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| 1 // Copyright (c) 2010 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 // This file is based on the SMSLib library. |
| 6 // |
| 7 // SMSLib Sudden Motion Sensor Access Library |
| 8 // Copyright (c) 2010 Suitable Systems |
| 9 // All rights reserved. |
| 10 // |
| 11 // Developed by: Daniel Griscom |
| 12 // Suitable Systems |
| 13 // http://www.suitable.com |
| 14 // |
| 15 // Permission is hereby granted, free of charge, to any person obtaining a |
| 16 // copy of this software and associated documentation files (the |
| 17 // "Software"), to deal with the Software without restriction, including |
| 18 // without limitation the rights to use, copy, modify, merge, publish, |
| 19 // distribute, sublicense, and/or sell copies of the Software, and to |
| 20 // permit persons to whom the Software is furnished to do so, subject to |
| 21 // the following conditions: |
| 22 // |
| 23 // - Redistributions of source code must retain the above copyright notice, |
| 24 // this list of conditions and the following disclaimers. |
| 25 // |
| 26 // - Redistributions in binary form must reproduce the above copyright |
| 27 // notice, this list of conditions and the following disclaimers in the |
| 28 // documentation and/or other materials provided with the distribution. |
| 29 // |
| 30 // - Neither the names of Suitable Systems nor the names of its |
| 31 // contributors may be used to endorse or promote products derived from |
| 32 // this Software without specific prior written permission. |
| 33 // |
| 34 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| 35 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 36 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 37 // IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR |
| 38 // ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 39 // TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 40 // SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE SOFTWARE. |
| 41 // |
| 42 // For more information about SMSLib, see |
| 43 // <http://www.suitable.com/tools/smslib.html> |
| 44 // or contact |
| 45 // Daniel Griscom |
| 46 // Suitable Systems |
| 47 // 1 Centre Street, Suite 204 |
| 48 // Wakefield, MA 01880 |
| 49 // (781) 665-0053 |
| 50 |
| 51 #include "chrome/browser/device_orientation/accelerometer_mac.h" |
| 52 |
| 53 #include <math.h> // For isfinite. |
| 54 #include <sys/sysctl.h> |
| 55 |
| 56 #include "base/logging.h" |
| 57 #include "base/scoped_ptr.h" |
| 58 #include "chrome/browser/device_orientation/orientation.h" |
| 59 |
| 60 namespace device_orientation { |
| 61 |
| 62 // Per-axis sensor data. |
| 63 struct AccelerometerMac::AxisData { |
| 64 // Non-zero if the axis is valid in this sensor. |
| 65 int enabled; |
| 66 |
| 67 // Location in struct of first byte. |
| 68 int index; |
| 69 |
| 70 // Number of bytes of the axis data. |
| 71 int size; |
| 72 |
| 73 // Value meaning "zero g". |
| 74 float zero_g; |
| 75 |
| 76 // (can be negative if the sensor axis is reversed). |
| 77 float one_g; |
| 78 }; |
| 79 |
| 80 // Sudden Motion Sensor descriptor. |
| 81 struct AccelerometerMac::SensorDescriptor { |
| 82 // Prefix of model to be tested. |
| 83 const char* model_name; |
| 84 |
| 85 // Name of device to be read. |
| 86 const char* service_name; |
| 87 |
| 88 // Kernel function index. |
| 89 unsigned int function; |
| 90 |
| 91 // Size of record to be sent/received. |
| 92 unsigned int record_size; |
| 93 |
| 94 // Description of three axes (x,y,z). |
| 95 AxisData axes[3]; |
| 96 }; |
| 97 |
| 98 // Supported sensor descriptors. Add entries here to enhance compatibility. |
| 99 // All non-tested entries from SMSLib have been removed. |
| 100 const AccelerometerMac::SensorDescriptor |
| 101 AccelerometerMac::kSupportedSensors[] = { |
| 102 // Tested by leandrogracia on a 15'' MacBook Pro. |
| 103 { "MacBookPro5,4", "SMCMotionSensor", 5, 40, { |
| 104 { 1, 0, 2, 0, 251 }, |
| 105 { 1, 2, 2, 0, 251 }, |
| 106 { 1, 4, 2, 0, 251 } |
| 107 } }, |
| 108 |
| 109 // Tested by leandrogracia on a 13'' MacBook Pro. |
