Add jerk thresholded pruning.
This will change MotionPredictor::predict() outputs once
enable_prediction_pruning_via_jerk_thresholding is enabled.
Test: atest libinput_tests --host with local flag override to enable
enable_prediction_pruning_via_jerk_thresholding.
Test: atest CtsInputTestCases
Test: atest MotionPredictorBenchmark MotionPredictorTest
Bug: 266747654
Change-Id: I11eb1972246468a1f3824656f5ac57e01e0359cd
diff --git a/libs/input/MotionPredictor.cpp b/libs/input/MotionPredictor.cpp
index 77292d4..5b61d39 100644
--- a/libs/input/MotionPredictor.cpp
+++ b/libs/input/MotionPredictor.cpp
@@ -18,6 +18,7 @@
#include <input/MotionPredictor.h>
+#include <algorithm>
#include <array>
#include <cinttypes>
#include <cmath>
@@ -62,6 +63,11 @@
return {.x = axisTo.x + x_delta, .y = axisTo.y + y_delta};
}
+float normalizeRange(float x, float min, float max) {
+ const float normalized = (x - min) / (max - min);
+ return std::min(1.0f, std::max(0.0f, normalized));
+}
+
} // namespace
// --- JerkTracker ---
@@ -255,6 +261,17 @@
int64_t predictionTime = mBuffers->lastTimestamp();
const int64_t futureTime = timestamp + mPredictionTimestampOffsetNanos;
+ const float jerkMagnitude = mJerkTracker.jerkMagnitude().value_or(0);
+ const float fractionKept =
+ 1 - normalizeRange(jerkMagnitude, mModel->config().lowJerk, mModel->config().highJerk);
+ // float to ensure proper division below.
+ const float predictionTimeWindow = futureTime - predictionTime;
+ const int maxNumPredictions = static_cast<int>(
+ std::ceil(predictionTimeWindow / mModel->config().predictionInterval * fractionKept));
+ ALOGD_IF(isDebug(),
+ "jerk (d^3p/normalizedDt^3): %f, fraction of prediction window pruned: %f, max number "
+ "of predictions: %d",
+ jerkMagnitude, 1 - fractionKept, maxNumPredictions);
for (size_t i = 0; i < static_cast<size_t>(predictedR.size()) && predictionTime <= futureTime;
++i) {
if (predictedR[i] < mModel->config().distanceNoiseFloor) {
@@ -269,13 +286,12 @@
break;
}
if (input_flags::enable_prediction_pruning_via_jerk_thresholding()) {
- // TODO(b/266747654): Stop predictions if confidence is < some threshold
- // Arbitrarily high pruning index, will correct once jerk thresholding is implemented.
- const size_t upperBoundPredictionIndex = std::numeric_limits<size_t>::max();
- if (i > upperBoundPredictionIndex) {
+ if (i >= static_cast<size_t>(maxNumPredictions)) {
break;
}
}
+ // TODO(b/266747654): Stop predictions if confidence is < some
+ // threshold. Currently predictions are pruned via jerk thresholding.
const TfLiteMotionPredictorSample::Point predictedPoint =
convertPrediction(axisFrom, axisTo, predictedR[i], predictedPhi[i]);
diff --git a/libs/input/TfLiteMotionPredictor.cpp b/libs/input/TfLiteMotionPredictor.cpp
index d17476e..b843a4b 100644
--- a/libs/input/TfLiteMotionPredictor.cpp
+++ b/libs/input/TfLiteMotionPredictor.cpp
@@ -281,6 +281,8 @@
Config config{
.predictionInterval = parseXMLInt64(*configRoot, "prediction-interval"),
.distanceNoiseFloor = parseXMLFloat(*configRoot, "distance-noise-floor"),
+ .lowJerk = parseXMLFloat(*configRoot, "low-jerk"),
+ .highJerk = parseXMLFloat(*configRoot, "high-jerk"),
};
return std::unique_ptr<TfLiteMotionPredictorModel>(
diff --git a/libs/input/tests/Android.bp b/libs/input/tests/Android.bp
index e67a65a..ee140b7 100644
--- a/libs/input/tests/Android.bp
+++ b/libs/input/tests/Android.bp
@@ -36,6 +36,7 @@
"tensorflow_headers",
],
static_libs: [
+ "libflagtest",
"libgmock",
"libgui_window_info_static",
"libinput",
diff --git a/libs/input/tests/MotionPredictor_test.cpp b/libs/input/tests/MotionPredictor_test.cpp
index f74874c..dc38fef 100644
--- a/libs/input/tests/MotionPredictor_test.cpp
+++ b/libs/input/tests/MotionPredictor_test.cpp
@@ -14,9 +14,12 @@
* limitations under the License.
*/
+// TODO(b/331815574): Decouple this test from assumed config values.
#include <chrono>
#include <cmath>
+#include <com_android_input_flags.h>
+#include <flag_macros.h>
#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include <gui/constants.h>
@@ -197,18 +200,14 @@
TEST(MotionPredictorTest, FollowsGesture) {
MotionPredictor predictor(/*predictionTimestampOffsetNanos=*/0,
[]() { return true /*enable prediction*/; });
+ predictor.record(getMotionEvent(DOWN, 3.75, 3, 20ms));
+ predictor.record(getMotionEvent(MOVE, 4.8, 3, 30ms));
+ predictor.record(getMotionEvent(MOVE, 6.2, 3, 40ms));
+ predictor.record(getMotionEvent(MOVE, 8, 3, 50ms));
+ EXPECT_NE(nullptr, predictor.predict(90 * NSEC_PER_MSEC));
- // MOVE without a DOWN is ignored.
