/// <summary>
/// 点と三角形ポリゴンとの最短距離を返します
/// </summary>
/// <param name="anchorPoint">基準点</param>
/// <param name="vertex1">三角形の頂点</param>
/// <param name="vertex2">三角形の頂点</param>
/// <param name="vertex3">三角形の頂点</param>
/// <param name="location">基準点に対して最も近い三角形上の点</param>
/// <returns></returns>
public static float GetDistanceWithTriangle(Vector3 anchorPoint, Vector3 vertex1, Vector3 vertex2, Vector3 vertex3, out Vector3 location)
{
Vector3 edge2 = vertex2 - vertex1;
Vector3 edge3 = vertex3 - vertex1;
Vector3 triangleVert = Vector3.Normalize(Vector3.Cross(edge2, edge3));
Vector3 toAnchor = anchorPoint - vertex1;
float vertDistance = Vector3.Dot(triangleVert, toAnchor);
Vector3 testDir = -triangleVert * vertDistance * 2;
Motion.Old.MotionDataLine vertLine = new Motion.Old.MotionDataLine(anchorPoint, testDir);
float distance;
if (GeometryCalc.GetCollisionTriangle(vertLine.End, vertLine.AnotherEnd, vertex1, vertex2, vertex3, out distance))
{
location = anchorPoint + Vector3.Normalize(testDir) * distance;
return(distance);
}
Vector3 location1, location2, location3;
float distance1 = GeometryCalc.GetDistanceWithLine(anchorPoint, vertex1, vertex2, out location1);
float distance2 = GeometryCalc.GetDistanceWithLine(anchorPoint, vertex2, vertex3, out location2);
float distance3 = GeometryCalc.GetDistanceWithLine(anchorPoint, vertex3, vertex1, out location3);
if (distance1 < distance2 && distance1 < distance3)
{
location = location1;
return(distance1);
}
else if (distance2 < distance1 && distance2 < distance3)
{
location = location2;
return(distance2);
}
else
{
location = location3;
return(distance3);
}
}
