/
transform.js
2130 lines (1795 loc) · 89 KB
/
transform.js
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
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// @flow
import LngLat from './lng_lat.js';
import LngLatBounds from './lng_lat_bounds.js';
import MercatorCoordinate, {mercatorXfromLng, mercatorYfromLat, mercatorZfromAltitude, latFromMercatorY, MAX_MERCATOR_LATITUDE, circumferenceAtLatitude} from './mercator_coordinate.js';
import {getProjection} from './projection/index.js';
import {tileAABB} from '../geo/projection/tile_transform.js';
import Point from '@mapbox/point-geometry';
import {wrap, clamp, pick, radToDeg, degToRad, getAABBPointSquareDist, furthestTileCorner, warnOnce, deepEqual} from '../util/util.js';
import {number as interpolate} from '../style-spec/util/interpolate.js';
import EXTENT from '../data/extent.js';
import {vec4, mat4, mat2, vec3, quat} from 'gl-matrix';
import {Frustum, FrustumCorners, Ray} from '../util/primitives.js';
import EdgeInsets from './edge_insets.js';
import {FreeCamera, FreeCameraOptions, orientationFromFrame} from '../ui/free_camera.js';
import assert from 'assert';
import getProjectionAdjustments, {getProjectionAdjustmentInverted, getScaleAdjustment, getProjectionInterpolationT} from './projection/adjustments.js';
import {getPixelsToTileUnitsMatrix} from '../source/pixels_to_tile_units.js';
import {UnwrappedTileID, OverscaledTileID, CanonicalTileID} from '../source/tile_id.js';
import {calculateGlobeMatrix, GLOBE_ZOOM_THRESHOLD_MIN, GLOBE_SCALE_MATCH_LATITUDE} from '../geo/projection/globe_util.js';
import {projectClamped} from '../symbol/projection.js';
import type Projection from '../geo/projection/projection.js';
import type {Elevation} from '../terrain/elevation.js';
import type {PaddingOptions} from './edge_insets.js';
import type Tile from '../source/tile.js';
import type {ProjectionSpecification} from '../style-spec/types.js';
import type {FeatureDistanceData} from '../style-spec/feature_filter/index.js';
import type {Mat4, Vec3, Vec4, Quat} from 'gl-matrix';
const NUM_WORLD_COPIES = 3;
const DEFAULT_MIN_ZOOM = 0;
type RayIntersectionResult = { p0: Vec4, p1: Vec4, t: number};
type ElevationReference = "sea" | "ground";
/**
* A single transform, generally used for a single tile to be
* scaled, rotated, and zoomed.
* @private
*/
class Transform {
tileSize: number;
tileZoom: number;
maxBounds: ?LngLatBounds;
// 2^zoom (worldSize = tileSize * scale)
scale: number;
// Map viewport size (not including the pixel ratio)
width: number;
height: number;
// Bearing, radians, in [-pi, pi]
angle: number;
// 2D rotation matrix in the horizontal plane, as a function of bearing
rotationMatrix: Float32Array;
// Zoom, modulo 1
zoomFraction: number;
// The scale factor component of the conversion from pixels ([0, w] x [h, 0]) to GL
// NDC ([1, -1] x [1, -1]) (note flipped y)
pixelsToGLUnits: [number, number];
// Distance from camera to the center, in screen pixel units, independent of zoom
cameraToCenterDistance: number;
// Projection from mercator coordinates ([0, 0] nw, [1, 1] se) to GL clip coordinates
mercatorMatrix: Array<number>;
// Translate points in mercator coordinates to be centered about the camera, with units chosen
// for screen-height-independent scaling of fog. Not affected by orientation of camera.