- predictor.record(getMotionEvent(MOVE, 1, 3, 10ms));
- EXPECT_EQ(nullptr, predictor.predict(20 * NSEC_PER_MSEC));
-
- predictor.record(getMotionEvent(DOWN, 2, 5, 20ms));
- predictor.record(getMotionEvent(MOVE, 2, 7, 30ms));
- predictor.record(getMotionEvent(MOVE, 3, 9, 40ms));
- EXPECT_NE(nullptr, predictor.predict(50 * NSEC_PER_MSEC));
-
- predictor.record(getMotionEvent(UP, 4, 11, 50ms));
- EXPECT_EQ(nullptr, predictor.predict(20 * NSEC_PER_MSEC));
+ predictor.record(getMotionEvent(UP, 10.25, 3, 60ms));
+ EXPECT_EQ(nullptr, predictor.predict(100 * NSEC_PER_MSEC));
}
TEST(MotionPredictorTest, MultipleDevicesNotSupported) {
@@ -250,6 +249,63 @@
ASSERT_FALSE(predictor.isPredictionAvailable(/*deviceId=*/1, AINPUT_SOURCE_TOUCHSCREEN));
}
+TEST_WITH_FLAGS(
+ MotionPredictorTest, LowJerkNoPruning,
+ REQUIRES_FLAGS_ENABLED(ACONFIG_FLAG(com::android::input::flags,
+ enable_prediction_pruning_via_jerk_thresholding))) {
+ MotionPredictor predictor(/*predictionTimestampOffsetNanos=*/0,
+ []() { return true /*enable prediction*/; });
+
+ // Jerk is low (0.05 normalized).
+ predictor.record(getMotionEvent(DOWN, 2, 7, 20ms));
+ predictor.record(getMotionEvent(MOVE, 2.75, 7, 30ms));
+ predictor.record(getMotionEvent(MOVE, 3.8, 7, 40ms));
+ predictor.record(getMotionEvent(MOVE, 5.2, 7, 50ms));
+ predictor.record(getMotionEvent(MOVE, 7, 7, 60ms));
+ std::unique_ptr<MotionEvent> predicted = predictor.predict(90 * NSEC_PER_MSEC);
+ EXPECT_NE(nullptr, predicted);
+ EXPECT_EQ(static_cast<size_t>(5), predicted->getHistorySize() + 1);
+}
+
+TEST_WITH_FLAGS(
+ MotionPredictorTest, HighJerkPredictionsPruned,
+ REQUIRES_FLAGS_ENABLED(ACONFIG_FLAG(com::android::input::flags,
+ enable_prediction_pruning_via_jerk_thresholding))) {
+ MotionPredictor predictor(/*predictionTimestampOffsetNanos=*/0,
+ []() { return true /*enable prediction*/; });
+
+ // Jerk is incredibly high.
+ predictor.record(getMotionEvent(DOWN, 0, 5, 20ms));
+ predictor.record(getMotionEvent(MOVE, 0, 70, 30ms));
+ predictor.record(getMotionEvent(MOVE, 0, 139, 40ms));
+ predictor.record(getMotionEvent(MOVE, 0, 1421, 50ms));
+ predictor.record(getMotionEvent(MOVE, 0, 41233, 60ms));
+ std::unique_ptr<MotionEvent> predicted = predictor.predict(90 * NSEC_PER_MSEC);
+ EXPECT_EQ(nullptr, predicted);
+}
+
+TEST_WITH_FLAGS(
+ MotionPredictorTest, MediumJerkPredictionsSomePruned,
+ REQUIRES_FLAGS_ENABLED(ACONFIG_FLAG(com::android::input::flags,
+ enable_prediction_pruning_via_jerk_thresholding))) {
+ MotionPredictor predictor(/*predictionTimestampOffsetNanos=*/0,
+ []() { return true /*enable prediction*/; });
+
+ // Jerk is medium (1.5 normalized, which is halfway between LOW_JANK and HIGH_JANK)
+ predictor.record(getMotionEvent(DOWN, 0, 4, 20ms));
+ predictor.record(getMotionEvent(MOVE, 0, 6.25, 30ms));
+ predictor.record(getMotionEvent(MOVE, 0, 9.4, 40ms));
+ predictor.record(getMotionEvent(MOVE, 0, 13.6, 50ms));
+ predictor.record(getMotionEvent(MOVE, 0, 19, 60ms));
+ std::unique_ptr<MotionEvent> predicted = predictor.predict(82 * NSEC_PER_MSEC);
+ EXPECT_NE(nullptr, predicted);
+ // Halfway between LOW_JANK and HIGH_JANK means that half of the predictions
+ // will be pruned. If model prediction window is close enough to predict()
+ // call time window, then half of the model predictions (5/2 -> 2) will be
+ // ouputted.
+ EXPECT_EQ(static_cast<size_t>(3), predicted->getHistorySize() + 1);
+}
+
using AtomFields = MotionPredictorMetricsManager::AtomFields;
using ReportAtomFunction = MotionPredictorMetricsManager::ReportAtomFunction;