/
line_bucket.ts
592 lines (495 loc) · 25.6 KB
/
line_bucket.ts
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
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
import {LineLayoutArray, LineExtLayoutArray} from '../array_types.g';
import {members as layoutAttributes} from './line_attributes';
import {members as layoutAttributesExt} from './line_attributes_ext';
import {SegmentVector} from '../segment';
import {ProgramConfigurationSet} from '../program_configuration';
import {TriangleIndexArray} from '../index_array_type';
import {EXTENT} from '../extent';
import mvt from '@mapbox/vector-tile';
const vectorTileFeatureTypes = mvt.VectorTileFeature.types;
import {register} from '../../util/web_worker_transfer';
import {hasPattern, addPatternDependencies} from './pattern_bucket_features';
import {loadGeometry} from '../load_geometry';
import {toEvaluationFeature} from '../evaluation_feature';
import {EvaluationParameters} from '../../style/evaluation_parameters';
import type {CanonicalTileID} from '../../source/tile_id';
import type {
Bucket,
BucketParameters,
BucketFeature,
IndexedFeature,
PopulateParameters
} from '../bucket';
import type {LineStyleLayer} from '../../style/style_layer/line_style_layer';
import type Point from '@mapbox/point-geometry';
import type {Segment} from '../segment';
import {RGBAImage} from '../../util/image';
import type {Context} from '../../gl/context';
import type {Texture} from '../../render/texture';
import type {IndexBuffer} from '../../gl/index_buffer';
import type {VertexBuffer} from '../../gl/vertex_buffer';
import type {FeatureStates} from '../../source/source_state';
import type {ImagePosition} from '../../render/image_atlas';
import type {VectorTileLayer} from '@mapbox/vector-tile';
// NOTE ON EXTRUDE SCALE:
// scale the extrusion vector so that the normal length is this value.
// contains the "texture" normals (-1..1). this is distinct from the extrude
// normals for line joins, because the x-value remains 0 for the texture
// normal array, while the extrude normal actually moves the vertex to create
// the acute/bevelled line join.
const EXTRUDE_SCALE = 63;
/*
* Sharp corners cause dashed lines to tilt because the distance along the line
* is the same at both the inner and outer corners. To improve the appearance of
* dashed lines we add extra points near sharp corners so that a smaller part
* of the line is tilted.
*
* COS_HALF_SHARP_CORNER controls how sharp a corner has to be for us to add an
* extra vertex. The default is 75 degrees.
*
* The newly created vertices are placed SHARP_CORNER_OFFSET pixels from the corner.
*/
const COS_HALF_SHARP_CORNER = Math.cos(75 / 2 * (Math.PI / 180));
const SHARP_CORNER_OFFSET = 15;
// Angle per triangle for approximating round line joins.
const DEG_PER_TRIANGLE = 20;
// The number of bits that is used to store the line distance in the buffer.
const LINE_DISTANCE_BUFFER_BITS = 15;
// We don't have enough bits for the line distance as we'd like to have, so
// use this value to scale the line distance (in tile units) down to a smaller
// value. This lets us store longer distances while sacrificing precision.
const LINE_DISTANCE_SCALE = 1 / 2;
// The maximum line distance, in tile units, that fits in the buffer.
