void VelocityTracker::addMovement(nsecs_t eventTime, BitSet32 idBits, const Position* positions) {
while (idBits.count() > MAX_POINTERS) {
idBits.clearLastMarkedBit();
}
if ((mCurrentPointerIdBits.value & idBits.value)
&& eventTime >= mLastEventTime + ASSUME_POINTER_STOPPED_TIME) {
#if DEBUG_VELOCITY
ALOGD("VelocityTracker: stopped for %0.3f ms, clearing state.",
(eventTime - mLastEventTime) * 0.000001f);
#endif
// We have not received any movements for too long. Assume that all pointers
// have stopped.
mStrategy->clear();
}
mLastEventTime = eventTime;
mCurrentPointerIdBits = idBits;
if (mActivePointerId < 0 || !idBits.hasBit(mActivePointerId)) {
mActivePointerId = idBits.isEmpty() ? -1 : idBits.firstMarkedBit();
}
mStrategy->addMovement(eventTime, idBits, positions);
#if DEBUG_VELOCITY
ALOGD("VelocityTracker: addMovement eventTime=%" PRId64 ", idBits=0x%08x, activePointerId=%d",
eventTime, idBits.value, mActivePointerId);
for (BitSet32 iterBits(idBits); !iterBits.isEmpty(); ) {
uint32_t id = iterBits.firstMarkedBit();
uint32_t index = idBits.getIndexOfBit(id);
iterBits.clearBit(id);
Estimator estimator;
getEstimator(id, &estimator);
ALOGD(" %d: position (%0.3f, %0.3f), "
"estimator (degree=%d, xCoeff=%s, yCoeff=%s, confidence=%f)",
id, positions[index].x, positions[index].y,
int(estimator.degree),
vectorToString(estimator.xCoeff, estimator.degree + 1).c_str(),
vectorToString(estimator.yCoeff, estimator.degree + 1).c_str(),
estimator.confidence);
}
#endif
}
void VelocityTrackerState::getVelocity(int32_t id, float* outVx, float* outVy) {
if (id == ACTIVE_POINTER_ID) {
id = mVelocityTracker.getActivePointerId();
}
float vx, vy;
if (id >= 0 && id <= MAX_POINTER_ID && mCalculatedIdBits.hasBit(id)) {
uint32_t index = mCalculatedIdBits.getIndexOfBit(id);
const Velocity& velocity = mCalculatedVelocity[index];
vx = velocity.vx;
vy = velocity.vy;
} else {
vx = 0;
vy = 0;
}
if (outVx) {
*outVx = vx;
}
if (outVy) {
*outVy = vy;
}
}
void VelocityTracker::addMovement(const MotionEvent* event) {
int32_t actionMasked = event->getActionMasked();
switch (actionMasked) {
case AMOTION_EVENT_ACTION_DOWN:
case AMOTION_EVENT_ACTION_HOVER_ENTER:
// Clear all pointers on down before adding the new movement.
clear();
break;
case AMOTION_EVENT_ACTION_POINTER_DOWN: {
// Start a new movement trace for a pointer that just went down.
// We do this on down instead of on up because the client may want to query the
// final velocity for a pointer that just went up.
BitSet32 downIdBits;
downIdBits.markBit(event->getPointerId(event->getActionIndex()));
clearPointers(downIdBits);
break;
}
case AMOTION_EVENT_ACTION_MOVE:
case AMOTION_EVENT_ACTION_HOVER_MOVE:
break;
default:
// Ignore all other actions because they do not convey any new information about
// pointer movement. We also want to preserve the last known velocity of the pointers.
// Note that ACTION_UP and ACTION_POINTER_UP always report the last known position
// of the pointers that went up. ACTION_POINTER_UP does include the new position of
// pointers that remained down but we will also receive an ACTION_MOVE with this
// information if any of them actually moved. Since we don't know how many pointers
// will be going up at once it makes sense to just wait for the following ACTION_MOVE
// before adding the movement.
return;
}
size_t pointerCount = event->getPointerCount();
if (pointerCount > MAX_POINTERS) {
pointerCount = MAX_POINTERS;
}
BitSet32 idBits;
for (size_t i = 0; i < pointerCount; i++) {
idBits.markBit(event->getPointerId(i));
}
uint32_t pointerIndex[MAX_POINTERS];
for (size_t i = 0; i < pointerCount; i++) {
pointerIndex[i] = idBits.getIndexOfBit(event->getPointerId(i));
}
nsecs_t eventTime;
Position positions[pointerCount];
size_t historySize = event->getHistorySize();
for (size_t h = 0; h < historySize; h++) {
eventTime = event->getHistoricalEventTime(h);
for (size_t i = 0; i < pointerCount; i++) {
uint32_t index = pointerIndex[i];
positions[index].x = event->getHistoricalX(i, h);
positions[index].y = event->getHistoricalY(i, h);
}
addMovement(eventTime, idBits, positions);
}
eventTime = event->getEventTime();
for (size_t i = 0; i < pointerCount; i++) {
uint32_t index = pointerIndex[i];
positions[index].x = event->getX(i);
positions[index].y = event->getY(i);
}
addMovement(eventTime, idBits, positions);
}
