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// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "third_party/blink/renderer/modules/sensor/sensor_reading_remapper.h"
#include "base/notreached.h"
#include "services/device/public/mojom/sensor.mojom-shared.h"
using device::SensorReading;
using device::SensorReadingXYZ;
using device::SensorReadingQuat;
using device::mojom::blink::SensorType;
namespace blink {
namespace {
constexpr int SinScreenAngle(uint16_t angle) {
switch (angle) {
case 0:
return 0;
case 90:
return 1;
case 180:
return 0;
case 270:
return -1;
default:
NOTREACHED();
}
}
constexpr int CosScreenAngle(uint16_t angle) {
switch (angle) {
case 0:
return 1;
case 90:
return 0;
case 180:
return -1;
case 270:
return 0;
default:
NOTREACHED();
}
}
void RemapSensorReadingXYZ(uint16_t angle, SensorReadingXYZ& reading) {
int cos = CosScreenAngle(angle);
int sin = SinScreenAngle(angle);
double x = reading.x;
double y = reading.y;
reading.x = x * cos + y * sin;
reading.y = y * cos - x * sin;
}
constexpr double kInverseSqrt2 = 0.70710678118;
// Returns sin(-angle/2) for the given orientation angle.
constexpr double SinNegativeHalfScreenAngle(uint16_t angle) {
switch (angle) {
case 0:
return 0; // sin 0
case 90:
return -kInverseSqrt2; // sin -45
case 180:
return -1; // sin -90
case 270:
return -kInverseSqrt2; // sin -135
default:
NOTREACHED();
}
}
// Returns cos(-angle/2) for the given orientation angle.
constexpr double CosNegativeHalfScreenAngle(uint16_t angle) {
switch (angle) {
case 0:
return 1; // cos 0
case 90:
return kInverseSqrt2; // cos -45
case 180:
return 0; // cos -90
case 270:
return -kInverseSqrt2; // cos -135
default:
NOTREACHED();
}
}
void RemapSensorReadingQuat(uint16_t angle, SensorReadingQuat& reading) {
// Remapping quaternion = q = [qx, qy, qz, qw] =
// [0, 0, sin(-angle / 2), cos(-angle / 2)] - unit quaternion.
// reading = [x, y, z, w] - unit quaternion.
// Resulting unit quaternion = reading * q.
double qw = CosNegativeHalfScreenAngle(angle);
double qz = SinNegativeHalfScreenAngle(angle);
double x = reading.x;
double y = reading.y;
double z = reading.z;
double w = reading.w;
// Given that qx == 0 and qy == 0.
reading.x = qw * x + qz * y;
reading.y = qw * y - qz * x;
reading.z = qw * z + qz * w;
reading.w = qw * w - qz * z;
}
} // namespace
// static
void SensorReadingRemapper::RemapToScreenCoords(
SensorType type,
uint16_t angle,
device::SensorReading* reading) {
DCHECK(reading);
switch (type) {
case SensorType::AMBIENT_LIGHT:
NOTREACHED() << "Remap must not be performed for the sensor type "
<< type;
case SensorType::ACCELEROMETER:
case SensorType::LINEAR_ACCELERATION:
case SensorType::GRAVITY:
RemapSensorReadingXYZ(angle, reading->accel);
break;
case SensorType::GYROSCOPE:
RemapSensorReadingXYZ(angle, reading->gyro);
break;
case SensorType::MAGNETOMETER:
RemapSensorReadingXYZ(angle, reading->magn);
break;
case SensorType::ABSOLUTE_ORIENTATION_QUATERNION:
case SensorType::RELATIVE_ORIENTATION_QUATERNION:
RemapSensorReadingQuat(angle, reading->orientation_quat);
break;
case SensorType::ABSOLUTE_ORIENTATION_EULER_ANGLES:
case SensorType::RELATIVE_ORIENTATION_EULER_ANGLES:
NOTREACHED() << "Remap is not yet implemented for the sensor type "
<< type;
}
}
} // namespace blink
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