public void Select(int start, int vertexCount)
{
VertexCount = vertexCount;
VertexOffset = start;
Current = null;
if (vertexCount <= 0)
{
return;
}
TriangulationVertex first = null;
TriangulationVertex last = null;
int max = start + vertexCount;
for (int i = start; i < max; i++)
{
TriangulationVertex newVertex = new TriangulationVertex(Vertices[i], i);
if (i == start)
{
first = last = newVertex;
}
else
{
newVertex.Previous = last;
last = last.Next = newVertex;
}
}
last.Next = first;
first.Previous = last;
Current = first;
}
public void Select(int start,int vertexCount){
VertexCount=vertexCount;
VertexOffset=start;
Current=null;
if(vertexCount<=0){
return;
}
TriangulationVertex first=null;
TriangulationVertex last=null;
int max=start+vertexCount;
for(int i=start;i<max;i++){
TriangulationVertex newVertex=new TriangulationVertex(Vertices[i],i);
if(i==start){
first=last=newVertex;
}else{
newVertex.Previous=last;
last=last.Next=newVertex;
}
}
last.Next=first;
first.Previous=last;
Current=first;
}
/// <summary>Adds a vertex to the current set of open vertices.</summary>
public void AddVertex(Vector3 vert, ref TriangulationVertex first, ref TriangulationVertex last)
{
TriangulationVertex newVertex = new TriangulationVertex(vert, VertexOffset + VertexCount, UseZ);
if (VertexCount == 0)
{
first = last = newVertex;
}
else
{
newVertex.Previous = last;
last = last.Next = newVertex;
}
VertexCount++;
}
/// <summary>Gets the area of the polygon to triangulate.
/// Note: may be negative.</summary>
private float GetSignedArea()
{
float sum = 0f;
TriangulationVertex node = Current;
for (int i = 0; i < VertexCount; i++)
{
// Grab the next one:
TriangulationVertex nextNode = node.Next;
// Add them into the sum:
sum += node.X * nextNode.Y - nextNode.X * node.Y;
// Hop to next one:
node = nextNode;
}
return(sum / 2f);
}
private bool InsideTriangle(TriangulationVertex A, TriangulationVertex B, TriangulationVertex C, TriangulationVertex P)
{
float ax = C.X - B.X;
float ay = C.Y - B.Y;
float bpx = P.X - B.X;
float bpy = P.Y - B.Y;
float cross = (ax * bpy - ay * bpx); //A crossed with BP.
if (cross > 0f)
{
return(false);
}
else if (cross == 0f)
{
// Is B or C==P?
if ((B.X == P.X && B.Y == P.Y) || (C.X == P.X && C.Y == P.Y))
{
return(false);
}
}
float bx = A.X - C.X;
float by = A.Y - C.Y;
float cpx = P.X - C.X;
float cpy = P.Y - C.Y;
cross = (bx * cpy - by * cpx); //B crossed with CP.
if (cross > 0f)
{
return(false);
}
else if (cross == 0f)
{
// Is A or C==P?
if ((A.X == P.X && A.Y == P.Y) || (C.X == P.X && C.Y == P.Y))
{
return(false);
}
}
float cx = B.X - A.X;
float cy = B.Y - A.Y;
float apx = P.X - A.X;
float apy = P.Y - A.Y;
cross = (cx * apy - cy * apx); //C crossed with AP.
if (cross > 0f)
{
return(false);
}
else if (cross == 0f)
{
// Is A or B==P?
if ((A.X == P.X && A.Y == P.Y) || (B.X == P.X && B.Y == P.Y))
{
return(false);
}
}
return(true);
}
public void Triangulate(int[] triangles, int triangleCount, int offset)
{
Triangles = triangles;
TriangleIndex = offset;
int vertexMaximum = VertexOffset + VertexCount - 1;
for (int i = 0; i < triangleCount; i++)
{
// Foreach triangle..
// Find a set of 3 vertices that make a valid 'ear'.
// This keeps a linked loop (start is linked to end) of vertices going.
TriangulationVertex current = Current;
for (int vert = vertexMaximum; vert >= VertexOffset; vert--)
{
TriangulationVertex A = current;
TriangulationVertex B = current.Previous;
TriangulationVertex C = current.Next;
// Is this triangle convex?
if (Clockwise)
{
if (((B.Y - A.Y) * (C.X - A.X)) < (((B.X - A.X) * (C.Y - A.Y))))
{
// Yes, not a valid option.
current = current.Next;
continue;
}
// Only vertices left in the loop can potentially go inside this triangle.
// So, starting from the vertex after C, loop around until B is found.