mercatorFogMatrix: Float32Array;
// Projection from world coordinates (mercator scaled by worldSize) to clip coordinates
projMatrix: Array<number>;
invProjMatrix: Float64Array;
// Same as projMatrix, pixel-aligned to avoid fractional pixels for raster tiles
alignedProjMatrix: Float64Array;
// From world coordinates to screen pixel coordinates (projMatrix premultiplied by labelPlaneMatrix)
pixelMatrix: Float64Array;
pixelMatrixInverse: Float64Array;
worldToFogMatrix: Float64Array;
skyboxMatrix: Float32Array;
// Transform from screen coordinates to GL NDC, [0, w] x [h, 0] --> [-1, 1] x [-1, 1]
// Roughly speaking, applies pixelsToGLUnits scaling with a translation
glCoordMatrix: Float32Array;
// Inverse of glCoordMatrix, from NDC to screen coordinates, [-1, 1] x [-1, 1] --> [0, w] x [h, 0]
labelPlaneMatrix: Float32Array;
// globe coordinate transformation matrix
globeMatrix: Float64Array;
globeCenterInViewSpace: [number, number, number];
globeRadius: number;
inverseAdjustmentMatrix: Array<number>;
mercatorFromTransition: boolean;
minLng: number;
maxLng: number;
minLat: number;
maxLat: number;
worldMinX: number;
worldMaxX: number;
worldMinY: number;
worldMaxY: number;
frustumCorners: FrustumCorners;
freezeTileCoverage: boolean;
cameraElevationReference: ElevationReference;
fogCullDistSq: ?number;
_averageElevation: number;
projectionOptions: ProjectionSpecification;
projection: Projection;
_elevation: ?Elevation;
_fov: number;
_pitch: number;
_zoom: number;
_seaLevelZoom: ?number;
_unmodified: boolean;
_renderWorldCopies: boolean;
_minZoom: number;
_maxZoom: number;
_minPitch: number;
_maxPitch: number;
_center: LngLat;
_edgeInsets: EdgeInsets;
_constraining: boolean;
_projMatrixCache: {[_: number]: Float32Array};
_alignedProjMatrixCache: {[_: number]: Float32Array};
_pixelsToTileUnitsCache: {[_: number]: Float32Array};
_fogTileMatrixCache: {[_: number]: Float32Array};
_distanceTileDataCache: {[_: number]: FeatureDistanceData};
_camera: FreeCamera;
_centerAltitude: number;
_centerAltitudeValidForExaggeration: ?number;
_horizonShift: number;
_pixelsPerMercatorPixel: number;
_nearZ: number;
_farZ: number;
_mercatorScaleRatio: number;
constructor(minZoom: ?number, maxZoom: ?number, minPitch: ?number, maxPitch: ?number, renderWorldCopies: boolean | void, projection?: ?ProjectionSpecification, bounds: ?LngLatBounds) {
this.tileSize = 512; // constant
this._renderWorldCopies = renderWorldCopies === undefined ? true : renderWorldCopies;
this._minZoom = minZoom || DEFAULT_MIN_ZOOM;
this._maxZoom = maxZoom || 22;
this._minPitch = (minPitch === undefined || minPitch === null) ? 0 : minPitch;
this._maxPitch = (maxPitch === undefined || maxPitch === null) ? 60 : maxPitch;
this.setProjection(projection);
this.setMaxBounds(bounds);
this.width = 0;
this.height = 0;
this._center = new LngLat(0, 0);
this.zoom = 0;
this.angle = 0;
this._fov = 0.6435011087932844;
this._pitch = 0;
this._nearZ = 0;
this._farZ = 0;
this._unmodified = true;
this._edgeInsets = new EdgeInsets();
this._projMatrixCache = {};
this._alignedProjMatrixCache = {};
this._fogTileMatrixCache = {};
this._distanceTileDataCache = {};
this._camera = new FreeCamera();
this._centerAltitude = 0;
this._averageElevation = 0;
this.cameraElevationReference = "ground";
this._pixelsPerMercatorPixel = 1.0;
this.globeRadius = 0;
this.globeCenterInViewSpace = [0, 0, 0];
// Move the horizon closer to the center. 0 would not shift the horizon. 1 would put the horizon at the center.
this._horizonShift = 0.1;
}
clone(): Transform {
const clone = new Transform(this._minZoom, this._maxZoom, this._minPitch, this.maxPitch, this._renderWorldCopies, this.getProjection());
clone._elevation = this._elevation;
clone._centerAltitude = this._centerAltitude;
clone._centerAltitudeValidForExaggeration = this._centerAltitudeValidForExaggeration;
clone.tileSize = this.tileSize;
clone.mercatorFromTransition = this.mercatorFromTransition;
clone.width = this.width;
clone.height = this.height;
clone.cameraElevationReference = this.cameraElevationReference;
clone._center = this._center;
clone._setZoom(this.zoom);
clone._seaLevelZoom = this._seaLevelZoom;
clone.angle = this.angle;
clone._fov = this._fov;
clone._pitch = this._pitch;
clone._nearZ = this._nearZ;
clone._farZ = this._farZ;
clone._averageElevation = this._averageElevation;
clone._unmodified = this._unmodified;
clone._edgeInsets = this._edgeInsets.clone();
clone._camera = this._camera.clone();
clone._calcMatrices();
clone.freezeTileCoverage = this.freezeTileCoverage;
clone.frustumCorners = this.frustumCorners;
return clone;
}
get elevation(): ?Elevation { return this._elevation; }
set elevation(elevation: ?Elevation) {
if (this._elevation === elevation) return;
this._elevation = elevation;
this._updateCameraOnTerrain();
this._calcMatrices();
}
updateElevation(constrainCameraOverTerrain: boolean) { // On render, no need for higher granularity on update reasons.
