private void AddStackLinesToLayer(AlgorithmStatusLayer layer, Stack <Vector> stack)
{
var a = stack.ToArray <Vector>();
for (int i = 0; i < a.Length - 1; i++)
{
var ap = a[i].Alternates;
var ap2 = a[i + 1].Alternates;
if (ap == null || ap2 == null)
{
return;
}
layer.AddCommand(new AddLineCommand
{
AssociatedAlgorithm = this,
StartXIndex = ap.DotIndexLeft,
StartYIndex = ap.DotIndexTop,
EndXIndex = ap2.DotIndexLeft,
EndYIndex = ap2.DotIndexTop,
Comments = ""
});
}
}
protected void AddNonIndexedPolygonCommand(AlgorithmStatusLayer layer, PolygonModel poly)
{
layer.AddCommand(new AddNonIndexedPolygonCommand
{
AssociatedAlgorithm = this,
Polygon = poly
});
}
protected void AddNonIndexedLineCommand(AlgorithmStatusLayer layer, Vector v1, Vector v2)
{
layer.AddCommand(new AddNonIndexedLineCommand
{
AssociatedAlgorithm = this,
StartX = v1.X,
StartY = v1.Y,
EndX = v2.X,
EndY = v2.Y,
Comments = ""
});
}
private void AddEdgesToLayer(AlgorithmStatusLayer layer)
{
for (int ei = 0; ei < Edges.Count; ei++)
{
var e = Edges[ei];
if (e.BadEdge)
{
continue;
}
var v1 = e.VStart;
var v2 = e.VEnd;
AddLineCommand(layer, v1, v2);
}
}
protected void AddLineCommand(AlgorithmStatusLayer layer, Vector v1, Vector v2)
{
if (v1.Alternates == null || v2.Alternates == null)
{
//Debugger.Break();
return;
}
layer.AddCommand(new AddLineCommand
{
AssociatedAlgorithm = this,
StartXIndex = v1.Alternates.DotIndexLeft,
StartYIndex = v1.Alternates.DotIndexTop,
EndXIndex = v2.Alternates.DotIndexLeft,
EndYIndex = v2.Alternates.DotIndexTop,
Comments = ""
});
}
private void AddTriangleLinesToLayer(AlgorithmStatusLayer layer)
{
for (int ti = 0; ti < Triangles.Count; ti++)
{
var tri = Triangles[ti];
if (tri.IsBad)
{
continue;
}
var v1 = tri.V1;
var v2 = tri.V2;
var v3 = tri.V3;
AddLineCommand(layer, v1, v2);
AddLineCommand(layer, v2, v3);
AddLineCommand(layer, v3, v1);
}
}
public void Compute()
{
SortPolygons();
List <Vector> P = SortedPoly1;
List <Vector> Q = SortedPoly2;
int n = SortedPoly1.Count;
int m = SortedPoly2.Count;
int a, b;
int a1, b1;
Vector A = new Vector(), B = new Vector();
int cross;
int bHA, aHB;
Vector origin = new Vector {
X = 0, Y = 0
};
Vector p = new Vector(), q = new Vector();
int inFlag;
int aa, ba;
bool firstPoint;
Vector p0 = new Vector();
int code;
a = 0; b = 0; aa = 0; ba = 0;
inFlag = INFLAG_UNKNOWN;
firstPoint = true;
activeStatusLayer = History.CreateAndAddNewLayer("Setup");
activeStatusLayer.AddCommand(new AddTextStatusCommand {
AssociatedAlgorithm = this,
Comments = "The 'in' flag starts as unknown, initial vectors start at index 0"
});
do
{
a1 = (a + n - 1) % n;
b1 = (b + m - 1) % m;
activeStatusLayer = History.CreateAndAddNewLayer("Main loop, a=" + a + ", b=" + b + ", a1=" + a1 + ", b1=" + b1);
// SubVec(P[a], P[a1], A);
A.X = P[a].X - P[a1].X;
A.Y = P[a].Y - P[a1].Y;
// SubVec(Q[b], Q[b1], B);
B.X = Q[b].X - Q[b1].X;
B.Y = Q[b].Y - Q[b1].Y;
activeStatusLayer.AddCommand(new ClearTextStatusCommand {
AssociatedAlgorithm = this
});
AddNonIndexedLineCommand(activeStatusLayer, new Vector {
X = P[a1].X, Y = P[a1].Y
}, new Vector {
X = P[a].X, Y = P[a].Y
});
AddNonIndexedLineCommand(activeStatusLayer, new Vector {
X = Q[b1].X, Y = Q[b1].Y
}, new Vector {
X = Q[b].X, Y = Q[b].Y
});
cross = AreaSign(origin, A, B);
aHB = AreaSign(Q[b1], Q[b], P[a]);
bHA = AreaSign(P[a1], P[a], Q[b]);
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "cross=" + cross
});
