//
// Copyright 2010 The Android Open Source Project
//
// Provides a pipe-based transport for native events in the NDK.
//
#define LOG_TAG "Input"
//#define LOG_NDEBUG 0
// Log debug messages about keymap probing.
#define DEBUG_PROBE 0
// Log debug messages about velocity tracking.
#define DEBUG_VELOCITY 0
// Log debug messages about least squares fitting.
#define DEBUG_LEAST_SQUARES 0
// Log debug messages about acceleration.
#define DEBUG_ACCELERATION 0
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>
#include <ui/Input.h>
#include <math.h>
#include <limits.h>
#ifdef HAVE_ANDROID_OS
#include <binder/Parcel.h>
#include "SkPoint.h"
#include "SkMatrix.h"
#include "SkScalar.h"
#endif
namespace android {
static const char* CONFIGURATION_FILE_DIR[] = {
"idc/",
"keylayout/",
"keychars/",
};
static const char* CONFIGURATION_FILE_EXTENSION[] = {
".idc",
".kl",
".kcm",
};
static bool isValidNameChar(char ch) {
return isascii(ch) && (isdigit(ch) || isalpha(ch) || ch == '-' || ch == '_');
}
static void appendInputDeviceConfigurationFileRelativePath(String8& path,
const String8& name, InputDeviceConfigurationFileType type) {
path.append(CONFIGURATION_FILE_DIR[type]);
for (size_t i = 0; i < name.length(); i++) {
char ch = name[i];
if (!isValidNameChar(ch)) {
ch = '_';
}
path.append(&ch, 1);
}
path.append(CONFIGURATION_FILE_EXTENSION[type]);
}
String8 getInputDeviceConfigurationFilePathByDeviceIdentifier(
const InputDeviceIdentifier& deviceIdentifier,
InputDeviceConfigurationFileType type) {
if (deviceIdentifier.vendor !=0 && deviceIdentifier.product != 0) {
if (deviceIdentifier.version != 0) {
// Try vendor product version.
String8 versionPath(getInputDeviceConfigurationFilePathByName(
String8::format("Vendor_%04x_Product_%04x_Version_%04x",
deviceIdentifier.vendor, deviceIdentifier.product,
deviceIdentifier.version),
type));
if (!versionPath.isEmpty()) {
return versionPath;
}
}
// Try vendor product.
String8 productPath(getInputDeviceConfigurationFilePathByName(
String8::format("Vendor_%04x_Product_%04x",
deviceIdentifier.vendor, deviceIdentifier.product),
type));
if (!productPath.isEmpty()) {
return productPath;
}
}
// Try device name.
return getInputDeviceConfigurationFilePathByName(deviceIdentifier.name, type);
}
String8 getInputDeviceConfigurationFilePathByName(
const String8& name, InputDeviceConfigurationFileType type) {
// Search system repository.
String8 path;
path.setTo(getenv("ANDROID_ROOT"));
path.append("/usr/");
appendInputDeviceConfigurationFileRelativePath(path, name, type);
#if DEBUG_PROBE
LOGD("Probing for system provided input device configuration file: path='%s'", path.string());
#endif
if (!access(path.string(), R_OK)) {
#if DEBUG_PROBE
LOGD("Found");
#endif
return path;
}
// Search user repository.
// TODO Should only look here if not in safe mode.
path.setTo(getenv("ANDROID_DATA"));
path.append("/system/devices/");
appendInputDeviceConfigurationFileRelativePath(path, name, type);
#if DEBUG_PROBE
LOGD("Probing for system user input device configuration file: path='%s'", path.string());
#endif
if (!access(path.string(), R_OK)) {
#if DEBUG_PROBE
LOGD("Found");
#endif
return path;
}
// Not found.
