Add resampling to InputConsumerNoResampling
Moved resampling into its own class and provided test coverage for it.
Bug: 297226446
Flag: EXEMPT refactor
Test: TEST=libinput_tests; m $TEST && $ANDROID_HOST_OUT/nativetest64/$TEST/$TEST --gtest_filter="*ResamplingTest*"
Change-Id: Ic6227b05120395c96643ab05e1cda373dba59e19
diff --git a/include/input/InputConsumerNoResampling.h b/include/input/InputConsumerNoResampling.h
index ae8de5f..65c2914 100644
--- a/include/input/InputConsumerNoResampling.h
+++ b/include/input/InputConsumerNoResampling.h
@@ -17,6 +17,7 @@
#pragma once
#include <input/InputTransport.h>
+#include <input/Resampler.h>
#include <utils/Looper.h>
namespace android {
@@ -47,13 +48,13 @@
/**
* Consumes input events from an input channel.
*
- * This is a re-implementation of InputConsumer that does not have resampling at the current moment.
- * A lot of the higher-level logic has been folded into this class, to make it easier to use.
- * In the legacy class, InputConsumer, the consumption logic was partially handled in the jni layer,
- * as well as various actions like adding the fd to the Choreographer.
+ * This is a re-implementation of InputConsumer. At the moment it only supports resampling for
+ * single pointer events. A lot of the higher-level logic has been folded into this class, to make
+ * it easier to use. In the legacy class, InputConsumer, the consumption logic was partially handled
+ * in the jni layer, as well as various actions like adding the fd to the Choreographer.
*
* TODO(b/297226446): use this instead of "InputConsumer":
- * - Add resampling to this class
+ * - Add resampling for multiple pointer events.
* - Allow various resampling strategies to be specified
* - Delete the old "InputConsumer" and use this class instead, renaming it to "InputConsumer".
* - Add tracing
@@ -64,8 +65,18 @@
*/
class InputConsumerNoResampling final {
public:
+ /**
+ * @param callbacks are used to interact with InputConsumerNoResampling. They're called whenever
+ * the event is ready to consume.
+ * @param looper needs to be sp and not shared_ptr because it inherits from
+ * RefBase
+ * @param resampler the resampling strategy to use. If null, no resampling will be
+ * performed.
+ */
explicit InputConsumerNoResampling(const std::shared_ptr<InputChannel>& channel,
- sp<Looper> looper, InputConsumerCallbacks& callbacks);
+ sp<Looper> looper, InputConsumerCallbacks& callbacks,
+ std::unique_ptr<Resampler> resampler);
+
~InputConsumerNoResampling();
/**
@@ -99,6 +110,7 @@
std::shared_ptr<InputChannel> mChannel;
sp<Looper> mLooper;
InputConsumerCallbacks& mCallbacks;
+ std::unique_ptr<Resampler> mResampler;
// Looper-related infrastructure
/**
diff --git a/include/input/Resampler.h b/include/input/Resampler.h
new file mode 100644
index 0000000..ff9c4b0
--- /dev/null
+++ b/include/input/Resampler.h
@@ -0,0 +1,115 @@
+/**
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <chrono>
+#include <optional>
+
+#include <input/Input.h>
+#include <input/InputTransport.h>
+#include <input/RingBuffer.h>
+#include <utils/Timers.h>
+
+namespace android {
+
+/**
+ * Resampler is an interface for resampling MotionEvents. Every resampling implementation
+ * must use this interface to enable resampling inside InputConsumer's logic.
+ */
+struct Resampler {
+ virtual ~Resampler() = default;
+
+ /**
+ * Tries to resample motionEvent at resampleTime. The provided resampleTime must be greater than
+ * the latest sample time of motionEvent. It is not guaranteed that resampling occurs at
+ * resampleTime. Interpolation may occur is futureSample is available. Otherwise, motionEvent
+ * may be resampled by another method, or not resampled at all. Furthermore, it is the
+ * implementer's responsibility to guarantee the following:
+ * - If resampling occurs, a single additional sample should be added to motionEvent. That is,
+ * if motionEvent had N samples before being passed to Resampler, then it will have N + 1
+ * samples by the end of the resampling. No other field of motionEvent should be modified.
+ * - If resampling does not occur, then motionEvent must not be modified in any way.