TriangulationVertex contained = current.Next.Next;
while (contained != current.Previous)
{
if (InsideTriangle(A, B, C, contained))
{
goto NextVert;
}
contained = contained.Next;
}
}
else
{
if (((B.Y - A.Y) * (C.X - A.X)) > (((B.X - A.X) * (C.Y - A.Y))))
{
// Yes, not a valid option.
current = current.Next;
continue;
}
// Only vertices left in the loop can potentially go inside this triangle.
// So, starting from the vertex after C, loop around until B is found.
TriangulationVertex contained = current.Next.Next;
while (contained != current.Previous)
{
if (InsideTriangleAnti(A, B, C, contained))
{
goto NextVert;
}
contained = contained.Next;
}
}
AddTriangle(current.Index, current.Next.Index, current.Previous.Index);
current.Remove();
if (current == Current)
{
Current = current.Next;
}
break;
NextVert:
current = current.Next;
}
}
}
private bool InsideTriangle(TriangulationVertex A, TriangulationVertex B,TriangulationVertex C,TriangulationVertex P){
float ax = C.X - B.X;
float ay = C.Y - B.Y;
float bpx = P.X - B.X;
float bpy = P.Y - B.Y;
float cross=(ax * bpy - ay * bpx); //A crossed with BP.
if(cross>0f){
return false;
}else if(cross==0f){
// Is B or C==P?
if( (B.X==P.X && B.Y==P.Y) || (C.X==P.X && C.Y==P.Y) ){
return false;
}
}
float bx = A.X - C.X;
float by = A.Y - C.Y;
float cpx = P.X - C.X;
float cpy = P.Y - C.Y;
cross=(bx * cpy - by * cpx); //B crossed with CP.
if(cross>0f){
return false;
}else if(cross==0f){
// Is A or C==P?
if( (A.X==P.X && A.Y==P.Y) || (C.X==P.X && C.Y==P.Y) ){
return false;
}
}
float cx = B.X - A.X;
float cy = B.Y - A.Y;
float apx = P.X - A.X;
float apy = P.Y - A.Y;
cross=(cx * apy - cy * apx); //C crossed with AP.
if(cross>0f){
return false;
}else if(cross==0f){
// Is A or B==P?
if( (A.X==P.X && A.Y==P.Y) || (B.X==P.X && B.Y==P.Y) ){
return false;
}
}
return true;
}
public void Triangulate(int[] triangles,int triangleCount,int offset){
Triangles=triangles;
TriangleIndex=offset;
int vertexMaximum=VertexOffset+VertexCount-1;
for(int i=0;i<triangleCount;i++){
// Foreach triangle..
// Find a set of 3 vertices that make a valid 'ear'.
// This keeps a linked loop (start is linked to end) of vertices going.
TriangulationVertex current=Current;
for(int vert=vertexMaximum;vert>=VertexOffset;vert--){
TriangulationVertex A=current;
TriangulationVertex B=current.Previous;
TriangulationVertex C=current.Next;
// Is this triangle convex?
if(Clockwise){
if(((B.Y - A.Y) * (C.X - A.X))<(((B.X - A.X) * (C.Y - A.Y)))){
// Yes, not a valid option.
current=current.Next;
continue;
}
// Only vertices left in the loop can potentially go inside this triangle.
// So, starting from the vertex after C, loop around until B is found.
TriangulationVertex contained=current.Next.Next;
while(contained!=current.Previous){
if(InsideTriangle(A,B,C,contained)){
goto NextVert;
}
contained=contained.Next;
}
}else{
if(((B.Y - A.Y) * (C.X - A.X))>(((B.X - A.X) * (C.Y - A.Y)))){
// Yes, not a valid option.
current=current.Next;
continue;
}
// Only vertices left in the loop can potentially go inside this triangle.
// So, starting from the vertex after C, loop around until B is found.
TriangulationVertex contained=current.Next.Next;
while(contained!=current.Previous){
if(InsideTriangleAnti(A,B,C,contained)){
goto NextVert;
}
contained=contained.Next;
}
}
AddTriangle(current.Index,current.Next.Index,current.Previous.Index);
current.Remove();
if(current==Current){
Current=current.Next;
}
break;
NextVert:
current=current.Next;
}
}
}
/// <summary>Completes an externally built triangulation set.</summary>
public void Complete(TriangulationVertex first, TriangulationVertex last)
{
last.Next = first;
first.Previous = last;
Current = first;
}
/// <summary>Resets the triangulator.</summary>
public void Reset()
{
VertexCount = 0;
VertexOffset = 0;
Current = null;
}