#if DEBUG_PROBE
LOGD("Probe failed to find input device configuration file: name='%s', type=%d",
name.string(), type);
#endif
return String8();
}
// --- InputEvent ---
void InputEvent::initialize(int32_t deviceId, int32_t source) {
mDeviceId = deviceId;
mSource = source;
}
void InputEvent::initialize(const InputEvent& from) {
mDeviceId = from.mDeviceId;
mSource = from.mSource;
}
// --- KeyEvent ---
bool KeyEvent::hasDefaultAction(int32_t keyCode) {
switch (keyCode) {
case AKEYCODE_HOME:
case AKEYCODE_BACK:
case AKEYCODE_CALL:
case AKEYCODE_ENDCALL:
case AKEYCODE_VOLUME_UP:
case AKEYCODE_VOLUME_DOWN:
case AKEYCODE_VOLUME_MUTE:
case AKEYCODE_POWER:
case AKEYCODE_CAMERA:
case AKEYCODE_HEADSETHOOK:
case AKEYCODE_MENU:
case AKEYCODE_NOTIFICATION:
case AKEYCODE_FOCUS:
case AKEYCODE_SEARCH:
case AKEYCODE_MEDIA_PLAY:
case AKEYCODE_MEDIA_PAUSE:
case AKEYCODE_MEDIA_PLAY_PAUSE:
case AKEYCODE_MEDIA_STOP:
case AKEYCODE_MEDIA_NEXT:
case AKEYCODE_MEDIA_PREVIOUS:
case AKEYCODE_MEDIA_REWIND:
case AKEYCODE_MEDIA_RECORD:
case AKEYCODE_MEDIA_FAST_FORWARD:
case AKEYCODE_MUTE:
return true;
}
return false;
}
bool KeyEvent::hasDefaultAction() const {
return hasDefaultAction(getKeyCode());
}
bool KeyEvent::isSystemKey(int32_t keyCode) {
switch (keyCode) {
case AKEYCODE_MENU:
case AKEYCODE_SOFT_RIGHT:
case AKEYCODE_HOME:
case AKEYCODE_BACK:
case AKEYCODE_CALL:
case AKEYCODE_ENDCALL:
case AKEYCODE_VOLUME_UP:
case AKEYCODE_VOLUME_DOWN:
case AKEYCODE_VOLUME_MUTE:
case AKEYCODE_MUTE:
case AKEYCODE_POWER:
case AKEYCODE_HEADSETHOOK:
case AKEYCODE_MEDIA_PLAY:
case AKEYCODE_MEDIA_PAUSE:
case AKEYCODE_MEDIA_PLAY_PAUSE:
case AKEYCODE_MEDIA_STOP:
case AKEYCODE_MEDIA_NEXT:
case AKEYCODE_MEDIA_PREVIOUS:
case AKEYCODE_MEDIA_REWIND:
case AKEYCODE_MEDIA_RECORD:
case AKEYCODE_MEDIA_FAST_FORWARD:
case AKEYCODE_CAMERA:
case AKEYCODE_FOCUS:
case AKEYCODE_SEARCH:
return true;
}
return false;
}
bool KeyEvent::isSystemKey() const {
return isSystemKey(getKeyCode());
}
void KeyEvent::initialize(
int32_t deviceId,
int32_t source,
int32_t action,
int32_t flags,
int32_t keyCode,
int32_t scanCode,
int32_t metaState,
int32_t repeatCount,
nsecs_t downTime,
nsecs_t eventTime) {
InputEvent::initialize(deviceId, source);
mAction = action;
mFlags = flags;
mKeyCode = keyCode;
mScanCode = scanCode;
mMetaState = metaState;
mRepeatCount = repeatCount;
mDownTime = downTime;
mEventTime = eventTime;
}
void KeyEvent::initialize(const KeyEvent& from) {
InputEvent::initialize(from);
mAction = from.mAction;
mFlags = from.mFlags;
mKeyCode = from.mKeyCode;
mScanCode = from.mScanCode;
mMetaState = from.mMetaState;
mRepeatCount = from.mRepeatCount;
mDownTime = from.mDownTime;
mEventTime = from.mEventTime;
}
// --- PointerCoords ---
float PointerCoords::getAxisValue(int32_t axis) const {
if (axis < 0 || axis > 63) {
return 0;
}
uint64_t axisBit = 1LL << axis;
if (!(bits & axisBit)) {
return 0;
}
uint32_t index = __builtin_popcountll(bits & (axisBit - 1LL));
return values[index];
}
status_t PointerCoords::setAxisValue(int32_t axis, float value) {
if (axis < 0 || axis > 63) {
return NAME_NOT_FOUND;
}
uint64_t axisBit = 1LL << axis;
uint32_t index = __builtin_popcountll(bits & (axisBit - 1LL));
if (!(bits & axisBit)) {
if (value == 0) {
return OK; // axes with value 0 do not need to be stored
}
uint32_t count = __builtin_popcountll(bits);
if (count >= MAX_AXES) {
tooManyAxes(axis);
return NO_MEMORY;
}
bits |= axisBit;
for (uint32_t i = count; i > index; i--) {
values[i] = values[i - 1];
}
}
values[index] = value;
return OK;
}
static inline void scaleAxisValue(PointerCoords& c, int axis, float scaleFactor) {
float value = c.getAxisValue(axis);
if (value != 0) {
c.setAxisValue(axis, value * scaleFactor);
}
}
void PointerCoords::scale(float scaleFactor) {
// No need to scale pressure or size since they are normalized.
