = map[f.v2];
lstNeighbor.Add(vpn);
vpn = new VPNeighbor();
vpn.Vid = map[f.v3];
lstNeighbor.Add(vpn);
//各顶点度数增1
LstVertexInfo[map[f.v1]].Degree++;
LstVertexInfo[map[f.v2]].Degree++;
LstVertexInfo[map[f.v3]].Degree++;
//添加到链表
LstPatches.Add(pat);
}
}
//添加多边形面片
for (i = 0; i < gw.LstPlanes.Count; i++)
{
List <int> planes = gw.LstPlanes[i];
//取前三个点构造平面几何信息
Vector3 v1 = gw.LstVertex[planes[0]];
Vector3 v2 = gw.LstVertex[planes[1]];
Vector3 v3 = gw.LstVertex[planes[2]];
Patch pat = new Patch(this);
pat.Set(v1, v2, v3); //几何信息
//依次向Neighbors中添加元素
VPNeighbor vpn = new VPNeighbor();
List <VPNeighbor> lstNeighbors = pat.LstNeighbors;
for (int j = 0; j < planes.Count; j++)
{
vpn = new VPNeighbor();
vpn.Vid = map[planes[j]]; //这里必须作一个映射
lstNeighbors.Add(vpn);
LstVertexInfo[vpn.Vid].Degree++; //顶点度数增1
}
//添加到链表
LstPatches.Add(pat);
}
}
else
{
//说明是2D Hull的情况
List <int> lstCHVs = gw.GetCHVertecies();
if (lstCHVs == null)
{
return(false);
}
if (lstCHVs.Count < 3) //至少是一个三角形
{
return(false);
}
//顶点信息
VertexInfo vInfo = new VertexInfo();
vInfo.Degree = 3; //直棱拄所有顶点的面度数均为3
HalfSpace planeOut = new HalfSpace();
HalfSpace planeIn = new HalfSpace();
//取前三个点构造平面几何信息
Vector3 v1 = gw.LstVertex[lstCHVs[0]];
Vector3 v2 = gw.LstVertex[lstCHVs[1]];
Vector3 v3 = gw.LstVertex[lstCHVs[2]];
//构造两个平面PlaneOut和PlaneIn，分别表示顶面和底面
planeOut.Set(v1, v2, v3);
planeIn.Normal = -planeOut.Normal;
planeIn.Dist = -planeOut.Dist;
planeIn.Translate(HULL2D_HALF_THICKNESS);
planeOut.Translate(HULL2D_HALF_THICKNESS);
Vector3 vOutNormal = planeOut.Normal;
Vector3 vInNormal = planeIn.Normal;
//分别求出PlaneOut,PlaneIn上的两点
Vector3 vOut = v1 + HULL2D_HALF_THICKNESS * vOutNormal;
Vector3 vIn = v1 + HULL2D_HALF_THICKNESS * vInNormal;
//构造顶点及顶点信息
int i;
for (i = 0; i < lstCHVs.Count; i++)
{
//同时添加底面和顶面的一个顶点
Vector3 vec1 = gw.LstVertex[lstCHVs[i]];
Vector3 vec2 = vec1;
if (i < 3)
{
vec1 += HULL2D_HALF_THICKNESS * vOutNormal;
vec2 += HULL2D_HALF_THICKNESS * vInNormal;
}
else
{
Vector3 vDiff = vec1 - vOut;
vec1 -= Vector3.Dot(vDiff, vOutNormal) * vOutNormal;
vDiff = vec2 - vIn;
vec2 -= Vector3.Dot(vDiff, vInNormal) * vInNormal;
}
LstVertecies.Add(vec1);
LstVertecies.Add(vec2);
//相应的，添加两个顶点信息
LstVertexInfo.Add(vInfo);
LstVertexInfo.Add(vInfo);
}
//开始构造平面面片
//向外的面
Patch pat = new Patch(this);
pat.Normal = vOutNormal; //几何信息
pat.Dist = planeOut.Dist;
//依次向Neighbors中添加元素
VPNeighbor vpn = new VPNeighbor();
List <VPNeighbor> lstNeighbors1 = pat.LstNeighbors;
for (i = 0; i < lstCHVs.Count; i++)
{
vpn = new VPNeighbor();
vpn.Vid = 2 * i;
lstNeighbors1.Add(vpn);
}
//添加到链表
LstPatches.Add(pat);
//向内的面
pat = new Patch(this);
pat.Normal = vInNormal; //几何信息
pat.Dist = planeIn.Dist;
//依次向Neighbors中添加元素
List <VPNeighbor> lstNeighbors2 = pat.LstNeighbors;
//顶面按照逆序添加
for (i = lstCHVs.Count - 1; i >= 0; i--)
{
vpn = new VPNeighbor();
vpn.Vid = 2 * i + 1;
lstNeighbors2.Add(vpn);
}
//添加到链表
LstPatches.Add(pat);
//开始添加各个侧面
for (i = 0; i < lstCHVs.Count; i++)
{
pat = new Patch(this);
List <VPNeighbor> lstNeighbors = pat.LstNeighbors;
//每个侧面都是一个矩形
if (i < lstCHVs.Count - 1)
{
v1 = LstVertecies[2 * i + 2];
v2 = LstVertecies[2 * i];
v3 = LstVertecies[2 * i + 1];
pat.Set(v1, v2, v3);
vpn = new VPNeighbor();
vpn.Vid = 2 * i;
lstNeighbors.Add(vpn);
vpn = new VPNeighbor();
vpn.Vid = 2 * i + 1;
lstNeighbors.Add(vpn);
vpn = new VPNeighbor();
vpn.Vid = 2 * i + 3;
lstNeighbors.Add(vpn);
vpn = new VPNeighbor();
vpn.Vid = 2 * i + 2;
lstNeighbors.Add(vpn);
}
else
{
//最后一个矩形的情况比较特殊
v1 = LstVertecies[0];
v2 = LstVertecies[2 * i];
v3 = LstVertecies[2 * i + 1];
pat.Set(v1, v2, v3);
vpn = new VPNeighbor();
vpn.Vid = 2 * i;
lstNeighbors.Add(vpn);
vpn = new VPNeighbor();
vpn.Vid = 2 * i + 1;
lstNeighbors.Add(vpn);
vpn = new VPNeighbor();
vpn.Vid = 1;
lstNeighbors.Add(vpn);
vpn = new VPNeighbor();
vpn.Vid = 0;
lstNeighbors.Add(vpn);
}
LstPatches.Add(pat);
}
}
OriginPatchNum = LstPatches.Count;
CurVNum = LstVertecies.Count;
//初始化删除误差
if (mLstRemovedError == null)
{
mLstRemovedError = new List <float>(OriginPatchNum + 1);
}
mLstRemovedError.Clear();
for (int i = 0; i < OriginPatchNum + 1; i++)
{
mLstRemovedError.Add(-1.0f); //0,1,2,3都置为无效值
}
ExceptionOccur = false;
//计算每个patch的邻域patch
ComputePatchNeighbors();
//HalfSpace::SetDistThresh(1e-3); //恢复到缺省的阈值
//寻找最小删除误差对应的面片
SearchLeastErrorPatch();
//开始简化，简化到头
ReduceAll();
return(true);
}
