1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
/**
* Created by cp on 2016/5/6.
*/
//#region 验证两个面是否相交的算法 polygon1LinearRings参数1多点,polygon2LinearRings多点
function intersectsMoth () {
var obj={};
// polygon1LinearRings : array[LinearRing,...]
function intersectsByPolygon (polygon1LinearRings, polygon2LinearRings) {
var intersect = false;
intersect = intersectsByLinearRings(polygon1LinearRings, polygon2LinearRings);
if(!intersect) {
// check if this poly contains points of the ring/linestring
for(i=0;i<polygon2LinearRings.length; i++) {
var point = polygon2LinearRings[i];
intersect = containsPointByLinearRing(point, polygon1LinearRings);
if(intersect) {
break;
}
}
}
//包含
if(!intersect){
// var b1=contentFunc(polygon1LinearRings, polygon2LinearRings);
var b2=contentFunc(polygon2LinearRings, polygon1LinearRings);
intersect=b2;
}
return intersect;
}
obj.intersectsByPolygon=intersectsByPolygon;
//判定包含方法 polygon1LinearRings, polygon2LinearRings多边形
function contentFunc(polygon1LinearRings,polygon2LinearRings){
var left1=180;
var right1=-180;
var top1=-90;
var btom1=90;
//获取边界
for( var i=0;i<polygon1LinearRings.length;i++){
var p1=polygon1LinearRings[i];
if(p1.x<left1){
left1=p1.x;
}
if(right1<p1.x){
right1=p1.x;
}
if(p1.y<btom1){
btom1=p1.y;
}
if(p1.y>top1){
top1=p1.y;
}
}
for(var j=0;j<polygon2LinearRings.length;j++){
var p2=polygon2LinearRings[j];
//包含
if(p2.x<=right1&&p2.x>=left1&&p2.y<=top1&&p2.y>=btom1){
}else{
return false;
}
}
return true;
}
obj.contentFunc=contentFunc;
// 点和面的相交关系
function containsPointByPolygon (point, LinearRings) {
var numRings = LinearRings.length;
var contained = false;
if(numRings > 0) {
contained = containsPointByLinearRing(point, LinearRings[0]);
if( numRings > 1) {
// check interior rings
var hole;
for(var i=1; i<LinearRings.length;i++) {
hole = containsPointByLinearRing(point, LinearRings[i]);
if(hole) {
if(hole === 1) {
// on edge
contained = 1;
} else {
// in hole
contained = false;
}
break;
}
}
}
}
return contained;
}
obj.containsPointByPolygon=containsPointByPolygon;
//
// 点和线的相交关系
function containsPointByLinearRing (point, LinearRing) {
//limitSigDigs
function approx(num, sig) {
var fig = 0;
if (sig > 0) {
fig = parseFloat(num.toPrecision(sig));
}
return fig;
}
var digs = 14;
var px = approx(point.x, digs);
var py = approx(point.y, digs);
function getX(y, x1, y1, x2, y2) {
return (y - y2) * ((x2 - x1) / (y2 - y1)) + x2;
}
var numSeg = LinearRing.length - 1;
var start, end, x1, y1, x2, y2, cx, cy;
var crosses = 0;
for(var i=0; i<LinearRing.length-1;i++) {
start = LinearRing[i];
x1 = approx(start.x, digs);
y1 = approx(start.y, digs);
end = LinearRing[i + 1];
x2 = approx(end.x, digs);
y2 = approx(end.y, digs);
if(y1 == y2) {
// horizontal edge
if(py == y1) {
// point on horizontal line
if(x1 <= x2 && (px >= x1 && px <= x2) || // right or vert
x1 >= x2 && (px <= x1 && px >= x2)) { // left or vert
// point on edge
crosses = -1;
break;
}
}
// ignore other horizontal edges
continue;
}
cx = approx(getX(py, x1, y1, x2, y2), digs);
if(cx == px) {
// point on line
if(y1 < y2 && (py >= y1 && py <= y2) || // upward
y1 > y2 && (py <= y1 && py >= y2)) { // downward
// point on edge
crosses = -1;
break;
}
}
if(cx <= px) {
// no crossing to the right
continue;
}
if(x1 != x2 && (cx < Math.min(x1, x2) || cx > Math.max(x1, x2))) {
// no crossing
continue;
}
if(y1 < y2 && (py >= y1 && py < y2) || // upward
y1 > y2 && (py < y1 && py >= y2)) { // downward
++crosses;
}
}
var contained = (crosses == -1) ?