// No need to scale orientation since it is meaningless to do so.
scaleAxisValue(*this, AMOTION_EVENT_AXIS_X, scaleFactor);
scaleAxisValue(*this, AMOTION_EVENT_AXIS_Y, scaleFactor);
scaleAxisValue(*this, AMOTION_EVENT_AXIS_TOUCH_MAJOR, scaleFactor);
scaleAxisValue(*this, AMOTION_EVENT_AXIS_TOUCH_MINOR, scaleFactor);
scaleAxisValue(*this, AMOTION_EVENT_AXIS_TOOL_MAJOR, scaleFactor);
scaleAxisValue(*this, AMOTION_EVENT_AXIS_TOOL_MINOR, scaleFactor);
}
#ifdef HAVE_ANDROID_OS
status_t PointerCoords::readFromParcel(Parcel* parcel) {
bits = parcel->readInt64();
uint32_t count = __builtin_popcountll(bits);
if (count > MAX_AXES) {
return BAD_VALUE;
}
for (uint32_t i = 0; i < count; i++) {
values[i] = parcel->readInt32();
}
return OK;
}
status_t PointerCoords::writeToParcel(Parcel* parcel) const {
parcel->writeInt64(bits);
uint32_t count = __builtin_popcountll(bits);
for (uint32_t i = 0; i < count; i++) {
parcel->writeInt32(values[i]);
}
return OK;
}
#endif
void PointerCoords::tooManyAxes(int axis) {
LOGW("Could not set value for axis %d because the PointerCoords structure is full and "
"cannot contain more than %d axis values.", axis, int(MAX_AXES));
}
bool PointerCoords::operator==(const PointerCoords& other) const {
if (bits != other.bits) {
return false;
}
uint32_t count = __builtin_popcountll(bits);
for (uint32_t i = 0; i < count; i++) {
if (values[i] != other.values[i]) {
return false;
}
}
return true;
}
void PointerCoords::copyFrom(const PointerCoords& other) {
bits = other.bits;
uint32_t count = __builtin_popcountll(bits);
for (uint32_t i = 0; i < count; i++) {
values[i] = other.values[i];
}
}
// --- PointerProperties ---
bool PointerProperties::operator==(const PointerProperties& other) const {
return id == other.id
&& toolType == other.toolType;
}
void PointerProperties::copyFrom(const PointerProperties& other) {
id = other.id;
toolType = other.toolType;
}
// --- MotionEvent ---
void MotionEvent::initialize(
int32_t deviceId,
int32_t source,
int32_t action,
int32_t flags,
int32_t edgeFlags,
int32_t metaState,
int32_t buttonState,
float xOffset,
float yOffset,
float xPrecision,
float yPrecision,
nsecs_t downTime,
nsecs_t eventTime,
size_t pointerCount,
const PointerProperties* pointerProperties,
const PointerCoords* pointerCoords) {
InputEvent::initialize(deviceId, source);
mAction = action;
mFlags = flags;
mEdgeFlags = edgeFlags;
mMetaState = metaState;
mButtonState = buttonState;
mXOffset = xOffset;
mYOffset = yOffset;
mXPrecision = xPrecision;
mYPrecision = yPrecision;
mDownTime = downTime;
mPointerProperties.clear();
mPointerProperties.appendArray(pointerProperties, pointerCount);
mSampleEventTimes.clear();
mSamplePointerCoords.clear();
addSample(eventTime, pointerCoords);
}
void MotionEvent::copyFrom(const MotionEvent* other, bool keepHistory) {
InputEvent::initialize(other->mDeviceId, other->mSource);
mAction = other->mAction;
mFlags = other->mFlags;
mEdgeFlags = other->mEdgeFlags;
mMetaState = other->mMetaState;
mButtonState = other->mButtonState;
mXOffset = other->mXOffset;
mYOffset = other->mYOffset;
mXPrecision = other->mXPrecision;
mYPrecision = other->mYPrecision;
mDownTime = other->mDownTime;
mPointerProperties = other->mPointerProperties;
if (keepHistory) {
mSampleEventTimes = other->mSampleEventTimes;
mSamplePointerCoords = other->mSamplePointerCoords;
} else {
mSampleEventTimes.clear();
mSampleEventTimes.push(other->getEventTime());
mSamplePointerCoords.clear();
size_t pointerCount = other->getPointerCount();
size_t historySize = other->getHistorySize();
mSamplePointerCoords.appendArray(other->mSamplePointerCoords.array()