const MAX_LINE_DISTANCE = Math.pow(2, LINE_DISTANCE_BUFFER_BITS - 1) / LINE_DISTANCE_SCALE;
type LineClips = {
start: number;
end: number;
};
type GradientTexture = {
texture?: Texture;
gradient?: RGBAImage;
version?: number;
};
/**
* @internal
* Line bucket class
*/
export class LineBucket implements Bucket {
distance: number;
totalDistance: number;
maxLineLength: number;
scaledDistance: number;
lineClips?: LineClips;
e1: number;
e2: number;
index: number;
zoom: number;
overscaling: number;
layers: Array<LineStyleLayer>;
layerIds: Array<string>;
gradients: {[x: string]: GradientTexture};
stateDependentLayers: Array<any>;
stateDependentLayerIds: Array<string>;
patternFeatures: Array<BucketFeature>;
lineClipsArray: Array<LineClips>;
layoutVertexArray: LineLayoutArray;
layoutVertexBuffer: VertexBuffer;
layoutVertexArray2: LineExtLayoutArray;
layoutVertexBuffer2: VertexBuffer;
indexArray: TriangleIndexArray;
indexBuffer: IndexBuffer;
hasPattern: boolean;
programConfigurations: ProgramConfigurationSet<LineStyleLayer>;
segments: SegmentVector;
uploaded: boolean;
constructor(options: BucketParameters<LineStyleLayer>) {
this.zoom = options.zoom;
this.overscaling = options.overscaling;
this.layers = options.layers;
this.layerIds = this.layers.map(layer => layer.id);
this.index = options.index;
this.hasPattern = false;
this.patternFeatures = [];
this.lineClipsArray = [];
this.gradients = {};
this.layers.forEach(layer => {
this.gradients[layer.id] = {};
});
this.layoutVertexArray = new LineLayoutArray();
this.layoutVertexArray2 = new LineExtLayoutArray();
this.indexArray = new TriangleIndexArray();
this.programConfigurations = new ProgramConfigurationSet(options.layers, options.zoom);
this.segments = new SegmentVector();
this.maxLineLength = 0;
this.stateDependentLayerIds = this.layers.filter((l) => l.isStateDependent()).map((l) => l.id);
}
populate(features: Array<IndexedFeature>, options: PopulateParameters, canonical: CanonicalTileID) {
this.hasPattern = hasPattern('line', this.layers, options);
const lineSortKey = this.layers[0].layout.get('line-sort-key');
const sortFeaturesByKey = !lineSortKey.isConstant();
const bucketFeatures: BucketFeature[] = [];
for (const {feature, id, index, sourceLayerIndex} of features) {
const needGeometry = this.layers[0]._featureFilter.needGeometry;
const evaluationFeature = toEvaluationFeature(feature, needGeometry);
if (!this.layers[0]._featureFilter.filter(new EvaluationParameters(this.zoom), evaluationFeature, canonical)) continue;
const sortKey = sortFeaturesByKey ?
lineSortKey.evaluate(evaluationFeature, {}, canonical) :
undefined;
const bucketFeature: BucketFeature = {
id,
properties: feature.properties,
type: feature.type,
sourceLayerIndex,
index,
geometry: needGeometry ? evaluationFeature.geometry : loadGeometry(feature),
patterns: {},
sortKey
};
bucketFeatures.push(bucketFeature);
}
if (sortFeaturesByKey) {
bucketFeatures.sort((a, b) => {
return (a.sortKey) - (b.sortKey);
});
}
for (const bucketFeature of bucketFeatures) {
const {geometry, index, sourceLayerIndex} = bucketFeature;
if (this.hasPattern) {
const patternBucketFeature = addPatternDependencies('line', this.layers, bucketFeature, this.zoom, options);
// pattern features are added only once the pattern is loaded into the image atlas
// so are stored during populate until later updated with positions by tile worker in addFeatures
this.patternFeatures.push(patternBucketFeature);
} else {
this.addFeature(bucketFeature, geometry, index, canonical, {});
}
const feature = features[index].feature;
options.featureIndex.insert(feature, geometry, index, sourceLayerIndex, this.index);
}
}
update(states: FeatureStates, vtLayer: VectorTileLayer, imagePositions: {[_: string]: ImagePosition}) {
if (!this.stateDependentLayers.length) return;
