1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define LOG_TAG "VelocityTracker_test"
18 
19 #include <math.h>
20 #include <array>
21 #include <chrono>
22 #include <limits>
23 
24 #include <android-base/stringprintf.h>
25 #include <attestation/HmacKeyManager.h>
26 #include <gtest/gtest.h>
27 #include <input/VelocityTracker.h>
28 
29 using std::literals::chrono_literals::operator""ms;
30 using std::literals::chrono_literals::operator""ns;
31 using std::literals::chrono_literals::operator""us;
32 using android::base::StringPrintf;
33 
34 namespace android {
35 
36 constexpr ui::LogicalDisplayId DISPLAY_ID = ui::LogicalDisplayId::DEFAULT; // default display id
37 
38 constexpr int32_t DEFAULT_POINTER_ID = 0; // pointer ID used for manually defined tests
39 
40 // velocity must be in the range (1-tol)*EV <= velocity <= (1+tol)*EV
41 // here EV = expected value, tol = VELOCITY_TOLERANCE
42 constexpr float VELOCITY_TOLERANCE = 0.2;
43 
44 // quadratic velocity must be within 0.001% of the target value
45 constexpr float QUADRATIC_VELOCITY_TOLERANCE = 0.00001;
46 
47 // --- VelocityTrackerTest ---
48 class VelocityTrackerTest : public testing::Test { };
49 
50 /*
51  * Similar to EXPECT_NEAR, but ensures that the difference between the two float values
52  * is at most a certain fraction of the target value.
53  * If fraction is zero, require exact match.
54  */
EXPECT_NEAR_BY_FRACTION(float actual,float target,float fraction)55 static void EXPECT_NEAR_BY_FRACTION(float actual, float target, float fraction) {
56     float tolerance = fabsf(target * fraction);
57 
58     if (target == 0 && fraction != 0) {
59         // If target is zero, this would force actual == target, which is too harsh.
60         // Relax this requirement a little. The value is determined empirically from the
61         // coefficients computed by the quadratic least squares algorithms.
62         tolerance = 1E-6;
63     }
64     EXPECT_NEAR(actual, target, tolerance);
65 }
66 
checkVelocity(std::optional<float> Vactual,std::optional<float> Vtarget)67 static void checkVelocity(std::optional<float> Vactual, std::optional<float> Vtarget) {
68     if (Vactual != std::nullopt) {
69         if (Vtarget == std::nullopt) {
70             FAIL() << "Expected no velocity, but found " << *Vactual;
71         }
72         EXPECT_NEAR_BY_FRACTION(*Vactual, *Vtarget, VELOCITY_TOLERANCE);
73     } else if (Vtarget != std::nullopt) {
74         FAIL() << "Expected  velocity, but found no velocity";
75     }
76 }
77 
78 struct Position {
79     float x;
80     float y;
81 
82     bool isResampled = false;
83 
84     /**
85      * If both values are NAN, then this is considered to be an empty entry (no pointer data).
86      * If only one of the values is NAN, this is still a valid entry,
87      * because we may only care about a single axis.
88      */
isValidandroid::Position89     bool isValid() const {
90         return !(isnan(x) && isnan(y));
91     }
92 };
93 
94 struct PlanarMotionEventEntry {
95     std::chrono::nanoseconds eventTime;
96     std::vector<Position> positions;
97 };
98 
getValidPointers(const std::vector<Position> & positions)99 static BitSet32 getValidPointers(const std::vector<Position>& positions) {
100     BitSet32 pointers;
101     for (size_t i = 0; i < positions.size(); i++) {
102         if (positions[i].isValid()) {
103             pointers.markBit(i);
104         }
105     }
106     return pointers;
107 }
108 
getChangingPointerId(BitSet32 pointers,BitSet32 otherPointers)109 static uint32_t getChangingPointerId(BitSet32 pointers, BitSet32 otherPointers) {
110     BitSet32 difference(pointers.value ^ otherPointers.value);
111     uint32_t pointerId = difference.clearFirstMarkedBit();
112     EXPECT_EQ(0U, difference.value) << "Only 1 pointer can enter or leave at a time";
113     return pointerId;
114 }
115 
resolveAction(const std::vector<Position> & lastPositions,const std::vector<Position> & currentPositions,const std::vector<Position> & nextPositions)116 static int32_t resolveAction(const std::vector<Position>& lastPositions,
117         const std::vector<Position>& currentPositions,
118         const std::vector<Position>& nextPositions) {
119     BitSet32 pointers = getValidPointers(currentPositions);
120     const uint32_t pointerCount = pointers.count();
121 
122     BitSet32 lastPointers = getValidPointers(lastPositions);
123     const uint32_t lastPointerCount = lastPointers.count();
124     if (lastPointerCount < pointerCount) {
125         // A new pointer is down
126         uint32_t pointerId = getChangingPointerId(pointers, lastPointers);
127         return AMOTION_EVENT_ACTION_POINTER_DOWN |
128                 (pointerId << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT);
129     }
130 
131     BitSet32 nextPointers = getValidPointers(nextPositions);
132     const uint32_t nextPointerCount = nextPointers.count();
133     if (pointerCount > nextPointerCount) {
134         // An existing pointer is leaving
135         uint32_t pointerId = getChangingPointerId(pointers, nextPointers);
136         return AMOTION_EVENT_ACTION_POINTER_UP |
137                 (pointerId << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT);
138     }
139 
140     return AMOTION_EVENT_ACTION_MOVE;
141 }
142 
createAxisScrollMotionEventStream(const std::vector<std::pair<std::chrono::nanoseconds,float>> & motions)143 static std::vector<MotionEvent> createAxisScrollMotionEventStream(
144         const std::vector<std::pair<std::chrono::nanoseconds, float>>& motions) {
145     std::vector<MotionEvent> events;
146     for (const auto& [timeStamp, value] : motions) {
147         EXPECT_TRUE(!isnan(value)) << "The entry at pointerId must be valid";
148 
149         PointerCoords coords[1];
150         coords[0].setAxisValue(AMOTION_EVENT_AXIS_SCROLL, value);
151 
152         PointerProperties properties[1];
153         properties[0].id = DEFAULT_POINTER_ID;
154 
155         MotionEvent event;
156         ui::Transform identityTransform;
157         event.initialize(InputEvent::nextId(), /*deviceId=*/5, AINPUT_SOURCE_ROTARY_ENCODER,
158                          ui::LogicalDisplayId::INVALID, INVALID_HMAC, AMOTION_EVENT_ACTION_SCROLL,
159                          /*actionButton=*/0, /*flags=*/0, AMOTION_EVENT_EDGE_FLAG_NONE, AMETA_NONE,
160                          /*buttonState=*/0, MotionClassification::NONE, identityTransform,
161                          /*xPrecision=*/0, /*yPrecision=*/0, AMOTION_EVENT_INVALID_CURSOR_POSITION,
162                          AMOTION_EVENT_INVALID_CURSOR_POSITION, identityTransform, /*downTime=*/0,
163                          timeStamp.count(), /*pointerCount=*/1, properties, coords);
164 
165         events.emplace_back(event);
166     }
167 
168     return events;
169 }
170 
createTouchMotionEventStream(const std::vector<PlanarMotionEventEntry> & motions)171 static std::vector<MotionEvent> createTouchMotionEventStream(
172         const std::vector<PlanarMotionEventEntry>& motions) {
173     if (motions.empty()) {
174         ADD_FAILURE() << "Need at least 1 sample to create a MotionEvent. Received empty vector.";
175     }
176 
177     std::vector<MotionEvent> events;
178     for (size_t i = 0; i < motions.size(); i++) {
179         const PlanarMotionEventEntry& entry = motions[i];
180         BitSet32 pointers = getValidPointers(entry.positions);
181         const uint32_t pointerCount = pointers.count();
182 
183         int32_t action;
184         if (i == 0) {
185             action = AMOTION_EVENT_ACTION_DOWN;
186             EXPECT_EQ(1U, pointerCount) << "First event should only have 1 pointer";
187         } else if ((i == motions.size() - 1) && pointerCount == 1) {
188             action = AMOTION_EVENT_ACTION_UP;
189         } else {
190             const PlanarMotionEventEntry& previousEntry = motions[i-1];
191             const PlanarMotionEventEntry& nextEntry = motions[i+1];
192             action = resolveAction(previousEntry.positions, entry.positions, nextEntry.positions);
193         }
194 
195         PointerCoords coords[pointerCount];
196         PointerProperties properties[pointerCount];
197         uint32_t pointerIndex = 0;
198         while(!pointers.isEmpty()) {
199             uint32_t pointerId = pointers.clearFirstMarkedBit();
200 
201             coords[pointerIndex].clear();
202             // We are treating column positions as pointerId
203             const Position& position = entry.positions[pointerId];
204             EXPECT_TRUE(position.isValid()) << "The entry at " << pointerId << " must be valid";
205             coords[pointerIndex].setAxisValue(AMOTION_EVENT_AXIS_X, position.x);
206             coords[pointerIndex].setAxisValue(AMOTION_EVENT_AXIS_Y, position.y);
207             coords[pointerIndex].isResampled = position.isResampled;
208 
209             properties[pointerIndex].id = pointerId;
210             properties[pointerIndex].toolType = ToolType::FINGER;
211             pointerIndex++;
212         }
213         EXPECT_EQ(pointerIndex, pointerCount);
214 
215         MotionEvent event;
216         ui::Transform identityTransform;
217         event.initialize(InputEvent::nextId(), /*deviceId=*/0, AINPUT_SOURCE_TOUCHSCREEN,
218                          DISPLAY_ID, INVALID_HMAC, action, /*actionButton=*/0, /*flags=*/0,
219                          AMOTION_EVENT_EDGE_FLAG_NONE, AMETA_NONE, /*buttonState=*/0,
220                          MotionClassification::NONE, identityTransform, /*xPrecision=*/0,
221                          /*yPrecision=*/0, AMOTION_EVENT_INVALID_CURSOR_POSITION,
222                          AMOTION_EVENT_INVALID_CURSOR_POSITION, identityTransform, /*downTime=*/0,
223                          entry.eventTime.count(), pointerCount, properties, coords);
