private ContourLine TrackUnclosedContour(int crtTriangle, enumEdgeType crtEdge, double contValue)
{
if (_triangleIsUsed.IsTrue(crtTriangle))
{
return(null);
}
ContourLine cntLine = new ContourLine(contValue);
UpdateClassIndex(cntLine);
enumEdgeType firstEdge = crtEdge;
int firstTriangle = crtTriangle;
enumEdgeType[] otherEdges = new enumEdgeType[2];
int edgeIdx = ToEdgeIndex(crtTriangle, crtEdge);
bool edgeUsed = _edgeIsUsed.IsTrue(edgeIdx);
PointF vpt = TryGetVPoint(crtTriangle, crtEdge, contValue);
if (vpt.IsEmpty || edgeUsed)
{
return(null);
}
_edgeIsUsed.SetStatus(edgeIdx, true);
return(TrackClosedContourFromEdge(crtTriangle, crtEdge, contValue, vpt,
(idx) => { return IsBorderTriangle(idx); }, 2));
}
private int GetNextTriangle(int crtTriangle, ref enumEdgeType crtEdge)
{
bool isRightTop = crtTriangle % 2 != 0;
int span = (_gridWidth * 2 + 1);
try
{
switch (crtEdge)
{
case enumEdgeType.A:
if (isRightTop)
{
crtTriangle = crtTriangle - span;
}
else
{
crtTriangle = crtTriangle + span;
}
break;
case enumEdgeType.B:
if (isRightTop)
{
crtTriangle = crtTriangle + 1;
}
else
{
crtTriangle = crtTriangle - 1;
}
break;
case enumEdgeType.C:
if (isRightTop)
{
crtTriangle = crtTriangle - 1;
}
else
{
crtTriangle = crtTriangle + 1;
}
break;
}
}
finally
{
if (crtTriangle > _triangleCount - 1 || crtTriangle < 0)
{
crtTriangle = -1;
}
}
return(crtTriangle);
}
private int ToEdgeIndex(int crtTriangle, enumEdgeType crtEdge)
{
int pixelRow = crtTriangle / _triWidth;
int pixelCol = crtTriangle % _triWidth / 2;
bool isLeftBottom = crtTriangle % 2 == 0;
int idx = 0;
if (pixelRow == 0)
{
idx = _gridWidth + pixelCol * 3;
}
else
{
idx = pixelRow * (_gridWidth * 3 + 1) + _gridWidth + pixelCol * (_gridWidth - 1);
}
if (isLeftBottom)
{
switch (crtEdge)
{
case enumEdgeType.A:
return(idx + 1);
case enumEdgeType.B:
return(idx);
case enumEdgeType.C:
return(idx + 2);
}
}
else
{
switch (crtEdge)
{
case enumEdgeType.A:
if (pixelRow == 0)
{
return(pixelCol);
}
else
{
return(idx - _gridWidth * 3);
}
case enumEdgeType.B:
return(idx + 3);
case enumEdgeType.C:
return(idx + 2);
}
}
return(-1);
}
private void SetOthterEdges(enumEdgeType crtEdge, ref enumEdgeType[] otherEdges)
{
if (crtEdge == enumEdgeType.A)
{
otherEdges[0] = enumEdgeType.B;
otherEdges[1] = enumEdgeType.C;
}
else if (crtEdge == enumEdgeType.B)
{
otherEdges[0] = enumEdgeType.A;
otherEdges[1] = enumEdgeType.C;
}
else if (crtEdge == enumEdgeType.C)
{
otherEdges[0] = enumEdgeType.A;
otherEdges[1] = enumEdgeType.B;
}
}
/*
* var factor = (float)((value - edge.P1.Value) / (edge.P2.Value - edge.P1.Value));
* result.X = edge.P1.X + factor * (edge.P2.X - edge.P1.X);
* result.Y = edge.P1.Y + factor * (edge.P2.Y - edge.P1.Y);
*/
protected override PointF GetVPoint(enumEdgeType edgeType, int pixelIdxV1, int pixelIdxV2, double contValue)
{
float factor = (float)(contValue - _bandValues[pixelIdxV1]) / (_bandValues[pixelIdxV2] - _bandValues[pixelIdxV1]);
int y = pixelIdxV1 / _width; //row
int x = pixelIdxV1 % _width; //col
switch (edgeType)
{
case enumEdgeType.A:
return(new PointF(x + factor, y));
case enumEdgeType.B:
return(new PointF(x, y + factor));
case enumEdgeType.C:
return(new PointF(x + factor, y + factor));
}
return(PointF.Empty);
}
private bool IsBorderEdge(int idxTriangle, enumEdgeType edge)
{
if (idxTriangle % _triWidth == 0 && edge == enumEdgeType.B) //left
{
return(true);
}
else if ((idxTriangle + 1) % _triWidth == 0 && edge == enumEdgeType.B) //right
{
return(true);
}
else if (idxTriangle / _triWidth == 0 && edge == enumEdgeType.A) //top
{
return(true);
}
else if (idxTriangle / _triWidth == _gridHeight - 1 && edge == enumEdgeType.A) //bottom
{
return(true);
}
return(false);
}
private ContourLine TrackClosedContour(int crtTriangle, enumEdgeType crtEdge, double contValue)