this.programConfigurations.updatePaintArrays(states, vtLayer, this.stateDependentLayers, imagePositions);
}
addFeatures(options: PopulateParameters, canonical: CanonicalTileID, imagePositions: {[_: string]: ImagePosition}) {
for (const feature of this.patternFeatures) {
this.addFeature(feature, feature.geometry, feature.index, canonical, imagePositions);
}
}
isEmpty() {
return this.layoutVertexArray.length === 0;
}
uploadPending() {
return !this.uploaded || this.programConfigurations.needsUpload;
}
upload(context: Context) {
if (!this.uploaded) {
if (this.layoutVertexArray2.length !== 0) {
this.layoutVertexBuffer2 = context.createVertexBuffer(this.layoutVertexArray2, layoutAttributesExt);
}
this.layoutVertexBuffer = context.createVertexBuffer(this.layoutVertexArray, layoutAttributes);
this.indexBuffer = context.createIndexBuffer(this.indexArray);
}
this.programConfigurations.upload(context);
this.uploaded = true;
}
destroy() {
if (!this.layoutVertexBuffer) return;
this.layoutVertexBuffer.destroy();
this.indexBuffer.destroy();
this.programConfigurations.destroy();
this.segments.destroy();
}
lineFeatureClips(feature: BucketFeature): LineClips | undefined {
if (!!feature.properties && Object.prototype.hasOwnProperty.call(feature.properties, 'mapbox_clip_start') && Object.prototype.hasOwnProperty.call(feature.properties, 'mapbox_clip_end')) {
const start = +feature.properties['mapbox_clip_start'];
const end = +feature.properties['mapbox_clip_end'];
return {start, end};
}
}
addFeature(feature: BucketFeature, geometry: Array<Array<Point>>, index: number, canonical: CanonicalTileID, imagePositions: {[_: string]: ImagePosition}) {
const layout = this.layers[0].layout;
const join = layout.get('line-join').evaluate(feature, {});
const cap = layout.get('line-cap');
const miterLimit = layout.get('line-miter-limit');
const roundLimit = layout.get('line-round-limit');
this.lineClips = this.lineFeatureClips(feature);
for (const line of geometry) {
this.addLine(line, feature, join, cap, miterLimit, roundLimit);
}
this.programConfigurations.populatePaintArrays(this.layoutVertexArray.length, feature, index, imagePositions, canonical);
}
addLine(vertices: Array<Point>, feature: BucketFeature, join: string, cap: string, miterLimit: number, roundLimit: number) {
this.distance = 0;
this.scaledDistance = 0;
this.totalDistance = 0;
if (this.lineClips) {
this.lineClipsArray.push(this.lineClips);
// Calculate the total distance, in tile units, of this tiled line feature
for (let i = 0; i < vertices.length - 1; i++) {
this.totalDistance += vertices[i].dist(vertices[i + 1]);
}
this.updateScaledDistance();
this.maxLineLength = Math.max(this.maxLineLength, this.totalDistance);
}
const isPolygon = vectorTileFeatureTypes[feature.type] === 'Polygon';
// If the line has duplicate vertices at the ends, adjust start/length to remove them.
let len = vertices.length;
while (len >= 2 && vertices[len - 1].equals(vertices[len - 2])) {
len--;
}
let first = 0;
while (first < len - 1 && vertices[first].equals(vertices[first + 1])) {
first++;
}
// Ignore invalid geometry.
if (len < (isPolygon ? 3 : 2)) return;
if (join === 'bevel') miterLimit = 1.05;
const sharpCornerOffset = this.overscaling <= 16 ?
SHARP_CORNER_OFFSET * EXTENT / (512 * this.overscaling) :
0;
// we could be more precise, but it would only save a negligible amount of space
const segment = this.segments.prepareSegment(len * 10, this.layoutVertexArray, this.indexArray);
let currentVertex: Point;
let prevVertex: Point;
let nextVertex: Point;
let prevNormal: Point;
let nextNormal: Point;
// the last two vertices added
this.e1 = this.e2 = -1;
if (isPolygon) {
currentVertex = vertices[len - 2];
nextNormal = vertices[first].sub(currentVertex)._unit()._perp();
}
for (let i = first; i < len; i++) {
nextVertex = i === len - 1 ?