+ */
+ virtual void resampleMotionEvent(const std::chrono::nanoseconds resampleTime,
+ MotionEvent& motionEvent,
+ const InputMessage* futureSample) = 0;
+};
+
+class LegacyResampler final : public Resampler {
+public:
+ /**
+ * Tries to resample `motionEvent` at `resampleTime` by adding a resampled sample at the end of
+ * `motionEvent` with eventTime equal to `resampleTime` and pointer coordinates determined by
+ * linear interpolation or linear extrapolation. An earlier `resampleTime` will be used if
+ * extrapolation takes place and `resampleTime` is too far in the future. If `futureSample` is
+ * not null, interpolation will occur. If `futureSample` is null and there is enough historical
+ * data, LegacyResampler will extrapolate. Otherwise, no resampling takes place and
+ * `motionEvent` is unmodified.
+ */
+ void resampleMotionEvent(const std::chrono::nanoseconds resampleTime, MotionEvent& motionEvent,
+ const InputMessage* futureSample) override;
+
+private:
+ struct Pointer {
+ PointerProperties properties;
+ PointerCoords coords;
+ };
+
+ struct Sample {
+ std::chrono::nanoseconds eventTime;
+ Pointer pointer;
+
+ Sample(const std::chrono::nanoseconds eventTime, const PointerProperties& properties,
+ const PointerCoords& coords)
+ : eventTime{eventTime}, pointer{properties, coords} {}
+ };
+
+ /**
+ * Keeps track of the previous MotionEvent deviceId to enable comparison between the previous
+ * and the current deviceId.
+ */
+ std::optional<DeviceId> mPreviousDeviceId;
+
+ /**
+ * Up to two latest samples from MotionEvent. Updated every time resampleMotionEvent is called.
+ * Note: We store up to two samples in order to simplify the implementation. Although,
+ * calculations are possible with only one previous sample.
+ */
+ RingBuffer<Sample> mLatestSamples{/*capacity=*/2};
+
+ /**
+ * Adds up to mLatestSamples.capacity() of motionEvent's latest samples to mLatestSamples. (If
+ * motionEvent has fewer samples than mLatestSamples.capacity(), then the available samples are
+ * added to mLatestSamples.)
+ */
+ void updateLatestSamples(const MotionEvent& motionEvent);
+
+ /**
+ * May add a sample at the end of motionEvent with eventTime equal to resampleTime, and
+ * interpolated coordinates between the latest motionEvent sample and futureSample.
+ */
+ void interpolate(const std::chrono::nanoseconds resampleTime, MotionEvent& motionEvent,
+ const InputMessage& futureSample) const;
+
+ /**
+ * May add a sample at the end of motionEvent by extrapolating from the latest two samples. The
+ * added sample either has eventTime equal to resampleTime, or an earlier time if resampleTime
+ * is too far in the future.
+ */
+ void extrapolate(const std::chrono::nanoseconds resampleTime, MotionEvent& motionEvent) const;
+};
+} // namespace android
\ No newline at end of file
diff --git a/libs/input/Android.bp b/libs/input/Android.bp
index 8fbf5c6..e4e81ad 100644
--- a/libs/input/Android.bp
+++ b/libs/input/Android.bp
@@ -232,6 +232,7 @@
"MotionPredictorMetricsManager.cpp",
"PrintTools.cpp",
"PropertyMap.cpp",
+ "Resampler.cpp",
"TfLiteMotionPredictor.cpp",
"TouchVideoFrame.cpp",
"VelocityControl.cpp",
diff --git a/libs/input/InputConsumerNoResampling.cpp b/libs/input/InputConsumerNoResampling.cpp
index c145d5c..99ffa68 100644
--- a/libs/input/InputConsumerNoResampling.cpp
+++ b/libs/input/InputConsumerNoResampling.cpp
@@ -17,6 +17,8 @@
#define LOG_TAG "InputTransport"
#define ATRACE_TAG ATRACE_TAG_INPUT
+#include <chrono>
+
#include <inttypes.h>
#include <android-base/logging.h>
@@ -168,6 +170,10 @@
return msg;
}
+bool isPointerEvent(const MotionEvent& motionEvent) {
+ return (motionEvent.getSource() & AINPUT_SOURCE_CLASS_POINTER) == AINPUT_SOURCE_CLASS_POINTER;
+}
+
} // namespace
using android::base::Result;
@@ -177,8 +183,13 @@
InputConsumerNoResampling::InputConsumerNoResampling(const std::shared_ptr<InputChannel>& channel,
sp<Looper> looper,
- InputConsumerCallbacks& callbacks)
- : mChannel(channel), mLooper(looper), mCallbacks(callbacks), mFdEvents(0) {
+ InputConsumerCallbacks& callbacks,
+ std::unique_ptr<Resampler> resampler)
+ : mChannel(channel),
+ mLooper(looper),
+ mCallbacks(callbacks),
+ mResampler(std::move(resampler)),
+ mFdEvents(0) {
LOG_ALWAYS_FATAL_IF(mLooper == nullptr);
mCallback = sp<LooperEventCallback>::make(
std::bind(&InputConsumerNoResampling::handleReceiveCallback, this,
@@ -463,6 +474,15 @@
}
messages.pop();
}
+ // Check if resampling should be performed.
