private bool SplitPolygonEdge(Vertices polygon, Vector2 coordInsideThePolygon,
out int vertex1Index, out int vertex2Index)
{
Vector2 slope;
int nearestEdgeVertex1Index = 0;
int nearestEdgeVertex2Index = 0;
bool edgeFound = false;
float shortestDistance = float.MaxValue;
bool edgeCoordFound = false;
Vector2 foundEdgeCoord = Vector2.zero;
List <float> xCoords = SearchCrossingEdges(polygon, (int)coordInsideThePolygon.y);
vertex1Index = 0;
vertex2Index = 0;
foundEdgeCoord.y = coordInsideThePolygon.y;
if (xCoords != null && xCoords.Count > 1 && xCoords.Count % 2 == 0)
{
float distance;
for (int i = 0; i < xCoords.Count; i++)
{
if (xCoords[i] < coordInsideThePolygon.x)
{
distance = coordInsideThePolygon.x - xCoords[i];
if (distance < shortestDistance)
{
shortestDistance = distance;
foundEdgeCoord.x = xCoords[i];
edgeCoordFound = true;
}
}
}
if (edgeCoordFound)
{
shortestDistance = float.MaxValue;
int edgeVertex2Index = polygon.Count - 1;
int edgeVertex1Index;
for (edgeVertex1Index = 0; edgeVertex1Index < polygon.Count; edgeVertex1Index++)
{
Vector2 tempVector1 = polygon[edgeVertex1Index];
Vector2 tempVector2 = polygon[edgeVertex2Index];
distance = LineTools.DistanceBetweenPointAndLineSegment(ref foundEdgeCoord,
ref tempVector1, ref tempVector2);
if (distance < shortestDistance)
{
shortestDistance = distance;
nearestEdgeVertex1Index = edgeVertex1Index;
nearestEdgeVertex2Index = edgeVertex2Index;
edgeFound = true;
}
edgeVertex2Index = edgeVertex1Index;
}
if (edgeFound)
{
slope = polygon[nearestEdgeVertex2Index] - polygon[nearestEdgeVertex1Index];
slope.Normalize();
Vector2 tempVector = polygon[nearestEdgeVertex1Index];
distance = LineTools.DistanceBetweenPointAndPoint(ref tempVector, ref foundEdgeCoord);
vertex1Index = nearestEdgeVertex1Index;
vertex2Index = nearestEdgeVertex1Index + 1;
polygon.Insert(nearestEdgeVertex1Index, distance * slope + polygon[vertex1Index]);
polygon.Insert(nearestEdgeVertex1Index, distance * slope + polygon[vertex2Index]);
return(true);
}
}
}
return(false);
}
private static bool SplitPolygonEdge(Vertices polygon, EdgeAlignment edgeAlign, Vector2 coordInsideThePolygon,
out int vertex1Index, out int vertex2Index)
{
List <CrossingEdgeInfo> edges;
Vector2 slope;
int nearestEdgeVertex1Index = 0;
int nearestEdgeVertex2Index = 0;
bool edgeFound = false;
float shortestDistance = float.MaxValue;
bool edgeCoordFound = false;
Vector2 foundEdgeCoord = Vector2.Zero;
vertex1Index = 0;
vertex2Index = 0;
switch (edgeAlign)
{
case EdgeAlignment.Vertical:
edges = GetCrossingEdges(polygon, EdgeAlignment.Vertical, (int)coordInsideThePolygon.Y);
foundEdgeCoord.Y = coordInsideThePolygon.Y;
if (edges != null && edges.Count > 1 && edges.Count % 2 == 0)
{
float distance;
for (int i = 0; i < edges.Count; i++)
{
if (edges[i].CrossingPoint.X < coordInsideThePolygon.X)
{
distance = coordInsideThePolygon.X - edges[i].CrossingPoint.X;
if (distance < shortestDistance)
{
shortestDistance = distance;
foundEdgeCoord.X = edges[i].CrossingPoint.X;
edgeCoordFound = true;
}
}
}
if (edgeCoordFound)
{
shortestDistance = float.MaxValue;
int edgeVertex2Index = polygon.Count - 1;
int edgeVertex1Index;
for (edgeVertex1Index = 0; edgeVertex1Index < polygon.Count; edgeVertex1Index++)
{
Vector2 tempVector1 = polygon[edgeVertex1Index];
Vector2 tempVector2 = polygon[edgeVertex2Index];
distance = LineTools.DistanceBetweenPointAndLineSegment(ref foundEdgeCoord,
ref tempVector1, ref tempVector2);
if (distance < shortestDistance)
{
shortestDistance = distance;
nearestEdgeVertex1Index = edgeVertex1Index;
nearestEdgeVertex2Index = edgeVertex2Index;
edgeFound = true;
}
edgeVertex2Index = edgeVertex1Index;
}
if (edgeFound)
{
slope = polygon[nearestEdgeVertex2Index] - polygon[nearestEdgeVertex1Index];
slope.Normalize();
Vector2 tempVector = polygon[nearestEdgeVertex1Index];
distance = LineTools.DistanceBetweenPointAndPoint(ref tempVector, ref foundEdgeCoord);
vertex1Index = nearestEdgeVertex1Index;
vertex2Index = nearestEdgeVertex1Index + 1;
polygon.Insert(nearestEdgeVertex1Index, distance * slope + polygon[vertex1Index]);
polygon.Insert(nearestEdgeVertex1Index, distance * slope + polygon[vertex2Index]);
return(true);
}
}
}
break;
case EdgeAlignment.Horizontal:
throw new Exception("EdgeAlignment.Horizontal isn't implemented yet. Sorry.");
}
return(false);
}