(isPolygon ? vertices[first + 1] : undefined) : // if it's a polygon, treat the last vertex like the first
vertices[i + 1]; // just the next vertex
// if two consecutive vertices exist, skip the current one
if (nextVertex && vertices[i].equals(nextVertex)) continue;
if (nextNormal) prevNormal = nextNormal;
if (currentVertex) prevVertex = currentVertex;
currentVertex = vertices[i];
// Calculate the normal towards the next vertex in this line. In case
// there is no next vertex, pretend that the line is continuing straight,
// meaning that we are just using the previous normal.
nextNormal = nextVertex ? nextVertex.sub(currentVertex)._unit()._perp() : prevNormal;
// If we still don't have a previous normal, this is the beginning of a
// non-closed line, so we're doing a straight "join".
prevNormal = prevNormal || nextNormal;
// Determine the normal of the join extrusion. It is the angle bisector
// of the segments between the previous line and the next line.
// In the case of 180° angles, the prev and next normals cancel each other out:
// prevNormal + nextNormal = (0, 0), its magnitude is 0, so the unit vector would be
// undefined. In that case, we're keeping the joinNormal at (0, 0), so that the cosHalfAngle
// below will also become 0 and miterLength will become Infinity.
let joinNormal = prevNormal.add(nextNormal);
if (joinNormal.x !== 0 || joinNormal.y !== 0) {
joinNormal._unit();
}
/* joinNormal prevNormal
* ↖ ↑
* .________. prevVertex
* |
* nextNormal ← | currentVertex
* |
* nextVertex !
*
*/
// calculate cosines of the angle (and its half) using dot product
const cosAngle = prevNormal.x * nextNormal.x + prevNormal.y * nextNormal.y;
const cosHalfAngle = joinNormal.x * nextNormal.x + joinNormal.y * nextNormal.y;
// Calculate the length of the miter (the ratio of the miter to the width)
// as the inverse of cosine of the angle between next and join normals
const miterLength = cosHalfAngle !== 0 ? 1 / cosHalfAngle : Infinity;
// approximate angle from cosine
const approxAngle = 2 * Math.sqrt(2 - 2 * cosHalfAngle);
const isSharpCorner = cosHalfAngle < COS_HALF_SHARP_CORNER && prevVertex && nextVertex;
const lineTurnsLeft = prevNormal.x * nextNormal.y - prevNormal.y * nextNormal.x > 0;
if (isSharpCorner && i > first) {
const prevSegmentLength = currentVertex.dist(prevVertex);
if (prevSegmentLength > 2 * sharpCornerOffset) {
const newPrevVertex = currentVertex.sub(currentVertex.sub(prevVertex)._mult(sharpCornerOffset / prevSegmentLength)._round());
this.updateDistance(prevVertex, newPrevVertex);
this.addCurrentVertex(newPrevVertex, prevNormal, 0, 0, segment);
prevVertex = newPrevVertex;
}
}
// The join if a middle vertex, otherwise the cap.
const middleVertex = prevVertex && nextVertex;
let currentJoin = middleVertex ? join : isPolygon ? 'butt' : cap;
if (middleVertex && currentJoin === 'round') {
if (miterLength < roundLimit) {
currentJoin = 'miter';
} else if (miterLength <= 2) {
currentJoin = 'fakeround';
}
}
if (currentJoin === 'miter' && miterLength > miterLimit) {
currentJoin = 'bevel';
}
if (currentJoin === 'bevel') {
// The maximum extrude length is 128 / 63 = 2 times the width of the line
// so if miterLength >= 2 we need to draw a different type of bevel here.
if (miterLength > 2) currentJoin = 'flipbevel';
// If the miterLength is really small and the line bevel wouldn't be visible,
// just draw a miter join to save a triangle.
