private void AddPoint(GeoPointsArray2 polygon2, Vector2 p)
{
int cnt = polygon2.Count;
List <bool> convexMask = new List <bool>();
for (int i = 0; i < cnt; ++i)
{
int j = i + 1;
if (j == cnt)
{
j = 0;
}
convexMask.Add(GeoPolygonUtils.IsConvexAngle(polygon2[i], polygon2[j], p));
}
int start = -1;
int end = -1;
for (int i = 0; i < cnt; i++)
{
int j = i + 1;
if (j == cnt)
{
j = 0;
}
if (start == -1 && convexMask[i] == false && convexMask[j] == true)
{
start = j;
}
if (end == -1 && convexMask[i] == true && convexMask[j] == false)
{
end = j;
}
if (start != -1 && end != -1)
{
break;
}
}
if (start != -1 && end != -1)
{
GeoPointsArray2 other = new GeoPointsArray2();
if (start <= end)
{
for (int i = start; i <= end; ++i)
{
other.Add(polygon2[i]);
}
}
else
{
for (int i = start; i < cnt; ++i)
{
other.Add(polygon2[i]);
}
for (int i = 0; i <= end; ++i)
{
other.Add(polygon2[i]);
}
}
other.Add(p);
polygon2.Clear();
polygon2.mPointArray.AddRange(other.mPointArray);
}
}
// CCW
private GeoPointsArray2 FirstTriangle()
{
GeoPointsArray2 polygon2 = new GeoPointsArray2();
int minIndex = 0;
int maxIndex = 0;
float minX = mPoints[0].x;
float maxX = mPoints[0].x;
for (int i = 1; i < mCount; ++i)
{
if (mPoints[i].x < minX)
{
minX = mPoints[i].x;
minIndex = i;
}
if (mPoints[i].x > maxX)
{
maxX = mPoints[i].x;
maxIndex = i;
}
}
Vector2 max = mPoints[maxIndex];
Vector2 min = mPoints[minIndex];
if (maxIndex > minIndex)
{
mPoints.RemoveAt(maxIndex);
mPoints.RemoveAt(minIndex);
}
else
{
mPoints.RemoveAt(minIndex);
mPoints.RemoveAt(maxIndex);
}
mCount = mPoints.Count;
Vector2 dir = max - min;
// 逆时针
Vector2 left = new Vector2(-dir.y, dir.x);
maxX = -1e10f;
int sign = 0;
for (int i = 0; i < mCount; ++i)
{
dir = mPoints[i] - min;
float d = Vector2.Dot(dir, left);
bool s = d < 0;
if (s)
{
d = -d;
}
if (d > maxX)
{
maxX = d;
sign = s ? -1 : 1;
maxIndex = i;
}
}
Vector2 threePoint = mPoints[maxIndex];
mPoints.RemoveAt(maxIndex);
mCount = mPoints.Count;
Assert.IsTrue(maxX > -1.0f, "wrong");
polygon2.Add(min);
if (sign == 1)
{
polygon2.Add(max);
polygon2.Add(threePoint);
}
else
{
polygon2.Add(threePoint);
polygon2.Add(max);
}
return(polygon2);
}