package?srs.Geometry;

import?java.util.ArrayList;
import?java.util.List;

import?srs.Geometry.SpatialOp.Line;

public?class?Difference?{

	public?static?List?JoinRingPoints?=?new?ArrayList（）;
	static?double?EP=Math.pow（0.1?8）;
	static?double?p=0.0005;
	/**兩個多邊形求差P-Q
	?*?@param?polysP
	?*?@param?polysQ
	?*/
	public?static?IPolygon?DifferenceResault（List>?polysPList>?polysQ）{
		//將兩個多邊形左邊全部轉換成3D格式polysP3D和polysQ3D
		List>?polysP3D?=?new?ArrayList>（）;
		List>?polysQ3D?=?new?ArrayList>（）;
		List>?Lpolys?=?new?ArrayList>（）;
		IPolygon?polygon?=?new?Polygon（）;
		polysP3D?=?PolygonTo3D（polysP）;
		polysQ3D?=?PolygonTo3D（polysQ）;
		//求出兩個多邊形多個環的所有交點JoinRingPoints
		for（int?i=0;i			for（int?j=0;j				List?list?=?new?ArrayList（）;
				list?=?InterPoints（polysP3D.get（i）polysQ3D.get（j））;
				if（list.size（）?!=?0）{
					int?h=?list.size（）;					
					for（int?l=0;l						if（JoinRingPoints.size（）==0）{
							JoinRingPoints.add（list.get（l））;
						}
						else{
							for（int?k=0;k								if（SpatialOp.Point_Equal（JoinRingPoints.get（k）.Point（）?list.get（l）.Point（））==true）{
									JoinRingPoints.remove（list.get（l））;
									break;
								}								
							}
							JoinRingPoints.add（list.get（l））;
						}
					}
				}								
			}
		}
		if（JoinRingPoints.size（）>1）{
			//循環幾次就是幾個環			
			for（;JoinRingPoints.size（）>0;）{
				//遍歷所有交點
				int[]?a?=?new?int[4];//點在PQ中的位置
				double?b?;
				List?list?=?new?ArrayList（）;
				Lpolys.add（list）;
				list.add（JoinRingPoints.get（0））;
				a?=?LocationOnPQ（JoinRingPoints.get（0）polysP3DpolysQ3D）;
				Point3D?p?=polysP3D.get（a[0]）.get（a[2]-1）;
				Point3D?pp?=polysP3D.get（a[0]）.get（a[2]+1）;
				Point3D?q?=?polysQ3D.get（a[1]）.get（a[3]-1）;
				Point3D?qq?=?polysQ3D.get（a[1]）.get（a[3]+1）;
				b?=?getAngle（ppqqpq）;
				JoinRingPoints.remove（0）;
				if（b<=180）{
					list.add（polysQ3D.get（a[1]）.get（a[3]+1））;
					JoinRingPoints.remove（polysQ3D.get（a[1]）.get（a[3]+1））;
				}
				else?if（b>180）
				{
					list.add（polysP3D.get（a[0]）.get（a[2]+1））;
					JoinRingPoints.remove（polysP3D.get（a[0]）.get（a[2]+1））;
				}
				for（;list.get（0）!=list.get（list.size（）-1）;）//不是出發點
				{
					//list里最后一個點y
					Point3D?y?=?list.get（list.size（）-1）;
					if（y.Z（）==1）//是交點
					{			????					????				????			
						int[]?aa?=?new?int[4];
						double?bb;
						aa?=?LocationOnPQ（ypolysP3DpolysQ3D）;
						bb?=?getAngle（polysP3D.get（aa[0]）.get（aa[2]+1）polysQ3D.get（aa[1]）.get（aa[3]+1）polysP3D.get（aa[0]）.get（aa[2]-1）polysQ3D.get（aa[1]）.get（aa[3]-1））;
						if（bb<=180）
						{
							list.add（polysQ3D.get（aa[1]）.get（aa[3]+1））;
							JoinRingPoints.remove（y）;
							JoinRingPoints.remove（polysQ3D.get（aa[1]）.get（aa[3]+1））;
							if（