224 
225         events.emplace_back(event);
226     }
227 
228     return events;
229 }
230 
computeVelocity(const VelocityTracker::Strategy strategy,const std::vector<MotionEvent> & events,int32_t axis,uint32_t pointerId=DEFAULT_POINTER_ID)231 static std::optional<float> computeVelocity(const VelocityTracker::Strategy strategy,
232                                             const std::vector<MotionEvent>& events, int32_t axis,
233                                             uint32_t pointerId = DEFAULT_POINTER_ID) {
234     VelocityTracker vt(strategy);
235 
236     for (const MotionEvent& event : events) {
237         vt.addMovement(event);
238     }
239 
240     return vt.getVelocity(axis, pointerId);
241 }
242 
computePlanarVelocity(const VelocityTracker::Strategy strategy,const std::vector<PlanarMotionEventEntry> & motions,int32_t axis,uint32_t pointerId)243 static std::optional<float> computePlanarVelocity(
244         const VelocityTracker::Strategy strategy,
245         const std::vector<PlanarMotionEventEntry>& motions, int32_t axis, uint32_t pointerId) {
246     std::vector<MotionEvent> events = createTouchMotionEventStream(motions);
247     return computeVelocity(strategy, events, axis, pointerId);
248 }
249 
computeAndCheckVelocity(const VelocityTracker::Strategy strategy,const std::vector<PlanarMotionEventEntry> & motions,int32_t axis,std::optional<float> targetVelocity,uint32_t pointerId=DEFAULT_POINTER_ID)250 static void computeAndCheckVelocity(const VelocityTracker::Strategy strategy,
251                                     const std::vector<PlanarMotionEventEntry>& motions,
252                                     int32_t axis, std::optional<float> targetVelocity,
253                                     uint32_t pointerId = DEFAULT_POINTER_ID) {
254     checkVelocity(computePlanarVelocity(strategy, motions, axis, pointerId), targetVelocity);
255 }
256 
computeAndCheckAxisScrollVelocity(const VelocityTracker::Strategy strategy,const std::vector<std::pair<std::chrono::nanoseconds,float>> & motions,std::optional<float> targetVelocity)257 static void computeAndCheckAxisScrollVelocity(
258         const VelocityTracker::Strategy strategy,
259         const std::vector<std::pair<std::chrono::nanoseconds, float>>& motions,
260         std::optional<float> targetVelocity) {
261     std::vector<MotionEvent> events = createAxisScrollMotionEventStream(motions);
262     checkVelocity(computeVelocity(strategy, events, AMOTION_EVENT_AXIS_SCROLL), targetVelocity);
263     // The strategy LSQ2 is not compatible with AXIS_SCROLL. In those situations, we should fall
264     // back to a strategy that supports differential axes.
265     checkVelocity(computeVelocity(VelocityTracker::Strategy::LSQ2, events,
266                                   AMOTION_EVENT_AXIS_SCROLL),
267                   targetVelocity);
268 }
269 
computeAndCheckQuadraticVelocity(const std::vector<PlanarMotionEventEntry> & motions,float velocity)270 static void computeAndCheckQuadraticVelocity(const std::vector<PlanarMotionEventEntry>& motions,
271                                              float velocity) {
272     std::optional<float> velocityX =
273             computePlanarVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
274                                   DEFAULT_POINTER_ID);
275     std::optional<float> velocityY =
276             computePlanarVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
277                                   DEFAULT_POINTER_ID);
278     ASSERT_TRUE(velocityX);
279     ASSERT_TRUE(velocityY);
280 
281     EXPECT_NEAR_BY_FRACTION(*velocityX, velocity, QUADRATIC_VELOCITY_TOLERANCE);
282     EXPECT_NEAR_BY_FRACTION(*velocityY, velocity, QUADRATIC_VELOCITY_TOLERANCE);
283 }
284 
285 /*
286  *================== VelocityTracker tests that do not require test motion data ====================
287  */
TEST(SimpleVelocityTrackerTest,TestSupportedAxis)288 TEST(SimpleVelocityTrackerTest, TestSupportedAxis) {
289     // Note that we are testing up to the max possible axis value, plus 3 more values. We are going
290     // beyond the max value to add a bit more protection. "3" is chosen arbitrarily to cover a few
291     // more values beyond the max.
292     for (int32_t axis = 0; axis <= AMOTION_EVENT_MAXIMUM_VALID_AXIS_VALUE + 3; axis++) {
293         switch (axis) {
294             case AMOTION_EVENT_AXIS_X:
295             case AMOTION_EVENT_AXIS_Y:
296             case AMOTION_EVENT_AXIS_SCROLL:
297                 EXPECT_TRUE(VelocityTracker::isAxisSupported(axis)) << axis << " is supported";
298                 break;
299             default:
300                 EXPECT_FALSE(VelocityTracker::isAxisSupported(axis)) << axis << " is NOT supported";
301         }
302     }
303 }
304 
305 /*
306  * ================== VelocityTracker tests generated manually =====================================
307  */
TEST_F(VelocityTrackerTest,TestDefaultStrategiesForPlanarAxes)308 TEST_F(VelocityTrackerTest, TestDefaultStrategiesForPlanarAxes) {
309     std::vector<PlanarMotionEventEntry> motions = {{10ms, {{2, 4}}},
310                                                    {20ms, {{4, 12}}},
311                                                    {30ms, {{6, 20}}},
312                                                    {40ms, {{10, 30}}}};
313 
314     EXPECT_EQ(computePlanarVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
315                                     DEFAULT_POINTER_ID),
316               computePlanarVelocity(VelocityTracker::Strategy::DEFAULT, motions,
317                                     AMOTION_EVENT_AXIS_X, DEFAULT_POINTER_ID));
318     EXPECT_EQ(computePlanarVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
319                                     DEFAULT_POINTER_ID),
320               computePlanarVelocity(VelocityTracker::Strategy::DEFAULT, motions,
321                                     AMOTION_EVENT_AXIS_Y, DEFAULT_POINTER_ID));
322 }
323 
TEST_F(VelocityTrackerTest,TestComputedVelocity)324 TEST_F(VelocityTrackerTest, TestComputedVelocity) {
325     VelocityTracker::ComputedVelocity computedVelocity;
326 
327     computedVelocity.addVelocity(AMOTION_EVENT_AXIS_X, /*id=*/0, /*velocity=*/200);
328     computedVelocity.addVelocity(AMOTION_EVENT_AXIS_X, /*id=*/26U, /*velocity=*/400);
329     computedVelocity.addVelocity(AMOTION_EVENT_AXIS_X, /*id=*/27U, /*velocity=*/650);
330     computedVelocity.addVelocity(AMOTION_EVENT_AXIS_X, MAX_POINTER_ID, /*velocity=*/750);
331     computedVelocity.addVelocity(AMOTION_EVENT_AXIS_Y, /*id=*/0, /*velocity=*/1000);
332     computedVelocity.addVelocity(AMOTION_EVENT_AXIS_Y, /*id=*/26U, /*velocity=*/2000);
333     computedVelocity.addVelocity(AMOTION_EVENT_AXIS_Y, /*id=*/27U, /*velocity=*/3000);
334     computedVelocity.addVelocity(AMOTION_EVENT_AXIS_Y, MAX_POINTER_ID, /*velocity=*/4000);
335 
336     // Check the axes/indices with velocity.
337     EXPECT_EQ(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, /*id=*/0U)), 200);
338     EXPECT_EQ(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, /*id=*/26U)), 400);
339     EXPECT_EQ(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, /*id=*/27U)), 650);
340     EXPECT_EQ(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, MAX_POINTER_ID)), 750);
341     EXPECT_EQ(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_Y, /*id=*/0U)), 1000);
342     EXPECT_EQ(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_Y, /*id=*/26U)), 2000);
343     EXPECT_EQ(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_Y, /*id=*/27U)), 3000);
344     EXPECT_EQ(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_Y, MAX_POINTER_ID)), 4000);
345     for (uint32_t id = 0; id <= MAX_POINTER_ID; id++) {
346         // Since no data was added for AXIS_SCROLL, expect empty value for the axis for any id.
347         EXPECT_FALSE(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_SCROLL, id))
348                 << "Empty scroll data expected at id=" << id;
349         if (id == 0 || id == 26U || id == 27U || id == MAX_POINTER_ID) {
350             // Already checked above; continue.
351             continue;
352         }
353         // No data was added to X/Y for this id, expect empty value.
354         EXPECT_FALSE(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, id))
355                 << "Empty X data expected at id=" << id;
356         EXPECT_FALSE(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_Y, id))
357                 << "Empty Y data expected at id=" << id;
358     }
359     // Out-of-bounds ids should given empty values.
360     EXPECT_FALSE(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, -1));
361     EXPECT_FALSE(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, MAX_POINTER_ID + 1));
362 }
363 
364 /**
365  * For a single pointer, the resampled data is ignored.
366  */
TEST_F(VelocityTrackerTest,SinglePointerResampledData)367 TEST_F(VelocityTrackerTest, SinglePointerResampledData) {
368     std::vector<PlanarMotionEventEntry> motions = {{10ms, {{1, 2}}},
369                                                    {20ms, {{2, 4}}},
370                                                    {30ms, {{3, 6}}},
371                                                    {35ms, {{30, 60, .isResampled = true}}},
372                                                    {40ms, {{4, 8}}}};
373 
374     computeAndCheckVelocity(VelocityTracker::Strategy::DEFAULT, motions, AMOTION_EVENT_AXIS_X, 100);
375     computeAndCheckVelocity(VelocityTracker::Strategy::DEFAULT, motions, AMOTION_EVENT_AXIS_Y, 200);
376 }
377 
378 /**
379  * For multiple pointers, the resampled data is ignored on a per-pointer basis. If a certain pointer
380  * does not have a resampled value, all of the points are used.
