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Diffstat (limited to 'widget/gonk/ProcessOrientation.cpp')
| -rw-r--r-- | widget/gonk/ProcessOrientation.cpp | 519 |
1 files changed, 0 insertions, 519 deletions
diff --git a/widget/gonk/ProcessOrientation.cpp b/widget/gonk/ProcessOrientation.cpp deleted file mode 100644 index bbdcface8..000000000 --- a/widget/gonk/ProcessOrientation.cpp +++ /dev/null @@ -1,519 +0,0 @@ -/* - * Copyright (c) 2013, Linux Foundation. All rights reserved - * - * Copyright (C) 2008 The Android Open Source Project - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -#include "base/basictypes.h" -#include "mozilla/Hal.h" -#include "mozilla/Unused.h" -#include "nsIScreen.h" -#include "nsIScreenManager.h" -#include "OrientationObserver.h" -#include "ProcessOrientation.h" -#include "mozilla/HalSensor.h" -#include "math.h" -#include "limits.h" -#include "android/log.h" - -#if 0 -#define LOGD(args...) __android_log_print(ANDROID_LOG_DEBUG, "ProcessOrientation" , ## args) -#else -#define LOGD(args...) -#endif - -namespace mozilla { - -// We work with all angles in degrees in this class. -#define RADIANS_TO_DEGREES (180/M_PI) - -// Number of nanoseconds per millisecond. -#define NANOS_PER_MS 1000000 - -// Indices into SensorEvent.values for the accelerometer sensor. -#define ACCELEROMETER_DATA_X 0 -#define ACCELEROMETER_DATA_Y 1 -#define ACCELEROMETER_DATA_Z 2 - -// The minimum amount of time that a predicted rotation must be stable before -// it is accepted as a valid rotation proposal. This value can be quite small -// because the low-pass filter already suppresses most of the noise so we're -// really just looking for quick confirmation that the last few samples are in -// agreement as to the desired orientation. -#define PROPOSAL_SETTLE_TIME_NANOS (40*NANOS_PER_MS) - -// The minimum amount of time that must have elapsed since the device last -// exited the flat state (time since it was picked up) before the proposed -// rotation can change. -#define PROPOSAL_MIN_TIME_SINCE_FLAT_ENDED_NANOS (500*NANOS_PER_MS) - -// The minimum amount of time that must have elapsed since the device stopped -// swinging (time since device appeared to be in the process of being put down -// or put away into a pocket) before the proposed rotation can change. -#define PROPOSAL_MIN_TIME_SINCE_SWING_ENDED_NANOS (300*NANOS_PER_MS) - -// The minimum amount of time that must have elapsed since the device stopped -// undergoing external acceleration before the proposed rotation can change. -#define PROPOSAL_MIN_TIME_SINCE_ACCELERATION_ENDED_NANOS (500*NANOS_PER_MS) - -// If the tilt angle remains greater than the specified angle for a minimum of -// the specified time, then the device is deemed to be lying flat -// (just chillin' on a table). -#define FLAT_ANGLE 75 -#define FLAT_TIME_NANOS (1000*NANOS_PER_MS) - -// If the tilt angle has increased by at least delta degrees within the -// specified amount of time, then the device is deemed to be swinging away -// from the user down towards flat (tilt = 90). -#define SWING_AWAY_ANGLE_DELTA 20 -#define SWING_TIME_NANOS (300*NANOS_PER_MS) - -// The maximum sample inter-arrival time in milliseconds. If the acceleration -// samples are further apart than this amount in time, we reset the state of -// the low-pass filter and orientation properties. This helps to handle -// boundary conditions when the device is turned on, wakes from suspend or -// there is a significant gap in samples. -#define MAX_FILTER_DELTA_TIME_NANOS (1000*NANOS_PER_MS) - -// The acceleration filter time constant. -// -// This time constant is used to tune the acceleration filter such that -// impulses and vibrational noise (think car dock) is suppressed before we try -// to calculate the tilt and orientation angles. -// -// The filter time constant is related to the filter cutoff frequency, which -// is the frequency at which signals are attenuated by 3dB (half the passband -// power). Each successive octave beyond this frequency is attenuated by an -// additional 6dB. -// -// Given a time constant t in seconds, the filter cutoff frequency Fc in Hertz -// is given by Fc = 1 / (2pi * t). -// -// The higher the time constant, the lower the cutoff frequency, so more noise -// will be suppressed. -// -// Filtering adds latency proportional the time constant (inversely -// proportional to the cutoff frequency) so we don't want to make the time -// constant too large or we can lose responsiveness. Likewise we don't want -// to make it too small or we do a poor job suppressing acceleration spikes. -// Empirically, 100ms seems to be too small and 500ms is too large. Android -// default is 200. -#define FILTER_TIME_CONSTANT_MS 200.0f - -// State for orientation detection. Thresholds for minimum and maximum -// allowable deviation from gravity. -// -// If the device is undergoing external acceleration (being bumped, in a car -// that is turning around a corner or a plane taking off) then the magnitude -// may be substantially more or less than gravity. This can skew our -// orientation detection by making us think that up is pointed in a different -// direction. -// -// Conversely, if the device is in freefall, then there will be no gravity to -// measure at all. This is problematic because we cannot detect the orientation -// without gravity to tell us which way is up. A magnitude near 0 produces -// singularities in the tilt and orientation calculations. -// -// In both cases, we postpone choosing an orientation. -// -// However, we need to tolerate some acceleration because the angular momentum -// of turning the device can skew the observed acceleration for a short period -// of time. -#define NEAR_ZERO_MAGNITUDE 1 // m/s^2 -#define ACCELERATION_TOLERANCE 4 // m/s^2 -#define STANDARD_GRAVITY 9.80665f -#define MIN_ACCELERATION_MAGNITUDE (STANDARD_GRAVITY-ACCELERATION_TOLERANCE) -#define MAX_ACCELERATION_MAGNITUDE (STANDARD_GRAVITY+ACCELERATION_TOLERANCE) - -// Maximum absolute tilt angle at which to consider orientation data. Beyond -// this (i.e. when screen is facing the sky or ground), we completely ignore -// orientation data. -#define MAX_TILT 75 - -// The gap angle in degrees between adjacent orientation angles for -// hysteresis.This creates a "dead zone" between the current orientation and a -// proposed adjacent orientation. No orientation proposal is made when the -// orientation angle is within the gap between the current orientation and the -// adjacent orientation. -#define ADJACENT_ORIENTATION_ANGLE_GAP 45 - -const int -ProcessOrientation::tiltTolerance[][4] = { - {-25, 70}, // ROTATION_0 - {-25, 65}, // ROTATION_90 - {-25, 60}, // ROTATION_180 - {-25, 65} // ROTATION_270 -}; - -int -ProcessOrientation::GetProposedRotation() -{ - return mProposedRotation; -} - -int -ProcessOrientation::OnSensorChanged(const SensorData& event, - int deviceCurrentRotation) -{ - // The vector given in the SensorEvent points straight up (towards the sky) - // under ideal conditions (the phone is not accelerating). I'll call this up - // vector elsewhere. - const InfallibleTArray<float>& values = event.values(); - float x = values[ACCELEROMETER_DATA_X]; - float y = values[ACCELEROMETER_DATA_Y]; - float z = values[ACCELEROMETER_DATA_Z]; - - LOGD - ("ProcessOrientation: Raw acceleration vector: x = %f, y = %f, z = %f," - "magnitude = %f\n", x, y, z, sqrt(x * x + y * y + z * z)); - // Apply a low-pass filter to the acceleration up vector in cartesian space. - // Reset the orientation listener state if the samples are too far apart in - // time or when we see values of (0, 0, 0) which indicates that we polled the - // accelerometer too soon after turning it on and we don't have any data yet. - const int64_t now = (int64_t) event.timestamp(); - const int64_t then = mLastFilteredTimestampNanos; - const float timeDeltaMS = (now - then) * 0.000001f; - bool skipSample = false; - if (now < then - || now > then + MAX_FILTER_DELTA_TIME_NANOS - || (x == 0 && y == 0 && z == 0)) { - LOGD - ("ProcessOrientation: Resetting orientation listener."); - Reset(); - skipSample = true; - } else { - const float alpha = timeDeltaMS / (FILTER_TIME_CONSTANT_MS + timeDeltaMS); - x = alpha * (x - mLastFilteredX) + mLastFilteredX; - y = alpha * (y - mLastFilteredY) + mLastFilteredY; - z = alpha * (z - mLastFilteredZ) + mLastFilteredZ; - LOGD - ("ProcessOrientation: Filtered acceleration vector: x=%f, y=%f, z=%f," - "magnitude=%f", z, y, z, sqrt(x * x + y * y + z * z)); - skipSample = false; - } - mLastFilteredTimestampNanos = now; - mLastFilteredX = x; - mLastFilteredY = y; - mLastFilteredZ = z; - - bool isAccelerating = false; - bool isFlat = false; - bool isSwinging = false; - if (skipSample) { - return -1; - } - - // Calculate the magnitude of the acceleration vector. - const float magnitude = sqrt(x * x + y * y + z * z); - if (magnitude < NEAR_ZERO_MAGNITUDE) { - LOGD - ("ProcessOrientation: Ignoring sensor data, magnitude too close to" - " zero."); - ClearPredictedRotation(); - } else { - // Determine whether the device appears to be undergoing external - // acceleration. - if (this->IsAccelerating(magnitude)) { - isAccelerating = true; - mAccelerationTimestampNanos = now; - } - // Calculate the tilt angle. This is the angle between the up vector and - // the x-y plane (the plane of the screen) in a range of [-90, 90] - // degrees. - // -90 degrees: screen horizontal and facing the ground (overhead) - // 0 degrees: screen vertical - // 90 degrees: screen horizontal and facing the sky (on table) - const int tiltAngle = - static_cast<int>(roundf(asin(z / magnitude) * RADIANS_TO_DEGREES)); - AddTiltHistoryEntry(now, tiltAngle); - - // Determine whether the device appears to be flat or swinging. - if (this->IsFlat(now)) { - isFlat = true; - mFlatTimestampNanos = now; - } - if (this->IsSwinging(now, tiltAngle)) { - isSwinging = true; - mSwingTimestampNanos = now; - } - // If the tilt angle is too close to horizontal then we cannot determine - // the orientation angle of the screen. - if (abs(tiltAngle) > MAX_TILT) { - LOGD - ("ProcessOrientation: Ignoring sensor data, tilt angle too high:" - " tiltAngle=%d", tiltAngle); - ClearPredictedRotation(); - } else { - // Calculate the orientation angle. - // This is the angle between the x-y projection of the up vector onto - // the +y-axis, increasing clockwise in a range of [0, 360] degrees. - int orientationAngle = - static_cast<int>(roundf(-atan2f(-x, y) * RADIANS_TO_DEGREES)); - if (orientationAngle < 0) { - // atan2 returns [-180, 180]; normalize to [0, 360] - orientationAngle += 360; - } - // Find the nearest rotation. - int nearestRotation = (orientationAngle + 45) / 90; - if (nearestRotation == 4) { - nearestRotation = 0; - } - // Determine the predicted orientation. - if (IsTiltAngleAcceptable(nearestRotation, tiltAngle) - && - IsOrientationAngleAcceptable - (nearestRotation, orientationAngle, deviceCurrentRotation)) { - UpdatePredictedRotation(now, nearestRotation); - LOGD - ("ProcessOrientation: