/// <summary>
/// 凸多角形の「左側」または「右側」の上から下に向かう連結辺を作成する
/// </summary>
public static Edge CreateEdgeChain(ConvexPolygon polygon, bool left)
{
//凸多角形のy座標最小/最大値の頂点番号を取得
int minYIndex = 0, maxYIndex = 0;
polygon.GetYMinMaxindex(ref minYIndex, ref maxYIndex);
//凸多角形の辺配列をを前進するか後退するかを決定
bool ccw = polygon.rotation == ConvexPolygon.Rotation.CCW;
bool forward = (ccw && left) || (!ccw && !left);
//要素の準備
int size = polygon.GetEdgeCount();
int nextIndex = 0;
Edge firstEdge = null;
Edge lastEdge = null;
//最上点の位置から開始し，最下点に到達するまで続ける
for (int i = maxYIndex; i != minYIndex; i = nextIndex)
{
Edge edge = new Edge();
if (forward)
{
//前進
nextIndex = (i + 1) % size;
edge.segment = polygon.GetEdge(i);
edge.index = i;
}
else
{
//後退
nextIndex = (i + size - 1) % size;
edge.segment = polygon.GetEdge(nextIndex);
edge.index = nextIndex;
}
//辺の始点と終点
edge.startPoint = polygon.GetVertex(i);
edge.endPoint = polygon.GetVertex(nextIndex);
//辺の連結処理
if (firstEdge == null)
{
firstEdge = edge;
}
else
{
lastEdge.next = edge;
}
lastEdge = edge;
}
return(firstEdge);
}
private void OnGUI()
{
if (polygon == null)
{
return;
}
StringBuilder sb = new StringBuilder();
int size = polygon.GetEdgeCount();
sb.AppendLine("Vertex Count = " + size);
for (int i = 0; i < size; ++i)
{
sb.AppendLine("[" + i + "] = " + polygon.GetVertex(i));
}
int min = 0, max = 0;
polygon.GetYMinMaxindex(ref min, ref max);
sb.AppendLine("MinYIndex = " + min + " : MaxYIndex = " + max);
GUILayout.Label(sb.ToString());
}