+ if (motionEvent != nullptr && isPointerEvent(*motionEvent) && mResampler != nullptr) {
+ InputMessage* futureSample = nullptr;
+ if (!messages.empty()) {
+ futureSample = &messages.front();
+ }
+ mResampler->resampleMotionEvent(static_cast<std::chrono::nanoseconds>(frameTime),
+ *motionEvent, futureSample);
+ }
return std::make_pair(std::move(motionEvent), firstSeqForBatch);
}
diff --git a/libs/input/Resampler.cpp b/libs/input/Resampler.cpp
new file mode 100644
index 0000000..af8354c
--- /dev/null
+++ b/libs/input/Resampler.cpp
@@ -0,0 +1,151 @@
+/**
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "LegacyResampler"
+
+#include <algorithm>
+#include <chrono>
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+
+#include <input/Resampler.h>
+#include <utils/Timers.h>
+
+using std::chrono::nanoseconds;
+
+namespace android {
+
+namespace {
+
+const bool IS_DEBUGGABLE_BUILD =
+#if defined(__ANDROID__)
+ android::base::GetBoolProperty("ro.debuggable", false);
+#else
+ true;
+#endif
+
+bool debugResampling() {
+ if (!IS_DEBUGGABLE_BUILD) {
+ static const bool DEBUG_TRANSPORT_RESAMPLING =
+ __android_log_is_loggable(ANDROID_LOG_DEBUG, LOG_TAG "Resampling",
+ ANDROID_LOG_INFO);
+ return DEBUG_TRANSPORT_RESAMPLING;
+ }
+ return __android_log_is_loggable(ANDROID_LOG_DEBUG, LOG_TAG "Resampling", ANDROID_LOG_INFO);
+}
+
+constexpr std::chrono::milliseconds RESAMPLE_LATENCY{5};
+
+constexpr std::chrono::milliseconds RESAMPLE_MIN_DELTA{2};
+
+constexpr std::chrono::milliseconds RESAMPLE_MAX_DELTA{20};
+
+constexpr std::chrono::milliseconds RESAMPLE_MAX_PREDICTION{8};
+
+inline float lerp(float a, float b, float alpha) {
+ return a + alpha * (b - a);
+}
+
+const PointerCoords calculateResampledCoords(const PointerCoords& a, const PointerCoords& b,
+ const float alpha) {
+ // Ensure the struct PointerCoords is initialized.
+ PointerCoords resampledCoords{};
+ resampledCoords.isResampled = true;
+ resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_X, lerp(a.getX(), b.getX(), alpha));
+ resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_Y, lerp(a.getY(), b.getY(), alpha));
+ return resampledCoords;
+}
+} // namespace
+
+void LegacyResampler::updateLatestSamples(const MotionEvent& motionEvent) {
+ const size_t motionEventSampleSize = motionEvent.getHistorySize() + 1;
+ for (size_t i = 0; i < motionEventSampleSize; ++i) {
+ Sample sample{static_cast<nanoseconds>(motionEvent.getHistoricalEventTime(i)),
+ *motionEvent.getPointerProperties(0),
+ motionEvent.getSamplePointerCoords()[i]};
+ mLatestSamples.pushBack(sample);
+ }
+}
+
+void LegacyResampler::interpolate(const nanoseconds resampleTime, MotionEvent& motionEvent,
+ const InputMessage& futureSample) const {
+ const Sample pastSample = mLatestSamples.back();
+ const nanoseconds delta =
+ static_cast<nanoseconds>(futureSample.body.motion.eventTime) - pastSample.eventTime;
+ if (delta < RESAMPLE_MIN_DELTA) {
+ LOG_IF(INFO, debugResampling()) << "Not resampled. Delta is too small: " << delta << "ns.";
+ return;
+ }
+ const float alpha =
+ std::chrono::duration<float, std::milli>(resampleTime - pastSample.eventTime) / delta;
+
+ const PointerCoords resampledCoords =
+ calculateResampledCoords(pastSample.pointer.coords,
+ futureSample.body.motion.pointers[0].coords, alpha);
+ motionEvent.addSample(resampleTime.count(), &resampledCoords, motionEvent.getId());
+}
+
+void LegacyResampler::extrapolate(const nanoseconds resampleTime, MotionEvent& motionEvent) const {
+ if (mLatestSamples.size() < 2) {
+ return;
+ }
+ const Sample pastSample = *(mLatestSamples.end() - 2);
+ const Sample presentSample = *(mLatestSamples.end() - 1);
+ const nanoseconds delta =
+ static_cast<nanoseconds>(presentSample.eventTime - pastSample.eventTime);
+ if (delta < RESAMPLE_MIN_DELTA) {
+ LOG_IF(INFO, debugResampling()) << "Not resampled. Delta is too small: " << delta << "ns.";
+ return;
+ } else if (delta > RESAMPLE_MAX_DELTA) {
+ LOG_IF(INFO, debugResampling()) << "Not resampled. Delta is too large: " << delta << "ns.";
+ return;
+ }
+ // The farthest future time to which we can extrapolate. If the given resampleTime exceeds this,
+ // we use this value as the resample time target.