Predicted: tiltAngle=%d, orientationAngle=%d," - " predictedRotation=%d, predictedRotationAgeMS=%f", - tiltAngle, - orientationAngle, - mPredictedRotation, - ((now - mPredictedRotationTimestampNanos) * 0.000001f)); - } else { - LOGD - ("ProcessOrientation: Ignoring sensor data, no predicted rotation:" - " tiltAngle=%d, orientationAngle=%d", - tiltAngle, - orientationAngle); - ClearPredictedRotation(); - } - } - } - - // Determine new proposed rotation. - const int oldProposedRotation = mProposedRotation; - if (mPredictedRotation < 0 || IsPredictedRotationAcceptable(now)) { - mProposedRotation = mPredictedRotation; - } - // Write final statistics about where we are in the orientation detection - // process. - LOGD - ("ProcessOrientation: Result: oldProposedRotation=%d,currentRotation=%d, " - "proposedRotation=%d, predictedRotation=%d, timeDeltaMS=%f, " - "isAccelerating=%d, isFlat=%d, isSwinging=%d, timeUntilSettledMS=%f, " - "timeUntilAccelerationDelayExpiredMS=%f, timeUntilFlatDelayExpiredMS=%f, " - "timeUntilSwingDelayExpiredMS=%f", - oldProposedRotation, - deviceCurrentRotation, mProposedRotation, - mPredictedRotation, timeDeltaMS, isAccelerating, isFlat, - isSwinging, RemainingMS(now, - mPredictedRotationTimestampNanos + - PROPOSAL_SETTLE_TIME_NANOS), - RemainingMS(now, - mAccelerationTimestampNanos + - PROPOSAL_MIN_TIME_SINCE_ACCELERATION_ENDED_NANOS), - RemainingMS(now, - mFlatTimestampNanos + - PROPOSAL_MIN_TIME_SINCE_FLAT_ENDED_NANOS), - RemainingMS(now, - mSwingTimestampNanos + - PROPOSAL_MIN_TIME_SINCE_SWING_ENDED_NANOS)); - - // Avoid unused-but-set compile warnings for these variables, when LOGD is - // a no-op, as it is by default: - Unused << isAccelerating; - Unused << isFlat; - Unused << isSwinging; - - // Tell the listener. - if (mProposedRotation != oldProposedRotation && mProposedRotation >= 0) { - LOGD - ("ProcessOrientation: Proposed rotation changed! proposedRotation=%d, " - "oldProposedRotation=%d", - mProposedRotation, - oldProposedRotation); - return mProposedRotation; - } - // Don't rotate screen - return -1; -} - -bool -ProcessOrientation::IsTiltAngleAcceptable(int rotation, int tiltAngle) -{ - return (tiltAngle >= tiltTolerance[rotation][0] - && tiltAngle <= tiltTolerance[rotation][1]); -} - -bool -ProcessOrientation::IsOrientationAngleAcceptable(int rotation, - int orientationAngle, - int currentRotation) -{ - // If there is no current rotation, then there is no gap. - // The gap is used only to introduce hysteresis among advertised orientation - // changes to avoid flapping. - if (currentRotation < 0) { - return true; - } - // If the specified rotation is the same or is counter-clockwise adjacent - // to the current rotation, then we set a lower bound on the orientation - // angle. For example, if currentRotation is ROTATION_0 and proposed is - // ROTATION_90, then we want to check orientationAngle > 45 + GAP / 2. - if (rotation == currentRotation || rotation == (currentRotation + 1) % 4) { - int lowerBound = rotation * 90 - 45 + ADJACENT_ORIENTATION_ANGLE_GAP / 2; - if (rotation == 0) { - if (orientationAngle >= 315 && orientationAngle < lowerBound + 360) { - return false; - } - } else { - if (orientationAngle < lowerBound) { - return false; - } - } - } - // If the specified rotation is the same or is clockwise adjacent, then we - // set an upper bound on the orientation angle. For example, if - // currentRotation is ROTATION_0 and rotation is ROTATION_270, then we want - // to check orientationAngle < 315 - GAP / 2. - if (rotation == currentRotation || rotation == (currentRotation + 3) % 4) { - int upperBound = rotation * 90 + 45 - ADJACENT_ORIENTATION_ANGLE_GAP / 2; - if (rotation == 0) { - if (orientationAngle <= 45 && orientationAngle > upperBound) { - return false; - } - } else { - if (orientationAngle > upperBound) { - return false; - } - } - } - return true; -} - -bool -ProcessOrientation::IsPredictedRotationAcceptable(int64_t now) -{ - // The predicted rotation must have settled long enough. - if (now < mPredictedRotationTimestampNanos + PROPOSAL_SETTLE_TIME_NANOS) { - return false; - } - // The last flat state (time since picked up) must have been sufficiently long - // ago. - if (now < mFlatTimestampNanos + PROPOSAL_MIN_TIME_SINCE_FLAT_ENDED_NANOS) { - return false; - } - // The last swing state (time since last movement to put down) must have been - // sufficiently long ago. - if (now < mSwingTimestampNanos + PROPOSAL_MIN_TIME_SINCE_SWING_ENDED_NANOS) { - return false; - } - // The last acceleration state must have been sufficiently long ago. - if (now < mAccelerationTimestampNanos - + PROPOSAL_MIN_TIME_SINCE_ACCELERATION_ENDED_NANOS) { - return false; - } - // Looks good! - return true; -} - -int -ProcessOrientation::Reset() -{ - mLastFilteredTimestampNanos = std::numeric_limits<int64_t>::min(); - mProposedRotation = -1; - mFlatTimestampNanos = std::numeric_limits<int64_t>::min(); - mSwingTimestampNanos = std::numeric_limits<int64_t>::min(); - mAccelerationTimestampNanos = std::numeric_limits<int64_t>::min(); - ClearPredictedRotation(); - ClearTiltHistory(); - return -1; -} - -void -ProcessOrientation::ClearPredictedRotation() -{ - mPredictedRotation = -1; - mPredictedRotationTimestampNanos = std::numeric_limits<int64_t>::min(); -} - -void -ProcessOrientation::UpdatePredictedRotation(int64_t now, int rotation) -{ - if (mPredictedRotation != rotation) { - mPredictedRotation = rotation; - mPredictedRotationTimestampNanos = now; - } -} - -bool -ProcessOrientation::IsAccelerating(float magnitude) -{ - return magnitude < MIN_ACCELERATION_MAGNITUDE - || magnitude > MAX_ACCELERATION_MAGNITUDE; -} - -void -ProcessOrientation::ClearTiltHistory() -{ - mTiltHistory.history[0].timestampNanos = std::numeric_limits<int64_t>::min(); - mTiltHistory.index = 1; -} - -void -ProcessOrientation::AddTiltHistoryEntry(int64_t now, float tilt) -{ - mTiltHistory.history[mTiltHistory.index].tiltAngle = tilt; - mTiltHistory.history[mTiltHistory.index].timestampNanos = now; - mTiltHistory.index = (mTiltHistory.index + 1) % TILT_HISTORY_SIZE; - mTiltHistory.history[mTiltHistory.index].timestampNanos = std::numeric_limits<int64_t>::min(); -} - -bool -ProcessOrientation::IsFlat(int64_t now) -{ - for (int i = mTiltHistory.index; (i = NextTiltHistoryIndex(i)) >= 0;) { - if (mTiltHistory.history[i].tiltAngle < FLAT_ANGLE) { - break; - } - if (mTiltHistory.history[i].timestampNanos + FLAT_TIME_NANOS <= now) { - // Tilt has remained greater than FLAT_TILT_ANGLE for FLAT_TIME_NANOS. - return true; - } - } - return false; -} - -bool -ProcessOrientation::IsSwinging(int64_t now, float tilt) -{ - for (int i = mTiltHistory.index; (i = NextTiltHistoryIndex(i)) >= 0;) { - if (mTiltHistory.history[i].timestampNanos + SWING_TIME_NANOS < now) { - break; - } - if (mTiltHistory.history[i].tiltAngle + SWING_AWAY_ANGLE_DELTA <= tilt) { - // Tilted away by SWING_AWAY_ANGLE_DELTA within SWING_TIME_NANOS. - return true; - } - } - return false; -} - -int -ProcessOrientation::NextTiltHistoryIndex(int index) -{ - index = (index == 0 ? TILT_HISTORY_SIZE : index) - 1; - return mTiltHistory.history[index].timestampNanos != std::numeric_limits<int64_t>::min() ? index : -1; -} - -float -ProcessOrientation::RemainingMS(int64_t now, int64_t until) -{ - return now >= until ? 0 : (until - now) * 0.000001f; -} - -} // namespace mozilla |