{
if (_triangleIsUsed.IsTrue(crtTriangle))
{
return(null);
}
int edgeIdx = 0;
enumEdgeType firstEdge = crtEdge;
int firstTriangle = crtTriangle;
enumEdgeType[] otherEdges = new enumEdgeType[2] {
enumEdgeType.B, enumEdgeType.C
};
PointF vpt = PointF.Empty;
vpt = TryGetVPoint(crtTriangle, crtEdge, contValue);
edgeIdx = ToEdgeIndex(crtTriangle, crtEdge);
if (vpt.IsEmpty || _edgeIsUsed.IsTrue(edgeIdx))
{
for (int i = 0; i < 2; i++)
{
crtEdge = otherEdges[i];
vpt = TryGetVPoint(crtTriangle, crtEdge, contValue);
edgeIdx = ToEdgeIndex(crtTriangle, crtEdge);
if (!vpt.IsEmpty && !_edgeIsUsed.IsTrue(edgeIdx))
{
break;
}
}
}
if (vpt.IsEmpty || _edgeIsUsed.IsTrue(edgeIdx))
{
//当前三角形三条边均不存在等值点，标记为已使用
_triangleIsUsed.SetStatus(crtTriangle, true);
return(null);
}
return(TrackClosedContourFromEdge(crtTriangle, crtEdge, contValue, vpt,
(idx) => { return idx == firstTriangle || IsBorderTriangle(idx); }, 6));
}
protected abstract PointF GetVPoint(enumEdgeType edgeType, int pixelIdxV1, int pixelIdxV2, double contValue);
private PointF TryGetVPoint(int crtTriangle, enumEdgeType crtEdge, double contValue)
{
int pixelRow = crtTriangle / _triWidth;
int pixelCol = crtTriangle % _triWidth / 2;
bool isRightTop = crtTriangle % 2 != 0;//是右上三角形
if (isRightTop)
{
pixelCol += 1;
}
else
{
pixelRow += 1;
}
int pixelIdx = pixelRow * _width + pixelCol;
int pixelIdxV1 = pixelIdx, pixelIdxV2 = pixelIdx;
switch (crtEdge)
{
case enumEdgeType.A:
if (isRightTop)
{
pixelIdxV1 -= 1;
}
else
{
pixelIdxV2 += 1;
}
break;
case enumEdgeType.B:
if (isRightTop)
{
pixelIdxV2 += _width;
}
else
{
pixelIdxV1 -= _width;
}
break;
case enumEdgeType.C:
if (isRightTop)
{
pixelIdxV1 -= 1;
pixelIdxV2 += _width;
}
else
{
pixelIdxV1 -= _width;
pixelIdxV2 += 1;
}
break;
}
if (!CheckIsContained(_bandValues[pixelIdxV1], _bandValues[pixelIdxV2], ToTValue(contValue)))
{
return(PointF.Empty);
}
PointF vpt = GetVPoint(crtEdge, pixelIdxV1, pixelIdxV2, contValue);
//经过采样
if (_sample > 1)
{
vpt.X *= _sample;
vpt.Y *= _sample;
}
return(vpt);
}
private ContourLine TrackClosedContourFromEdge(int crtTriangle, enumEdgeType crtEdge, double contValue, PointF vpt, Func <int, bool> isStop, int minPoints)
{
bool isSharePointed = false;
bool edgeUsed = false;
ContourLine cntLine = new ContourLine(contValue);
UpdateClassIndex(cntLine);
enumEdgeType[] otherEdges = new enumEdgeType[2];
int edgeIdx = 0;
bool isClosed = false;
while (true)
{
//等值线进入当前三角形
if (!isSharePointed)
{
cntLine.AddPoint(vpt);
}
//查找等值线离开当前三角形的出口点
SetOthterEdges(crtEdge, ref otherEdges);
crtEdge = otherEdges[0];
edgeIdx = ToEdgeIndex(crtTriangle, crtEdge);
edgeUsed = _edgeIsUsed.IsTrue(edgeIdx);
vpt = !edgeUsed?TryGetVPoint(crtTriangle, crtEdge, contValue) : PointF.Empty;
if (vpt.IsEmpty)//该边不包含等值点或者已被使用
{
crtEdge = otherEdges[1];
edgeIdx = ToEdgeIndex(crtTriangle, crtEdge);
edgeUsed = _edgeIsUsed.IsTrue(edgeIdx);
vpt = !edgeUsed?TryGetVPoint(crtTriangle, crtEdge, contValue) : PointF.Empty;
if (vpt.IsEmpty)//没有找到出口
{
break;
}
else
{
cntLine.AddPoint(vpt);
_edgeIsUsed.SetStatus(edgeIdx, true);
}
}
else
{
cntLine.AddPoint(vpt);
_edgeIsUsed.SetStatus(edgeIdx, true);
}
//标记当前三角形已经使用
_triangleIsUsed.SetStatus(crtTriangle, true);
//查找当前三角形相连的三角形作为当前三角形
crtTriangle = GetNextTriangle(crtTriangle, ref crtEdge);
//退出条件
if (crtTriangle == -1)
{
break;
}
edgeIdx = ToEdgeIndex(crtTriangle, crtEdge);
_edgeIsUsed.SetStatus(edgeIdx, false);//两个三角形的共享边标记为未使用
if (isStop(crtTriangle))
{
isClosed = true;
_edgeIsUsed.SetStatus(edgeIdx, true);
break;
}
if (_triangleIsUsed.IsTrue(crtTriangle))
{
break;
}
isSharePointed = true;
}
if (_isOutputUncompleted)
{
return(cntLine.Count >= minPoints ? cntLine : null);
}
else
{
if (isClosed)
{
return(cntLine.Count >= minPoints ? cntLine : null);
}
return(null);
}
}
