This repository has been archived by the owner on Aug 8, 2023. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 1.3k
/
transform.cpp
662 lines (553 loc) · 25.9 KB
/
transform.cpp
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
#include <mbgl/map/camera.hpp>
#include <mbgl/map/transform.hpp>
#include <mbgl/util/constants.hpp>
#include <mbgl/util/mat4.hpp>
#include <mbgl/util/math.hpp>
#include <mbgl/util/unitbezier.hpp>
#include <mbgl/util/interpolate.hpp>
#include <mbgl/util/chrono.hpp>
#include <mbgl/util/projection.hpp>
#include <mbgl/math/clamp.hpp>
#include <mbgl/util/logging.hpp>
#include <mbgl/util/platform.hpp>
#include <cmath>
#include <cstdio>
#include <utility>
namespace mbgl {
/** Converts the given angle (in radians) to be numerically close to the anchor angle, allowing it to be interpolated properly without sudden jumps. */
static double _normalizeAngle(double angle, double anchorAngle)
{
if (std::isnan(angle) || std::isnan(anchorAngle)) {
return 0;
}
angle = util::wrap(angle, -M_PI, M_PI);
if (angle == -M_PI) angle = M_PI;
double diff = std::abs(angle - anchorAngle);
if (std::abs(angle - util::M2PI - anchorAngle) < diff) {
angle -= util::M2PI;
}
if (std::abs(angle + util::M2PI - anchorAngle) < diff) {
angle += util::M2PI;
}
return angle;
}
Transform::Transform(MapObserver& observer_,
ConstrainMode constrainMode,
ViewportMode viewportMode)
: observer(observer_), state(constrainMode, viewportMode) {
}
#pragma mark - Map View
void Transform::resize(const Size size) {
if (size.isEmpty()) {
throw std::runtime_error("failed to resize: size is empty");
}
if (state.getSize() == size) {
return;
}
observer.onCameraWillChange(MapObserver::CameraChangeMode::Immediate);
state.setSize(size);
double scale{state.getScale()};
double x{state.getX()};
double y{state.getY()};
state.constrain(scale, x, y);
state.setProperties(TransformStateProperties().withScale(scale).withX(x).withY(y));
observer.onCameraDidChange(MapObserver::CameraChangeMode::Immediate);
}
#pragma mark - Camera
CameraOptions Transform::getCameraOptions(const optional<EdgeInsets>& padding) const {
return state.getCameraOptions(padding);
}
/**
* Change any combination of center, zoom, bearing, and pitch, without
* a transition. The map will retain the current values for any options
* not included in `options`.
*/
void Transform::jumpTo(const CameraOptions& camera) {
easeTo(camera);
}
/**
* Change any combination of center, zoom, bearing, pitch and edgeInsets, with a
* smooth animation between old and new values. The map will retain the current
* values for any options not included in `options`.
*/
void Transform::easeTo(const CameraOptions& camera, const AnimationOptions& animation) {
Duration duration = animation.duration.value_or(Duration::zero());
if (state.getLatLngBounds() == LatLngBounds() && !isGestureInProgress() && duration != Duration::zero()) {
// reuse flyTo, without exaggerated animation, to achieve constant ground speed.
return flyTo(camera, animation, true);
}
const EdgeInsets& padding = camera.padding.value_or(state.getEdgeInsets());
LatLng startLatLng = getLatLng(LatLng::Unwrapped);
const LatLng& unwrappedLatLng = camera.center.value_or(startLatLng);
const LatLng& latLng = state.getLatLngBounds() != LatLngBounds() ? unwrappedLatLng : unwrappedLatLng.wrapped();
double zoom = camera.zoom.value_or(getZoom());
double bearing = camera.bearing ? -*camera.bearing * util::DEG2RAD : getBearing();
double pitch = camera.pitch ? *camera.pitch * util::DEG2RAD : getPitch();
if (std::isnan(zoom) || std::isnan(bearing) || std::isnan(pitch)) {
if (animation.transitionFinishFn) {
animation.transitionFinishFn();
}
return;
}
if (state.getLatLngBounds() == LatLngBounds()) {
if (isGestureInProgress()) {
// If gesture in progress, we transfer the wrap rounds from the end longitude into
// start, so the "scroll effect" of rounding the world is the same while assuring the
// end longitude remains wrapped.
