content/browser/device_sensors/data_fetcher_shared_memory_mac.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/device_sensors/data_fetcher_shared_memory.h"
   6
   7 #include "base/logging.h"
   8 #include "base/metrics/histogram.h"
   9 #include "content/browser/device_sensors/ambient_light_mac.h"
  10 #include "third_party/sudden_motion_sensor/sudden_motion_sensor_mac.h"
  11
  12 namespace {
  13
  14 const double kMeanGravity = 9.80665;
  15
  16 double LMUvalueToLux(uint64_t raw_value) {
  17   // Conversion formula from regression.
  18   // https://bugzilla.mozilla.org/show_bug.cgi?id=793728
  19   // Let x = raw_value, then
  20   // lux = -2.978303814*(10^-27)*x^4 + 2.635687683*(10^-19)*x^3 -
  21   //       3.459747434*(10^-12)*x^2 + 3.905829689*(10^-5)*x - 0.1932594532
  22
  23   static const long double k4 = pow(10.L, -7);
  24   static const long double k3 = pow(10.L, -4);
  25   static const long double k2 = pow(10.L, -2);
  26   static const long double k1 = pow(10.L, 5);
  27   long double scaled_value = raw_value / k1;
  28
  29   long double lux_value =
  30       (-3 * k4 * pow(scaled_value, 4)) + (2.6 * k3 * pow(scaled_value, 3)) +
  31       (-3.4 * k2 * pow(scaled_value, 2)) + (3.9 * scaled_value) - 0.19;
  32
  33   double lux = ceil(static_cast<double>(lux_value));
  34   return lux > 0 ? lux : 0;
  35 }
  36
  37 void FetchLight(content::AmbientLightSensor* sensor,
  38                 content::DeviceLightHardwareBuffer* buffer) {
  39   DCHECK(sensor);
  40   DCHECK(buffer);
  41   // Macbook pro has 2 lux values, left and right, we take the average.
  42   // The raw sensor values are converted to lux using LMUvalueToLux(raw_value)
  43   // similar to how it is done in Firefox.
  44   uint64_t lux_value[2];
  45   if (!sensor->ReadSensorValue(lux_value))
  46     return;
  47   uint64_t mean = (lux_value[0] + lux_value[1]) / 2;
  48   double lux = LMUvalueToLux(mean);
  49   buffer->seqlock.WriteBegin();
  50   buffer->data.value = lux;
  51   buffer->seqlock.WriteEnd();
  52 }
  53
  54 void FetchMotion(SuddenMotionSensor* sensor,
  55     content::DeviceMotionHardwareBuffer* buffer) {
  56   DCHECK(sensor);
  57   DCHECK(buffer);
  58
  59   float axis_value[3];
  60   if (!sensor->ReadSensorValues(axis_value))
  61     return;
  62
  63   buffer->seqlock.WriteBegin();
  64   buffer->data.accelerationIncludingGravityX = axis_value[0] * kMeanGravity;
  65   buffer->data.hasAccelerationIncludingGravityX = true;
  66   buffer->data.accelerationIncludingGravityY = axis_value[1] * kMeanGravity;
  67   buffer->data.hasAccelerationIncludingGravityY = true;
  68   buffer->data.accelerationIncludingGravityZ = axis_value[2] * kMeanGravity;
  69   buffer->data.hasAccelerationIncludingGravityZ = true;
  70   buffer->data.allAvailableSensorsAreActive = true;
  71   buffer->seqlock.WriteEnd();
  72 }
  73
  74 void FetchOrientation(SuddenMotionSensor* sensor,
  75     content::DeviceOrientationHardwareBuffer* buffer) {
  76   DCHECK(sensor);
  77   DCHECK(buffer);
  78
  79   // Retrieve per-axis calibrated values.
  80   float axis_value[3];
  81   if (!sensor->ReadSensorValues(axis_value))
  82     return;
  83
  84   // Transform the accelerometer values to W3C draft angles.
  85   //
  86   // Accelerometer values are just dot products of the sensor axes
  87   // by the gravity vector 'g' with the result for the z axis inverted.
