// Oldest sample to consider when calculating the velocity.
static const nsecs_t MAX_AGE = 200 * 1000000; // 200 ms
+ // When the total duration of the window of samples being averaged is less
+ // than the window size, the resulting velocity is scaled to reduce the impact
+ // of overestimation in short traces.
+ static const nsecs_t MIN_WINDOW = 100 * 1000000; // 100 ms
+
// The minimum duration between samples when estimating velocity.
static const nsecs_t MIN_DURATION = 10 * 1000000; // 10 ms
const Position& oldestPosition =
oldestMovement.positions[oldestMovement.idBits.getIndexOfBit(id)];
nsecs_t lastDuration = 0;
+
while (numTouches-- > 1) {
if (++index == HISTORY_SIZE) {
index = 0;
// Make sure we used at least one sample.
if (samplesUsed != 0) {
+ // Scale the velocity linearly if the window of samples is small.
+ nsecs_t totalDuration = newestMovement.eventTime - oldestMovement.eventTime;
+ if (totalDuration < MIN_WINDOW) {
+ float scale = float(totalDuration) / float(MIN_WINDOW);
+ accumVx *= scale;
+ accumVy *= scale;
+ }
+
*outVx = accumVx;
*outVy = accumVy;
return true;
#endif
void Looper::sendMessage(const sp<MessageHandler>& handler, const Message& message) {
- sendMessageAtTime(LLONG_MIN, handler, message);
+ nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
+ sendMessageAtTime(now, handler, message);
}
void Looper::sendMessageDelayed(nsecs_t uptimeDelay, const sp<MessageHandler>& handler,