{x: -6.29, y: 2.45}	        	{x: 5.68, y: 3.42}

	      {x: -2.33, y: 1.15}

	                     	{x: 4.12, y: -2.77}
  {x: -5.94, y: -4.89}		


params:
pt, p1, p2, p3, p4
{x: -2.33, y: 1.15, v: 0}, {x: -6.29, y: 2.45, v: 1}, {x: 5.68, y: 3.42, v: 2}, {x: 4.12, y: -2.77, v: 3}, {x: -5.94, y: -4.89, v: 2}

without value:
pt, p1, p2, p3, p4
{x: -2.33, y: 1.15}, {x: -6.29, y: 2.45}, {x: 5.68, y: 3.42}, {x: 4.12, y: -2.77}, {x: -5.94, y: -4.89}


一个点在1、4号点的外围

外围点：{x: -10, y: 0}

	{x: -8.0336, y: 6.1536}



																					{x: 4.0793, y: 0.5787}


{x: -9.0849, y: -2.0879}


								{x: -4.3149, y: -4.833}



双线性插值点

{x: 17, y: 30, v: 2}				{x: 24, y: 30, v: 2}

				{x: 19, y: 25, v: 0}

{x: 17, y: 21, v: 2}				{x: 24, y: 21, v: 2}

{x: 19, y: 25, v: 0}, {x: 17, y: 30, v: 2}, {x: 24, y: 30, v: 2}, {x: 24, y: 21, v: 2}, {x: 17, y: 21, v: 2}