  88   //
  89   // To understand this transformation calculate the 3rd row of the z-x-y
  90   // Euler angles rotation matrix (because of the 'g' vector, only 3rd row
  91   // affects to the result). Note that z-x-y matrix means R = Ry * Rx * Rz.
  92   // Then, assume alpha = 0 and you get this:
  93   //
  94   // x_acc = sin(gamma)
  95   // y_acc = - cos(gamma) * sin(beta)
  96   // z_acc = cos(beta) * cos(gamma)
  97   //
  98   // After that the rest is just a bit of trigonometry.
  99   //
 100   // Also note that alpha can't be provided but it's assumed to be always zero.
 101   // This is necessary in order to provide enough information to solve
 102   // the equations.
 103   //
 104   const double kRad2deg = 180.0 / M_PI;
 105   double beta = kRad2deg * atan2(-axis_value[1], axis_value[2]);
 106   double gamma = kRad2deg * asin(axis_value[0]);
 107
 108   // Make sure that the interval boundaries comply with the specification. At
 109   // this point, beta is [-180, 180] and gamma is [-90, 90], but the spec has
 110   // the upper bound open on both.
 111   if (beta == 180.0)
 112     beta = -180;  // -180 == 180 (upside-down)
 113   if (gamma == 90.0)
 114     gamma = nextafter(90, 0);
 115
 116   // At this point, DCHECKing is paranoia. Never hurts.
 117   DCHECK_GE(beta, -180.0);
 118   DCHECK_LT(beta,  180.0);
 119   DCHECK_GE(gamma, -90.0);
 120   DCHECK_LT(gamma,  90.0);
 121
 122   buffer->seqlock.WriteBegin();
 123   buffer->data.beta = beta;
 124   buffer->data.hasBeta = true;
 125   buffer->data.gamma = gamma;
 126   buffer->data.hasGamma = true;
 127   buffer->data.allAvailableSensorsAreActive = true;
 128   buffer->seqlock.WriteEnd();
 129 }
 130
 131 }  // namespace
 132
 133 namespace content {
 134
 135 DataFetcherSharedMemory::DataFetcherSharedMemory() {
 136 }
 137
 138 DataFetcherSharedMemory::~DataFetcherSharedMemory() {
 139 }
 140
 141 void DataFetcherSharedMemory::Fetch(unsigned consumer_bitmask) {
 142   DCHECK(base::MessageLoop::current() == GetPollingMessageLoop());
 143   DCHECK(consumer_bitmask & CONSUMER_TYPE_ORIENTATION ||
 144          consumer_bitmask & CONSUMER_TYPE_MOTION ||
 145          consumer_bitmask & CONSUMER_TYPE_LIGHT);
 146
 147   if (consumer_bitmask & CONSUMER_TYPE_ORIENTATION)
 148     FetchOrientation(sudden_motion_sensor_.get(), orientation_buffer_);
 149   if (consumer_bitmask & CONSUMER_TYPE_MOTION)
 150     FetchMotion(sudden_motion_sensor_.get(), motion_buffer_);
 151   if (consumer_bitmask & CONSUMER_TYPE_LIGHT)
 152     FetchLight(ambient_light_sensor_.get(), light_buffer_);
 153 }
 154
 155 DataFetcherSharedMemory::FetcherType DataFetcherSharedMemory::GetType() const {
 156   return FETCHER_TYPE_POLLING_CALLBACK;
 157 }
 158
 159 bool DataFetcherSharedMemory::Start(ConsumerType consumer_type, void* buffer) {
 160   DCHECK(base::MessageLoop::current() == GetPollingMessageLoop());
 161   DCHECK(buffer);
 162
 163   switch (consumer_type) {
 164     case CONSUMER_TYPE_MOTION: {
 165       if (!sudden_motion_sensor_)
 166         sudden_motion_sensor_.reset(SuddenMotionSensor::Create());
 167       bool sudden_motion_sensor_available =
 168           sudden_motion_sensor_.get() != nullptr;
 169
 170       motion_buffer_ = static_cast<DeviceMotionHardwareBuffer*>(buffer);
 171       UMA_HISTOGRAM_BOOLEAN("InertialSensor.MotionMacAvailable",
 172           sudden_motion_sensor_available);
 173       if (!sudden_motion_sensor_available) {
 174         // No motion sensor available, fire an all-null event.