const centerAltitudeChanged = this._elevation && this._elevation.exaggeration() !== this._centerAltitudeValidForExaggeration;
if (this._seaLevelZoom == null || centerAltitudeChanged) {
this._updateCameraOnTerrain();
}
if (constrainCameraOverTerrain || centerAltitudeChanged) {
this._constrainCameraAltitude();
}
this._calcMatrices();
}
getProjection(): ProjectionSpecification {
return (pick(this.projection, ['name', 'center', 'parallels']): ProjectionSpecification);
}
// Returns whether the projection changes
setProjection(projection?: ?ProjectionSpecification): boolean {
this.projectionOptions = projection || {name: 'mercator'};
const oldProjection = this.projection ? this.getProjection() : undefined;
this.projection = getProjection(this.projectionOptions);
const newProjection = this.getProjection();
const projectionHasChanged = !deepEqual(oldProjection, newProjection);
if (projectionHasChanged) {
this._calcMatrices();
}
this.mercatorFromTransition = false;
return projectionHasChanged;
}
setMercatorFromTransition(): boolean {
const oldProjection = this.projection.name;
this.mercatorFromTransition = true;
this.projectionOptions = {name: 'mercator'};
this.projection = getProjection({name: 'mercator'});
const projectionHasChanged = oldProjection !== this.projection.name;
if (projectionHasChanged) {
this._calcMatrices();
}
return projectionHasChanged;
}
get minZoom(): number { return this._minZoom; }
set minZoom(zoom: number) {
if (this._minZoom === zoom) return;
this._minZoom = zoom;
this.zoom = Math.max(this.zoom, zoom);
}
get maxZoom(): number { return this._maxZoom; }
set maxZoom(zoom: number) {
if (this._maxZoom === zoom) return;
this._maxZoom = zoom;
this.zoom = Math.min(this.zoom, zoom);
}
get minPitch(): number { return this._minPitch; }
set minPitch(pitch: number) {
if (this._minPitch === pitch) return;
this._minPitch = pitch;
this.pitch = Math.max(this.pitch, pitch);
}
get maxPitch(): number { return this._maxPitch; }
set maxPitch(pitch: number) {
if (this._maxPitch === pitch) return;
this._maxPitch = pitch;
this.pitch = Math.min(this.pitch, pitch);
}
get renderWorldCopies(): boolean {
return this._renderWorldCopies && this.projection.supportsWorldCopies === true;
}
set renderWorldCopies(renderWorldCopies?: ?boolean) {
if (renderWorldCopies === undefined) {
renderWorldCopies = true;
} else if (renderWorldCopies === null) {
renderWorldCopies = false;
}
this._renderWorldCopies = renderWorldCopies;
}
get worldSize(): number {
return this.tileSize * this.scale;
}
get cameraWorldSize(): number {
const distance = Math.max(this._camera.getDistanceToElevation(this._averageElevation), Number.EPSILON);
return this._worldSizeFromZoom(this._zoomFromMercatorZ(distance));
}
// `pixelsPerMeter` is used to describe relation between real world and pixel distances.
// In mercator projection it is dependant on latitude value meaning that one meter covers
// less pixels at the equator than near polar regions. Globe projection in other hand uses
// fixed ratio everywhere.
get pixelsPerMeter(): number {
return this.projection.pixelsPerMeter(this.center.lat, this.worldSize);
}
get cameraPixelsPerMeter(): number {
return mercatorZfromAltitude(this.center.lat, this.cameraWorldSize);
}
get centerOffset(): Point {
return this.centerPoint._sub(this.size._div(2));
}
get size(): Point {
return new Point(this.width, this.height);
}
get bearing(): number {
return wrap(this.rotation, -180, 180);
}
set bearing(bearing: number) {
this.rotation = bearing;
}
get rotation(): number {
return -this.angle / Math.PI * 180;
}
set rotation(rotation: number) {
const b = -rotation * Math.PI / 180;
if (this.angle === b) return;
this._unmodified = false;
this.angle = b;
this._calcMatrices();
// 2x2 matrix for rotating points
this.rotationMatrix = mat2.create();
mat2.rotate(this.rotationMatrix, this.rotationMatrix, this.angle);
}
get pitch(): number {
return this._pitch / Math.PI * 180;
}
set pitch(pitch: number) {
const p = clamp(pitch, this.minPitch, this.maxPitch) / 180 * Math.PI;
if (this._pitch === p) return;
this._unmodified = false;
this._pitch = p;
this._calcMatrices();
}
get aspect(): number {
return this.width / this.height;
}
get fovX(): number {
return this._fov;
}
get fovY(): number {
const focalLength = 1.0 / Math.tan(this.fovX * 0.5);
return 2 * Math.atan((1.0 / this.aspect) / focalLength);
}
set fov(fov: number) {
fov = Math.max(0.01, Math.min(60, fov));
if (this._fov === fov) return;
this._unmodified = false;
this._fov = degToRad(fov);
this._calcMatrices();
}
get averageElevation(): number {
return this._averageElevation;
}
set averageElevation(averageElevation: number) {
this._averageElevation = averageElevation;
this._calcFogMatrices();
this._distanceTileDataCache = {};
}
get zoom(): number { return this._zoom; }
set zoom(zoom: number) {
const z = Math.min(Math.max(zoom, this.minZoom), this.maxZoom);
if (this._zoom === z) return;
this._unmodified = false;
this._setZoom(z);
this._updateSeaLevelZoom();
this._constrain();
this._calcMatrices();
}
_setZoom(z: number) {
this._zoom = z;
this.scale = this.zoomScale(z);
this.tileZoom = Math.floor(z);
this.zoomFraction = z - this.tileZoom;
}
_updateCameraOnTerrain() {
if (!this._elevation || !this._elevation.isDataAvailableAtPoint(this.locationCoordinate(this.center))) {
// Elevation data not loaded yet, reset
this._centerAltitude = 0;
this._seaLevelZoom = null;
this._centerAltitudeValidForExaggeration = undefined;
return;
}
const elevation: Elevation = this._elevation;
this._centerAltitude = elevation.getAtPointOrZero(this.locationCoordinate(this.center));
this._centerAltitudeValidForExaggeration = elevation.exaggeration();
this._updateSeaLevelZoom();
}
_updateSeaLevelZoom() {
if (this._centerAltitudeValidForExaggeration === undefined) {
return;
}
const height = this.cameraToCenterDistance;
const terrainElevation = this.pixelsPerMeter * this._centerAltitude;
const mercatorZ = (terrainElevation + height) / this.worldSize;
// MSL (Mean Sea Level) zoom describes the distance of the camera to the sea level (altitude).
