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Commit dcab190b authored by Jeff Brown's avatar Jeff Brown
Browse files

Fix pointer indexing issue in VelocityTracker. 

VelocityTracker was implicitly assuming that the pointer ids in
a MotionEvent were ordered.  That is not necessarily the case
so we need to be careful while copying the pointer coordinates out.

Bug: 6413587
Change-Id: I3b23a954f893eebdf786f2a94207149b092ef036
parent 7174a491

libs/androidfw/VelocityTracker.cpp

+13 −6
Original line number Diff line number Diff line
@@ -145,8 +145,8 @@ void VelocityTracker::addMovement(nsecs_t eventTime, BitSet32 idBits, const Posi 
                "estimator (degree=%d, xCoeff=%s, yCoeff=%s, confidence=%f)",

                id, positions[index].x, positions[index].y,

                int(estimator.degree),

                vectorToString(estimator.xCoeff, estimator.degree).string(),

                vectorToString(estimator.yCoeff, estimator.degree).string(),

                vectorToString(estimator.xCoeff, estimator.degree + 1).string(),

                vectorToString(estimator.yCoeff, estimator.degree + 1).string(),

                estimator.confidence);

    }

#endif
@@ -195,6 +195,11 @@ void VelocityTracker::addMovement(const MotionEvent* event) { 
        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];
@@ -202,16 +207,18 @@ void VelocityTracker::addMovement(const MotionEvent* event) { 
    for (size_t h = 0; h < historySize; h++) {

        eventTime = event->getHistoricalEventTime(h);

        for (size_t i = 0; i < pointerCount; i++) {

            positions[i].x = event->getHistoricalX(i, h);

            positions[i].y = event->getHistoricalY(i, h);

            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++) {

        positions[i].x = event->getX(i);

        positions[i].y = event->getY(i);

        uint32_t index = pointerIndex[i];

        positions[index].x = event->getX(i);

        positions[index].y = event->getY(i);

    }

    addMovement(eventTime, idBits, positions);

}