+ (historySize * pointerCount), pointerCount);
}
}
void MotionEvent::addSample(
int64_t eventTime,
const PointerCoords* pointerCoords) {
mSampleEventTimes.push(eventTime);
mSamplePointerCoords.appendArray(pointerCoords, getPointerCount());
}
const PointerCoords* MotionEvent::getRawPointerCoords(size_t pointerIndex) const {
return &mSamplePointerCoords[getHistorySize() * getPointerCount() + pointerIndex];
}
float MotionEvent::getRawAxisValue(int32_t axis, size_t pointerIndex) const {
return getRawPointerCoords(pointerIndex)->getAxisValue(axis);
}
float MotionEvent::getAxisValue(int32_t axis, size_t pointerIndex) const {
float value = getRawPointerCoords(pointerIndex)->getAxisValue(axis);
switch (axis) {
case AMOTION_EVENT_AXIS_X:
return value + mXOffset;
case AMOTION_EVENT_AXIS_Y:
return value + mYOffset;
}
return value;
}
const PointerCoords* MotionEvent::getHistoricalRawPointerCoords(
size_t pointerIndex, size_t historicalIndex) const {
return &mSamplePointerCoords[historicalIndex * getPointerCount() + pointerIndex];
}
float MotionEvent::getHistoricalRawAxisValue(int32_t axis, size_t pointerIndex,
size_t historicalIndex) const {
return getHistoricalRawPointerCoords(pointerIndex, historicalIndex)->getAxisValue(axis);
}
float MotionEvent::getHistoricalAxisValue(int32_t axis, size_t pointerIndex,
size_t historicalIndex) const {
float value = getHistoricalRawPointerCoords(pointerIndex, historicalIndex)->getAxisValue(axis);
switch (axis) {
case AMOTION_EVENT_AXIS_X:
return value + mXOffset;
case AMOTION_EVENT_AXIS_Y:
return value + mYOffset;
}
return value;
}
ssize_t MotionEvent::findPointerIndex(int32_t pointerId) const {
size_t pointerCount = mPointerProperties.size();
for (size_t i = 0; i < pointerCount; i++) {
if (mPointerProperties.itemAt(i).id == pointerId) {
return i;
}
}
return -1;
}
void MotionEvent::offsetLocation(float xOffset, float yOffset) {
mXOffset += xOffset;
mYOffset += yOffset;
}
void MotionEvent::scale(float scaleFactor) {
mXOffset *= scaleFactor;
mYOffset *= scaleFactor;
mXPrecision *= scaleFactor;
mYPrecision *= scaleFactor;
size_t numSamples = mSamplePointerCoords.size();
for (size_t i = 0; i < numSamples; i++) {
mSamplePointerCoords.editItemAt(i).scale(scaleFactor);
}
}
#ifdef HAVE_ANDROID_OS
static inline float transformAngle(const SkMatrix* matrix, float angleRadians) {
// Construct and transform a vector oriented at the specified clockwise angle from vertical.
// Coordinate system: down is increasing Y, right is increasing X.
SkPoint vector;
vector.fX = SkFloatToScalar(sinf(angleRadians));
vector.fY = SkFloatToScalar(-cosf(angleRadians));
matrix->mapVectors(& vector, 1);
// Derive the transformed vector's clockwise angle from vertical.
float result = atan2f(SkScalarToFloat(vector.fX), SkScalarToFloat(-vector.fY));
if (result < - M_PI_2) {
result += M_PI;
} else if (result > M_PI_2) {
result -= M_PI;
}
return result;
}
void MotionEvent::transform(const SkMatrix* matrix) {
float oldXOffset = mXOffset;
float oldYOffset = mYOffset;
// The tricky part of this implementation is to preserve the value of
// rawX and rawY. So we apply the transformation to the first point
// then derive an appropriate new X/Y offset that will preserve rawX and rawY.
SkPoint point;
float rawX = getRawX(0);
float rawY = getRawY(0);
matrix->mapXY(SkFloatToScalar(rawX + oldXOffset), SkFloatToScalar(rawY + oldYOffset),
& point);
float newX = SkScalarToFloat(point.fX);
float newY = SkScalarToFloat(point.fY);
float newXOffset = newX - rawX;
float newYOffset = newY - rawY;
mXOffset = newXOffset;
mYOffset = newYOffset;
// Apply the transformation to all samples.
