if (index >= 0) {
TouchState& touchState = mTouchStates.editItemAt(index);
touchState.addHistory(msg);
- bool messageRewritten = rewriteMessage(touchState, msg);
- if (!messageRewritten) {
- touchState.lastResample.idBits.clear();
- }
+ rewriteMessage(touchState, msg);
}
break;
}
case AMOTION_EVENT_ACTION_SCROLL: {
ssize_t index = findTouchState(deviceId, source);
if (index >= 0) {
- const TouchState& touchState = mTouchStates.itemAt(index);
+ TouchState& touchState = mTouchStates.editItemAt(index);
rewriteMessage(touchState, msg);
}
break;
case AMOTION_EVENT_ACTION_CANCEL: {
ssize_t index = findTouchState(deviceId, source);
if (index >= 0) {
- const TouchState& touchState = mTouchStates.itemAt(index);
+ TouchState& touchState = mTouchStates.editItemAt(index);
rewriteMessage(touchState, msg);
mTouchStates.removeAt(index);
}
}
}
-bool InputConsumer::rewriteMessage(const TouchState& state, InputMessage& msg) {
- bool messageRewritten = false;
+/**
+ * Replace the coordinates in msg with the coordinates in lastResample, if necessary.
+ *
+ * If lastResample is no longer valid for a specific pointer (i.e. the lastResample time
+ * is in the past relative to msg and the past two events do not contain identical coordinates),
+ * then invalidate the lastResample data for that pointer.
+ * If the two past events have identical coordinates, then lastResample data for that pointer will
+ * remain valid, and will be used to replace these coordinates. Thus, if a certain coordinate x0 is
+ * resampled to the new value x1, then x1 will always be used to replace x0 until some new value
+ * not equal to x0 is received.
+ */
+void InputConsumer::rewriteMessage(TouchState& state, InputMessage& msg) {
nsecs_t eventTime = msg.body.motion.eventTime;
for (uint32_t i = 0; i < msg.body.motion.pointerCount; i++) {
uint32_t id = msg.body.motion.pointers[i].properties.id;
if (state.lastResample.idBits.hasBit(id)) {
- PointerCoords& msgCoords = msg.body.motion.pointers[i].coords;
- const PointerCoords& resampleCoords = state.lastResample.getPointerById(id);
if (eventTime < state.lastResample.eventTime ||
state.recentCoordinatesAreIdentical(id)) {
- msgCoords.setAxisValue(AMOTION_EVENT_AXIS_X, resampleCoords.getX());
- msgCoords.setAxisValue(AMOTION_EVENT_AXIS_Y, resampleCoords.getY());
+ PointerCoords& msgCoords = msg.body.motion.pointers[i].coords;
+ const PointerCoords& resampleCoords = state.lastResample.getPointerById(id);
#if DEBUG_RESAMPLING
ALOGD("[%d] - rewrite (%0.3f, %0.3f), old (%0.3f, %0.3f)", id,
resampleCoords.getX(), resampleCoords.getY(),
msgCoords.getX(), msgCoords.getY());
#endif
- messageRewritten = true;
+ msgCoords.setAxisValue(AMOTION_EVENT_AXIS_X, resampleCoords.getX());
+ msgCoords.setAxisValue(AMOTION_EVENT_AXIS_Y, resampleCoords.getY());
+ } else {
+ state.lastResample.idBits.clearBit(id);
}
}
}
- return messageRewritten;
}
void InputConsumer::resampleTouchState(nsecs_t sampleTime, MotionEvent* event,
}
// Ensure that the current sample has all of the pointers that need to be reported.
- // Also ensure that the past two "real" touch events do not contain duplicate coordinates
const History* current = touchState.getHistory(0);
size_t pointerCount = event->getPointerCount();
for (size_t i = 0; i < pointerCount; i++) {
#endif
return;
}
- if (touchState.recentCoordinatesAreIdentical(id)) {
-#if DEBUG_RESAMPLING
- ALOGD("Not resampled, past two historical events have duplicate coordinates");
-#endif
- return;
- }
}
// Find the data to use for resampling.
}
// Resample touch coordinates.
+ History oldLastResample;
+ oldLastResample.initializeFrom(touchState.lastResample);
touchState.lastResample.eventTime = sampleTime;
touchState.lastResample.idBits.clear();
for (size_t i = 0; i < pointerCount; i++) {
uint32_t id = event->getPointerId(i);
touchState.lastResample.idToIndex[id] = i;
touchState.lastResample.idBits.markBit(id);
+ if (oldLastResample.hasPointerId(id) && touchState.recentCoordinatesAreIdentical(id)) {
+ // We maintain the previously resampled value for this pointer (stored in
+ // oldLastResample) when the coordinates for this pointer haven't changed since then.
+ // This way we don't introduce artificial jitter when pointers haven't actually moved.
+
+ // We know here that the coordinates for the pointer haven't changed because we
+ // would've cleared the resampled bit in rewriteMessage if they had. We can't modify
+ // lastResample in place becasue the mapping from pointer ID to index may have changed.
+ touchState.lastResample.pointers[i].copyFrom(oldLastResample.getPointerById(id));
+ continue;
+ }
+
PointerCoords& resampledCoords = touchState.lastResample.pointers[i];
const PointerCoords& currentCoords = current->getPointerById(id);
+ resampledCoords.copyFrom(currentCoords);
if (other->idBits.hasBit(id)
&& shouldResampleTool(event->getToolType(i))) {
const PointerCoords& otherCoords = other->getPointerById(id);
- resampledCoords.copyFrom(currentCoords);
resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_X,
lerp(currentCoords.getX(), otherCoords.getX(), alpha));
resampledCoords.setAxisValue(AMOTION_EVENT_AXIS_Y,
alpha);
#endif
} else {
- resampledCoords.copyFrom(currentCoords);
#if DEBUG_RESAMPLING
ALOGD("[%d] - out (%0.3f, %0.3f), cur (%0.3f, %0.3f)",
id, resampledCoords.getX(), resampledCoords.getY(),
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