private static bool GetNextHullPoint(PolygonCreationAssistance pca, ref Vector2 last, ref Vector2 current,
out Vector2 next)
{
int x;
int y;
int indexOfFirstPixelToCheck = GetIndexOfFirstPixelToCheck(last, current);
int indexOfPixelToCheck;
const int pixelsToCheck = 8; // _closePixels.Length;
for (int i = 0; i < pixelsToCheck; i++)
{
indexOfPixelToCheck = (indexOfFirstPixelToCheck + i) % pixelsToCheck;
x = (int)current.X + ClosePixels[indexOfPixelToCheck, 0];
y = (int)current.Y + ClosePixels[indexOfPixelToCheck, 1];
if (x >= 0 && x < pca.Width && y >= 0 && y <= pca.Height)
{
if (pca.IsSolid(x, y)) //todo
{
next = new Vector2(x, y);
return(true);
}
}
}
next = Vector2.Zero;
return(false);
}
private static bool GetNextHullEntrance(PolygonCreationAssistance pca, Vector2 start, out Vector2?entrance)
{
// Search for first solid pixel.
int size = pca.Height * pca.Width;
int x;
bool foundTransparent = false;
for (int i = (int)start.X + (int)start.Y * pca.Width; i <= size; i++)
{
if (pca.IsSolid(i))
{
if (foundTransparent)
{
x = i % pca.Width;
entrance = new Vector2(x, (i - x) / pca.Width);
return(true);
}
}
else
{
foundTransparent = true;
}
}
// If there are no solid pixels.
entrance = null;
return(false);
}
private static bool GetHullEntrance(PolygonCreationAssistance pca, out Vector2 entrance)
{
// Search for first solid pixel.
for (int y = 0; y <= pca.Height; y++)
{
for (int x = 0; x <= pca.Width; x++)
{
if (pca.IsSolid(x, y))
{
entrance = new Vector2(x, y);
return(true);
}
}
}
// If there are no solid pixels.
entrance = Vector2.Zero;
return(false);
}
private static bool SearchNearPixels(PolygonCreationAssistance pca, bool searchingForSolidPixel,
ref Vector2 current, out Vector2 foundPixel)
{
for (int i = 0; i < 8; i++)
{
int x = (int)current.X + ClosePixels[i, 0];
int y = (int)current.Y + ClosePixels[i, 1];
if (!searchingForSolidPixel ^ pca.IsSolid(x, y))
{
foundPixel = new Vector2(x, y);
return(true);
}
}
// Nothing found.
foundPixel = Vector2.Zero;
return(false);
}
private static bool GetNextHullPoint(PolygonCreationAssistance pca, ref Vector2 last, ref Vector2 current,
out Vector2 next)
{
int x;
int y;
int indexOfFirstPixelToCheck = GetIndexOfFirstPixelToCheck(ref last, ref current);
int indexOfPixelToCheck;
const int pixelsToCheck = 8; // _closePixels.Length;
for (int i = 0; i < pixelsToCheck; i++)
{
indexOfPixelToCheck = (indexOfFirstPixelToCheck + i)%pixelsToCheck;
x = (int) current.X + ClosePixels[indexOfPixelToCheck, 0];
y = (int) current.Y + ClosePixels[indexOfPixelToCheck, 1];
if (x >= 0 && x < pca.Width && y >= 0 && y <= pca.Height)
{
if (pca.IsSolid(x, y)) //todo
{
next = new Vector2(x, y);
return true;
}
}
}
next = Vector2.Zero;
return false;
}
private static bool GetNextHullEntrance(PolygonCreationAssistance pca, Vector2 start, out Vector2? entrance)
{
// Search for first solid pixel.
int size = pca.Height*pca.Width;
int x;
bool foundTransparent = false;
for (int i = (int) start.X + (int) start.Y*pca.Width; i <= size; i++)
{
if (pca.IsSolid(i))
{
if (foundTransparent)
{
x = i%pca.Width;
entrance = new Vector2(x, (i - x)/(float) pca.Width);
return true;
}
}
else
{
foundTransparent = true;
}
}
// If there are no solid pixels.
entrance = null;
return false;
}
private static bool GetHullEntrance(PolygonCreationAssistance pca, out Vector2 entrance)
{
// Search for first solid pixel.
for (int y = 0; y <= pca.Height; y++)
{
for (int x = 0; x <= pca.Width; x++)
{
if (pca.IsSolid(x, y))
{
entrance = new Vector2(x, y);
return true;
}
}
}
// If there are no solid pixels.