// It is used only for manipulating the camera location. The standard zoom (this._zoom)
// defines the camera distance to the terrain (height). Its behavior and conceptual
// meaning in determining which tiles to stream is same with or without the terrain.
this._seaLevelZoom = this._zoomFromMercatorZ(mercatorZ);
}
sampleAverageElevation(): number {
if (!this._elevation) return 0;
const elevation: Elevation = this._elevation;
const elevationSamplePoints = [
[0.5, 0.2],
[0.3, 0.5],
[0.5, 0.5],
[0.7, 0.5],
[0.5, 0.8]
];
const horizon = this.horizonLineFromTop();
let elevationSum = 0.0;
let weightSum = 0.0;
for (let i = 0; i < elevationSamplePoints.length; i++) {
const pt = new Point(
elevationSamplePoints[i][0] * this.width,
horizon + elevationSamplePoints[i][1] * (this.height - horizon)
);
const hit = elevation.pointCoordinate(pt);
if (!hit) continue;
const distanceToHit = Math.hypot(hit[0] - this._camera.position[0], hit[1] - this._camera.position[1]);
const weight = 1 / distanceToHit;
elevationSum += hit[3] * weight;
weightSum += weight;
}
if (weightSum === 0) return NaN;
return elevationSum / weightSum;
}
get center(): LngLat { return this._center; }
set center(center: LngLat) {
if (center.lat === this._center.lat && center.lng === this._center.lng) return;
this._unmodified = false;
this._center = center;
if (this._terrainEnabled()) {
if (this.cameraElevationReference === "ground") {
this._updateCameraOnTerrain();
} else {
this._updateZoomFromElevation();
}
}
this._constrain();
this._calcMatrices();
}
_updateZoomFromElevation() {
if (this._seaLevelZoom == null || !this._elevation)
return;
// Compute zoom level from the height of the camera relative to the terrain
const seaLevelZoom: number = this._seaLevelZoom;
const elevationAtCenter = this._elevation.getAtPointOrZero(this.locationCoordinate(this.center));
const mercatorElevation = this.pixelsPerMeter / this.worldSize * elevationAtCenter;
const altitude = this._mercatorZfromZoom(seaLevelZoom);
const minHeight = this._mercatorZfromZoom(this._maxZoom);
const height = Math.max(altitude - mercatorElevation, minHeight);
this._setZoom(this._zoomFromMercatorZ(height));
}
get padding(): PaddingOptions { return this._edgeInsets.toJSON(); }
set padding(padding: PaddingOptions) {
if (this._edgeInsets.equals(padding)) return;
this._unmodified = false;
//Update edge-insets inplace
this._edgeInsets.interpolate(this._edgeInsets, padding, 1);
this._calcMatrices();
}
/**
* Computes a zoom value relative to a map plane that goes through the provided mercator position.
*
* @param {MercatorCoordinate} position A position defining the altitude of the the map plane.
* @returns {number} The zoom value.
*/
computeZoomRelativeTo(position: MercatorCoordinate): number {
// Find map center position on the target plane by casting a ray from screen center towards the plane.