if (miterLength < miterLimit) currentJoin = 'miter';
}
// Calculate how far along the line the currentVertex is
if (prevVertex) this.updateDistance(prevVertex, currentVertex);
if (currentJoin === 'miter') {
joinNormal._mult(miterLength);
this.addCurrentVertex(currentVertex, joinNormal, 0, 0, segment);
} else if (currentJoin === 'flipbevel') {
// miter is too big, flip the direction to make a beveled join
if (miterLength > 100) {
// Almost parallel lines
joinNormal = nextNormal.mult(-1);
} else {
const bevelLength = miterLength * prevNormal.add(nextNormal).mag() / prevNormal.sub(nextNormal).mag();
joinNormal._perp()._mult(bevelLength * (lineTurnsLeft ? -1 : 1));
}
this.addCurrentVertex(currentVertex, joinNormal, 0, 0, segment);
this.addCurrentVertex(currentVertex, joinNormal.mult(-1), 0, 0, segment);
} else if (currentJoin === 'bevel' || currentJoin === 'fakeround') {
const offset = -Math.sqrt(miterLength * miterLength - 1);
const offsetA = lineTurnsLeft ? offset : 0;
const offsetB = lineTurnsLeft ? 0 : offset;
// Close previous segment with a bevel
if (prevVertex) {
this.addCurrentVertex(currentVertex, prevNormal, offsetA, offsetB, segment);
}
if (currentJoin === 'fakeround') {
// The join angle is sharp enough that a round join would be visible.
// Bevel joins fill the gap between segments with a single pie slice triangle.
// Create a round join by adding multiple pie slices. The join isn't actually round, but
// it looks like it is at the sizes we render lines at.
// pick the number of triangles for approximating round join by based on the angle between normals
const n = Math.round((approxAngle * 180 / Math.PI) / DEG_PER_TRIANGLE);
for (let m = 1; m < n; m++) {
let t = m / n;
if (t !== 0.5) {
// approximate spherical interpolation https://observablehq.com/@mourner/approximating-geometric-slerp
const t2 = t - 0.5;
const A = 1.0904 + cosAngle * (-3.2452 + cosAngle * (3.55645 - cosAngle * 1.43519));
const B = 0.848013 + cosAngle * (-1.06021 + cosAngle * 0.215638);
t = t + t * t2 * (t - 1) * (A * t2 * t2 + B);
}
const extrude = nextNormal.sub(prevNormal)._mult(t)._add(prevNormal)._unit()._mult(lineTurnsLeft ? -1 : 1);
this.addHalfVertex(currentVertex, extrude.x, extrude.y, false, lineTurnsLeft, 0, segment);
}
}
if (nextVertex) {
// Start next segment
this.addCurrentVertex(currentVertex, nextNormal, -offsetA, -offsetB, segment);
}
} else if (currentJoin === 'butt') {
this.addCurrentVertex(currentVertex, joinNormal, 0, 0, segment); // butt cap
} else if (currentJoin === 'square') {
const offset = prevVertex ? 1 : -1; // closing or starting square cap
this.addCurrentVertex(currentVertex, joinNormal, offset, offset, segment);
} else if (currentJoin === 'round') {
if (prevVertex) {
// Close previous segment with butt
this.addCurrentVertex(currentVertex, prevNormal, 0, 0, segment);
// Add round cap or linejoin at end of segment
this.addCurrentVertex(currentVertex, prevNormal, 1, 1, segment, true);
}
if (nextVertex) {
// Add round cap before first segment
this.addCurrentVertex(currentVertex, nextNormal, -1, -1, segment, true);
// Start next segment with a butt
this.addCurrentVertex(currentVertex, nextNormal, 0, 0, segment);
}
}
if (isSharpCorner && i < len - 1) {
const nextSegmentLength = currentVertex.dist(nextVertex);
if (nextSegmentLength > 2 * sharpCornerOffset) {
const newCurrentVertex = currentVertex.add(nextVertex.sub(currentVertex)._mult(sharpCornerOffset / nextSegmentLength)._round());
this.updateDistance(currentVertex, newCurrentVertex);
this.addCurrentVertex(newCurrentVertex, nextNormal, 0, 0, segment);
currentVertex = newCurrentVertex;
}
}
}
}
/**
* Add two vertices to the buffers.