+ const nanoseconds farthestPrediction = static_cast<nanoseconds>(presentSample.eventTime) +
+ std::min<nanoseconds>(delta / 2, RESAMPLE_MAX_PREDICTION);
+ const nanoseconds newResampleTime =
+ (resampleTime > farthestPrediction) ? (farthestPrediction) : (resampleTime);
+ LOG_IF(INFO, debugResampling() && newResampleTime == farthestPrediction)
+ << "Resample time is too far in the future. Adjusting prediction from "
+ << (resampleTime - presentSample.eventTime) << " to "
+ << (farthestPrediction - presentSample.eventTime) << "ns.";
+ const float alpha =
+ std::chrono::duration<float, std::milli>(newResampleTime - pastSample.eventTime) /
+ delta;
+
+ const PointerCoords resampledCoords =
+ calculateResampledCoords(pastSample.pointer.coords, presentSample.pointer.coords,
+ alpha);
+ motionEvent.addSample(newResampleTime.count(), &resampledCoords, motionEvent.getId());
+}
+
+void LegacyResampler::resampleMotionEvent(const nanoseconds resampleTime, MotionEvent& motionEvent,
+ const InputMessage* futureSample) {
+ if (mPreviousDeviceId && *mPreviousDeviceId != motionEvent.getDeviceId()) {
+ mLatestSamples.clear();
+ }
+ mPreviousDeviceId = motionEvent.getDeviceId();
+ updateLatestSamples(motionEvent);
+ if (futureSample) {
+ interpolate(resampleTime, motionEvent, *futureSample);
+ } else {
+ extrapolate(resampleTime, motionEvent);
+ }
+ LOG_IF(INFO, debugResampling()) << "Not resampled. Not enough data.";
+}
+} // namespace android
diff --git a/libs/input/tests/Android.bp b/libs/input/tests/Android.bp
index e9d799e..132866b 100644
--- a/libs/input/tests/Android.bp
+++ b/libs/input/tests/Android.bp
@@ -23,6 +23,7 @@
"InputVerifier_test.cpp",
"MotionPredictor_test.cpp",
"MotionPredictorMetricsManager_test.cpp",
+ "Resampler_test.cpp",
"RingBuffer_test.cpp",
"TfLiteMotionPredictor_test.cpp",
"TouchResampling_test.cpp",
diff --git a/libs/input/tests/InputPublisherAndConsumerNoResampling_test.cpp b/libs/input/tests/InputPublisherAndConsumerNoResampling_test.cpp
index e710613..467c3b4 100644
--- a/libs/input/tests/InputPublisherAndConsumerNoResampling_test.cpp
+++ b/libs/input/tests/InputPublisherAndConsumerNoResampling_test.cpp
@@ -396,8 +396,9 @@
break;
}
case LooperMessage::CREATE_CONSUMER: {
- mConsumer = std::make_unique<InputConsumerNoResampling>(std::move(mClientChannel),
- mLooper, *this);
+ mConsumer =
+ std::make_unique<InputConsumerNoResampling>(std::move(mClientChannel), mLooper,
+ *this, /*resampler=*/nullptr);
break;
}
case LooperMessage::DESTROY_CONSUMER: {
diff --git a/libs/input/tests/Resampler_test.cpp b/libs/input/tests/Resampler_test.cpp
new file mode 100644
index 0000000..e160ca0
--- /dev/null
+++ b/libs/input/tests/Resampler_test.cpp
@@ -0,0 +1,417 @@
+/**
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <input/Resampler.h>
+
+#include <gtest/gtest.h>
+
+#include <chrono>
+#include <memory>
+#include <vector>
+
+#include <input/Input.h>
+#include <input/InputEventBuilders.h>
+#include <input/InputTransport.h>
+#include <utils/Timers.h>
+
+namespace android {
+
+namespace {
+
+using namespace std::literals::chrono_literals;
+
+constexpr float EPSILON = MotionEvent::ROUNDING_PRECISION;
+
+struct Pointer {
+ int32_t id{0};
+ ToolType toolType{ToolType::FINGER};
+ float x{0.0f};
+ float y{0.0f};
+ bool isResampled{false};
+ /**
+ * Converts from Pointer to PointerCoords. Enables calling LegacyResampler methods and
+ * assertions only with the relevant data for tests.
