CursorInputMapper: share acceleration curves with touchpad
The new touchpad mapper implemented in Android 14 replaced our simple
cursor movement acceleration curves (where the acceleration factor
increased linearly with speed between minimum and maximum values) with
more sophisticated multi-segment curves. However, cursor movement using
mice remained on the old curves. For consistency and to improve pointing
accuracy, use the same curves for mice, too.
This is also a good opportunity to improve the documentation comments
and naming now that I've wrapped my head around the maths a bit better.
Bug: 315313622
Test: atest inputflinger_tests
Test: check pointer movement with a mouse, including changing the
pointer speed setting and checking that the movement speed changes
Change-Id: Ifcf43f4de6017f06b66f37d5e03a13cc257d92d5
diff --git a/libs/input/VelocityControl.cpp b/libs/input/VelocityControl.cpp
index c835a08..edd31e9 100644
--- a/libs/input/VelocityControl.cpp
+++ b/libs/input/VelocityControl.cpp
@@ -15,7 +15,6 @@
*/
#define LOG_TAG "VelocityControl"
-//#define LOG_NDEBUG 0
// Log debug messages about acceleration.
static constexpr bool DEBUG_ACCELERATION = false;
@@ -23,6 +22,7 @@
#include <math.h>
#include <limits.h>
+#include <android-base/logging.h>
#include <input/VelocityControl.h>
#include <utils/BitSet.h>
#include <utils/Timers.h>
@@ -37,15 +37,6 @@
reset();
}
-const VelocityControlParameters& VelocityControl::getParameters() const{
- return mParameters;
-}
-
-void VelocityControl::setParameters(const VelocityControlParameters& parameters) {
- mParameters = parameters;
- reset();
-}
-
void VelocityControl::reset() {
mLastMovementTime = LLONG_MIN;
mRawPositionX = 0;
@@ -54,65 +45,156 @@
}
void VelocityControl::move(nsecs_t eventTime, float* deltaX, float* deltaY) {
- if ((deltaX && *deltaX) || (deltaY && *deltaY)) {
- if (eventTime >= mLastMovementTime + STOP_TIME) {
- if (DEBUG_ACCELERATION && mLastMovementTime != LLONG_MIN) {
- ALOGD("VelocityControl: stopped, last movement was %0.3fms ago",
- (eventTime - mLastMovementTime) * 0.000001f);
- }
- reset();
+ if ((deltaX == nullptr || *deltaX == 0) && (deltaY == nullptr || *deltaY == 0)) {
+ return;
+ }
+ if (eventTime >= mLastMovementTime + STOP_TIME) {
+ ALOGD_IF(DEBUG_ACCELERATION && mLastMovementTime != LLONG_MIN,
+ "VelocityControl: stopped, last movement was %0.3fms ago",
+ (eventTime - mLastMovementTime) * 0.000001f);
+ reset();
+ }
+
+ mLastMovementTime = eventTime;
+ if (deltaX) {
+ mRawPositionX += *deltaX;
+ }
+ if (deltaY) {
+ mRawPositionY += *deltaY;
+ }
+ mVelocityTracker.addMovement(eventTime, /*pointerId=*/0, AMOTION_EVENT_AXIS_X, mRawPositionX);
+ mVelocityTracker.addMovement(eventTime, /*pointerId=*/0, AMOTION_EVENT_AXIS_Y, mRawPositionY);
+ scaleDeltas(deltaX, deltaY);
+}
+
+// --- SimpleVelocityControl ---
+
+const VelocityControlParameters& SimpleVelocityControl::getParameters() const {
+ return mParameters;
+}
+
+void SimpleVelocityControl::setParameters(const VelocityControlParameters& parameters) {
+ mParameters = parameters;
+ reset();
+}
+
+void SimpleVelocityControl::scaleDeltas(float* deltaX, float* deltaY) {
+ std::optional<float> vx = mVelocityTracker.getVelocity(AMOTION_EVENT_AXIS_X, 0);
+ std::optional<float> vy = mVelocityTracker.getVelocity(AMOTION_EVENT_AXIS_Y, 0);
+ float scale = mParameters.scale;
+ if (vx.has_value() && vy.has_value()) {
+ float speed = hypotf(*vx, *vy) * scale;
+ if (speed >= mParameters.highThreshold) {
+ // Apply full acceleration above the high speed threshold.
+ scale *= mParameters.acceleration;
+ } else if (speed > mParameters.lowThreshold) {
+ // Linearly interpolate the acceleration to apply between the low and high
+ // speed thresholds.
+ scale *= 1 +
+ (speed - mParameters.lowThreshold) /
+ (mParameters.highThreshold - mParameters.lowThreshold) *
+ (mParameters.acceleration - 1);
}
- mLastMovementTime = eventTime;
- if (deltaX) {
- mRawPositionX += *deltaX;
- }
- if (deltaY) {
- mRawPositionY += *deltaY;
- }
- mVelocityTracker.addMovement(eventTime, /*pointerId=*/0, AMOTION_EVENT_AXIS_X,
- mRawPositionX);
- mVelocityTracker.addMovement(eventTime, /*pointerId=*/0, AMOTION_EVENT_AXIS_Y,
- mRawPositionY);
+ ALOGD_IF(DEBUG_ACCELERATION,
+ "SimpleVelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): "
+ "vx=%0.3f, vy=%0.3f, speed=%0.3f, accel=%0.3f",
+ mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold,
+ mParameters.acceleration, *vx, *vy, speed, scale / mParameters.scale);
- std::optional<float> vx = mVelocityTracker.getVelocity(AMOTION_EVENT_AXIS_X, 0);
- std::optional<float> vy = mVelocityTracker.getVelocity(AMOTION_EVENT_AXIS_Y, 0);
- float scale = mParameters.scale;
- if (vx && vy) {
- float speed = hypotf(*vx, *vy) * scale;
- if (speed >= mParameters.highThreshold) {
- // Apply full acceleration above the high speed threshold.