const double wrap = unwrappedLatLng.longitude() - latLng.longitude();
startLatLng = LatLng(startLatLng.latitude(), startLatLng.longitude() - wrap);
} else {
// Find the shortest path otherwise.
startLatLng.unwrapForShortestPath(latLng);
}
}
const Point<double> startPoint = Projection::project(startLatLng, state.getScale());
const Point<double> endPoint = Projection::project(latLng, state.getScale());
// Constrain camera options.
zoom = util::clamp(zoom, state.getMinZoom(), state.getMaxZoom());
pitch = util::clamp(pitch, state.getMinPitch(), state.getMaxPitch());
// Minimize rotation by taking the shorter path around the circle.
bearing = _normalizeAngle(bearing, state.getBearing());
state.setBearing(_normalizeAngle(state.getBearing(), bearing));
const double startZoom = state.getZoom();
const double startBearing = state.getBearing();
const double startPitch = state.getPitch();
state.setProperties(TransformStateProperties()
.withPanningInProgress(unwrappedLatLng != startLatLng)
.withScalingInProgress(zoom != startZoom)
.withRotatingInProgress(bearing != startBearing));
const EdgeInsets startEdgeInsets = state.getEdgeInsets();
startTransition(
camera,
animation,
[=](double t) {
Point<double> framePoint = util::interpolate(startPoint, endPoint, t);
LatLng frameLatLng = Projection::unproject(framePoint, state.zoomScale(startZoom));
double frameZoom = util::interpolate(startZoom, zoom, t);
state.setLatLngZoom(frameLatLng, frameZoom);
if (bearing != startBearing) {
state.setBearing(util::wrap(util::interpolate(startBearing, bearing, t), -M_PI, M_PI));
}
if (padding != startEdgeInsets) {
// Interpolate edge insets
EdgeInsets edgeInsets;
state.setEdgeInsets({util::interpolate(startEdgeInsets.top(), padding.top(), t),
util::interpolate(startEdgeInsets.left(), padding.left(), t),
util::interpolate(startEdgeInsets.bottom(), padding.bottom(), t),
util::interpolate(startEdgeInsets.right(), padding.right(), t)});
}
double maxPitch = getMaxPitchForEdgeInsets(state.getEdgeInsets());
if (pitch != startPitch || maxPitch < startPitch) {
state.setPitch(std::min(maxPitch, util::interpolate(startPitch, pitch, t)));
}
},
duration);
}
/** This method implements an “optimal path” animation, as detailed in:
Van Wijk, Jarke J.; Nuij, Wim A. A. “Smooth and efficient zooming and
panning.” INFOVIS ’03. pp. 15–22.
<https://www.win.tue.nl/~vanwijk/zoompan.pdf#page=5>.
Where applicable, local variable documentation begins with the associated
variable or function in van Wijk (2003). */
void Transform::flyTo(const CameraOptions& camera, const AnimationOptions& animation, bool linearZoomInterpolation) {
const EdgeInsets& padding = camera.padding.value_or(state.getEdgeInsets());
const LatLng& latLng = camera.center.value_or(getLatLng(LatLng::Unwrapped)).wrapped();
double zoom = camera.zoom.value_or(getZoom());
double bearing = camera.bearing ? -*camera.bearing * util::DEG2RAD : getBearing();
double pitch = camera.pitch ? *camera.pitch * util::DEG2RAD : getPitch();
if (std::isnan(zoom) || std::isnan(bearing) || std::isnan(pitch) || state.getSize().isEmpty()) {
if (animation.transitionFinishFn) {
animation.transitionFinishFn();
}
return;
}
// Determine endpoints.
LatLng startLatLng = getLatLng(LatLng::Unwrapped).wrapped();
startLatLng.unwrapForShortestPath(latLng);
const Point<double> startPoint = Projection::project(startLatLng, state.getScale());
const Point<double> endPoint = Projection::project(latLng, state.getScale());
// Constrain camera options.
zoom = util::clamp(zoom, state.getMinZoom(), state.getMaxZoom());
pitch = util::clamp(pitch, state.getMinPitch(), state.getMaxPitch());
// Minimize rotation by taking the shorter path around the circle.
bearing = _normalizeAngle(bearing, state.getBearing());
state.setBearing(_normalizeAngle(state.getBearing(), bearing));
const double startZoom = state.scaleZoom(state.getScale());
const double startBearing = state.getBearing();
const double startPitch = state.getPitch();
/// w₀: Initial visible span, measured in pixels at the initial scale.