381  */
TEST_F(VelocityTrackerTest,MultiPointerResampledData)382 TEST_F(VelocityTrackerTest, MultiPointerResampledData) {
383     std::vector<PlanarMotionEventEntry> motions = {
384             {0ms, {{0, 0}}},
385             {10ms, {{1, 0}, {1, 0}}},
386             {20ms, {{2, 0}, {2, 0}}},
387             {30ms, {{3, 0}, {3, 0}}},
388             {35ms, {{30, 0, .isResampled = true}, {30, 0}}},
389             {40ms, {{4, 0}, {4, 0}}},
390             {45ms, {{5, 0}}}, // ACTION_UP
391     };
392 
393     // Sample at t=35ms breaks trend. It's marked as resampled for the first pointer, so it should
394     // be ignored, and the resulting velocity should be linear. For the second pointer, it's not
395     // resampled, so it should cause the velocity to be non-linear.
396     computeAndCheckVelocity(VelocityTracker::Strategy::DEFAULT, motions, AMOTION_EVENT_AXIS_X, 100,
397                             /*pointerId=*/0);
398     computeAndCheckVelocity(VelocityTracker::Strategy::DEFAULT, motions, AMOTION_EVENT_AXIS_X, 3455,
399                             /*pointerId=*/1);
400 }
401 
TEST_F(VelocityTrackerTest,TestGetComputedVelocity)402 TEST_F(VelocityTrackerTest, TestGetComputedVelocity) {
403     std::vector<PlanarMotionEventEntry> motions = {
404             {235089067457000ns, {{528.00, 0}}}, {235089084684000ns, {{527.00, 0}}},
405             {235089093349000ns, {{527.00, 0}}}, {235089095677625ns, {{527.00, 0}}},
406             {235089101859000ns, {{527.00, 0}}}, {235089110378000ns, {{528.00, 0}}},
407             {235089112497111ns, {{528.25, 0}}}, {235089118760000ns, {{531.00, 0}}},
408             {235089126686000ns, {{535.00, 0}}}, {235089129316820ns, {{536.33, 0}}},
409             {235089135199000ns, {{540.00, 0}}}, {235089144297000ns, {{546.00, 0}}},
410             {235089146136443ns, {{547.21, 0}}}, {235089152923000ns, {{553.00, 0}}},
411             {235089160784000ns, {{559.00, 0}}}, {235089162955851ns, {{560.66, 0}}},
412             {235089162955851ns, {{560.66, 0}}}, // ACTION_UP
413     };
414     VelocityTracker vt(VelocityTracker::Strategy::IMPULSE);
415     std::vector<MotionEvent> events = createTouchMotionEventStream(motions);
416     for (const MotionEvent& event : events) {
417         vt.addMovement(event);
418     }
419 
420     float maxFloat = std::numeric_limits<float>::max();
421     VelocityTracker::ComputedVelocity computedVelocity;
422     computedVelocity = vt.getComputedVelocity(/*units=*/1000, maxFloat);
423     checkVelocity(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, DEFAULT_POINTER_ID)),
424                   764.345703);
425 
426     // Expect X velocity to be scaled with respective to provided units.
427     computedVelocity = vt.getComputedVelocity(/*units=*/1000000, maxFloat);
428     checkVelocity(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, DEFAULT_POINTER_ID)),
429                   764345.703);
430 
431     // Expect X velocity to be clamped by provided max velocity.
432     computedVelocity = vt.getComputedVelocity(/*units=*/1000000, 1000);
433     checkVelocity(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, DEFAULT_POINTER_ID)), 1000);
434 
435     // All 0 data for Y; expect 0 velocity.
436     EXPECT_EQ(*(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_Y, DEFAULT_POINTER_ID)), 0);
437 
438     // No data for scroll-axis; expect empty velocity.
439     EXPECT_FALSE(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_SCROLL, DEFAULT_POINTER_ID));
440 }
441 
TEST_F(VelocityTrackerTest,TestApiInteractionsWithNoMotionEvents)442 TEST_F(VelocityTrackerTest, TestApiInteractionsWithNoMotionEvents) {
443     VelocityTracker vt(VelocityTracker::Strategy::DEFAULT);
444 
445     EXPECT_FALSE(vt.getVelocity(AMOTION_EVENT_AXIS_X, DEFAULT_POINTER_ID));
446 
447     VelocityTracker::ComputedVelocity computedVelocity = vt.getComputedVelocity(1000, 1000);
448     for (uint32_t id = 0; id <= MAX_POINTER_ID; id++) {
449         EXPECT_FALSE(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_X, id));
450         EXPECT_FALSE(computedVelocity.getVelocity(AMOTION_EVENT_AXIS_Y, id));
451     }
452 
453     EXPECT_EQ(-1, vt.getActivePointerId());
454 
455     // Make sure that the clearing functions execute without an issue.
456     vt.clearPointer(7U);
457     vt.clear();
458 }
459 
TEST_F(VelocityTrackerTest,ThreePointsPositiveVelocityTest)460 TEST_F(VelocityTrackerTest, ThreePointsPositiveVelocityTest) {
461     // Same coordinate is reported 2 times in a row
462     // It is difficult to determine the correct answer here, but at least the direction
463     // of the reported velocity should be positive.
464     std::vector<PlanarMotionEventEntry> motions = {
465             {0ms, {{273, 0}}},
466             {12585us, {{293, 0}}},
467             {14730us, {{293, 0}}},
468             {14730us, {{293, 0}}}, // ACTION_UP
469     };
470     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
471                             1600);
472 }
473 
TEST_F(VelocityTrackerTest,ThreePointsZeroVelocityTest)474 TEST_F(VelocityTrackerTest, ThreePointsZeroVelocityTest) {
475     // Same coordinate is reported 3 times in a row
476     std::vector<PlanarMotionEventEntry> motions = {
477             {0ms, {{293, 0}}},
478             {6132us, {{293, 0}}},
479             {11283us, {{293, 0}}},
480             {11283us, {{293, 0}}}, // ACTION_UP
481     };
482     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X, 0);
483     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X, 0);
484 }
485 
TEST_F(VelocityTrackerTest,ThreePointsLinearVelocityTest)486 TEST_F(VelocityTrackerTest, ThreePointsLinearVelocityTest) {
487     // Fixed velocity at 5 points per 10 milliseconds
488     std::vector<PlanarMotionEventEntry> motions = {
489             {0ms, {{0, 0}}}, {10ms, {{5, 0}}}, {20ms, {{10, 0}}}, {20ms, {{10, 0}}}, // ACTION_UP
490     };
491     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X, 500);
492     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X, 500);
493 }
494 
495 /**
496  * When the stream is terminated with ACTION_CANCEL, the resulting velocity should be 0.
497  */
TEST_F(VelocityTrackerTest,ActionCancelResultsInZeroVelocity)498 TEST_F(VelocityTrackerTest, ActionCancelResultsInZeroVelocity) {
499     std::vector<PlanarMotionEventEntry> motions = {
500             {0ms, {{0, 0}}},    // DOWN
501             {10ms, {{5, 10}}},  // MOVE
502             {20ms, {{10, 20}}}, // MOVE
503             {20ms, {{10, 20}}}, // ACTION_UP
504     };
505     std::vector<MotionEvent> events = createTouchMotionEventStream(motions);
506     // By default, `createTouchMotionEventStream` produces an event stream that terminates with
507     // ACTION_UP. We need to manually change it to ACTION_CANCEL.
508     MotionEvent& lastEvent = events.back();
509     lastEvent.setAction(AMOTION_EVENT_ACTION_CANCEL);
510     lastEvent.setFlags(lastEvent.getFlags() | AMOTION_EVENT_FLAG_CANCELED);
511     const int32_t pointerId = lastEvent.getPointerId(0);
512     checkVelocity(computeVelocity(VelocityTracker::Strategy::IMPULSE, events, AMOTION_EVENT_AXIS_X,
513                                   pointerId),
514                   /*targetVelocity*/ std::nullopt);
515     checkVelocity(computeVelocity(VelocityTracker::Strategy::IMPULSE, events, AMOTION_EVENT_AXIS_Y,
516                                   pointerId),
517                   /*targetVelocity*/ std::nullopt);
518     checkVelocity(computeVelocity(VelocityTracker::Strategy::LSQ2, events, AMOTION_EVENT_AXIS_X,
519                                   pointerId),
520                   /*targetVelocity*/ std::nullopt);
521     checkVelocity(computeVelocity(VelocityTracker::Strategy::LSQ2, events, AMOTION_EVENT_AXIS_Y,
522                                   pointerId),
523                   /*targetVelocity*/ std::nullopt);
524 }
525 
526 /**
527  * When the stream is terminated with ACTION_CANCEL, the resulting velocity should be 0.