// on edge
1 :
// even (out) or odd (in)
!!(crosses & 1);
return contained;
}
obj.containsPointByLinearRing=containsPointByLinearRing;
//两条线的相交关系
function intersectsByLinearRings (LinearRing1, LinearRings2) {
var intersect = false;
var segs1 = getSortedSegments(LinearRing1);
var segs2 = getSortedSegments(LinearRings2);
var seg1, seg1x1, seg1x2, seg1y1, seg1y2,
seg2, seg2y1, seg2y2;
// sweep right
outer: for(var i=0;i<segs1.length; i++) {
seg1 = segs1[i];
seg1x1 = seg1.x1;
seg1x2 = seg1.x2;
seg1y1 = seg1.y1;
seg1y2 = seg1.y2;
inner: for(var j=0; j<segs2.length; j++) {
seg2 = segs2[j];
if(seg2.x1 > seg1x2) {
// seg1 still left of seg2
break;
}
if(seg2.x2 < seg1x1) {
// seg2 still left of seg1
continue;
}
seg2y1 = seg2.y1;
seg2y2 = seg2.y2;
if(Math.min(seg2y1, seg2y2) > Math.max(seg1y1, seg1y2)) {
// seg2 above seg1
continue;
}
if(Math.max(seg2y1, seg2y2) < Math.min(seg1y1, seg1y2)) {
// seg2 below seg1
continue;
}
if(segmentsIntersect(seg1, seg2)) {
intersect = true;
break outer;
}
}
}
return intersect;
}
obj.intersectsByLinearRings=intersectsByLinearRings
//对点的排序
function getSortedSegments(points) {
var numSeg = points.length - 1;
var segments = new Array(numSeg), point1, point2;
for(var i=0; i<segments.length;i++) {
point1 = points[i];
point2 = points[i + 1];
if(point1.x < point2.x) {
segments[i] = {
x1: point1.x,
y1: point1.y,
x2: point2.x,
y2: point2.y
};
} else {
segments[i] = {
x1: point2.x,
y1: point2.y,
x2: point1.x,
y2: point1.y
};
}
}
// more efficient to define this somewhere static
function byX1(seg1, seg2) {
return seg1.x1 - seg2.x1;
}
return segments.sort(byX1);
}
obj.getSortedSegments=getSortedSegments;
//射线算法判断相交
function segmentsIntersect(seg1, seg2, options) {
var point = options && options.point;
var tolerance = options && options.tolerance;
var intersection = false;
var x11_21 = seg1.x1 - seg2.x1;
var y11_21 = seg1.y1 - seg2.y1;
var x12_11 = seg1.x2 - seg1.x1;
var y12_11 = seg1.y2 - seg1.y1;
var y22_21 = seg2.y2 - seg2.y1;
var x22_21 = seg2.x2 - seg2.x1;
var d = (y22_21 * x12_11) - (x22_21 * y12_11);
var n1 = (x22_21 * y11_21) - (y22_21 * x11_21);
var n2 = (x12_11 * y11_21) - (y12_11 * x11_21);
if(d == 0) {
// parallel
if(n1 == 0 && n2 == 0) {
// coincident
intersection = true;
}
} else {
var along1 = n1 / d;
var along2 = n2 / d;
if(along1 >= 0 && along1 <= 1 && along2 >=0 && along2 <= 1) {
// intersect
if(!point) {
intersection = true;
} else {
// calculate the intersection point
var x = seg1.x1 + (along1 * x12_11);
var y = seg1.y1 + (along1 * y12_11);
intersection = { 'x':x, 'y':y };
}
}
}
if(tolerance) {
var dist;
if(intersection) {
if(point) {
var segs = [seg1, seg2];
var seg, x, y;
// check segment endpoints for proximity to intersection
// set intersection to first endpoint within the tolerance
outer: for(var i=0; i<2; ++i) {
seg = segs[i];
for(var j=1; j<3; ++j) {
x = seg["x" + j];
y = seg["y" + j];
dist = Math.sqrt(
Math.pow(x - intersection.x, 2) +
Math.pow(y - intersection.y, 2)
);
if(dist < tolerance) {
intersection.x = x;
intersection.y = y;
break outer;
}
}
}
}
} else {
// no calculated intersection, but segments could be within
// the tolerance of one another
var segs = [seg1, seg2];
var source, target, x, y, p, result;
// check segment endpoints for proximity to intersection
// set intersection to first endpoint within the tolerance
outer: for(var i=0; i<2; ++i) {
source = segs[i];
target = segs[(i+1)%2];
for(var j=1; j<3; ++j) {
p = {x: source["x"+j], y: source["y"+j]};
result = distanceToSegment(p, target);
if(result.distance < tolerance) {
if(point) {
intersection = { 'x':p.x, 'y':p.y };
} else {
intersection = true;
}
break outer;
}
}
}
}
}
return intersection;
};
//距离判断
function distanceToSegment(point, segment) {
var result = distanceSquaredToSegment(point, segment);
result.distance = Math.sqrt(result.distance);
return result;
};
obj.distanceToSegment=distanceToSegment;
//距离判断
function distanceSquaredToSegment(point, segment) {
var x0 = point.x;
var y0 = point.y;
var x1 = segment.x1;
var y1 = segment.y1;
var x2 = segment.x2;
var y2 = segment.y2;
var dx = x2 - x1;
var dy = y2 - y1;
var along = ((dx * (x0 - x1)) + (dy * (y0 - y1))) /
(Math.pow(dx, 2) + Math.pow(dy, 2));
var x, y;
if(along <= 0.0) {
x = x1;
y = y1;
} else if(along >= 1.0) {
x = x2;
y = y2;
} else {
x = x1 + along * dx;
y = y1 + along * dy;
}
return {
distance: Math.pow(x - x0, 2) + Math.pow(y - y0, 2),
x: x, y: y,
along: along
};
}
//获取面的点数据
function getRings (polygon1) {
var cpts = polygon1.getGeometry().getCoordinates();
// .getCoordinates();
var ret=[];
for (var i = 0; i < cpts.length; i++) {
var linearRings = cpts[i];
for (var j = 0; j < linearRings.length; j++) {
var point = linearRings[j];
ret.push({x:point[0], y:point[1]});
};
};
return ret;
}
obj.getRings=getRings;
function clearPolygon () {
var features = map.layers[1].features;
for (var i = features.length - 1; i >= 0; i--) {
features[i].destroy();
};
}
obj.clearPolygon=clearPolygon;
return obj;
}
export {intersectsMoth}