/// Known henceforth as a <i>screenful</i>.
double w0 = std::max(state.getSize().width - padding.left() - padding.right(),
state.getSize().height - padding.top() - padding.bottom());
/// w₁: Final visible span, measured in pixels with respect to the initial
/// scale.
double w1 = w0 / state.zoomScale(zoom - startZoom);
/// Length of the flight path as projected onto the ground plane, measured
/// in pixels from the world image origin at the initial scale.
double u1 = ::hypot((endPoint - startPoint).x, (endPoint - startPoint).y);
/** ρ: The relative amount of zooming that takes place along the flight
path. A high value maximizes zooming for an exaggerated animation, while
a low value minimizes zooming for something closer to easeTo().
1.42 is the average value selected by participants in the user study in
van Wijk (2003). A value of 6<sup>¼</sup> would be equivalent to the
root mean squared average velocity, V<sub>RMS</sub>. A value of 1
produces a circular motion. */
double rho = 1.42;
if (animation.minZoom || linearZoomInterpolation) {
double minZoom = util::min(animation.minZoom.value_or(startZoom), startZoom, zoom);
minZoom = util::clamp(minZoom, state.getMinZoom(), state.getMaxZoom());
/// w<sub>m</sub>: Maximum visible span, measured in pixels with respect
/// to the initial scale.
double wMax = w0 / state.zoomScale(minZoom - startZoom);
rho = u1 != 0 ? std::sqrt(wMax / u1 * 2) : 1.0;
}
/// ρ²
double rho2 = rho * rho;
/** rᵢ: Returns the zoom-out factor at one end of the animation.
@param i 0 for the ascent or 1 for the descent. */
auto r = [=](double i) {
/// bᵢ
double b = (w1 * w1 - w0 * w0 + (i ? -1 : 1) * rho2 * rho2 * u1 * u1) / (2 * (i ? w1 : w0) * rho2 * u1);
return std::log(std::sqrt(b * b + 1) - b);
};
/// r₀: Zoom-out factor during ascent.
double r0 = u1 != 0 ? r(0) : INFINITY; // Silence division by 0 on sanitize bot.
double r1 = u1 != 0 ? r(1) : INFINITY;
// When u₀ = u₁, the optimal path doesn’t require both ascent and descent.
bool isClose = std::abs(u1) < 0.000001 || !std::isfinite(r0) || !std::isfinite(r1);
/** w(s): Returns the visible span on the ground, measured in pixels with
respect to the initial scale.
Assumes an angular field of view of 2 arctan ½ ≈ 53°. */
auto w = [=](double s) {
return (isClose ? std::exp((w1 < w0 ? -1 : 1) * rho * s)
: (std::cosh(r0) / std::cosh(r0 + rho * s)));
};
/// u(s): Returns the distance along the flight path as projected onto the
/// ground plane, measured in pixels from the world image origin at the
/// initial scale.
auto u = [=](double s) {
return (isClose ? 0.
: (w0 * (std::cosh(r0) * std::tanh(r0 + rho * s) - std::sinh(r0)) / rho2 / u1));
};
/// S: Total length of the flight path, measured in ρ-screenfuls.
double S = (isClose ? (std::abs(std::log(w1 / w0)) / rho)
: ((r1 - r0) / rho));
Duration duration;
if (animation.duration) {
duration = *animation.duration;
} else {
/// V: Average velocity, measured in ρ-screenfuls per second.
double velocity = 1.2;
if (animation.velocity) {
velocity = *animation.velocity / rho;
}
duration = std::chrono::duration_cast<Duration>(std::chrono::duration<double>(S / velocity));
}
if (duration == Duration::zero()) {
// Perform an instantaneous transition.
jumpTo(camera);
if (animation.transitionFinishFn) {
animation.transitionFinishFn();
}
return;
}
const double startScale = state.getScale();
state.setProperties(
TransformStateProperties().withPanningInProgress(true).withScalingInProgress(true).withRotatingInProgress(
bearing != startBearing));
const EdgeInsets startEdgeInsets = state.getEdgeInsets();
startTransition(
camera,
animation,
[=](double k) {
/// s: The distance traveled along the flight path, measured in
/// ρ-screenfuls.
double s = k * S;
double us = k == 1.0 ? 1.0 : u(s);
// Calculate the current point and zoom level along the flight path.