528  */
TEST_F(VelocityTrackerTest,ActionPointerCancelResultsInZeroVelocityForThatPointer)529 TEST_F(VelocityTrackerTest, ActionPointerCancelResultsInZeroVelocityForThatPointer) {
530     std::vector<PlanarMotionEventEntry> motions = {
531             {0ms, {{0, 5}, {NAN, NAN}}},    // DOWN
532             {0ms, {{0, 5}, {10, 15}}},      // POINTER_DOWN
533             {10ms, {{5, 10}, {15, 20}}},    // MOVE
534             {20ms, {{10, 15}, {20, 25}}},   // MOVE
535             {30ms, {{10, 15}, {20, 25}}},   // POINTER_UP
536             {30ms, {{10, 15}, {NAN, NAN}}}, // UP
537     };
538     std::vector<MotionEvent> events = createTouchMotionEventStream(motions);
539     // Cancel the lifting pointer of the ACTION_POINTER_UP event
540     MotionEvent& pointerUpEvent = events.rbegin()[1];
541     pointerUpEvent.setFlags(pointerUpEvent.getFlags() | AMOTION_EVENT_FLAG_CANCELED);
542     const int32_t pointerId = pointerUpEvent.getPointerId(pointerUpEvent.getActionIndex());
543     // Double check the stream
544     ASSERT_EQ(1, pointerId);
545     ASSERT_EQ(AMOTION_EVENT_ACTION_POINTER_UP, pointerUpEvent.getActionMasked());
546     ASSERT_EQ(AMOTION_EVENT_ACTION_UP, events.back().getActionMasked());
547 
548     // Ensure the velocity of the lifting pointer is zero
549     checkVelocity(computeVelocity(VelocityTracker::Strategy::IMPULSE, events, AMOTION_EVENT_AXIS_X,
550                                   pointerId),
551                   /*targetVelocity*/ std::nullopt);
552     checkVelocity(computeVelocity(VelocityTracker::Strategy::IMPULSE, events, AMOTION_EVENT_AXIS_Y,
553                                   pointerId),
554                   /*targetVelocity*/ std::nullopt);
555     checkVelocity(computeVelocity(VelocityTracker::Strategy::LSQ2, events, AMOTION_EVENT_AXIS_X,
556                                   pointerId),
557                   /*targetVelocity*/ std::nullopt);
558     checkVelocity(computeVelocity(VelocityTracker::Strategy::LSQ2, events, AMOTION_EVENT_AXIS_Y,
559                                   pointerId),
560                   /*targetVelocity*/ std::nullopt);
561 
562     // The remaining pointer should have the correct velocity.
563     const int32_t remainingPointerId = events.back().getPointerId(0);
564     ASSERT_EQ(0, remainingPointerId);
565     checkVelocity(computeVelocity(VelocityTracker::Strategy::IMPULSE, events, AMOTION_EVENT_AXIS_X,
566                                   remainingPointerId),
567                   /*targetVelocity*/ 500);
568     checkVelocity(computeVelocity(VelocityTracker::Strategy::IMPULSE, events, AMOTION_EVENT_AXIS_Y,
569                                   remainingPointerId),
570                   /*targetVelocity*/ 500);
571     checkVelocity(computeVelocity(VelocityTracker::Strategy::LSQ2, events, AMOTION_EVENT_AXIS_X,
572                                   remainingPointerId),
573                   /*targetVelocity*/ 500);
574     checkVelocity(computeVelocity(VelocityTracker::Strategy::LSQ2, events, AMOTION_EVENT_AXIS_Y,
575                                   remainingPointerId),
576                   /*targetVelocity*/ 500);
577 }
578 
579 /**
580  * ================== VelocityTracker tests generated by recording real events =====================
581  *
582  * To add a test, record the input coordinates and event times to all calls
583  * to void VelocityTracker::addMovement(const MotionEvent* event).
584  * Also record all calls to VelocityTracker::clear().
585  * Finally, record the output of VelocityTracker::getVelocity(...)
586  * This will give you the necessary data to create a new test.
587  *
588  * Another good way to generate this data is to use 'dumpsys input' just after the event has
589  * occurred.
590  */
591 
592 // --------------- Recorded by hand on swordfish ---------------------------------------------------
TEST_F(VelocityTrackerTest,SwordfishFlingDown)593 TEST_F(VelocityTrackerTest, SwordfishFlingDown) {
594     // Recording of a fling on Swordfish that could cause a fling in the wrong direction
595     std::vector<PlanarMotionEventEntry> motions = {
596         { 0ms, {{271, 96}} },
597         { 16071042ns, {{269.786346, 106.922775}} },
598         { 35648403ns, {{267.983063, 156.660034}} },
599         { 52313925ns, {{262.638397, 220.339081}} },
600         { 68976522ns, {{266.138824, 331.581116}} },
601         { 85639375ns, {{274.79245, 428.113159}} },
602         { 96948871ns, {{274.79245, 428.113159}} },
603         { 96948871ns, {{274.79245, 428.113159}} }, // ACTION_UP
604     };
605     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
606                             623.577637);
607     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
608                             5970.7309);
609 }
610 
611 // --------------- Recorded by hand on sailfish, generated by a script -----------------------------
612 // For some of these tests, the X-direction velocity checking has been removed, because the lsq2
613 // and the impulse VelocityTrackerStrategies did not agree within 20%.
614 // Since the flings were recorded in the Y-direction, the intentional user action should only
615 // be relevant for the Y axis.
616 // There have been also cases where lsq2 and impulse disagreed more than 20% in the Y-direction.
617 // Those recordings have been discarded because we didn't feel one strategy's interpretation was
618 // more correct than another's but didn't want to increase the tolerance for the entire test suite.
619 //
620 // There are 18 tests total below: 9 in the positive Y direction and 9 in the opposite.
621 // The recordings were loosely binned into 3 categories - slow, faster, and fast, which roughly
622 // characterizes the velocity of the finger motion.
623 // These can be treated approximately as:
624 // slow - less than 1 page gets scrolled
625 // faster - more than 1 page gets scrolled, but less than 3
626 // fast - entire list is scrolled (fling is done as hard as possible)
627 
TEST_F(VelocityTrackerTest,SailfishFlingUpSlow1)628 TEST_F(VelocityTrackerTest, SailfishFlingUpSlow1) {
629     // Sailfish - fling up - slow - 1
630     std::vector<PlanarMotionEventEntry> motions = {
631         { 235089067457000ns, {{528.00, 983.00}} },
632         { 235089084684000ns, {{527.00, 981.00}} },
633         { 235089093349000ns, {{527.00, 977.00}} },
634         { 235089095677625ns, {{527.00, 975.93}} },
635         { 235089101859000ns, {{527.00, 970.00}} },
636         { 235089110378000ns, {{528.00, 960.00}} },
637         { 235089112497111ns, {{528.25, 957.51}} },
638         { 235089118760000ns, {{531.00, 946.00}} },
639         { 235089126686000ns, {{535.00, 931.00}} },
640         { 235089129316820ns, {{536.33, 926.02}} },
641         { 235089135199000ns, {{540.00, 914.00}} },
642         { 235089144297000ns, {{546.00, 896.00}} },
643         { 235089146136443ns, {{547.21, 892.36}} },
644         { 235089152923000ns, {{553.00, 877.00}} },
645         { 235089160784000ns, {{559.00, 851.00}} },
646         { 235089162955851ns, {{560.66, 843.82}} },
647         { 235089162955851ns, {{560.66, 843.82}} }, // ACTION_UP
648     };
649     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
650                             764.345703);
651     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
652                             951.698181);
653     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
654                             -3604.819336);
655     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
656                             -3044.966064);
657 }
658 
659 
TEST_F(VelocityTrackerTest,SailfishFlingUpSlow2)660 TEST_F(VelocityTrackerTest, SailfishFlingUpSlow2) {
661     // Sailfish - fling up - slow - 2
662     std::vector<PlanarMotionEventEntry> motions = {
663         { 235110560704000ns, {{522.00, 1107.00}} },
664         { 235110575764000ns, {{522.00, 1107.00}} },
665         { 235110584385000ns, {{522.00, 1107.00}} },
666         { 235110588421179ns, {{521.52, 1106.52}} },
667         { 235110592830000ns, {{521.00, 1106.00}} },
668         { 235110601385000ns, {{520.00, 1104.00}} },
669         { 235110605088160ns, {{519.14, 1102.27}} },
670         { 235110609952000ns, {{518.00, 1100.00}} },
671         { 235110618353000ns, {{517.00, 1093.00}} },
672         { 235110621755146ns, {{516.60, 1090.17}} },
673         { 235110627010000ns, {{517.00, 1081.00}} },
674         { 235110634785000ns, {{518.00, 1063.00}} },
675         { 235110638422450ns, {{518.87, 1052.58}} },
676         { 235110643161000ns, {{520.00, 1039.00}} },
677         { 235110651767000ns, {{524.00, 1011.00}} },
678         { 235110655089581ns, {{525.54, 1000.19}} },
679         { 235110660368000ns, {{530.00, 980.00}} },
680         { 235110660368000ns, {{530.00, 980.00}} }, // ACTION_UP
681     };
682     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
683                             -4096.583008);
684     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
685                             -3455.094238);
686 }
687 
688 
TEST_F(VelocityTrackerTest,SailfishFlingUpSlow3)689 TEST_F(VelocityTrackerTest, SailfishFlingUpSlow3) {
690     // Sailfish - fling up - slow - 3
691     std::vector<PlanarMotionEventEntry> motions = {
692         { 792536237000ns, {{580.00, 1317.00}} },
693         { 792541538987ns, {{580.63, 1311.94}} },
694         { 792544613000ns, {{581.00, 1309.00}} },
695         { 792552301000ns, {{583.00, 1295.00}} },
696         { 792558362309ns, {{585.13, 1282.92}} },
697         { 792560828000ns, {{586.00, 1278.00}} },
698         { 792569446000ns, {{589.00, 1256.00}} },
699         { 792575185095ns, {{591.54, 1241.41}} },
700         { 792578491000ns, {{593.00, 1233.00}} },
701         { 792587044000ns, {{597.00, 1211.00}} },
702         { 792592008172ns, {{600.28, 1195.92}} },
703         { 792594616000ns, {{602.00, 1188.00}} },
704         { 792603129000ns, {{607.00, 1167.00}} },
705         { 792608831290ns, {{609.48, 1155.83}} },
706         { 792612321000ns, {{611.00, 1149.00}} },
707         { 792620768000ns, {{615.00, 1131.00}} },
708         { 792625653873ns, {{617.32, 1121.73}} },
709         { 792629200000ns, {{619.00, 1115.00}} },
710         { 792629200000ns, {{619.00, 1115.00}} }, // ACTION_UP
711     };
712     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
713                             574.33429);
714     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
715                             617.40564);