 175         motion_buffer_->seqlock.WriteBegin();
 176         motion_buffer_->data.allAvailableSensorsAreActive = true;
 177         motion_buffer_->seqlock.WriteEnd();
 178       }
 179       return sudden_motion_sensor_available;
 180     }
 181     case CONSUMER_TYPE_ORIENTATION: {
 182       if (!sudden_motion_sensor_)
 183         sudden_motion_sensor_.reset(SuddenMotionSensor::Create());
 184       bool sudden_motion_sensor_available =
 185           sudden_motion_sensor_.get() != nullptr;
 186
 187       orientation_buffer_ =
 188           static_cast<DeviceOrientationHardwareBuffer*>(buffer);
 189       UMA_HISTOGRAM_BOOLEAN("InertialSensor.OrientationMacAvailable",
 190           sudden_motion_sensor_available);
 191       if (sudden_motion_sensor_available) {
 192         // On Mac we cannot provide absolute orientation.
 193         orientation_buffer_->seqlock.WriteBegin();
 194         orientation_buffer_->data.absolute = false;
 195         orientation_buffer_->data.hasAbsolute = true;
 196         orientation_buffer_->seqlock.WriteEnd();
 197       } else {
 198         // No motion sensor available, fire an all-null event.
 199         orientation_buffer_->seqlock.WriteBegin();
 200         orientation_buffer_->data.allAvailableSensorsAreActive = true;
 201         orientation_buffer_->seqlock.WriteEnd();
 202       }
 203       return sudden_motion_sensor_available;
 204     }
 205     case CONSUMER_TYPE_LIGHT: {
 206       if (!ambient_light_sensor_)
 207         ambient_light_sensor_ = AmbientLightSensor::Create();
 208       bool ambient_light_sensor_available =
 209           ambient_light_sensor_.get() != nullptr;
 210
 211       light_buffer_ = static_cast<DeviceLightHardwareBuffer*>(buffer);
 212       if (!ambient_light_sensor_available) {
 213         light_buffer_->seqlock.WriteBegin();
 214         light_buffer_->data.value = std::numeric_limits<double>::infinity();
 215         light_buffer_->seqlock.WriteEnd();
 216       }
 217       return ambient_light_sensor_available;
 218     }
 219     default:
 220       NOTREACHED();
 221   }
 222   return false;
 223 }
 224
 225 bool DataFetcherSharedMemory::Stop(ConsumerType consumer_type) {
 226   DCHECK(base::MessageLoop::current() == GetPollingMessageLoop());
 227
 228   switch (consumer_type) {
 229     case CONSUMER_TYPE_MOTION:
 230       if (motion_buffer_) {
 231         motion_buffer_->seqlock.WriteBegin();
 232         motion_buffer_->data.allAvailableSensorsAreActive = false;
 233         motion_buffer_->seqlock.WriteEnd();
 234         motion_buffer_ = nullptr;
 235       }
 236       return true;
 237     case CONSUMER_TYPE_ORIENTATION:
 238       if (orientation_buffer_) {
 239         orientation_buffer_->seqlock.WriteBegin();
 240         orientation_buffer_->data.allAvailableSensorsAreActive = false;
 241         orientation_buffer_->seqlock.WriteEnd();
 242         orientation_buffer_ = nullptr;
 243       }
 244       return true;
 245     case CONSUMER_TYPE_LIGHT:
 246       if (light_buffer_) {
 247         light_buffer_->seqlock.WriteBegin();
 248         light_buffer_->data.value = -1;
 249         light_buffer_->seqlock.WriteEnd();
 250         light_buffer_ = nullptr;
 251       }
 252       return true;
 253     default:
 254       NOTREACHED();
 255   }
 256   return false;
 257 }
 258
 259 }  // namespace content