size_t numSamples = mSamplePointerCoords.size();
for (size_t i = 0; i < numSamples; i++) {
PointerCoords& c = mSamplePointerCoords.editItemAt(i);
float x = c.getAxisValue(AMOTION_EVENT_AXIS_X) + oldXOffset;
float y = c.getAxisValue(AMOTION_EVENT_AXIS_Y) + oldYOffset;
matrix->mapXY(SkFloatToScalar(x), SkFloatToScalar(y), &point);
c.setAxisValue(AMOTION_EVENT_AXIS_X, SkScalarToFloat(point.fX) - newXOffset);
c.setAxisValue(AMOTION_EVENT_AXIS_Y, SkScalarToFloat(point.fY) - newYOffset);
float orientation = c.getAxisValue(AMOTION_EVENT_AXIS_ORIENTATION);
c.setAxisValue(AMOTION_EVENT_AXIS_ORIENTATION, transformAngle(matrix, orientation));
}
}
status_t MotionEvent::readFromParcel(Parcel* parcel) {
size_t pointerCount = parcel->readInt32();
size_t sampleCount = parcel->readInt32();
if (pointerCount == 0 || pointerCount > MAX_POINTERS || sampleCount == 0) {
return BAD_VALUE;
}
mDeviceId = parcel->readInt32();
mSource = parcel->readInt32();
mAction = parcel->readInt32();
mFlags = parcel->readInt32();
mEdgeFlags = parcel->readInt32();
mMetaState = parcel->readInt32();
mButtonState = parcel->readInt32();
mXOffset = parcel->readFloat();
mYOffset = parcel->readFloat();
mXPrecision = parcel->readFloat();
mYPrecision = parcel->readFloat();
mDownTime = parcel->readInt64();
mPointerProperties.clear();
mPointerProperties.setCapacity(pointerCount);
mSampleEventTimes.clear();
mSampleEventTimes.setCapacity(sampleCount);
mSamplePointerCoords.clear();
mSamplePointerCoords.setCapacity(sampleCount * pointerCount);
for (size_t i = 0; i < pointerCount; i++) {
mPointerProperties.push();
PointerProperties& properties = mPointerProperties.editTop();
properties.id = parcel->readInt32();
properties.toolType = parcel->readInt32();
}
while (sampleCount-- > 0) {
mSampleEventTimes.push(parcel->readInt64());
for (size_t i = 0; i < pointerCount; i++) {
mSamplePointerCoords.push();
status_t status = mSamplePointerCoords.editTop().readFromParcel(parcel);
if (status) {
return status;
}
}
}
return OK;
}
status_t MotionEvent::writeToParcel(Parcel* parcel) const {
size_t pointerCount = mPointerProperties.size();
size_t sampleCount = mSampleEventTimes.size();
parcel->writeInt32(pointerCount);
parcel->writeInt32(sampleCount);
parcel->writeInt32(mDeviceId);
parcel->writeInt32(mSource);
parcel->writeInt32(mAction);
parcel->writeInt32(mFlags);
parcel->writeInt32(mEdgeFlags);
parcel->writeInt32(mMetaState);
parcel->writeInt32(mButtonState);
parcel->writeFloat(mXOffset);
parcel->writeFloat(mYOffset);
parcel->writeFloat(mXPrecision);
parcel->writeFloat(mYPrecision);
parcel->writeInt64(mDownTime);
for (size_t i = 0; i < pointerCount; i++) {
const PointerProperties& properties = mPointerProperties.itemAt(i);
parcel->writeInt32(properties.id);
parcel->writeInt32(properties.toolType);
}
const PointerCoords* pc = mSamplePointerCoords.array();
for (size_t h = 0; h < sampleCount; h++) {
parcel->writeInt64(mSampleEventTimes.itemAt(h));
for (size_t i = 0; i < pointerCount; i++) {
status_t status = (pc++)->writeToParcel(parcel);
if (status) {
return status;
}
}
}
return OK;
}
#endif
bool MotionEvent::isTouchEvent(int32_t source, int32_t action) {
if (source & AINPUT_SOURCE_CLASS_POINTER) {
// Specifically excludes HOVER_MOVE and SCROLL.