entrance = Vector2.Zero;
return false;
}
private static bool SearchNearPixels(PolygonCreationAssistance pca, bool searchingForSolidPixel,
ref Vector2 current, out Vector2 foundPixel)
{
for (int i = 0; i < 8; i++)
{
int x = (int) current.X + ClosePixels[i, 0];
int y = (int) current.Y + ClosePixels[i, 1];
if (!searchingForSolidPixel ^ pca.IsSolid(x, y))
{
foundPixel = new Vector2(x, y);
return true;
}
}
// Nothing found.
foundPixel = Vector2.Zero;
return false;
}
private static Vertices CreateSimplePolygon(PolygonCreationAssistance pca, Vector2 entrance, Vector2 last)
{
bool entranceFound = false;
bool endOfHull = false;
Vertices polygon = new Vertices(32);
Vertices hullArea = new Vertices(32);
Vertices endOfHullArea = new Vertices(32);
Vector2 current = Vector2.Zero;
#region Entrance check
// Get the entrance point. //todo: alle möglichkeiten testen
if (entrance == Vector2.Zero || !pca.InBounds(ref entrance))
{
entranceFound = GetHullEntrance(pca, out entrance);
if (entranceFound)
{
current = new Vector2(entrance.X - 1f, entrance.Y);
}
}
else
{
if (pca.IsSolid(ref entrance))
{
if (IsNearPixel(pca, ref entrance, ref last))
{
current = last;
entranceFound = true;
}
else
{
Vector2 temp;
if (SearchNearPixels(pca, false, ref entrance, out temp))
{
current = temp;
entranceFound = true;
}
else
{
entranceFound = false;
}
}
}
}
#endregion
if (entranceFound)
{
polygon.Add(entrance);
hullArea.Add(entrance);
Vector2 next = entrance;
do
{
// Search in the pre vision list for an outstanding point.
Vector2 outstanding;
if (SearchForOutstandingVertex(hullArea, pca.HullTolerance, out outstanding))
{
if (endOfHull)
{
// We have found the next pixel, but is it on the last bit of the hull?
if (endOfHullArea.Contains(outstanding))
{
// Indeed.
polygon.Add(outstanding);
}
// That's enough, quit.
break;
}
// Add it and remove all vertices that don't matter anymore
// (all the vertices before the outstanding).
polygon.Add(outstanding);
hullArea.RemoveRange(0, hullArea.IndexOf(outstanding));
}
// Last point gets current and current gets next. Our little spider is moving forward on the hull ;).
last = current;
current = next;
// Get the next point on hull.
if (GetNextHullPoint(pca, ref last, ref current, out next))
{
// Add the vertex to a hull pre vision list.
hullArea.Add(next);
}
else
{
// Quit
break;
}
if (next == entrance && !endOfHull)
{
// It's the last bit of the hull, search on and exit at next found vertex.
endOfHull = true;
endOfHullArea.AddRange(hullArea);
}
} while (true);
}
return polygon;
}
private static Vector2? GetHoleHullEntrance(PolygonCreationAssistance pca, Vertices polygon,
Vector2? startVertex)
{
List<CrossingEdgeInfo> edges;
Vector2? entrance;
int startLine;
int endLine;
int lastSolid = 0;
bool foundSolid;
bool foundTransparent;
if (polygon != null && polygon.Count > 0)
{
if (startVertex.HasValue)
{
startLine = (int) startVertex.Value.Y;
}
else
{
startLine = (int) GetTopMostCoord(polygon);
}
endLine = (int) GetBottomMostCoord(polygon);
if (startLine > 0 && startLine < pca.Height && endLine > 0 && endLine < pca.Height)
{
// go from top to bottom of the polygon
for (int y = startLine; y <= endLine; y += pca.HoleDetectionLineStepSize)
{
// get x-coord of every polygon edge which crosses y
edges = GetCrossingEdges(polygon, EdgeAlignment.Vertical, y);
// we need an even number of crossing edges
if (edges.Count > 1 && edges.Count%2 == 0)
{
for (int i = 0; i < edges.Count; i += 2)
{
foundSolid = false;
foundTransparent = false;
for (int x = (int) edges[i].CrossingPoint.X;
x <= (int) edges[i + 1].CrossingPoint.X;
x++)
{
if (pca.IsSolid(x, y))
{
if (!foundTransparent)
{
foundSolid = true;
lastSolid = x;
}
if (foundSolid && foundTransparent)
{