716     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
717                             -2361.982666);
718     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
719                             -2500.055664);
720 }
721 
722 
TEST_F(VelocityTrackerTest,SailfishFlingUpFaster1)723 TEST_F(VelocityTrackerTest, SailfishFlingUpFaster1) {
724     // Sailfish - fling up - faster - 1
725     std::vector<PlanarMotionEventEntry> motions = {
726         { 235160420675000ns, {{610.00, 1042.00}} },
727         { 235160428220000ns, {{609.00, 1026.00}} },
728         { 235160436544000ns, {{609.00, 1024.00}} },
729         { 235160441852394ns, {{609.64, 1020.82}} },
730         { 235160444878000ns, {{610.00, 1019.00}} },
731         { 235160452673000ns, {{613.00, 1006.00}} },
732         { 235160458519743ns, {{617.18, 992.06}} },
733         { 235160461061000ns, {{619.00, 986.00}} },
734         { 235160469798000ns, {{627.00, 960.00}} },
735         { 235160475186713ns, {{632.22, 943.02}} },
736         { 235160478051000ns, {{635.00, 934.00}} },
737         { 235160486489000ns, {{644.00, 906.00}} },
738         { 235160491853697ns, {{649.56, 890.56}} },
739         { 235160495177000ns, {{653.00, 881.00}} },
740         { 235160504148000ns, {{662.00, 858.00}} },
741         { 235160509231495ns, {{666.81, 845.37}} },
742         { 235160512603000ns, {{670.00, 837.00}} },
743         { 235160520366000ns, {{679.00, 814.00}} },
744         { 235160520366000ns, {{679.00, 814.00}} }, // ACTION_UP
745     };
746     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
747                             1274.141724);
748     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
749                             1438.53186);
750     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
751                             -3001.4348);
752     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
753                             -3695.859619);
754 }
755 
756 
TEST_F(VelocityTrackerTest,SailfishFlingUpFaster2)757 TEST_F(VelocityTrackerTest, SailfishFlingUpFaster2) {
758     // Sailfish - fling up - faster - 2
759     std::vector<PlanarMotionEventEntry> motions = {
760         { 847153808000ns, {{576.00, 1264.00}} },
761         { 847171174000ns, {{576.00, 1262.00}} },
762         { 847179640000ns, {{576.00, 1257.00}} },
763         { 847185187540ns, {{577.41, 1249.22}} },
764         { 847187487000ns, {{578.00, 1246.00}} },
765         { 847195710000ns, {{581.00, 1227.00}} },
766         { 847202027059ns, {{583.93, 1209.40}} },
767         { 847204324000ns, {{585.00, 1203.00}} },
768         { 847212672000ns, {{590.00, 1176.00}} },
769         { 847218861395ns, {{594.36, 1157.11}} },
770         { 847221190000ns, {{596.00, 1150.00}} },
771         { 847230484000ns, {{602.00, 1124.00}} },
772         { 847235701400ns, {{607.56, 1103.83}} },
773         { 847237986000ns, {{610.00, 1095.00}} },
774         { 847237986000ns, {{610.00, 1095.00}} }, // ACTION_UP
775     };
776     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
777                             -4280.07959);
778     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
779                             -4241.004395);
780 }
781 
782 
TEST_F(VelocityTrackerTest,SailfishFlingUpFaster3)783 TEST_F(VelocityTrackerTest, SailfishFlingUpFaster3) {
784     // Sailfish - fling up - faster - 3
785     std::vector<PlanarMotionEventEntry> motions = {
786         { 235200532789000ns, {{507.00, 1084.00}} },
787         { 235200549221000ns, {{507.00, 1083.00}} },
788         { 235200557841000ns, {{507.00, 1081.00}} },
789         { 235200558051189ns, {{507.00, 1080.95}} },
790         { 235200566314000ns, {{507.00, 1078.00}} },
791         { 235200574876586ns, {{508.97, 1070.12}} },
792         { 235200575006000ns, {{509.00, 1070.00}} },
793         { 235200582900000ns, {{514.00, 1054.00}} },
794         { 235200591276000ns, {{525.00, 1023.00}} },
795         { 235200591701829ns, {{525.56, 1021.42}} },
796         { 235200600064000ns, {{542.00, 976.00}} },
797         { 235200608519000ns, {{563.00, 911.00}} },
798         { 235200608527086ns, {{563.02, 910.94}} },
799         { 235200616933000ns, {{590.00, 844.00}} },
800         { 235200616933000ns, {{590.00, 844.00}} }, // ACTION_UP
801     };
802     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
803                             -8715.686523);
804     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
805                             -7639.026367);
806 }
807 
808 
TEST_F(VelocityTrackerTest,SailfishFlingUpFast1)809 TEST_F(VelocityTrackerTest, SailfishFlingUpFast1) {
810     // Sailfish - fling up - fast - 1
811     std::vector<PlanarMotionEventEntry> motions = {
812         { 920922149000ns, {{561.00, 1412.00}} },
813         { 920930185000ns, {{559.00, 1377.00}} },
814         { 920930262463ns, {{558.98, 1376.66}} },
815         { 920938547000ns, {{559.00, 1371.00}} },
816         { 920947096857ns, {{562.91, 1342.68}} },
817         { 920947302000ns, {{563.00, 1342.00}} },
818         { 920955502000ns, {{577.00, 1272.00}} },
819         { 920963931021ns, {{596.87, 1190.54}} },
820         { 920963987000ns, {{597.00, 1190.00}} },
821         { 920972530000ns, {{631.00, 1093.00}} },
822         { 920980765511ns, {{671.31, 994.68}} },
823         { 920980906000ns, {{672.00, 993.00}} },
824         { 920989261000ns, {{715.00, 903.00}} },
825         { 920989261000ns, {{715.00, 903.00}} }, // ACTION_UP
826     };
827     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
828                             5670.329102);
829     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
830                             5991.866699);
831     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
832                             -13021.101562);
833     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
834                             -15093.995117);
835 }
836 
837 
TEST_F(VelocityTrackerTest,SailfishFlingUpFast2)838 TEST_F(VelocityTrackerTest, SailfishFlingUpFast2) {
839     // Sailfish - fling up - fast - 2
840     std::vector<PlanarMotionEventEntry> motions = {
841         { 235247153233000ns, {{518.00, 1168.00}} },
842         { 235247170452000ns, {{517.00, 1167.00}} },
843         { 235247178908000ns, {{515.00, 1159.00}} },
844         { 235247179556213ns, {{514.85, 1158.39}} },
845         { 235247186821000ns, {{515.00, 1125.00}} },
846         { 235247195265000ns, {{521.00, 1051.00}} },
847         { 235247196389476ns, {{521.80, 1041.15}} },
848         { 235247203649000ns, {{538.00, 932.00}} },
849         { 235247212253000ns, {{571.00, 794.00}} },
850         { 235247213222491ns, {{574.72, 778.45}} },
851         { 235247220736000ns, {{620.00, 641.00}} },
852         { 235247220736000ns, {{620.00, 641.00}} }, // ACTION_UP
853     };
854     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
855                             -20286.958984);
856     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
857                             -20494.587891);
858 }
859 
860 
TEST_F(VelocityTrackerTest,SailfishFlingUpFast3)861 TEST_F(VelocityTrackerTest, SailfishFlingUpFast3) {
862     // Sailfish - fling up - fast - 3
863     std::vector<PlanarMotionEventEntry> motions = {
864         { 235302568736000ns, {{529.00, 1167.00}} },
865         { 235302576644000ns, {{523.00, 1140.00}} },
866         { 235302579395063ns, {{520.91, 1130.61}} },
867         { 235302585140000ns, {{522.00, 1130.00}} },
868         { 235302593615000ns, {{527.00, 1065.00}} },
869         { 235302596207444ns, {{528.53, 1045.12}} },
870         { 235302602102000ns, {{559.00, 872.00}} },
871         { 235302610545000ns, {{652.00, 605.00}} },
872         { 235302613019881ns, {{679.26, 526.73}} },
873         { 235302613019881ns, {{679.26, 526.73}} }, // ACTION_UP
874     };
875     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
876                             -39295.941406);
877     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
878                             -36461.421875);
879 }
880 
881 
TEST_F(VelocityTrackerTest,SailfishFlingDownSlow1)882 TEST_F(VelocityTrackerTest, SailfishFlingDownSlow1) {
883     // Sailfish - fling down - slow - 1
884     std::vector<PlanarMotionEventEntry> motions = {
885         { 235655749552755ns, {{582.00, 432.49}} },
886         { 235655750638000ns, {{582.00, 433.00}} },
887         { 235655758865000ns, {{582.00, 440.00}} },
888         { 235655766221523ns, {{581.16, 448.43}} },
889         { 235655767594000ns, {{581.00, 450.00}} },
890         { 235655776044000ns, {{580.00, 462.00}} },
891         { 235655782890696ns, {{579.18, 474.35}} },
892         { 235655784360000ns, {{579.00, 477.00}} },
893         { 235655792795000ns, {{578.00, 496.00}} },
894         { 235655799559531ns, {{576.27, 515.04}} },
895         { 235655800612000ns, {{576.00, 518.00}} },
896         { 235655809535000ns, {{574.00, 542.00}} },
897         { 235655816988015ns, {{572.17, 564.86}} },
898         { 235655817685000ns, {{572.00, 567.00}} },
899         { 235655825981000ns, {{569.00, 595.00}} },
900         { 235655833808653ns, {{566.26, 620.60}} },
901         { 235655834541000ns, {{566.00, 623.00}} },
902         { 235655842893000ns, {{563.00, 649.00}} },
903         { 235655842893000ns, {{563.00, 649.00}} }, // ACTION_UP
904     };
905     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
906                             -419.749695);
907     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
908                             -398.303894);
909     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
910                             3309.016357);
911     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
912                             3969.099854);
913 }
914 
915 
TEST_F(VelocityTrackerTest,SailfishFlingDownSlow2)916 TEST_F(VelocityTrackerTest, SailfishFlingDownSlow2) {
917     // Sailfish - fling down - slow - 2
918     std::vector<PlanarMotionEventEntry> motions = {
919         { 235671152083370ns, {{485.24, 558.28}} },
920         { 235671154126000ns, {{485.00, 559.00}} },
921         { 235671162497000ns, {{484.00, 566.00}} },
922         { 235671168750511ns, {{483.27, 573.29}} },
923         { 235671171071000ns, {{483.00, 576.00}} },
924         { 235671179390000ns, {{482.00, 588.00}} },
925         { 235671185417210ns, {{481.31, 598.98}} },
926         { 235671188173000ns, {{481.00, 604.00}} },
927         { 235671196371000ns, {{480.00, 624.00}} },