switch (action & AMOTION_EVENT_ACTION_MASK) {
case AMOTION_EVENT_ACTION_DOWN:
case AMOTION_EVENT_ACTION_MOVE:
case AMOTION_EVENT_ACTION_UP:
case AMOTION_EVENT_ACTION_POINTER_DOWN:
case AMOTION_EVENT_ACTION_POINTER_UP:
case AMOTION_EVENT_ACTION_CANCEL:
case AMOTION_EVENT_ACTION_OUTSIDE:
return true;
}
}
return false;
}
// --- VelocityTracker ---
const uint32_t VelocityTracker::DEFAULT_DEGREE;
const nsecs_t VelocityTracker::DEFAULT_HORIZON;
const uint32_t VelocityTracker::HISTORY_SIZE;
static inline float vectorDot(const float* a, const float* b, uint32_t m) {
float r = 0;
while (m--) {
r += *(a++) * *(b++);
}
return r;
}
static inline float vectorNorm(const float* a, uint32_t m) {
float r = 0;
while (m--) {
float t = *(a++);
r += t * t;
}
return sqrtf(r);
}
#if DEBUG_LEAST_SQUARES || DEBUG_VELOCITY
static String8 vectorToString(const float* a, uint32_t m) {
String8 str;
str.append("[");
while (m--) {
str.appendFormat(" %f", *(a++));
if (m) {
str.append(",");
}
}
str.append(" ]");
return str;
}
static String8 matrixToString(const float* a, uint32_t m, uint32_t n, bool rowMajor) {
String8 str;
str.append("[");
for (size_t i = 0; i < m; i++) {
if (i) {
str.append(",");
}
str.append(" [");
for (size_t j = 0; j < n; j++) {
if (j) {
str.append(",");
}
str.appendFormat(" %f", a[rowMajor ? i * n + j : j * m + i]);
}
str.append(" ]");
}
str.append(" ]");
return str;
}
#endif
VelocityTracker::VelocityTracker() {
clear();
}
void VelocityTracker::clear() {
mIndex = 0;
mMovements[0].idBits.clear();
mActivePointerId = -1;
}
void VelocityTracker::clearPointers(BitSet32 idBits) {
BitSet32 remainingIdBits(mMovements[mIndex].idBits.value & ~idBits.value);
mMovements[mIndex].idBits = remainingIdBits;
if (mActivePointerId >= 0 && idBits.hasBit(mActivePointerId)) {
mActivePointerId = !remainingIdBits.isEmpty() ? remainingIdBits.firstMarkedBit() : -1;
}
}
void VelocityTracker::addMovement(nsecs_t eventTime, BitSet32 idBits, const Position* positions) {
if (++mIndex == HISTORY_SIZE) {
mIndex = 0;
}
while (idBits.count() > MAX_POINTERS) {
idBits.clearLastMarkedBit();
}
Movement& movement = mMovements[mIndex];
movement.eventTime = eventTime;
movement.idBits = idBits;
uint32_t count = idBits.count();
for (uint32_t i = 0; i < count; i++) {
movement.positions[i] = positions[i];
}
if (mActivePointerId < 0 || !idBits.hasBit(mActivePointerId)) {
mActivePointerId = count != 0 ? idBits.firstMarkedBit() : -1;
}
#if DEBUG_VELOCITY
LOGD("VelocityTracker: addMovement eventTime=%lld, 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, DEFAULT_DEGREE, DEFAULT_HORIZON, &estimator);
LOGD(" %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).string(),
vectorToString(estimator.yCoeff, estimator.degree).string(),
estimator.confidence);
}
#endif
}
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));
}
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++) {
positions[i].x = event->getHistoricalX(i, h);
positions[i].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);
}
addMovement(eventTime, idBits, positions);
}
/**
* Solves a linear least squares problem to obtain a N degree polynomial that fits
* the specified input data as nearly as possible.
*
* Returns true if a solution is found, false otherwise.
*
* The input consists of two vectors of data points X and Y with indices 0..m-1.
* The output is a vector B with indices 0..n-1 that describes a polynomial
* that fits the data, such the sum of abs(Y[i] - (B[0] + B[1] X[i] + B[2] X[i]^2 ... B[n] X[i]^n))
* for all i between 0 and m-1 is minimized.
*
* That is to say, the function that generated the input data can be approximated
* by y(x) ~= B[0] + B[1] x + B[2] x^2 + ... + B[n] x^n.
*
* The coefficient of determination (R^2) is also returned to describe the goodness
* of fit of the model for the given data. It is a value between 0 and 1, where 1
* indicates perfect correspondence.
*
* This function first expands the X vector to a m by n matrix A such that
* A[i][0] = 1, A[i][1] = X[i], A[i][2] = X[i]^2, ..., A[i][n] = X[i]^n.
*
* Then it calculates the QR decomposition of A yielding an m by m orthonormal matrix Q
* and an m by n upper triangular matrix R. Because R is upper triangular (lower
* part is all zeroes), we can simplify the decomposition into an m by n matrix
* Q1 and a n by n matrix R1 such that A = Q1 R1.
*
* Finally we solve the system of linear equations given by R1 B = (Qtranspose Y)
* to find B.
*
* For efficiency, we lay out A and Q column-wise in memory because we frequently
* operate on the column vectors. Conversely, we lay out R row-wise.
