void BaseMesh::ReCreateCylinder(Vec3f (*PositionFunction) (float), float Start, float End, float radius, UINT slices, UINT stacks)
{
MeshVertex *V = Vertices();
Matrix4 Face, Translate;
Vec3f Tangent;
float DeltaT = 0.0001f,Time,Theta;
float PI2_Slices = 2.0f * Math::PIf / float(slices);
Vec3f CurPos;
for(UINT i = 0; i <= stacks; i++)
{
Time = float(Math::LinearMap(0.0f,float(stacks),Start,End,float(i))); //get the approriate value between Start and End
CurPos = PositionFunction(Time); //get the current position along the curve
if(Time + DeltaT <= End) Tangent = PositionFunction(Time + DeltaT) - CurPos; //approximate the derivative (tangent vector)
else Tangent = CurPos - PositionFunction(Time - DeltaT);
Face = Matrix4::Face(Vec3f(0.0f, 0.0f, 1.0f), Tangent); //face Matrix4 causes the local cylinder ring to face the right direction
Translate = Matrix4::Translation(CurPos); //the local cylinder ring should be centered on CurPos
Face = Face * Translate;
for(UINT i2 = 0; i2 < slices; i2++)
{
Theta = float(i2) * PI2_Slices;
V[i*slices+i2].Pos = Vec3f(radius * cosf(Theta), radius * sinf(Theta), 0.0f); //construct the basic circle
V[i*slices+i2].Pos = Face.TransformPoint(V[i*slices+i2].Pos); //transform the circle to its approrpriate using the Matrix4
}
}
GenerateNormals();
}
void BaseMesh::Split(float (*PositionFunction) (Vec3f &), BaseMesh &M1, BaseMesh &M2)
{
int i,vc=VertexCount(),ic=IndexCount();
MeshVertex *V = Vertices();
DWORD *I = Indices();
Vector<MeshVertex> NV1,NV2;
Vector<TriMeshFace> NT1,NT2;
SplitVMapper *VMap = new SplitVMapper[vc];
float Value;
for(i=0;i<vc;i++)
{
Value = PositionFunction(V[i].Pos);
if(Value < 0.0f)
{
VMap[i].Side = 0;
VMap[i].NVMap1 = NV1.Length();
VMap[i].NVMap2 = -1;
NV1.PushEnd(V[i]);
} else {
VMap[i].Side = 1;
VMap[i].NVMap1 = -1;
VMap[i].NVMap2 = NV2.Length();
NV2.PushEnd(V[i]);
}
}
int TSide[3];
TriMeshFace Tri;
int Oddball,State;
for(i=0;i<ic;i+=3)
{
TSide[0] = VMap[I[i]].Side;
TSide[1] = VMap[I[i+1]].Side;
TSide[2] = VMap[I[i+2]].Side;
if(TSide[0] && TSide[1] && TSide[2]) //all O2
{
Tri.I[0] = VMap[I[i]].NVMap2;
Tri.I[1] = VMap[I[i+1]].NVMap2;
Tri.I[2] = VMap[I[i+2]].NVMap2;
NT2.PushEnd(Tri);
} else if(!(TSide[0] || TSide[1] || TSide[2])) //all O1
{
Tri.I[0] = VMap[I[i]].NVMap1;
Tri.I[1] = VMap[I[i+1]].NVMap1;
Tri.I[2] = VMap[I[i+2]].NVMap1;
NT1.PushEnd(Tri);
} else {
if(TSide[0] && TSide[1]) {Oddball = 2; State = 1;}
if(TSide[0] && TSide[2]) {Oddball = 1; State = 1;}
if(TSide[1] && TSide[2]) {Oddball = 0; State = 1;}
if(!(TSide[0] || TSide[1])) {Oddball = 2; State = 2;}
if(!(TSide[0] || TSide[2])) {Oddball = 1; State = 2;}
if(!(TSide[1] || TSide[2])) {Oddball = 0; State = 2;}
if(State == 1) //Add to Obj2
{
if(VMap[I[i+Oddball]].NVMap2 == -1)
{
VMap[I[i+Oddball]].NVMap2 = NV2.Length();
NV2.PushEnd(V[I[i+Oddball]]);
}
Tri.I[0] = VMap[I[i]].NVMap2;
Tri.I[1] = VMap[I[i+1]].NVMap2;
Tri.I[2] = VMap[I[i+2]].NVMap2;
NT2.PushEnd(Tri);
} else { //Add to Obj1
if(VMap[I[i+Oddball]].NVMap1 == -1)
{
VMap[I[i+Oddball]].NVMap1 = NV1.Length();
NV1.PushEnd(V[I[i+Oddball]]);
}
Tri.I[0] = VMap[I[i]].NVMap1;
Tri.I[1] = VMap[I[i+1]].NVMap1;
Tri.I[2] = VMap[I[i+2]].NVMap1;
NT1.PushEnd(Tri);
}
}
}
delete[] VMap;
M1.Allocate(NV1.Length(),NT1.Length());
M2.Allocate(NV2.Length(),NT2.Length());
memcpy(M1.Vertices(), NV1.CArray(), M1.VertexCount() * sizeof(MeshVertex));
memcpy(M2.Vertices(), NV2.CArray(), M2.VertexCount() * sizeof(MeshVertex));
memcpy(M1.Indices(), NT1.CArray(), M1.IndexCount() * sizeof(DWORD));
memcpy(M2.Indices(), NT2.CArray(), M2.IndexCount() * sizeof(DWORD));
}