// Direct distance to the target position is used if the target position is above camera position.
const centerOnTargetAltitude = this.rayIntersectionCoordinate(this.pointRayIntersection(this.centerPoint, position.toAltitude()));
let targetPosition: ?Vec3;
if (position.z < this._camera.position[2]) {
targetPosition = [centerOnTargetAltitude.x, centerOnTargetAltitude.y, centerOnTargetAltitude.z];
} else {
targetPosition = [position.x, position.y, position.z];
}
const distToTarget = vec3.length(vec3.sub([], this._camera.position, targetPosition));
return clamp(this._zoomFromMercatorZ(distToTarget), this._minZoom, this._maxZoom);
}
setFreeCameraOptions(options: FreeCameraOptions) {
if (!this.height)
return;
if (!options.position && !options.orientation)
return;
// Camera state must be up-to-date before accessing its getters
this._updateCameraState();
let changed = false;
if (options.orientation && !quat.exactEquals(options.orientation, this._camera.orientation)) {
changed = this._setCameraOrientation(options.orientation);
}
if (options.position) {
const newPosition = [options.position.x, options.position.y, options.position.z];
if (!vec3.exactEquals(newPosition, this._camera.position)) {
this._setCameraPosition(newPosition);
changed = true;
}
}
if (changed) {
this._updateStateFromCamera();
this.recenterOnTerrain();
}
}
getFreeCameraOptions(): FreeCameraOptions {
this._updateCameraState();
const pos = this._camera.position;
const options = new FreeCameraOptions();
options.position = new MercatorCoordinate(pos[0], pos[1], pos[2]);
options.orientation = this._camera.orientation;
options._elevation = this.elevation;
options._renderWorldCopies = this.renderWorldCopies;
return options;
}
_setCameraOrientation(orientation: Quat): boolean {
// zero-length quaternions are not valid
if (!quat.length(orientation))
return false;
quat.normalize(orientation, orientation);
// The new orientation must be sanitized by making sure it can be represented
// with a pitch and bearing. Roll-component must be removed and the camera can't be upside down
const forward = vec3.transformQuat([], [0, 0, -1], orientation);
const up = vec3.transformQuat([], [0, -1, 0], orientation);
if (up[2] < 0.0)
return false;
const updatedOrientation = orientationFromFrame(forward, up);
if (!updatedOrientation)
return false;
this._camera.orientation = updatedOrientation;
return true;
}
_setCameraPosition(position: Vec3) {
// Altitude must be clamped to respect min and max zoom
const minWorldSize = this.zoomScale(this.minZoom) * this.tileSize;
const maxWorldSize = this.zoomScale(this.maxZoom) * this.tileSize;
const distToCenter = this.cameraToCenterDistance;
position[2] = clamp(position[2], distToCenter / maxWorldSize, distToCenter / minWorldSize);
this._camera.position = position;
}
/**
* The center of the screen in pixels with the top-left corner being (0,0)
* and +y axis pointing downwards. This accounts for padding.
*
* @readonly
* @type {Point}
* @memberof Transform
*/
get centerPoint(): Point {
return this._edgeInsets.getCenter(this.width, this.height);
}
/**
* Returns the vertical half-fov, accounting for padding, in radians.
*
* @readonly
* @type {number}
* @private
*/
get fovAboveCenter(): number {
return this._fov * (0.5 + this.centerOffset.y / this.height);
}
/**
* Returns true if the padding options are equal.
*
* @param {PaddingOptions} padding The padding options to compare.
* @returns {boolean} True if the padding options are equal.
* @memberof Transform
*/
isPaddingEqual(padding: PaddingOptions): boolean {
return this._edgeInsets.equals(padding);
}
/**
* Helper method to update edge-insets inplace.
*
* @param {PaddingOptions} start The initial padding options.
* @param {PaddingOptions} target The target padding options.
* @param {number} t The interpolation variable.
* @memberof Transform
*/
interpolatePadding(start: PaddingOptions, target: PaddingOptions, t: number) {
this._unmodified = false;
this._edgeInsets.interpolate(start, target, t);
this._constrain();
this._calcMatrices();
}
/**
* Return the highest zoom level that fully includes all tiles within the transform's boundaries.
* @param {Object} options Options.
* @param {number} options.tileSize Tile size, expressed in screen pixels.
* @param {boolean} options.roundZoom Target zoom level. If true, the value will be rounded to the closest integer. Otherwise the value will be floored.
* @returns {number} An integer zoom level at which all tiles will be visible.
*/
coveringZoomLevel(options: {roundZoom?: boolean, tileSize: number}): number {
const z = (options.roundZoom ? Math.round : Math.floor)(
this.zoom + this.scaleZoom(this.tileSize / options.tileSize)
);
// At negative zoom levels load tiles from z0 because negative tile zoom levels don't exist.
return Math.max(0, z);
}
/**
* Return any "wrapped" copies of a given tile coordinate that are visible
* in the current view.