*
* @param p - the line vertex to add buffer vertices for
* @param normal - vertex normal
* @param endLeft - extrude to shift the left vertex along the line
* @param endRight - extrude to shift the left vertex along the line
* @param segment - the segment object to add the vertex to
* @param round - whether this is a round cap
*/
addCurrentVertex(p: Point, normal: Point, endLeft: number, endRight: number, segment: Segment, round: boolean = false) {
// left and right extrude vectors, perpendicularly shifted by endLeft/endRight
const leftX = normal.x + normal.y * endLeft;
const leftY = normal.y - normal.x * endLeft;
const rightX = -normal.x + normal.y * endRight;
const rightY = -normal.y - normal.x * endRight;
this.addHalfVertex(p, leftX, leftY, round, false, endLeft, segment);
this.addHalfVertex(p, rightX, rightY, round, true, -endRight, segment);
// There is a maximum "distance along the line" that we can store in the buffers.
// When we get close to the distance, reset it to zero and add the vertex again with
// a distance of zero. The max distance is determined by the number of bits we allocate
// to `linesofar`.
if (this.distance > MAX_LINE_DISTANCE / 2 && this.totalDistance === 0) {
this.distance = 0;
this.updateScaledDistance();
this.addCurrentVertex(p, normal, endLeft, endRight, segment, round);
}
}
addHalfVertex({x, y}: Point, extrudeX: number, extrudeY: number, round: boolean, up: boolean, dir: number, segment: Segment) {
const totalDistance = this.lineClips ? this.scaledDistance * (MAX_LINE_DISTANCE - 1) : this.scaledDistance;
// scale down so that we can store longer distances while sacrificing precision.
const linesofarScaled = totalDistance * LINE_DISTANCE_SCALE;
this.layoutVertexArray.emplaceBack(
// a_pos_normal
// Encode round/up the least significant bits
(x << 1) + (round ? 1 : 0),
(y << 1) + (up ? 1 : 0),
// a_data
// add 128 to store a byte in an unsigned byte
Math.round(EXTRUDE_SCALE * extrudeX) + 128,
Math.round(EXTRUDE_SCALE * extrudeY) + 128,
// Encode the -1/0/1 direction value into the first two bits of .z of a_data.
// Combine it with the lower 6 bits of `linesofarScaled` (shifted by 2 bits to make
// room for the direction value). The upper 8 bits of `linesofarScaled` are placed in
// the `w` component.
((dir === 0 ? 0 : (dir < 0 ? -1 : 1)) + 1) | ((linesofarScaled & 0x3F) << 2),
linesofarScaled >> 6);
// Constructs a second vertex buffer with higher precision line progress
if (this.lineClips) {
const progressRealigned = this.scaledDistance - this.lineClips.start;
const endClipRealigned = this.lineClips.end - this.lineClips.start;
const uvX = progressRealigned / endClipRealigned;
this.layoutVertexArray2.emplaceBack(uvX, this.lineClipsArray.length);
}
const e = segment.vertexLength++;
if (this.e1 >= 0 && this.e2 >= 0) {
this.indexArray.emplaceBack(this.e1, this.e2, e);
segment.primitiveLength++;
}
if (up) {
this.e2 = e;
} else {
this.e1 = e;
}
}
updateScaledDistance() {
// Knowing the ratio of the full linestring covered by this tiled feature, as well
// as the total distance (in tile units) of this tiled feature, and the distance
// (in tile units) of the current vertex, we can determine the relative distance
// of this vertex along the full linestring feature and scale it to [0, 2^15)
this.scaledDistance = this.lineClips ?
this.lineClips.start + (this.lineClips.end - this.lineClips.start) * this.distance / this.totalDistance :
this.distance;
}
updateDistance(prev: Point, next: Point) {
this.distance += prev.dist(next);
this.updateScaledDistance();
}
}
register('LineBucket', LineBucket, {omit: ['layers', 'patternFeatures']});