928         { 235671202084196ns, {{479.27, 639.98}} },
929         { 235671204235000ns, {{479.00, 646.00}} },
930         { 235671212554000ns, {{478.00, 673.00}} },
931         { 235671219471011ns, {{476.39, 697.12}} },
932         { 235671221159000ns, {{476.00, 703.00}} },
933         { 235671229592000ns, {{474.00, 734.00}} },
934         { 235671236281462ns, {{472.43, 758.38}} },
935         { 235671238098000ns, {{472.00, 765.00}} },
936         { 235671246532000ns, {{470.00, 799.00}} },
937         { 235671246532000ns, {{470.00, 799.00}} }, // ACTION_UP
938     };
939     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
940                             -262.80426);
941     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
942                             -243.665344);
943     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
944                             4215.682129);
945     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
946                             4587.986816);
947 }
948 
949 
TEST_F(VelocityTrackerTest,SailfishFlingDownSlow3)950 TEST_F(VelocityTrackerTest, SailfishFlingDownSlow3) {
951     // Sailfish - fling down - slow - 3
952     std::vector<PlanarMotionEventEntry> motions = {
953         { 170983201000ns, {{557.00, 533.00}} },
954         { 171000668000ns, {{556.00, 534.00}} },
955         { 171007359750ns, {{554.73, 535.27}} },
956         { 171011197000ns, {{554.00, 536.00}} },
957         { 171017660000ns, {{552.00, 540.00}} },
958         { 171024201831ns, {{549.97, 544.73}} },
959         { 171027333000ns, {{549.00, 547.00}} },
960         { 171034603000ns, {{545.00, 557.00}} },
961         { 171041043371ns, {{541.98, 567.55}} },
962         { 171043147000ns, {{541.00, 571.00}} },
963         { 171051052000ns, {{536.00, 586.00}} },
964         { 171051052000ns, {{536.00, 586.00}} }, // ACTION_UP
965     };
966     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
967                             -723.413513);
968     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
969                             -651.038452);
970     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
971                             2091.502441);
972     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
973                             1934.517456);
974 }
975 
976 
TEST_F(VelocityTrackerTest,SailfishFlingDownFaster1)977 TEST_F(VelocityTrackerTest, SailfishFlingDownFaster1) {
978     // Sailfish - fling down - faster - 1
979     std::vector<PlanarMotionEventEntry> motions = {
980         { 235695280333000ns, {{558.00, 451.00}} },
981         { 235695283971237ns, {{558.43, 454.45}} },
982         { 235695289038000ns, {{559.00, 462.00}} },
983         { 235695297388000ns, {{561.00, 478.00}} },
984         { 235695300638465ns, {{561.83, 486.25}} },
985         { 235695305265000ns, {{563.00, 498.00}} },
986         { 235695313591000ns, {{564.00, 521.00}} },
987         { 235695317305492ns, {{564.43, 532.68}} },
988         { 235695322181000ns, {{565.00, 548.00}} },
989         { 235695330709000ns, {{565.00, 577.00}} },
990         { 235695333972227ns, {{565.00, 588.10}} },
991         { 235695339250000ns, {{565.00, 609.00}} },
992         { 235695347839000ns, {{565.00, 642.00}} },
993         { 235695351313257ns, {{565.00, 656.18}} },
994         { 235695356412000ns, {{565.00, 677.00}} },
995         { 235695364899000ns, {{563.00, 710.00}} },
996         { 235695368118682ns, {{562.24, 722.52}} },
997         { 235695373403000ns, {{564.00, 744.00}} },
998         { 235695373403000ns, {{564.00, 744.00}} }, // ACTION_UP
999     };
1000     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
1001                             4254.639648);
1002     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
1003                             4698.415039);
1004 }
1005 
1006 
TEST_F(VelocityTrackerTest,SailfishFlingDownFaster2)1007 TEST_F(VelocityTrackerTest, SailfishFlingDownFaster2) {
1008     // Sailfish - fling down - faster - 2
1009     std::vector<PlanarMotionEventEntry> motions = {
1010         { 235709624766000ns, {{535.00, 579.00}} },
1011         { 235709642256000ns, {{534.00, 580.00}} },
1012         { 235709643350278ns, {{533.94, 580.06}} },
1013         { 235709650760000ns, {{532.00, 584.00}} },
1014         { 235709658615000ns, {{530.00, 593.00}} },
1015         { 235709660170495ns, {{529.60, 594.78}} },
1016         { 235709667095000ns, {{527.00, 606.00}} },
1017         { 235709675616000ns, {{524.00, 628.00}} },
1018         { 235709676983261ns, {{523.52, 631.53}} },
1019         { 235709684289000ns, {{521.00, 652.00}} },
1020         { 235709692763000ns, {{518.00, 682.00}} },
1021         { 235709693804993ns, {{517.63, 685.69}} },
1022         { 235709701438000ns, {{515.00, 709.00}} },
1023         { 235709709830000ns, {{512.00, 739.00}} },
1024         { 235709710626776ns, {{511.72, 741.85}} },
1025         { 235709710626776ns, {{511.72, 741.85}} }, // ACTION_UP
1026     };
1027     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
1028                             -430.440247);
1029     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
1030                             -447.600311);
1031     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
1032                             3953.859375);
1033     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
1034                             4316.155273);
1035 }
1036 
1037 
TEST_F(VelocityTrackerTest,SailfishFlingDownFaster3)1038 TEST_F(VelocityTrackerTest, SailfishFlingDownFaster3) {
1039     // Sailfish - fling down - faster - 3
1040     std::vector<PlanarMotionEventEntry> motions = {
1041         { 235727628927000ns, {{540.00, 440.00}} },
1042         { 235727636810000ns, {{537.00, 454.00}} },
1043         { 235727646176000ns, {{536.00, 454.00}} },
1044         { 235727653586628ns, {{535.12, 456.65}} },
1045         { 235727654557000ns, {{535.00, 457.00}} },
1046         { 235727663024000ns, {{534.00, 465.00}} },
1047         { 235727670410103ns, {{533.04, 479.45}} },
1048         { 235727670691000ns, {{533.00, 480.00}} },
1049         { 235727679255000ns, {{531.00, 501.00}} },
1050         { 235727687233704ns, {{529.09, 526.73}} },
1051         { 235727687628000ns, {{529.00, 528.00}} },
1052         { 235727696113000ns, {{526.00, 558.00}} },
1053         { 235727704057546ns, {{523.18, 588.98}} },
1054         { 235727704576000ns, {{523.00, 591.00}} },
1055         { 235727713099000ns, {{520.00, 626.00}} },
1056         { 235727720880776ns, {{516.33, 655.36}} },
1057         { 235727721580000ns, {{516.00, 658.00}} },
1058         { 235727721580000ns, {{516.00, 658.00}} }, // ACTION_UP
1059     };
1060     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
1061                             4484.617676);
1062     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
1063                             4927.92627);
1064 }
1065 
1066 
TEST_F(VelocityTrackerTest,SailfishFlingDownFast1)1067 TEST_F(VelocityTrackerTest, SailfishFlingDownFast1) {
1068     // Sailfish - fling down - fast - 1
1069     std::vector<PlanarMotionEventEntry> motions = {
1070         { 235762352849000ns, {{467.00, 286.00}} },
1071         { 235762360250000ns, {{443.00, 344.00}} },
1072         { 235762362787412ns, {{434.77, 363.89}} },
1073         { 235762368807000ns, {{438.00, 359.00}} },
1074         { 235762377220000ns, {{425.00, 423.00}} },
1075         { 235762379608561ns, {{421.31, 441.17}} },
1076         { 235762385698000ns, {{412.00, 528.00}} },
1077         { 235762394133000ns, {{406.00, 648.00}} },
1078         { 235762396429369ns, {{404.37, 680.67}} },
1079         { 235762396429369ns, {{404.37, 680.67}} }, //ACTION_UP
1080     };
1081     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
1082                             14227.0224);
1083     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
1084                             16064.685547);
1085 }
1086 
1087 
TEST_F(VelocityTrackerTest,SailfishFlingDownFast2)1088 TEST_F(VelocityTrackerTest, SailfishFlingDownFast2) {
1089     // Sailfish - fling down - fast - 2
1090     std::vector<PlanarMotionEventEntry> motions = {
1091         { 235772487188000ns, {{576.00, 204.00}} },
1092         { 235772495159000ns, {{553.00, 236.00}} },
1093         { 235772503568000ns, {{551.00, 240.00}} },
1094         { 235772508192247ns, {{545.55, 254.17}} },
1095         { 235772512051000ns, {{541.00, 266.00}} },
1096         { 235772520794000ns, {{520.00, 337.00}} },
1097         { 235772525015263ns, {{508.92, 394.43}} },
1098         { 235772529174000ns, {{498.00, 451.00}} },
1099         { 235772537635000ns, {{484.00, 589.00}} },
1100         { 235772537635000ns, {{484.00, 589.00}} }, // ACTION_UP
1101     };
1102     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
1103                             18660.048828);
1104     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
1105                             16918.439453);
1106 }
1107 
1108 
TEST_F(VelocityTrackerTest,SailfishFlingDownFast3)1109 TEST_F(VelocityTrackerTest, SailfishFlingDownFast3) {
1110     // Sailfish - fling down - fast - 3
1111     std::vector<PlanarMotionEventEntry> motions = {
1112         { 507650295000ns, {{628.00, 233.00}} },
1113         { 507658234000ns, {{605.00, 269.00}} },
1114         { 507666784000ns, {{601.00, 274.00}} },
1115         { 507669660483ns, {{599.65, 275.68}} },
1116         { 507675427000ns, {{582.00, 308.00}} },
1117         { 507683740000ns, {{541.00, 404.00}} },
1118         { 507686506238ns, {{527.36, 435.95}} },
1119         { 507692220000ns, {{487.00, 581.00}} },
1120         { 507700707000ns, {{454.00, 792.00}} },
1121         { 507703352649ns, {{443.71, 857.77}} },
1122         { 507703352649ns, {{443.71, 857.77}} }, // ACTION_UP
1123     };
1124     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
1125                             -4111.8173);
1126     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
1127                             -6388.48877);
1128     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
1129                             29765.908203);
1130     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
1131                             28354.796875);
1132 }
1133 
1134 /**
1135  * ================== Multiple pointers ============================================================
1136  *
1137  * Three fingers quickly tap the screen. Since this is a tap, the velocities should be empty.