+ */
+ operator PointerCoords() const;
+};
+
+Pointer::operator PointerCoords() const {
+ PointerCoords pointerCoords;
+ pointerCoords.setAxisValue(AMOTION_EVENT_AXIS_X, x);
+ pointerCoords.setAxisValue(AMOTION_EVENT_AXIS_Y, y);
+ pointerCoords.isResampled = isResampled;
+ return pointerCoords;
+}
+
+struct InputSample {
+ std::chrono::milliseconds eventTime{0};
+ std::vector<Pointer> pointers{};
+ /**
+ * Converts from InputSample to InputMessage. Enables calling LegacyResampler methods only with
+ * the relevant data for tests.
+ */
+ operator InputMessage() const;
+};
+
+InputSample::operator InputMessage() const {
+ InputMessage message;
+ message.header.type = InputMessage::Type::MOTION;
+ message.body.motion.pointerCount = pointers.size();
+ message.body.motion.eventTime = static_cast<std::chrono::nanoseconds>(eventTime).count();
+ message.body.motion.source = AINPUT_SOURCE_CLASS_POINTER;
+ message.body.motion.downTime = 0;
+ const uint32_t pointerCount = message.body.motion.pointerCount;
+ for (uint32_t i = 0; i < pointerCount; ++i) {
+ message.body.motion.pointers[i].properties.id = pointers[i].id;
+ message.body.motion.pointers[i].properties.toolType = pointers[i].toolType;
+ message.body.motion.pointers[i].coords.setAxisValue(AMOTION_EVENT_AXIS_X, pointers[i].x);
+ message.body.motion.pointers[i].coords.setAxisValue(AMOTION_EVENT_AXIS_Y, pointers[i].y);
+ message.body.motion.pointers[i].coords.isResampled = pointers[i].isResampled;
+ }
+ return message;
+}
+
+struct InputStream {
+ std::vector<InputSample> samples{};
+ int32_t action{0};
+ DeviceId deviceId{0};
+ /**
+ * Converts from InputStream to MotionEvent. Enables calling LegacyResampler methods only with
+ * the relevant data for tests.
+ */
+ operator MotionEvent() const;
+};
+
+InputStream::operator MotionEvent() const {
+ const InputSample& firstSample{*samples.begin()};
+ MotionEventBuilder motionEventBuilder =
+ MotionEventBuilder(action, AINPUT_SOURCE_CLASS_POINTER)
+ .downTime(0)
+ .eventTime(static_cast<std::chrono::nanoseconds>(firstSample.eventTime).count())
+ .deviceId(deviceId);
+ for (const Pointer& pointer : firstSample.pointers) {
+ const PointerBuilder pointerBuilder =
+ PointerBuilder(pointer.id, pointer.toolType).x(pointer.x).y(pointer.y);
+ motionEventBuilder.pointer(pointerBuilder);
+ }
+ MotionEvent motionEvent = motionEventBuilder.build();
+ const size_t numSamples = samples.size();
+ for (size_t i = 1; i < numSamples; ++i) {
+ std::vector<PointerCoords> pointersCoords{samples[i].pointers.begin(),
+ samples[i].pointers.end()};
+ motionEvent.addSample(static_cast<std::chrono::nanoseconds>(samples[i].eventTime).count(),
+ pointersCoords.data(), motionEvent.getId());
+ }
+ return motionEvent;
+}
+
+} // namespace
+
+class ResamplerTest : public testing::Test {
+protected:
+ ResamplerTest() : mResampler(std::make_unique<LegacyResampler>()) {}
+
+ ~ResamplerTest() override {}
+
+ void SetUp() override {}
+
+ void TearDown() override {}
+
+ std::unique_ptr<Resampler> mResampler;
+
+ MotionEvent buildMotionEvent(const int32_t action, const nsecs_t eventTime,
+ const std::vector<PointerBuilder>& pointers);
+
+ InputMessage createMessage(const uint32_t pointerCount, const nsecs_t eventTime,
+ const int32_t action,
+ const std::vector<PointerProperties>& properties,
+ const std::vector<PointerCoords>& coords);
+
+ /**
+ * Checks that beforeCall and afterCall are equal except for the mutated attributes by addSample
+ * member function.