*
* http://en.wikipedia.org/wiki/Numerical_methods_for_linear_least_squares
* http://en.wikipedia.org/wiki/Gram-Schmidt
*/
static bool solveLeastSquares(const float* x, const float* y, uint32_t m, uint32_t n,
float* outB, float* outDet) {
#if DEBUG_LEAST_SQUARES
LOGD("solveLeastSquares: m=%d, n=%d, x=%s, y=%s", int(m), int(n),
vectorToString(x, m).string(), vectorToString(y, m).string());
#endif
// Expand the X vector to a matrix A.
float a[n][m]; // column-major order
for (uint32_t h = 0; h < m; h++) {
a[0][h] = 1;
for (uint32_t i = 1; i < n; i++) {
a[i][h] = a[i - 1][h] * x[h];
}
}
#if DEBUG_LEAST_SQUARES
LOGD(" - a=%s", matrixToString(&a[0][0], m, n, false /*rowMajor*/).string());
#endif
// Apply the Gram-Schmidt process to A to obtain its QR decomposition.
float q[n][m]; // orthonormal basis, column-major order
float r[n][n]; // upper triangular matrix, row-major order
for (uint32_t j = 0; j < n; j++) {
for (uint32_t h = 0; h < m; h++) {
q[j][h] = a[j][h];
}
for (uint32_t i = 0; i < j; i++) {
float dot = vectorDot(&q[j][0], &q[i][0], m);
for (uint32_t h = 0; h < m; h++) {
q[j][h] -= dot * q[i][h];
}
}
float norm = vectorNorm(&q[j][0], m);
if (norm < 0.000001f) {
// vectors are linearly dependent or zero so no solution
#if DEBUG_LEAST_SQUARES
LOGD(" - no solution, norm=%f", norm);
#endif
return false;
}
float invNorm = 1.0f / norm;
for (uint32_t h = 0; h < m; h++) {
q[j][h] *= invNorm;
}
for (uint32_t i = 0; i < n; i++) {
r[j][i] = i < j ? 0 : vectorDot(&q[j][0], &a[i][0], m);
}
}
#if DEBUG_LEAST_SQUARES
LOGD(" - q=%s", matrixToString(&q[0][0], m, n, false /*rowMajor*/).string());
LOGD(" - r=%s", matrixToString(&r[0][0], n, n, true /*rowMajor*/).string());
// calculate QR, if we factored A correctly then QR should equal A
float qr[n][m];
for (uint32_t h = 0; h < m; h++) {
for (uint32_t i = 0; i < n; i++) {
qr[i][h] = 0;
for (uint32_t j = 0; j < n; j++) {
qr[i][h] += q[j][h] * r[j][i];
}
}
}
LOGD(" - qr=%s", matrixToString(&qr[0][0], m, n, false /*rowMajor*/).string());
#endif
// Solve R B = Qt Y to find B. This is easy because R is upper triangular.
// We just work from bottom-right to top-left calculating B's coefficients.
for (uint32_t i = n; i-- != 0; ) {
outB[i] = vectorDot(&q[i][0], y, m);
for (uint32_t j = n - 1; j > i; j--) {
outB[i] -= r[i][j] * outB[j];
}
outB[i] /= r[i][i];
}
#if DEBUG_LEAST_SQUARES
LOGD(" - b=%s", vectorToString(outB, n).string());
#endif
// Calculate the coefficient of determination as 1 - (SSerr / SStot) where
// SSerr is the residual sum of squares (squared variance of the error),
// and SStot is the total sum of squares (squared variance of the data).
float ymean = 0;
for (uint32_t h = 0; h < m; h++) {
ymean += y[h];
}
ymean /= m;
float sserr = 0;
float sstot = 0;
for (uint32_t h = 0; h < m; h++) {
float err = y[h] - outB[0];
float term = 1;
for (uint32_t i = 1; i < n; i++) {
term *= x[h];
err -= term * outB[i];
}
sserr += err * err;
float var = y[h] - ymean;
sstot += var * var;
}
*outDet = sstot > 0.000001f ? 1.0f - (sserr / sstot) : 1;
#if DEBUG_LEAST_SQUARES
LOGD(" - sserr=%f", sserr);
LOGD(" - sstot=%f", sstot);
LOGD(" - det=%f", *outDet);
#endif
return true;
}
bool VelocityTracker::getVelocity(uint32_t id, float* outVx, float* outVy) const {
Estimator estimator;
if (getEstimator(id, DEFAULT_DEGREE, DEFAULT_HORIZON, &estimator)) {
if (estimator.degree >= 1) {
*outVx = estimator.xCoeff[1];
*outVy = estimator.yCoeff[1];
return true;
}
}
*outVx = 0;
*outVy = 0;
return false;
}
bool VelocityTracker::getEstimator(uint32_t id, uint32_t degree, nsecs_t horizon,
Estimator* outEstimator) const {
outEstimator->clear();
// Iterate over movement samples in reverse time order and collect samples.