| 110 { "MacBookPro5,5", "SMCMotionSensor", 5, 40, { |
| 111 { 1, 0, 2, 0, -251 }, |
| 112 { 1, 2, 2, 0, -251 }, |
| 113 { 1, 4, 2, 0, 251 } |
| 114 } }, |
| 115 |
| 116 // Generic MacBook accelerometer sensor data. |
| 117 // Added for forward compatibility (there may be problems with inverted axes). |
| 118 {"", "SMCMotionSensor", 5, 40, { |
| 119 { 1, 0, 2, 0, -251 }, |
| 120 { 1, 2, 2, 0, -251 }, |
| 121 { 1, 4, 2, 0, 251 } |
| 122 } } |
| 123 }; |
| 124 |
| 125 // Create a AccelerometerMac object and return NULL if no valid sensor found. |
| 126 DataFetcher* AccelerometerMac::Create() { |
| 127 scoped_ptr<AccelerometerMac> accelerometer(new AccelerometerMac); |
| 128 return accelerometer->Init() ? accelerometer.release() : NULL; |
| 129 } |
| 130 |
| 131 AccelerometerMac::~AccelerometerMac() { |
| 132 IOServiceClose(io_connection_); |
| 133 } |
| 134 |
| 135 AccelerometerMac::AccelerometerMac() |
| 136 : sensor_(NULL), |
| 137 io_connection_(0) { |
| 138 } |
| 139 |
| 140 // Retrieve per-axis accelerometer values. |
| 141 // |
| 142 // Axes and angles are defined according to the W3C DeviceOrientation Draft. |
| 143 // See here: http://dev.w3.org/geo/api/spec-source-orientation.html |
| 144 // |
| 145 // Note: only beta and gamma angles are provided. Alpha is set to zero. |
| 146 // |
| 147 // Returns false in case of error or non-properly initialized object. |
| 148 // |
| 149 bool AccelerometerMac::GetOrientation(Orientation* orientation) { |
| 150 DCHECK(sensor_); |
| 151 |
| 152 // Reset output record memory buffer. |
| 153 std::fill(output_record_.begin(), output_record_.end(), 0x00); |
| 154 |
| 155 // Read record data from memory. |
| 156 const size_t kInputSize = sensor_->record_size; |
| 157 size_t output_size = sensor_->record_size; |
| 158 |
| 159 if (IOConnectCallStructMethod(io_connection_, sensor_->function, |
| 160 static_cast<const char *>(&input_record_[0]), kInputSize, |
| 161 &output_record_[0], &output_size) != KERN_SUCCESS) { |
| 162 return false; |
| 163 } |
| 164 |
| 165 // Calculate per-axis calibrated values. |
| 166 float axis_value[3]; |
| 167 |
| 168 for (int i = 0; i < 3; ++i) { |
| 169 int sensor_value = 0; |
| 170 int size = sensor_->axes[i].size; |
| 171 int index = sensor_->axes[i].index; |
| 172 |
| 173 // Important Note: little endian is assumed as this code is mac-only |
| 174 // and PowerPC is currently not supported. |
| 175 memcpy(&sensor_value, &output_record_[index], size); |
| 176 |
| 177 sensor_value = ExtendSign(sensor_value, size); |
| 178 |
| 179 // Correct value using the current calibration. |
| 180 axis_value[i] = static_cast<float>(sensor_value - sensor_->axes[i].zero_g) / |
| 181 sensor_->axes[i].one_g; |
| 182 |
| 183 // Make sure we reject any NaN or infinite values. |
| 184 if (!isfinite(axis_value[i])) |
| 185 return false; |
| 186 |
| 187 // Clamp value to the [-1, 1] range. |
| 188 if (axis_value[i] < -1.0) |
| 189 axis_value[i] = -1.0; |
| 190 else if (axis_value[i] > 1.0) |
| 191 axis_value[i] = 1.0; |
| 192 } |
| 193 |
| 194 // Transform the accelerometer values to W3C draft angles. |
| 195 // |
| 196 // Accelerometer values are just dot products of the sensor axes |
| 197 // by the gravity vector 'g' with the result for the z axis inverted. |
| 198 // |
| 199 // To understand this transformation calculate the 3rd row of the z-x-y |
| 200 // Euler angles rotation matrix (because of the 'g' vector, only 3rd row |
| 201 // affects to the result). Note that z-x-y matrix means R = Ry * Rx * Rz. |
| 202 // Then, assume alpha = 0 and you get this: |
| 203 // |
| 204 // x_acc = sin(gamma) |
| 205 // y_acc = - cos(gamma) * sin(beta) |
| 206 // z_acc = cos(beta) * cos(gamma) |
| 207 // |
| 208 // After that the rest is just a bit of trigonometry. |
| 209 // |
| 210 // Also note that alpha can't be provided but it's assumed to be always zero. |
| 211 // This is necessary in order to provide enough information to solve |
| 212 // the equations. |
| 213 // |
| 214 const double kRad2deg = 180.0 / M_PI; |
| 215 |
| 216 orientation->alpha_ = 0.0; |
| 217 orientation->beta_ = kRad2deg * atan2(-axis_value[1], axis_value[2]); |
