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]);