Point<double> framePoint = util::interpolate(startPoint, endPoint, us);
double frameZoom =
linearZoomInterpolation ? util::interpolate(startZoom, zoom, k) : startZoom + state.scaleZoom(1 / w(s));
// Zoom can be NaN if size is empty.
if (std::isnan(frameZoom)) {
frameZoom = zoom;
}
// Convert to geographic coordinates and set the new viewpoint.
LatLng frameLatLng = Projection::unproject(framePoint, startScale);
state.setLatLngZoom(frameLatLng, frameZoom);
if (bearing != startBearing) {
state.setBearing(util::wrap(util::interpolate(startBearing, bearing, k), -M_PI, M_PI));
}
if (padding != startEdgeInsets) {
// Interpolate edge insets
state.setEdgeInsets({util::interpolate(startEdgeInsets.top(), padding.top(), k),
util::interpolate(startEdgeInsets.left(), padding.left(), k),
util::interpolate(startEdgeInsets.bottom(), padding.bottom(), k),
util::interpolate(startEdgeInsets.right(), padding.right(), k)});
}
double maxPitch = getMaxPitchForEdgeInsets(state.getEdgeInsets());
if (pitch != startPitch || maxPitch < startPitch) {
state.setPitch(std::min(maxPitch, util::interpolate(startPitch, pitch, k)));
}
},
duration);
}
#pragma mark - Position
void Transform::moveBy(const ScreenCoordinate& offset, const AnimationOptions& animation) {
ScreenCoordinate centerOffset = {offset.x, offset.y};
ScreenCoordinate pointOnScreen =
state.getEdgeInsets().getCenter(state.getSize().width, state.getSize().height) - centerOffset;
// Use unwrapped LatLng to carry information about moveBy direction.
easeTo(CameraOptions().withCenter(screenCoordinateToLatLng(pointOnScreen, LatLng::Unwrapped)), animation);
}
LatLng Transform::getLatLng(LatLng::WrapMode wrap) const {
return state.getLatLng(wrap);
}
#pragma mark - Zoom
double Transform::getZoom() const {
return state.getZoom();
}
#pragma mark - Bounds
void Transform::setLatLngBounds(LatLngBounds bounds) {
if (!bounds.valid()) {
throw std::runtime_error("failed to set bounds: bounds are invalid");
}
state.setLatLngBounds(bounds);
}
void Transform::setMinZoom(const double minZoom) {
if (std::isnan(minZoom)) return;
state.setMinZoom(minZoom);
}
void Transform::setMaxZoom(const double maxZoom) {
if (std::isnan(maxZoom)) return;
state.setMaxZoom(maxZoom);
}
void Transform::setMinPitch(const double minPitch) {
if (std::isnan(minPitch)) return;
if (minPitch * util::DEG2RAD < util::PITCH_MIN) {
Log::Warning(Event::General,
"Trying to set minimum pitch below the limit (%.0f degrees), the value will be clamped.",
util::PITCH_MIN * util::RAD2DEG);
}
state.setMinPitch(minPitch * util::DEG2RAD);
}
void Transform::setMaxPitch(const double maxPitch) {
if (std::isnan(maxPitch)) return;
if (maxPitch * util::DEG2RAD > util::PITCH_MAX) {
Log::Warning(Event::General,
"Trying to set maximum pitch above the limit (%.0f degrees), the value will be clamped.",
util::PITCH_MAX * util::RAD2DEG);
}
state.setMaxPitch(maxPitch * util::DEG2RAD);
}
#pragma mark - Bearing
void Transform::rotateBy(const ScreenCoordinate& first,
const ScreenCoordinate& second,
const AnimationOptions& animation) {
ScreenCoordinate center = state.getEdgeInsets().getCenter(state.getSize().width, state.getSize().height);
const ScreenCoordinate offset = first - center;
const double distance = std::sqrt(std::pow(2, offset.x) + std::pow(2, offset.y));
// If the first click was too close to the center, move the center of rotation by 200 pixels
// in the direction of the click.