+ * @param beforeCall MotionEvent before passing it to resampleMotionEvent
+ * @param afterCall MotionEvent after passing it to resampleMotionEvent
+ */
+ void assertMotionEventMetaDataDidNotMutate(const MotionEvent& beforeCall,
+ const MotionEvent& afterCall);
+
+ /**
+ * Asserts the MotionEvent is resampled by checking an increment in history size and that the
+ * resampled coordinates are near the expected ones.
+ */
+ void assertMotionEventIsResampledAndCoordsNear(const MotionEvent& original,
+ const MotionEvent& resampled,
+ const PointerCoords& expectedCoords);
+
+ void assertMotionEventIsNotResampled(const MotionEvent& original,
+ const MotionEvent& notResampled);
+};
+
+MotionEvent ResamplerTest::buildMotionEvent(const int32_t action, const nsecs_t eventTime,
+ const std::vector<PointerBuilder>& pointerBuilders) {
+ MotionEventBuilder motionEventBuilder = MotionEventBuilder(action, AINPUT_SOURCE_CLASS_POINTER)
+ .downTime(0)
+ .eventTime(eventTime);
+ for (const PointerBuilder& pointerBuilder : pointerBuilders) {
+ motionEventBuilder.pointer(pointerBuilder);
+ }
+ return motionEventBuilder.build();
+}
+
+InputMessage ResamplerTest::createMessage(const uint32_t pointerCount, const nsecs_t eventTime,
+ const int32_t action,
+ const std::vector<PointerProperties>& properties,
+ const std::vector<PointerCoords>& coords) {
+ InputMessage message;
+ message.header.type = InputMessage::Type::MOTION;
+ message.body.motion.pointerCount = pointerCount;
+ message.body.motion.eventTime = eventTime;
+ message.body.motion.source = AINPUT_SOURCE_CLASS_POINTER;
+ message.body.motion.downTime = 0;
+ for (uint32_t i = 0; i < pointerCount; ++i) {
+ message.body.motion.pointers[i].properties = properties[i];
+ message.body.motion.pointers[i].coords = coords[i];
+ }
+ return message;
+}
+
+void ResamplerTest::assertMotionEventMetaDataDidNotMutate(const MotionEvent& beforeCall,
+ const MotionEvent& afterCall) {
+ EXPECT_EQ(beforeCall.getDeviceId(), afterCall.getDeviceId());
+ EXPECT_EQ(beforeCall.getAction(), afterCall.getAction());
+ EXPECT_EQ(beforeCall.getActionButton(), afterCall.getActionButton());
+ EXPECT_EQ(beforeCall.getButtonState(), afterCall.getButtonState());
+ EXPECT_EQ(beforeCall.getFlags(), afterCall.getFlags());
+ EXPECT_EQ(beforeCall.getEdgeFlags(), afterCall.getEdgeFlags());
+ EXPECT_EQ(beforeCall.getClassification(), afterCall.getClassification());
+ EXPECT_EQ(beforeCall.getPointerCount(), afterCall.getPointerCount());
+ EXPECT_EQ(beforeCall.getMetaState(), afterCall.getMetaState());
+ EXPECT_EQ(beforeCall.getSource(), afterCall.getSource());
+ EXPECT_EQ(beforeCall.getXPrecision(), afterCall.getXPrecision());
+ EXPECT_EQ(beforeCall.getYPrecision(), afterCall.getYPrecision());
+ EXPECT_EQ(beforeCall.getDownTime(), afterCall.getDownTime());
+ EXPECT_EQ(beforeCall.getDisplayId(), afterCall.getDisplayId());
+}
+
+void ResamplerTest::assertMotionEventIsResampledAndCoordsNear(const MotionEvent& original,
+ const MotionEvent& resampled,
+ const PointerCoords& expectedCoords) {
+ assertMotionEventMetaDataDidNotMutate(original, resampled);
+ const size_t originalSampleSize = original.getHistorySize() + 1;
+ const size_t resampledSampleSize = resampled.getHistorySize() + 1;
+ EXPECT_EQ(originalSampleSize + 1, resampledSampleSize);
+ const PointerCoords& resampledCoords =
+ resampled.getSamplePointerCoords()[resampled.getHistorySize()];
+ EXPECT_TRUE(resampledCoords.isResampled);
+ EXPECT_NEAR(expectedCoords.getX(), resampledCoords.getX(), EPSILON);
+ EXPECT_NEAR(expectedCoords.getY(), resampledCoords.getY(), EPSILON);