*
* @private
*/
getVisibleUnwrappedCoordinates(tileID: CanonicalTileID): Array<UnwrappedTileID> {
const result = [new UnwrappedTileID(0, tileID)];
if (this.renderWorldCopies) {
const utl = this.pointCoordinate(new Point(0, 0));
const utr = this.pointCoordinate(new Point(this.width, 0));
const ubl = this.pointCoordinate(new Point(this.width, this.height));
const ubr = this.pointCoordinate(new Point(0, this.height));
const w0 = Math.floor(Math.min(utl.x, utr.x, ubl.x, ubr.x));
const w1 = Math.floor(Math.max(utl.x, utr.x, ubl.x, ubr.x));
// Add an extra copy of the world on each side to properly render ImageSources and CanvasSources.
// Both sources draw outside the tile boundaries of the tile that "contains them" so we need
// to add extra copies on both sides in case offscreen tiles need to draw into on-screen ones.
const extraWorldCopy = 1;
for (let w = w0 - extraWorldCopy; w <= w1 + extraWorldCopy; w++) {
if (w === 0) continue;
result.push(new UnwrappedTileID(w, tileID));
}
}
return result;
}
/**
* Return all coordinates that could cover this transform for a covering
* zoom level.
* @param {Object} options
* @param {number} options.tileSize
* @param {number} options.minzoom
* @param {number} options.maxzoom
* @param {boolean} options.roundZoom
* @param {boolean} options.reparseOverscaled
* @returns {Array<OverscaledTileID>} OverscaledTileIDs
* @private
*/
coveringTiles(
options: {
tileSize: number,
minzoom?: number,
maxzoom?: number,
roundZoom?: boolean,
reparseOverscaled?: boolean,
renderWorldCopies?: boolean,
isTerrainDEM?: boolean
}
): Array<OverscaledTileID> {
let z = this.coveringZoomLevel(options);
const actualZ = z;
const useElevationData = this.elevation && !options.isTerrainDEM;
const isMercator = this.projection.name === 'mercator';
if (options.minzoom !== undefined && z < options.minzoom) return [];
if (options.maxzoom !== undefined && z > options.maxzoom) z = options.maxzoom;
const centerCoord = this.locationCoordinate(this.center);
const centerLatitude = this.center.lat;
const numTiles = 1 << z;
const centerPoint = [numTiles * centerCoord.x, numTiles * centerCoord.y, 0];
const isGlobe = this.projection.name === 'globe';
const zInMeters = !isGlobe;
const cameraFrustum = Frustum.fromInvProjectionMatrix(this.invProjMatrix, this.worldSize, z, zInMeters);
const cameraCoord = isGlobe ? this._camera.mercatorPosition : this.pointCoordinate(this.getCameraPoint());
const meterToTile = numTiles * mercatorZfromAltitude(1, this.center.lat);
const cameraAltitude = this._camera.position[2] / mercatorZfromAltitude(1, this.center.lat);
const cameraPoint = [numTiles * cameraCoord.x, numTiles * cameraCoord.y, cameraAltitude * (zInMeters ? 1 : meterToTile)];
// Let's consider an example for !roundZoom: e.g. tileZoom 16 is used from zoom 16 all the way to zoom 16.99.
// This would mean that the minimal distance to split would be based on distance from camera to center of 16.99 zoom.
// The same is already incorporated in logic behind roundZoom for raster (so there is no adjustment needed in following line).
// 0.02 added to compensate for precision errors, see "coveringTiles for terrain" test in transform.test.js.
const zoomSplitDistance = this.cameraToCenterDistance / options.tileSize * (options.roundZoom ? 1 : 0.502);
// No change of LOD behavior for pitch lower than 60 and when there is no top padding: return only tile ids from the requested zoom level
const minZoom = this.pitch <= 60.0 && this._edgeInsets.top <= this._edgeInsets.bottom && !this._elevation && !this.projection.isReprojectedInTileSpace ? z : 0;
// When calculating tile cover for terrain, create deep AABB for nodes, to ensure they intersect frustum: for sources,
// other than DEM, use minimum of visible DEM tiles and center altitude as upper bound (pitch is always less than 90°).
const maxRange = options.isTerrainDEM && this._elevation ? this._elevation.exaggeration() * 10000 : this._centerAltitude;
const minRange = options.isTerrainDEM ? -maxRange : this._elevation ? this._elevation.getMinElevationBelowMSL() : 0;
const scaleAdjustment = this.projection.isReprojectedInTileSpace ? getScaleAdjustment(this) : 1.0;
const relativeScaleAtMercatorCoord = mc => {
// Calculate how scale compares between projected coordinates and mercator coordinates.
// Returns a length. The units don't matter since the result is only
// used in a ratio with other values returned by this function.