if (distance < 200) {
const double heightOffset = -200;
const double rotateBearing = std::atan2(offset.y, offset.x);
center.x = first.x + std::cos(rotateBearing) * heightOffset;
center.y = first.y + std::sin(rotateBearing) * heightOffset;
}
const double bearing = -(state.getBearing() + util::angle_between(first - center, second - center)) * util::RAD2DEG;
easeTo(CameraOptions().withBearing(bearing), animation);
}
double Transform::getBearing() const {
return state.getBearing();
}
#pragma mark - Pitch
double Transform::getPitch() const {
return state.getPitch();
}
#pragma mark - North Orientation
void Transform::setNorthOrientation(NorthOrientation orientation) {
state.setNorthOrientation(orientation);
double scale{state.getScale()};
double x{state.getX()};
double y{state.getY()};
state.constrain(scale, x, y);
state.setProperties(TransformStateProperties().withScale(scale).withX(x).withY(y));
}
NorthOrientation Transform::getNorthOrientation() const {
return state.getNorthOrientation();
}
#pragma mark - Constrain mode
void Transform::setConstrainMode(mbgl::ConstrainMode mode) {
state.setConstrainMode(mode);
double scale{state.getScale()};
double x{state.getX()};
double y{state.getY()};
state.constrain(scale, x, y);
state.setProperties(TransformStateProperties().withScale(scale).withX(x).withY(y));
}
ConstrainMode Transform::getConstrainMode() const {
return state.getConstrainMode();
}
#pragma mark - Viewport mode
void Transform::setViewportMode(mbgl::ViewportMode mode) {
state.setViewportMode(mode);
}
ViewportMode Transform::getViewportMode() const {
return state.getViewportMode();
}
#pragma mark - Projection mode
void Transform::setProjectionMode(const ProjectionMode& options) {
state.setProperties(TransformStateProperties()
.withAxonometric(options.axonometric.value_or(state.getAxonometric()))
.withXSkew(options.xSkew.value_or(state.getXSkew()))
.withYSkew(options.ySkew.value_or(state.getYSkew())));
}
ProjectionMode Transform::getProjectionMode() const {
return ProjectionMode()
.withAxonometric(state.getAxonometric())
.withXSkew(state.getXSkew())
.withYSkew(state.getYSkew());
}
#pragma mark - Transition
void Transform::startTransition(const CameraOptions& camera,
const AnimationOptions& animation,
const std::function<void(double)>& frame,
const Duration& duration) {
if (transitionFinishFn) {
transitionFinishFn();
}
bool isAnimated = duration != Duration::zero();
observer.onCameraWillChange(isAnimated ? MapObserver::CameraChangeMode::Animated
: MapObserver::CameraChangeMode::Immediate);
// Associate the anchor, if given, with a coordinate.
// Anchor and center points are mutually exclusive, with preference for the
// center point when both are set.
optional<ScreenCoordinate> anchor = camera.center ? nullopt : camera.anchor;
LatLng anchorLatLng;
if (anchor) {
anchor->y = state.getSize().height - anchor->y;
anchorLatLng = state.screenCoordinateToLatLng(*anchor);
}
transitionStart = Clock::now();
transitionDuration = duration;
transitionFrameFn = [isAnimated, animation, frame, anchor, anchorLatLng, this](const TimePoint now) {
float t = isAnimated ? (std::chrono::duration<float>(now - transitionStart) / transitionDuration) : 1.0;
if (t >= 1.0) {
frame(1.0);
} else {
util::UnitBezier ease = animation.easing ? *animation.easing : util::DEFAULT_TRANSITION_EASE;
frame(ease.solve(t, 0.001));
}
if (anchor) state.moveLatLng(anchorLatLng, *anchor);
// At t = 1.0, a DidChangeAnimated notification should be sent from finish().