| 218 orientation->gamma_ = kRad2deg * asin(axis_value[0]); |
| 219 |
| 220 // Make sure that the interval boundaries comply with the specification. |
| 221 if (orientation->beta_ >= 180.0) |
| 222 orientation->beta_ -= 360.0; |
| 223 if (orientation->gamma_ >= 90.0) |
| 224 orientation->gamma_ -= 180.0; |
| 225 |
| 226 DCHECK_GE(orientation->beta_, -180.0); |
| 227 DCHECK_LT(orientation->beta_, 180.0); |
| 228 DCHECK_GE(orientation->gamma_, -90.0); |
| 229 DCHECK_LT(orientation->gamma_, 90.0); |
| 230 |
| 231 orientation->can_provide_alpha_ = false; |
| 232 orientation->can_provide_beta_ = true; |
| 233 orientation->can_provide_gamma_ = true; |
| 234 |
| 235 return true; |
| 236 } |
| 237 |
| 238 // Probe the local hardware looking for a supported sensor device |
| 239 // and initialize an I/O connection to it. |
| 240 bool AccelerometerMac::Init() { |
| 241 // Allocate local variables for model name string (size from SMSLib). |
| 242 static const int kNameSize = 32; |
| 243 char local_model[kNameSize]; |
| 244 |
| 245 // Request model name to the kernel. |
| 246 size_t name_size = kNameSize; |
| 247 int params[2] = { CTL_HW, HW_MODEL }; |
| 248 if (sysctl(params, 2, local_model, &name_size, NULL, 0) != 0) |
| 249 return NULL; |
| 250 |
| 251 const SensorDescriptor* sensor_candidate = NULL; |
| 252 |
| 253 // Look for the current model in the supported sensor list. |
| 254 io_object_t device = 0; |
| 255 const int kNumSensors = arraysize(kSupportedSensors); |
| 256 |
| 257 for (int i = 0; i < kNumSensors; ++i) { |
| 258 // Check if the supported sensor model name is a prefix |
| 259 // of the local hardware model (empty names are accepted). |
| 260 const char* p1 = kSupportedSensors[i].model_name; |
| 261 for (const char* p2 = local_model; *p1 != '\0' && *p1 == *p2; ++p1, ++p2) |
| 262 continue; |
| 263 if (*p1 != '\0') |
| 264 continue; |
| 265 |
| 266 // Local hardware found in the supported sensor list. |
| 267 sensor_candidate = &kSupportedSensors[i]; |
| 268 |
| 269 // Get a dictionary of the services matching to the one in the sensor. |
| 270 CFMutableDictionaryRef dict = |
| 271 IOServiceMatching(sensor_candidate->service_name); |
| 272 if (dict == NULL) |
| 273 continue; |
| 274 |
| 275 // Get an iterator for the matching services. |
| 276 io_iterator_t device_iterator; |
| 277 if (IOServiceGetMatchingServices(kIOMasterPortDefault, dict, |
| 278 &device_iterator) != KERN_SUCCESS) { |
| 279 continue; |
| 280 } |
| 281 |
| 282 // Get the first device in the list. |
| 283 if ((device = IOIteratorNext(device_iterator)) == 0) |
| 284 continue; |
| 285 |
| 286 // Try to open device. |
| 287 kern_return_t result; |
| 288 result = IOServiceOpen(device, mach_task_self(), 0, &io_connection_); |
| 289 IOObjectRelease(device); |
| 290 if (result != KERN_SUCCESS || io_connection_ == 0) |
| 291 return false; |
| 292 |
| 293 // Local sensor service confirmed by IOKit. |
| 294 sensor_ = sensor_candidate; |
| 295 break; |
| 296 } |
| 297 |
| 298 if (sensor_ == NULL) |
| 299 return false; |
| 300 |
| 301 // Allocate and initialize input/output records. |
| 302 input_record_.resize(sensor_->record_size, 0x01); |
| 303 output_record_.resize(sensor_->record_size, 0x00); |
| 304 |
| 305 // Try to retrieve the current orientation. |
| 306 Orientation test_orientation; |
| 307 return GetOrientation(&test_orientation); |
| 308 } |
| 309 |
| 310 // Extend the sign of an integer of less than 32 bits to a 32-bit integer. |
| 311 int AccelerometerMac::ExtendSign(int value, size_t size) { |
| 312 switch (size) { |
| 313 case 1: |
| 314 if (value & 0x00000080) |
| 315 return value | 0xffffff00; |
| 316 break; |
| 317 |
| 318 case 2: |
| 319 if (value & 0x00008000) |
| 320 return value | 0xffff0000; |
| 321 break; |
| 322 |
| 323 case 3: |
| 324 if (value & 0x00800000) |
| 325 return value | 0xff000000; |
| 326 break; |
| 327 |
| 328 default: |
| 329 LOG(FATAL) << "Invalid integer size for sign extension: " << size; |
| 330 } |
| 331 |
| 332 return value; |
| 333 } |
| 334 |
| 335 } // namespace device_orientation |
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