+}
+
+void ResamplerTest::assertMotionEventIsNotResampled(const MotionEvent& original,
+ const MotionEvent& notResampled) {
+ assertMotionEventMetaDataDidNotMutate(original, notResampled);
+ const size_t originalSampleSize = original.getHistorySize() + 1;
+ const size_t notResampledSampleSize = notResampled.getHistorySize() + 1;
+ EXPECT_EQ(originalSampleSize, notResampledSampleSize);
+}
+
+TEST_F(ResamplerTest, SinglePointerNotEnoughDataToResample) {
+ MotionEvent motionEvent =
+ InputStream{{{5ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE,
+ .deviceId = 0};
+ const MotionEvent originalMotionEvent = motionEvent;
+ mResampler->resampleMotionEvent(11ms, motionEvent, nullptr);
+ assertMotionEventIsNotResampled(originalMotionEvent, motionEvent);
+}
+
+TEST_F(ResamplerTest, SinglePointerDifferentDeviceIdBetweenMotionEvents) {
+ MotionEvent motionFromFirstDevice =
+ InputStream{{{4ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}},
+ {8ms, {{.id = 0, .x = 2.0f, .y = 2.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE,
+ .deviceId = 0};
+ mResampler->resampleMotionEvent(10ms, motionFromFirstDevice, nullptr);
+ MotionEvent motionFromSecondDevice =
+ InputStream{{{11ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE,
+ .deviceId = 1};
+ const MotionEvent originalMotionEvent = motionFromSecondDevice;
+ mResampler->resampleMotionEvent(12ms, motionFromSecondDevice, nullptr);
+ // The MotionEvent should not be resampled because the second event came from a different device
+ // than the previous event.
+ assertMotionEventIsNotResampled(originalMotionEvent, motionFromSecondDevice);
+}
+
+// Increments of 16 ms for display refresh rate
+// Increments of 6 ms for input frequency
+// Resampling latency is known to be 5 ms
+// Therefore, first resampling time will be 11 ms
+
+/**
+ * Timeline
+ * ----+----------------------+---------+---------+---------+----------
+ * 0ms 10ms 11ms 15ms 16ms
+ * DOWN MOVE | MSG |
+ * resample frame
+ * Resampling occurs at 11ms. It is possible to interpolate because there is a sample available
+ * after the resample time. It is assumed that the InputMessage frequency is 100Hz, and the frame
+ * frequency is 60Hz. This means the time between InputMessage samples is 10ms, and the time between
+ * frames is ~16ms. Resample time is frameTime - RESAMPLE_LATENCY. The resampled sample must be the
+ * last one in the batch to consume.
+ */
+TEST_F(ResamplerTest, SinglePointerSingleSampleInterpolation) {
+ MotionEvent motionEvent =
+ InputStream{{{10ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE};
+ const InputMessage futureSample =
+ InputSample{15ms, {{.id = 0, .x = 2.0f, .y = 2.0f, .isResampled = false}}};
+
+ const MotionEvent originalMotionEvent = motionEvent;
+
+ mResampler->resampleMotionEvent(11ms, motionEvent, &futureSample);
+
+ assertMotionEventIsResampledAndCoordsNear(originalMotionEvent, motionEvent,
+ Pointer{.id = 0,
+ .x = 1.2f,
+ .y = 1.2f,
+ .isResampled = true});
+}
+
+TEST_F(ResamplerTest, SinglePointerDeltaTooSmallInterpolation) {
+ MotionEvent motionEvent =
+ InputStream{{{10ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE};
+ const InputMessage futureSample =
+ InputSample{11ms, {{.id = 0, .x = 2.0f, .y = 2.0f, .isResampled = false}}};
+
+ const MotionEvent originalMotionEvent = motionEvent;
+
+ mResampler->resampleMotionEvent(10'500'000ns, motionEvent, &futureSample);
+
+ assertMotionEventIsNotResampled(originalMotionEvent, motionEvent);
+}
+
+/**
+ * Tests extrapolation given two MotionEvents with a single sample.