if (t < 1.0) {
if (animation.transitionFrameFn) {
animation.transitionFrameFn(t);
}
observer.onCameraIsChanging();
return false;
} else {
// Indicate that we need to terminate this transition
return true;
}
};
transitionFinishFn = [isAnimated, animation, this] {
state.setProperties(
TransformStateProperties().withPanningInProgress(false).withScalingInProgress(false).withRotatingInProgress(
false));
if (animation.transitionFinishFn) {
animation.transitionFinishFn();
}
observer.onCameraDidChange(isAnimated ? MapObserver::CameraChangeMode::Animated
: MapObserver::CameraChangeMode::Immediate);
};
if (!isAnimated) {
auto update = std::move(transitionFrameFn);
auto finish = std::move(transitionFinishFn);
transitionFrameFn = nullptr;
transitionFinishFn = nullptr;
update(Clock::now());
finish();
}
}
bool Transform::inTransition() const {
return transitionFrameFn != nullptr;
}
void Transform::updateTransitions(const TimePoint& now) {
// Use a temporary function to ensure that the transitionFrameFn lambda is
// called only once per update.
// This addresses the symptoms of https://github.com/mapbox/mapbox-gl-native/issues/11180
// where setting a shape source to nil (or similar) in the `onCameraIsChanging`
// observer function causes `Map::Impl::onUpdate()` to be called which
// in turn calls this function (before the current iteration has completed),
// leading to an infinite loop. See https://github.com/mapbox/mapbox-gl-native/issues/5833
// for a similar, related, issue.
//
// By temporarily nulling the `transitionFrameFn` (and then restoring it
// after the temporary has been called) we stop this recursion.
//
// It's important to note that the scope of this change is stop the above
// crashes. It doesn't address any potential deeper issue (for example
// user error, how often and when transition callbacks are called).
auto transition = std::move(transitionFrameFn);
transitionFrameFn = nullptr;
if (transition && transition(now)) {
// If the transition indicates that it is complete, then we should call
// the finish lambda (going via a temporary as above)
auto finish = std::move(transitionFinishFn);
transitionFinishFn = nullptr;
transitionFrameFn = nullptr;
if (finish) {
finish();
}
} else if (!transitionFrameFn) {
// We have to check `transitionFrameFn` is nil here, since a new transition
// may have been triggered in a user callback (from the transition call
// above)
transitionFrameFn = std::move(transition);
}
}
void Transform::cancelTransitions() {
if (transitionFinishFn) {
transitionFinishFn();
}
transitionFrameFn = nullptr;
transitionFinishFn = nullptr;
}
void Transform::setGestureInProgress(bool inProgress) {
state.setGestureInProgress(inProgress);
}
#pragma mark Conversion and projection
ScreenCoordinate Transform::latLngToScreenCoordinate(const LatLng& latLng) const {
ScreenCoordinate point = state.latLngToScreenCoordinate(latLng);
point.y = state.getSize().height - point.y;
return point;
}
LatLng Transform::screenCoordinateToLatLng(const ScreenCoordinate& point, LatLng::WrapMode wrapMode) const {
ScreenCoordinate flippedPoint = point;
flippedPoint.y = state.getSize().height - flippedPoint.y;
return state.screenCoordinateToLatLng(flippedPoint, wrapMode);
}
double Transform::getMaxPitchForEdgeInsets(const EdgeInsets& insets) const {
double centerOffsetY = 0.5 * (insets.top() - insets.bottom()); // See TransformState::getCenterOffset.
const auto height = state.getSize().height;
assert(height);
// For details, see description at https://github.com/mapbox/mapbox-gl-native/pull/15195
// The definition of half of TransformState::fov with no inset, is: fov = arctan((height / 2) / (height * 1.5)).
// We use half of fov, as it is field of view above perspective center.
// With inset, this angle changes and tangentOfFovAboveCenterAngle = (h/2 + centerOffsetY) / (height * 1.5).
// 1.03 is a bit extra added to prevent parallel ground to viewport clipping plane.
const double tangentOfFovAboveCenterAngle = 1.03 * (height / 2.0 + centerOffsetY) / (1.5 * height);
const double fovAboveCenter = std::atan(tangentOfFovAboveCenterAngle);
return M_PI * 0.5 - fovAboveCenter;
// e.g. Maximum pitch of 60 degrees is when perspective center's offset from the top is 84% of screen height.
}
FreeCameraOptions Transform::getFreeCameraOptions() const {
return state.getFreeCameraOptions();
}
void Transform::setFreeCameraOptions(const FreeCameraOptions& options) {
cancelTransitions();
state.setFreeCameraOptions(options);
}
} // namespace mbgl