// Construct a small square in Mercator coordinates.
const offset = 1 / 40000;
const mcEast = new MercatorCoordinate(mc.x + offset, mc.y, mc.z);
const mcSouth = new MercatorCoordinate(mc.x, mc.y + offset, mc.z);
// Convert the square to projected coordinates.
const ll = mc.toLngLat();
const llEast = mcEast.toLngLat();
const llSouth = mcSouth.toLngLat();
const p = this.locationCoordinate(ll);
const pEast = this.locationCoordinate(llEast);
const pSouth = this.locationCoordinate(llSouth);
// Calculate the size of each edge of the reprojected square
const dx = Math.hypot(pEast.x - p.x, pEast.y - p.y);
const dy = Math.hypot(pSouth.x - p.x, pSouth.y - p.y);
// Calculate the size of a projected square that would have the
// same area as the reprojected square.
return Math.sqrt(dx * dy) * scaleAdjustment / offset;
};
const newRootTile = (wrap: number): any => {
const max = maxRange;
const min = minRange;
return {
// With elevation, this._elevation provides z coordinate values. For 2D:
// All tiles are on zero elevation plane => z difference is zero
aabb: tileAABB(this, numTiles, 0, 0, 0, wrap, min, max, this.projection),
zoom: 0,
x: 0,
y: 0,
minZ: min,
maxZ: max,
wrap,
fullyVisible: false
};
};
// Do a depth-first traversal to find visible tiles and proper levels of detail
const stack = [];
let result = [];
const maxZoom = z;
const overscaledZ = options.reparseOverscaled ? actualZ : z;
const square = a => a * a;
const cameraHeightSqr = square((cameraAltitude - this._centerAltitude) * meterToTile); // in tile coordinates.
const getAABBFromElevation = (it) => {
assert(this._elevation);
if (!this._elevation || !it.tileID || !isMercator) return; // To silence flow.
const minmax = this._elevation.getMinMaxForTile(it.tileID);
const aabb = it.aabb;
if (minmax) {
aabb.min[2] = minmax.min;
aabb.max[2] = minmax.max;
aabb.center[2] = (aabb.min[2] + aabb.max[2]) / 2;
} else {
it.shouldSplit = shouldSplit(it);
if (!it.shouldSplit) {
// At final zoom level, while corresponding DEM tile is not loaded yet,
// assume center elevation. This covers ground to horizon and prevents
// loading unnecessary tiles until DEM cover is fully loaded.
aabb.min[2] = aabb.max[2] = aabb.center[2] = this._centerAltitude;
}
}
};
// Scale distance to split for acute angles.
// dzSqr: z component of camera to tile distance, square.
// dSqr: 3D distance of camera to tile, square.
const distToSplitScale = (dzSqr, dSqr) => {
// When the angle between camera to tile ray and tile plane is smaller
// than acuteAngleThreshold, scale the distance to split. Scaling is adaptive: smaller
// the angle, the scale gets lower value. Although it seems early to start at 45,
// it is not: scaling kicks in around 60 degrees pitch.
const acuteAngleThresholdSin = 0.707; // Math.sin(45)
const stretchTile = 1.1;
// Distances longer than 'dz / acuteAngleThresholdSin' gets scaled
// following geometric series sum: every next dz length in distance can be
// 'stretchTile times' longer. It is further, the angle is sharper. Total,
// adjusted, distance would then be:
// = dz / acuteAngleThresholdSin + (dz * stretchTile + dz * stretchTile ^ 2 + ... + dz * stretchTile ^ k),
// where k = (d - dz / acuteAngleThresholdSin) / dz = d / dz - 1 / acuteAngleThresholdSin;
// = dz / acuteAngleThresholdSin + dz * ((stretchTile ^ (k + 1) - 1) / (stretchTile - 1) - 1)
// or put differently, given that k is based on d and dz, tile on distance d could be used on distance scaled by:
// 1 / acuteAngleThresholdSin + (stretchTile ^ (k + 1) - 1) / (stretchTile - 1) - 1
if (dSqr * square(acuteAngleThresholdSin) < dzSqr) return 1.0; // Early return, no scale.
const r = Math.sqrt(dSqr / dzSqr);
const k = r - 1 / acuteAngleThresholdSin;
return r / (1 / acuteAngleThresholdSin + (Math.pow(stretchTile, k + 1) - 1) / (stretchTile - 1) - 1);
};
const shouldSplit = (it) => {
if (it.zoom < minZoom) {
return true;
} else if (it.zoom === maxZoom) {
return false;
}
if (it.shouldSplit != null) {
return it.shouldSplit;
}
const dx = it.aabb.distanceX(cameraPoint);
const dy = it.aabb.distanceY(cameraPoint);
let dzSqr = cameraHeightSqr;
let tileScaleAdjustment = 1;
if (isGlobe) {
dzSqr = square(it.aabb.distanceZ(cameraPoint));
// Compensate physical sizes of the tiles when determining which zoom level to use.
// In practice tiles closer to poles should use more aggressive LOD as their
// physical size is already smaller than size of tiles near the equator.
const tilesAtZoom = Math.pow(2, it.zoom);
const minLat = latFromMercatorY((it.y + 1) / tilesAtZoom);
const maxLat = latFromMercatorY((it.y) / tilesAtZoom);
const closestLat = Math.min(Math.max(centerLatitude, minLat), maxLat);
const relativeTileScale = circumferenceAtLatitude(closestLat) / circumferenceAtLatitude(centerLatitude);
// With globe, the rendered scale does not exactly match the mercator scale at low zoom levels.