+ */
+TEST_F(ResamplerTest, SinglePointerSingleSampleExtrapolation) {
+ MotionEvent previousMotionEvent =
+ InputStream{{{5ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE};
+
+ mResampler->resampleMotionEvent(10ms, previousMotionEvent, nullptr);
+
+ MotionEvent motionEvent =
+ InputStream{{{10ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE};
+
+ const MotionEvent originalMotionEvent = motionEvent;
+
+ mResampler->resampleMotionEvent(11ms, motionEvent, nullptr);
+
+ assertMotionEventIsResampledAndCoordsNear(originalMotionEvent, motionEvent,
+ Pointer{.id = 0,
+ .x = 1.0f,
+ .y = 1.0f,
+ .isResampled = true});
+ // Integrity of the whole motionEvent
+ // History size should increment by 1
+ // Check if the resampled value is the last one
+ // Check if the resampleTime is correct
+ // Check if the PointerCoords are consistent with the other computations
+}
+
+TEST_F(ResamplerTest, SinglePointerMultipleSampleInterpolation) {
+ MotionEvent motionEvent =
+ InputStream{{{5ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}},
+ {10ms, {{.id = 0, .x = 2.0f, .y = 2.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE};
+ const InputMessage futureSample =
+ InputSample{15ms, {{.id = 0, .x = 3.0f, .y = 3.0f, .isResampled = false}}};
+
+ const MotionEvent originalMotionEvent = motionEvent;
+
+ mResampler->resampleMotionEvent(11ms, motionEvent, &futureSample);
+
+ assertMotionEventIsResampledAndCoordsNear(originalMotionEvent, motionEvent,
+ Pointer{.id = 0,
+ .x = 2.2f,
+ .y = 2.2f,
+ .isResampled = true});
+}
+
+TEST_F(ResamplerTest, SinglePointerMultipleSampleExtrapolation) {
+ MotionEvent motionEvent =
+ InputStream{{{5ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}},
+ {10ms, {{.id = 0, .x = 2.0f, .y = 2.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE};
+
+ const MotionEvent originalMotionEvent = motionEvent;
+
+ mResampler->resampleMotionEvent(11ms, motionEvent, nullptr);
+
+ assertMotionEventIsResampledAndCoordsNear(originalMotionEvent, motionEvent,
+ Pointer{.id = 0,
+ .x = 2.2f,
+ .y = 2.2f,
+ .isResampled = true});
+}
+
+TEST_F(ResamplerTest, SinglePointerDeltaTooSmallExtrapolation) {
+ MotionEvent motionEvent =
+ InputStream{{{9ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}},
+ {10ms, {{.id = 0, .x = 2.0f, .y = 2.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE};
+
+ const MotionEvent originalMotionEvent = motionEvent;
+
+ mResampler->resampleMotionEvent(11ms, motionEvent, nullptr);
+
+ assertMotionEventIsNotResampled(originalMotionEvent, motionEvent);
+}
+
+TEST_F(ResamplerTest, SinglePointerDeltaTooLargeExtrapolation) {
+ MotionEvent motionEvent =
+ InputStream{{{5ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}},
+ {26ms, {{.id = 0, .x = 2.0f, .y = 2.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE};
+
+ const MotionEvent originalMotionEvent = motionEvent;
+
+ mResampler->resampleMotionEvent(27ms, motionEvent, nullptr);
+
+ assertMotionEventIsNotResampled(originalMotionEvent, motionEvent);
+}
+
+TEST_F(ResamplerTest, SinglePointerResampleTimeTooFarExtrapolation) {
+ MotionEvent motionEvent =
+ InputStream{{{5ms, {{.id = 0, .x = 1.0f, .y = 1.0f, .isResampled = false}}},
+ {25ms, {{.id = 0, .x = 2.0f, .y = 2.0f, .isResampled = false}}}},
+ AMOTION_EVENT_ACTION_MOVE};
+
+ const MotionEvent originalMotionEvent = motionEvent;
+
+ mResampler->resampleMotionEvent(43ms, motionEvent, nullptr);
+
+ assertMotionEventIsResampledAndCoordsNear(originalMotionEvent, motionEvent,
+ Pointer{.id = 0,
+ .x = 2.4f,
+ .y = 2.4f,
+ .isResampled = true});
+}
+} // namespace android