1138  * If the events with POINTER_UP or POINTER_DOWN are not handled correctly (these should not be
1139  * part of the fitted data), this can cause large velocity values to be reported instead.
1140  */
TEST_F(VelocityTrackerTest,LeastSquaresVelocityTrackerStrategy_ThreeFingerTap)1141 TEST_F(VelocityTrackerTest, LeastSquaresVelocityTrackerStrategy_ThreeFingerTap) {
1142     std::vector<PlanarMotionEventEntry> motions = {
1143         { 0us,      {{1063, 1128}, {NAN, NAN}, {NAN, NAN}} },
1144         { 10800us,  {{1063, 1128}, {682, 1318}, {NAN, NAN}} }, // POINTER_DOWN
1145         { 10800us,  {{1063, 1128}, {682, 1318}, {397, 1747}} }, // POINTER_DOWN
1146         { 267300us, {{1063, 1128}, {682, 1318}, {397, 1747}} }, // POINTER_UP
1147         { 267300us, {{1063, 1128}, {NAN, NAN}, {397, 1747}} }, // POINTER_UP
1148         { 272700us, {{1063, 1128}, {NAN, NAN}, {NAN, NAN}} },
1149     };
1150 
1151     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
1152                             std::nullopt);
1153     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y,
1154                             std::nullopt);
1155     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
1156                             std::nullopt);
1157     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y,
1158                             std::nullopt);
1159 }
1160 
1161 /**
1162  * ================= Pointer liftoff ===============================================================
1163  */
1164 
1165 /**
1166  * The last movement of a pointer is always ACTION_POINTER_UP or ACTION_UP. If there's a short delay
1167  * between the last ACTION_MOVE and the next ACTION_POINTER_UP or ACTION_UP, velocity should not be
1168  * affected by the liftoff.
1169  */
TEST_F(VelocityTrackerTest,ShortDelayBeforeActionUp)1170 TEST_F(VelocityTrackerTest, ShortDelayBeforeActionUp) {
1171     std::vector<PlanarMotionEventEntry> motions = {
1172             {0ms, {{10, 0}}}, {10ms, {{20, 0}}}, {20ms, {{30, 0}}}, {30ms, {{30, 0}}}, // ACTION_UP
1173     };
1174     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
1175                             1000);
1176     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X, 1000);
1177 }
1178 
1179 /**
1180  * The last movement of a single pointer is ACTION_UP. If there's a long delay between the last
1181  * ACTION_MOVE and the final ACTION_UP, velocity should be reported as empty because the pointer
1182  * should be assumed to have stopped.
1183  */
TEST_F(VelocityTrackerTest,LongDelayBeforeActionUp)1184 TEST_F(VelocityTrackerTest, LongDelayBeforeActionUp) {
1185     std::vector<PlanarMotionEventEntry> motions = {
1186             {0ms, {{10, 0}}},
1187             {10ms, {{20, 0}}},
1188             {20ms, {{30, 0}}},
1189             {3000ms, {{30, 0}}}, // ACTION_UP
1190     };
1191     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
1192                             std::nullopt);
1193     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
1194                             std::nullopt);
1195 }
1196 
1197 /**
1198  * The last movement of a pointer is always ACTION_POINTER_UP or ACTION_UP. If there's a long delay
1199  * before ACTION_POINTER_UP event, the movement should be assumed to have stopped.
1200  * The final velocity should be reported as empty for all pointers.
1201  */
TEST_F(VelocityTrackerTest,LongDelayBeforeActionPointerUp)1202 TEST_F(VelocityTrackerTest, LongDelayBeforeActionPointerUp) {
1203     std::vector<PlanarMotionEventEntry> motions = {
1204             {0ms, {{10, 0}}},
1205             {10ms, {{20, 0}, {100, 0}}},
1206             {20ms, {{30, 0}, {200, 0}}},
1207             {30ms, {{30, 0}, {300, 0}}},
1208             {40ms, {{30, 0}, {400, 0}}},
1209             {3000ms, {{30, 0}}}, // ACTION_POINTER_UP
1210     };
1211     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
1212                             std::nullopt,
1213                             /*pointerId*/ 0);
1214     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
1215                             std::nullopt,
1216                             /*pointerId*/ 0);
1217     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
1218                             std::nullopt,
1219                             /*pointerId*/ 1);
1220     computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X,
1221                             std::nullopt,
1222                             /*pointerId*/ 1);
1223 }
1224 
1225 /**
1226  * ================== Tests for least squares fitting ==============================================
1227  *
1228  * Special care must be taken when constructing tests for LeastSquaresVelocityTrackerStrategy
1229  * getVelocity function. In particular:
1230  * - inside the function, time gets converted from nanoseconds to seconds
1231  *   before being used in the fit.
1232  * - any values that are older than 100 ms are being discarded.
1233  * - the newest time gets subtracted from all of the other times before being used in the fit.
1234  * So these tests have to be designed with those limitations in mind.
1235  *
1236  * General approach for the tests below:
1237  * We only used timestamps in milliseconds, 0 ms, 1 ms, and 2 ms, to be sure that
1238  * we are well within the HORIZON range.
1239  * When specifying the expected values of the coefficients, we treat the x values as if
1240  * they were in ms. Then, to adjust for the time units, the coefficients get progressively
1241  * multiplied by powers of 1E3.
1242  * For example:
1243  * data: t(ms), x
1244  *        1 ms, 1
1245  *        2 ms, 4
1246  *        3 ms, 9
1247  * The coefficients are (0, 0, 1).
1248  * In the test, we would convert these coefficients to (0*(1E3)^0, 0*(1E3)^1, 1*(1E3)^2).
1249  */
TEST_F(VelocityTrackerTest,LeastSquaresVelocityTrackerStrategy_Constant)1250 TEST_F(VelocityTrackerTest, LeastSquaresVelocityTrackerStrategy_Constant) {
1251     std::vector<PlanarMotionEventEntry> motions = {
1252         { 0ms, {{1, 1}} }, // 0 s
1253         { 1ms, {{1, 1}} }, // 0.001 s
1254         { 2ms, {{1, 1}} }, // 0.002 s
1255         { 2ms, {{1, 1}} }, // ACTION_UP
1256     };
1257     // The data used for the fit will be as follows:
1258     // time(s), position
1259     // -0.002, 1
1260     // -0.001, 1
1261     // -0.ms, 1
1262     computeAndCheckQuadraticVelocity(motions, 0);
1263 }
1264 
1265 /*
1266  * Straight line y = x :: the constant and quadratic coefficients are zero.