// Account for this difference during LOD of loading so that you load the correct size tiles.
// We try to compromise between two conflicting requirements:
// - loading tiles at the camera's zoom level (for visual and styling consistency)
// - loading correct size tiles (to reduce the number of tiles loaded)
// These are arbitrarily balanced:
if (closestLat === centerLatitude) {
// For tiles that are in the middle of the viewport, prioritize matching the camera
// zoom and allow divergence from the true scale.
const maxDivergence = 0.3;
tileScaleAdjustment = 1 / Math.max(1, this._mercatorScaleRatio - maxDivergence);
} else {
// For other tiles, use the real scale to reduce tile counts near poles.
tileScaleAdjustment = Math.min(1, relativeTileScale / this._mercatorScaleRatio);
}
// Ensure that all tiles near the center have the same zoom level.
// With LOD tile loading, tile zoom levels can change when scale slightly changes.
// These differences can be pretty different in globe view. Work around this by
// making more tiles match the center tile's zoom level. If the tiles are nearly big enough,
// round up. Only apply this adjustment before the transition to mercator rendering has started.
if (this.zoom <= GLOBE_ZOOM_THRESHOLD_MIN && it.zoom === maxZoom - 1 && relativeTileScale >= 0.9) {
return true;
}
} else {
assert(zInMeters);
if (useElevationData) {
dzSqr = square(it.aabb.distanceZ(cameraPoint) * meterToTile);
}
if (this.projection.isReprojectedInTileSpace && actualZ <= 5) {
// In other projections, not all tiles are the same size.
// Account for the tile size difference by adjusting the distToSplit.
// Adjust by the ratio of the area at the tile center to the area at the map center.
// Adjustments are only needed at lower zooms where tiles are not similarly sized.
const numTiles = Math.pow(2, it.zoom);
const relativeScale = relativeScaleAtMercatorCoord(new MercatorCoordinate((it.x + 0.5) / numTiles, (it.y + 0.5) / numTiles));
// Fudge the ratio slightly so that all tiles near the center have the same zoom level.
tileScaleAdjustment = relativeScale > 0.85 ? 1 : relativeScale;
}
}
const distanceSqr = dx * dx + dy * dy + dzSqr;
const distToSplit = (1 << maxZoom - it.zoom) * zoomSplitDistance * tileScaleAdjustment;
const distToSplitSqr = square(distToSplit * distToSplitScale(Math.max(dzSqr, cameraHeightSqr), distanceSqr));
return distanceSqr < distToSplitSqr;
};
if (this.renderWorldCopies) {
// Render copy of the globe thrice on both sides
for (let i = 1; i <= NUM_WORLD_COPIES; i++) {
stack.push(newRootTile(-i));
stack.push(newRootTile(i));
}
}
stack.push(newRootTile(0));
while (stack.length > 0) {
const it = stack.pop();
const x = it.x;
const y = it.y;
let fullyVisible = it.fullyVisible;
// Visibility of a tile is not required if any of its ancestor is fully inside the frustum
if (!fullyVisible) {
const intersectResult = it.aabb.intersects(cameraFrustum);
if (intersectResult === 0)
continue;
fullyVisible = intersectResult === 2;
}
// Have we reached the target depth or is the tile too far away to be any split further?
if (it.zoom === maxZoom || !shouldSplit(it)) {
const tileZoom = it.zoom === maxZoom ? overscaledZ : it.zoom;
if (!!options.minzoom && options.minzoom > tileZoom) {
// Not within source tile range.
continue;
}
const dx = centerPoint[0] - ((0.5 + x + (it.wrap << it.zoom)) * (1 << (z - it.zoom)));
const dy = centerPoint[1] - 0.5 - y;
const id = it.tileID ? it.tileID : new OverscaledTileID(tileZoom, it.wrap, it.zoom, x, y);
result.push({tileID: id, distanceSq: dx * dx + dy * dy});
continue;
}
for (let i = 0; i < 4; i++) {
const childX = (x << 1) + (i % 2);
const childY = (y << 1) + (i >> 1);
const aabb = isMercator ? it.aabb.quadrant(i) : tileAABB(this, numTiles, it.zoom + 1, childX, childY, it.wrap, it.minZ, it.maxZ, this.projection);
const child = {aabb, zoom: it.zoom + 1, x: childX, y: childY, wrap: it.wrap, fullyVisible, tileID: undefined, shouldSplit: undefined, minZ: it.minZ, maxZ: it.maxZ};
if (useElevationData && !isGlobe) {
child.tileID = new OverscaledTileID(it.zoom + 1 === maxZoom ? overscaledZ : it.zoom + 1, it.wrap, it.zoom + 1, childX, childY);
getAABBFromElevation(child);
}
stack.push(child);
}