- scale *= mParameters.acceleration;
- } else if (speed > mParameters.lowThreshold) {
- // Linearly interpolate the acceleration to apply between the low and high
- // speed thresholds.
- scale *= 1 + (speed - mParameters.lowThreshold)
- / (mParameters.highThreshold - mParameters.lowThreshold)
- * (mParameters.acceleration - 1);
- }
+ } else {
+ ALOGD_IF(DEBUG_ACCELERATION,
+ "SimpleVelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): unknown velocity",
+ mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold,
+ mParameters.acceleration);
+ }
- if (DEBUG_ACCELERATION) {
- ALOGD("VelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): "
- "vx=%0.3f, vy=%0.3f, speed=%0.3f, accel=%0.3f",
- mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold,
- mParameters.acceleration, *vx, *vy, speed, scale / mParameters.scale);
- }
+ if (deltaX != nullptr) {
+ *deltaX *= scale;
+ }
+ if (deltaY != nullptr) {
+ *deltaY *= scale;
+ }
+}
- } else {
- if (DEBUG_ACCELERATION) {
- ALOGD("VelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): unknown velocity",
- mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold,
- mParameters.acceleration);
- }
- }
+// --- CurvedVelocityControl ---
- if (deltaX) {
- *deltaX *= scale;
- }
- if (deltaY) {
- *deltaY *= scale;
+namespace {
+
+/**
+ * The resolution that we assume a mouse to have, in counts per inch.
+ *
+ * Mouse resolutions vary wildly, but 800 CPI is probably the most common. There should be enough
+ * range in the available sensitivity settings to accommodate users of mice with other resolutions.
+ */
+constexpr int32_t MOUSE_CPI = 800;
+
+float countsToMm(float counts) {
+ return counts / MOUSE_CPI * 25.4;
+}
+
+} // namespace
+
+CurvedVelocityControl::CurvedVelocityControl()
+ : mCurveSegments(createAccelerationCurveForPointerSensitivity(0)) {}
+
+void CurvedVelocityControl::setCurve(const std::vector<AccelerationCurveSegment>& curve) {
+ mCurveSegments = curve;
+}
+
+void CurvedVelocityControl::setAccelerationEnabled(bool enabled) {
+ mAccelerationEnabled = enabled;
+}
+
+void CurvedVelocityControl::scaleDeltas(float* deltaX, float* deltaY) {
+ if (!mAccelerationEnabled) {
+ ALOGD_IF(DEBUG_ACCELERATION, "CurvedVelocityControl: acceleration disabled");
+ return;
+ }
+
+ std::optional<float> vx = mVelocityTracker.getVelocity(AMOTION_EVENT_AXIS_X, 0);
+ std::optional<float> vy = mVelocityTracker.getVelocity(AMOTION_EVENT_AXIS_Y, 0);
+
+ float ratio;
+ if (vx.has_value() && vy.has_value()) {
+ float vxMmPerS = countsToMm(*vx);
+ float vyMmPerS = countsToMm(*vy);
+ float speedMmPerS = sqrtf(vxMmPerS * vxMmPerS + vyMmPerS * vyMmPerS);
+
+ const AccelerationCurveSegment& seg = segmentForSpeed(speedMmPerS);
+ ratio = seg.baseGain + seg.reciprocal / speedMmPerS;
+ ALOGD_IF(DEBUG_ACCELERATION,
+ "CurvedVelocityControl: velocities (%0.3f, %0.3f) → speed %0.3f → ratio %0.3f",
+ vxMmPerS, vyMmPerS, speedMmPerS, ratio);
+ } else {
+ // We don't have enough data to compute a velocity yet. This happens early in the movement,
+ // when the speed is presumably low, so use the base gain of the first segment of the curve.
+ // (This would behave oddly for curves with a reciprocal term on the first segment, but we
+ // don't have any of those, and they'd be very strange at velocities close to zero anyway.)
+ ratio = mCurveSegments[0].baseGain;
+ ALOGD_IF(DEBUG_ACCELERATION,
+ "CurvedVelocityControl: unknown velocity, using base gain of first segment (%.3f)",
+ ratio);
+ }
+
+ if (deltaX != nullptr) {
+ *deltaX *= ratio;
+ }
+ if (deltaY != nullptr) {
+ *deltaY *= ratio;
+ }
+}
+
+const AccelerationCurveSegment& CurvedVelocityControl::segmentForSpeed(float speedMmPerS) {
+ for (const AccelerationCurveSegment& seg : mCurveSegments) {
+ if (speedMmPerS <= seg.maxPointerSpeedMmPerS) {
+ return seg;
}
}
+ ALOGE("CurvedVelocityControl: No segment found for speed %.3f; last segment should always have "
+ "a max speed of infinity.",
+ speedMmPerS);
+ return mCurveSegments.back();
}
} // namespace android