entrance = new Vector2(lastSolid, y);
if (DistanceToHullAcceptable(pca, polygon, entrance.Value, true))
{
return entrance;
}
entrance = null;
break;
}
}
else
{
if (foundSolid)
{
foundTransparent = true;
}
}
}
}
}
}
}
}
return null;
}
private static Vertices CreateSimplePolygon(PolygonCreationAssistance pca, Vector2 entrance, Vector2 last)
{
bool entranceFound = false;
bool endOfHull = false;
Vertices polygon = new Vertices();
Vertices hullArea = new Vertices();
Vertices endOfHullArea = new Vertices();
Vector2 current = Vector2.Zero;
#region Entrance check
// Get the entrance point. //todo: alle möglichkeiten testen
if (entrance == Vector2.Zero || !pca.InBounds(entrance))
{
entranceFound = GetHullEntrance(pca, out entrance);
if (entranceFound)
{
current = new Vector2(entrance.X - 1f, entrance.Y);
}
}
else
{
if (pca.IsSolid(entrance))
{
if (IsNearPixel(pca, entrance, last))
{
current = last;
entranceFound = true;
}
else
{
Vector2 temp;
if (SearchNearPixels(pca, false, entrance, out temp))
{
current = temp;
entranceFound = true;
}
else
{
entranceFound = false;
}
}
}
}
#endregion
if (entranceFound)
{
polygon.Add(entrance);
hullArea.Add(entrance);
Vector2 next = entrance;
do
{
// Search in the pre vision list for an outstanding point.
Vector2 outstanding;
if (SearchForOutstandingVertex(hullArea, pca.HullTolerance, out outstanding))
{
if (endOfHull)
{
// We have found the next pixel, but is it on the last bit of the hull?
if (endOfHullArea.Contains(outstanding))
{
// Indeed.
polygon.Add(outstanding);
}
// That's enough, quit.
break;
}
// Add it and remove all vertices that don't matter anymore
// (all the vertices before the outstanding).
polygon.Add(outstanding);
hullArea.RemoveRange(0, hullArea.IndexOf(outstanding));
}
// Last point gets current and current gets next. Our little spider is moving forward on the hull ;).
last = current;
current = next;
// Get the next point on hull.
if (GetNextHullPoint(pca, ref last, ref current, out next))
{
// Add the vertex to a hull pre vision list.
hullArea.Add(next);
}
else
{
// Quit
break;
}
if (next == entrance && !endOfHull)
{
// It's the last bit of the hull, search on and exit at next found vertex.
endOfHull = true;
endOfHullArea.AddRange(hullArea);
}
} while (true);
}
return(polygon);
}
private static Vector2?GetHoleHullEntrance(PolygonCreationAssistance pca, Vertices polygon,
Vector2?startVertex)
{
List <CrossingEdgeInfo> edges = new List <CrossingEdgeInfo>();
Vector2?entrance;
int startLine;
int endLine;
int lastSolid = 0;
bool foundSolid;
bool foundTransparent;
if (polygon != null && polygon.Count > 0)
{
if (startVertex.HasValue)
{
startLine = (int)startVertex.Value.Y;
}
else
{
startLine = (int)GetTopMostCoord(polygon);
}
endLine = (int)GetBottomMostCoord(polygon);
if (startLine > 0 && startLine < pca.Height && endLine > 0 && endLine < pca.Height)
{
// go from top to bottom of the polygon
for (int y = startLine; y <= endLine; y += pca.HoleDetectionLineStepSize)
{
// get x-coord of every polygon edge which crosses y
edges = GetCrossingEdges(polygon, EdgeAlignment.Vertical, y);
// we need an even number of crossing edges
if (edges.Count > 1 && edges.Count % 2 == 0)
{
for (int i = 0; i < edges.Count; i += 2)
{
foundSolid = false;
foundTransparent = false;
for (int x = (int)edges[i].CrossingPoint.X;
x <= (int)edges[i + 1].CrossingPoint.X;
x++)
{
if (pca.IsSolid(x, y))
{
if (!foundTransparent)
{
foundSolid = true;
lastSolid = x;
}
if (foundSolid && foundTransparent)
{
entrance = new Vector2(lastSolid, y);
if (DistanceToHullAcceptable(pca, polygon, entrance.Value, true))
{
return(entrance);
}
entrance = null;
break;
}
}
else
{
if (foundSolid)
{
foundTransparent = true;
}
}
}
}
}
}
}
}
return(null);
}