1267  */
TEST_F(VelocityTrackerTest,LeastSquaresVelocityTrackerStrategy_Linear)1268 TEST_F(VelocityTrackerTest, LeastSquaresVelocityTrackerStrategy_Linear) {
1269     std::vector<PlanarMotionEventEntry> motions = {
1270         { 0ms, {{-2, -2}} },
1271         { 1ms, {{-1, -1}} },
1272         { 2ms, {{-0, -0}} },
1273         { 2ms, {{-0, -0}} }, // ACTION_UP
1274     };
1275     // The data used for the fit will be as follows:
1276     // time(s), position
1277     // -0.002, -2
1278     // -0.001, -1
1279     // -0.000,  0
1280     computeAndCheckQuadraticVelocity(motions, 1E3);
1281 }
1282 
1283 /*
1284  * Parabola
1285  */
TEST_F(VelocityTrackerTest,LeastSquaresVelocityTrackerStrategy_Parabolic)1286 TEST_F(VelocityTrackerTest, LeastSquaresVelocityTrackerStrategy_Parabolic) {
1287     std::vector<PlanarMotionEventEntry> motions = {
1288         { 0ms, {{1, 1}} },
1289         { 1ms, {{4, 4}} },
1290         { 2ms, {{8, 8}} },
1291         { 2ms, {{8, 8}} }, // ACTION_UP
1292     };
1293     // The data used for the fit will be as follows:
1294     // time(s), position
1295     // -0.002, 1
1296     // -0.001, 4
1297     // -0.000, 8
1298     computeAndCheckQuadraticVelocity(motions, 4.5E3);
1299 }
1300 
1301 /*
1302  * Parabola
1303  */
TEST_F(VelocityTrackerTest,LeastSquaresVelocityTrackerStrategy_Parabolic2)1304 TEST_F(VelocityTrackerTest, LeastSquaresVelocityTrackerStrategy_Parabolic2) {
1305     std::vector<PlanarMotionEventEntry> motions = {
1306         { 0ms, {{1, 1}} },
1307         { 1ms, {{4, 4}} },
1308         { 2ms, {{9, 9}} },
1309         { 2ms, {{9, 9}} }, // ACTION_UP
1310     };
1311     // The data used for the fit will be as follows:
1312     // time(s), position
1313     // -0.002, 1
1314     // -0.001, 4
1315     // -0.000, 9
1316     computeAndCheckQuadraticVelocity(motions, 6E3);
1317 }
1318 
1319 /*
1320  * Parabola :: y = x^2 :: the constant and linear coefficients are zero.
1321  */
TEST_F(VelocityTrackerTest,LeastSquaresVelocityTrackerStrategy_Parabolic3)1322 TEST_F(VelocityTrackerTest, LeastSquaresVelocityTrackerStrategy_Parabolic3) {
1323     std::vector<PlanarMotionEventEntry> motions = {
1324         { 0ms, {{4, 4}} },
1325         { 1ms, {{1, 1}} },
1326         { 2ms, {{0, 0}} },
1327         { 2ms, {{0, 0}} }, // ACTION_UP
1328     };
1329     // The data used for the fit will be as follows:
1330     // time(s), position
1331     // -0.002, 4
1332     // -0.001, 1
1333     // -0.000, 0
1334     computeAndCheckQuadraticVelocity(motions, 0E3);
1335 }
1336 
1337 // Recorded by hand on sailfish, but only the diffs are taken to test cumulative axis velocity.
TEST_F(VelocityTrackerTest,AxisScrollVelocity)1338 TEST_F(VelocityTrackerTest, AxisScrollVelocity) {
1339     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {
1340             {235089067457000ns, 0.00}, {235089084684000ns, -1.00}, {235089093349000ns, 0.00},
1341             {235089095677625ns, 0.00}, {235089101859000ns, 0.00},  {235089110378000ns, 0.00},
1342             {235089112497111ns, 0.25}, {235089118760000ns, 1.75},  {235089126686000ns, 4.00},
1343             {235089129316820ns, 1.33}, {235089135199000ns, 3.67},  {235089144297000ns, 6.00},
1344             {235089146136443ns, 1.21}, {235089152923000ns, 5.79},  {235089160784000ns, 6.00},
1345             {235089162955851ns, 1.66},
1346     };
1347 
1348     computeAndCheckAxisScrollVelocity(VelocityTracker::Strategy::IMPULSE, motions, {764.345703});
1349 }
1350 
1351 // --------------- Recorded by hand on a Wear OS device using a rotating side button ---------------
TEST_F(VelocityTrackerTest,AxisScrollVelocity_ScrollDown)1352 TEST_F(VelocityTrackerTest, AxisScrollVelocity_ScrollDown) {
1353     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {
1354             {224598065152ns, -0.050100}, {224621871104ns, -0.133600}, {224645464064ns, -0.551100},
1355             {224669171712ns, -0.801600}, {224687063040ns, -1.035400}, {224706691072ns, -0.484300},
1356             {224738213888ns, -0.334000}, {224754401280ns, -0.083500},
1357     };
1358 
1359     computeAndCheckAxisScrollVelocity(VelocityTracker::Strategy::IMPULSE, motions, {-27.86});
1360 }
1361 
TEST_F(VelocityTrackerTest,AxisScrollVelocity_ScrollUp)1362 TEST_F(VelocityTrackerTest, AxisScrollVelocity_ScrollUp) {
1363     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {
1364             {269606010880ns, 0.050100}, {269626064896ns, 0.217100}, {269641973760ns, 0.267200},
1365             {269658079232ns, 0.267200}, {269674217472ns, 0.267200}, {269690683392ns, 0.367400},
1366             {269706133504ns, 0.551100}, {269722173440ns, 0.501000},
1367     };
1368 
1369     computeAndCheckAxisScrollVelocity(VelocityTracker::Strategy::IMPULSE, motions, {31.92});
1370 }
1371 
TEST_F(VelocityTrackerTest,AxisScrollVelocity_ScrollDown_ThenUp_ThenDown)1372 TEST_F(VelocityTrackerTest, AxisScrollVelocity_ScrollDown_ThenUp_ThenDown) {
1373     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {
1374             {2580534001664ns, -0.033400}, {2580549992448ns, -0.133600},
1375             {2580566769664ns, -0.250500}, {2580581974016ns, -0.183700},
1376             {2580597964800ns, -0.267200}, {2580613955584ns, -0.551100},
1377             {2580635189248ns, -0.601200}, {2580661927936ns, -0.450900},
1378             {2580683161600ns, -0.417500}, {2580705705984ns, -0.150300},
1379             {2580722745344ns, -0.016700}, {2580786446336ns, 0.050100},
1380             {2580801912832ns, 0.150300},  {2580822360064ns, 0.300600},
1381             {2580838088704ns, 0.300600},  {2580854341632ns, 0.400800},
1382             {2580869808128ns, 0.517700},  {2580886061056ns, 0.501000},
1383             {2580905984000ns, 0.350700},  {2580921974784ns, 0.350700},
1384             {2580937965568ns, 0.066800},  {2580974665728ns, 0.016700},
1385             {2581034434560ns, -0.066800}, {2581049901056ns, -0.116900},
1386             {2581070610432ns, -0.317300}, {2581086076928ns, -0.200400},
1387             {2581101805568ns, -0.233800}, {2581118058496ns, -0.417500},
1388             {2581134049280ns, -0.417500}, {2581150040064ns, -0.367400},
1389             {2581166030848ns, -0.267200}, {2581181759488ns, -0.150300},
1390             {2581199847424ns, -0.066800},
1391     };
1392 
1393     computeAndCheckAxisScrollVelocity(VelocityTracker::Strategy::IMPULSE, motions, {-9.73});
1394 }
1395 
1396 // ------------------------------- Hand generated test cases ---------------------------------------
TEST_F(VelocityTrackerTest,TestDefaultStrategyForAxisScroll)1397 TEST_F(VelocityTrackerTest, TestDefaultStrategyForAxisScroll) {
1398     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {
1399             {10ms, 20},
1400             {20ms, 25},
1401             {30ms, 50},
1402             {40ms, 100},
1403     };
1404 
1405     std::vector<MotionEvent> events = createAxisScrollMotionEventStream(motions);
1406     EXPECT_EQ(computeVelocity(VelocityTracker::Strategy::IMPULSE, events,
1407                               AMOTION_EVENT_AXIS_SCROLL),
1408               computeVelocity(VelocityTracker::Strategy::DEFAULT, events,
1409                               AMOTION_EVENT_AXIS_SCROLL));
1410 }
1411 
TEST_F(VelocityTrackerTest,AxisScrollVelocity_SimilarDifferentialValues)1412 TEST_F(VelocityTrackerTest, AxisScrollVelocity_SimilarDifferentialValues) {
1413     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {{1ns, 2.12},  {3ns, 2.12},
1414                                                                        {7ns, 2.12},  {8ns, 2.12},
1415                                                                        {15ns, 2.12}, {18ns, 2.12}};
1416 
1417     computeAndCheckAxisScrollVelocity(VelocityTracker::Strategy::IMPULSE, motions, {1690236059.86});
1418 }
1419 
TEST_F(VelocityTrackerTest,AxisScrollVelocity_OnlyTwoValues)1420 TEST_F(VelocityTrackerTest, AxisScrollVelocity_OnlyTwoValues) {
1421     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {{1ms, 5}, {2ms, 10}};
1422 
1423     computeAndCheckAxisScrollVelocity(VelocityTracker::Strategy::IMPULSE, motions, {10000});
1424 }
1425 
TEST_F(VelocityTrackerTest,AxisScrollVelocity_ConstantVelocity)1426 TEST_F(VelocityTrackerTest, AxisScrollVelocity_ConstantVelocity) {
1427     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {{1ms, 20}, {2ms, 20},
1428                                                                        {3ms, 20}, {4ms, 20},
1429                                                                        {5ms, 20}, {6ms, 20}};
1430 
1431     computeAndCheckAxisScrollVelocity(VelocityTracker::Strategy::IMPULSE, motions, {20000});
1432 }
1433 
TEST_F(VelocityTrackerTest,AxisScrollVelocity_NoMotion)1434 TEST_F(VelocityTrackerTest, AxisScrollVelocity_NoMotion) {
1435     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {{1ns, 0}, {2ns, 0},
1436                                                                        {3ns, 0}, {4ns, 0},
1437                                                                        {5ns, 0}, {6ns, 0}};
1438 
1439     computeAndCheckAxisScrollVelocity(VelocityTracker::Strategy::IMPULSE, motions, {0});
1440 }
1441 
TEST_F(VelocityTrackerTest,AxisScrollVelocity_NoData)1442 TEST_F(VelocityTrackerTest, AxisScrollVelocity_NoData) {
1443     std::vector<std::pair<std::chrono::nanoseconds, float>> motions = {};
1444 
1445     computeAndCheckAxisScrollVelocity(VelocityTracker::Strategy::IMPULSE, motions, std::nullopt);
1446 }
1447 
1448 } // namespace android
1449