float x[HISTORY_SIZE];
float y[HISTORY_SIZE];
float time[HISTORY_SIZE];
uint32_t m = 0;
uint32_t index = mIndex;
const Movement& newestMovement = mMovements[mIndex];
do {
const Movement& movement = mMovements[index];
if (!movement.idBits.hasBit(id)) {
break;
}
nsecs_t age = newestMovement.eventTime - movement.eventTime;
if (age > horizon) {
break;
}
const Position& position = movement.getPosition(id);
x[m] = position.x;
y[m] = position.y;
time[m] = -age * 0.000000001f;
index = (index == 0 ? HISTORY_SIZE : index) - 1;
} while (++m < HISTORY_SIZE);
if (m == 0) {
return false; // no data
}
// Calculate a least squares polynomial fit.
if (degree > Estimator::MAX_DEGREE) {
degree = Estimator::MAX_DEGREE;
}
if (degree > m - 1) {
degree = m - 1;
}
if (degree >= 1) {
float xdet, ydet;
uint32_t n = degree + 1;
if (solveLeastSquares(time, x, m, n, outEstimator->xCoeff, &xdet)
&& solveLeastSquares(time, y, m, n, outEstimator->yCoeff, &ydet)) {
outEstimator->degree = degree;
outEstimator->confidence = xdet * ydet;
#if DEBUG_LEAST_SQUARES
LOGD("estimate: degree=%d, xCoeff=%s, yCoeff=%s, confidence=%f",
int(outEstimator->degree),
vectorToString(outEstimator->xCoeff, n).string(),
vectorToString(outEstimator->yCoeff, n).string(),
outEstimator->confidence);
#endif
return true;
}
}
// No velocity data available for this pointer, but we do have its current position.
outEstimator->xCoeff[0] = x[0];
outEstimator->yCoeff[0] = y[0];
outEstimator->degree = 0;
outEstimator->confidence = 1;
return true;
}
// --- VelocityControl ---
const nsecs_t VelocityControl::STOP_TIME;
VelocityControl::VelocityControl() {
reset();
}
void VelocityControl::setParameters(const VelocityControlParameters& parameters) {
mParameters = parameters;
reset();
}
void VelocityControl::reset() {
mLastMovementTime = LLONG_MIN;
mRawPosition.x = 0;
mRawPosition.y = 0;
mVelocityTracker.clear();
}
void VelocityControl::move(nsecs_t eventTime, float* deltaX, float* deltaY) {
if ((deltaX && *deltaX) || (deltaY && *deltaY)) {
if (eventTime >= mLastMovementTime + STOP_TIME) {
#if DEBUG_ACCELERATION
LOGD("VelocityControl: stopped, last movement was %0.3fms ago",
(eventTime - mLastMovementTime) * 0.000001f);
#endif
reset();
}
mLastMovementTime = eventTime;
if (deltaX) {
mRawPosition.x += *deltaX;
}
if (deltaY) {
mRawPosition.y += *deltaY;
}
mVelocityTracker.addMovement(eventTime, BitSet32(BitSet32::valueForBit(0)), &mRawPosition);
float vx, vy;
float scale = mParameters.scale;
if (mVelocityTracker.getVelocity(0, &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);
}
#if DEBUG_ACCELERATION
LOGD("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);
#endif
} else {
#if DEBUG_ACCELERATION
LOGD("VelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): unknown velocity",
mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold,
mParameters.acceleration);
#endif
}
if (deltaX) {
*deltaX *= scale;
}
if (deltaY) {
*deltaY *= scale;
}
}
}
// --- InputDeviceInfo ---
InputDeviceInfo::InputDeviceInfo() {
initialize(-1, String8("uninitialized device info"));
}
InputDeviceInfo::InputDeviceInfo(const InputDeviceInfo& other) :
mId(other.mId), mName(other.mName), mSources(other.mSources),
mKeyboardType(other.mKeyboardType),
mMotionRanges(other.mMotionRanges) {
}
InputDeviceInfo::~InputDeviceInfo() {
}
void InputDeviceInfo::initialize(int32_t id, const String8& name) {
mId = id;
mName = name;
mSources = 0;
mKeyboardType = AINPUT_KEYBOARD_TYPE_NONE;
mMotionRanges.clear();
}
const InputDeviceInfo::MotionRange* InputDeviceInfo::getMotionRange(
int32_t axis, uint32_t source) const {
size_t numRanges = mMotionRanges.size();
for (size_t i = 0; i < numRanges; i++) {
const MotionRange& range = mMotionRanges.itemAt(i);
if (range.axis == axis && range.source == source) {
return ⦥
}
}
return NULL;
}
void InputDeviceInfo::addSource(uint32_t source) {
mSources |= source;
}
void InputDeviceInfo::addMotionRange(int32_t axis, uint32_t source, float min, float max,
float flat, float fuzz) {
MotionRange range = { axis, source, min, max, flat, fuzz };
mMotionRanges.add(range);
}
void InputDeviceInfo::addMotionRange(const MotionRange& range) {
mMotionRanges.add(range);
}
} // namespace android