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "aHB=" + aHB
});
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "bHA=" + bHA
});
code = SegSegInt(P[a1], P[a], Q[b1], Q[b], p, q);
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Segment intersection status: " + TranslateCode(code)
});
if (code == STATUS_1 || code == STATUS_V)
{
if (inFlag == STATUS_UNKNOWN && firstPoint)
{
aa = 0;
ba = 0;
firstPoint = false;
p0.X = p.X;
p0.Y = p.Y;
// moveto p0
MoveTo(p0);
}
LineTo(p);
inFlag = InOut(p, inFlag, aHB, bHA);
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Newly computed 'in' flag: " + TranslateInOut(inFlag)
});
}
if (code == STATUS_E && GeomMath.DotProduct(A, B) < 0)
{
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Shared segement and ..."
});
// print shared segment
// return
}
if (cross == 0 && aHB < 0 && bHA < 0)
{
// disjoint
// return
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Polygons are disjoint"
});
}
else if (cross == 0 && aHB == 0 && bHA == 0)
{
// advance but do not output point
// page 262
if (inFlag == INFLAG_PIN)
{
// b = Advance(b, &ba, m, inflag == Qin, Q[b]);
// if inFlag == Qin // always false here
// lineto Q[b]
ba++;
b = (b + 1) % m;
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Advancing b vector but not including in output as not part of interection"
});
}
else
{
// a = Advance(a, &aa, n, inflag == Pin, P[a]);
// if inFlag == Pin // always false here
// lineto P[a]
aa++;
a = (a + 1) % n;
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Advancing a vector but not including in output as not part of interection"
});
}
}
else if (cross >= 0)
{
if (bHA > 0)
{
// if inflag == PIN
// lineto P[a]
if (inFlag == INFLAG_PIN)
{
LineTo(P[a]);
}
aa++;
a = (a + 1) % n;
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Advancing a vector and including in output as part of interection"
});
}
else
{
// if inflag == QIN
// lineto Q[b]
if (inFlag == INFLAG_QIN)
{
LineTo(Q[b]);
}
ba++;
b = (b + 1) % m;
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Advancing b vector and including in output as part of interection"
});
}
}
else
{
// cross < 0
if (aHB > 0)
{
// if inflag == QIN
// lineto Q[b]
if (inFlag == INFLAG_QIN)
{
LineTo(Q[b]);
}
ba++;
b = (b + 1) % m;
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Advancing b vector and including in output as part of interection"
});
}
else
{
// if inflag == PIN
// lineto P[a]
if (inFlag == INFLAG_PIN)
{
LineTo(P[a]);
}
aa++;
a = (a + 1) % n;
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Advancing a vector and including in output as part of interection"
});
}
}
} while (((aa < n) || (ba < m)) && (aa < 2 * n) && (ba < 2 * m));
if (aa >= 2 * n)
{
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Termination condition met: aa >= 2*n"
});
}
else if (aa >= n)
{
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Termination condition met: aa >= n"
});
}
if (ba >= 2 * m)
{
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Termination condition met: ba >= 2*m"
});
}
else if (ba >= m)
{
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Termination condition met: ba >= m"
});
}
if (!firstPoint)
{
// close intesection, line to p0
LineTo(p0);
}
if (inFlag == INFLAG_UNKNOWN)
{
// boundaries do not cross
activeStatusLayer.AddCommand(new AddTextStatusCommand
{
AssociatedAlgorithm = this,
Comments = "Boundaries of polygons do not cross, no intersection"
});
}
}