From f35fd959fe499c61ee0d97d5b0c8feb469397a42 Mon Sep 17 00:00:00 2001 From: Kevin Powell Date: Mon, 19 Jul 2010 19:10:40 -0700 Subject: add new sensor types for handling gyro data and device orientation more efficiently. Change-Id: Ie19992f6599e528a79931f4ae592898dac15412e --- core/java/android/hardware/Sensor.java | 22 +++- core/java/android/hardware/SensorEvent.java | 32 +++++ core/java/android/hardware/SensorManager.java | 179 +++++++++++++++++++++++++- 3 files changed, 231 insertions(+), 2 deletions(-) (limited to 'core/java') diff --git a/core/java/android/hardware/Sensor.java b/core/java/android/hardware/Sensor.java index 317e547..710e533 100644 --- a/core/java/android/hardware/Sensor.java +++ b/core/java/android/hardware/Sensor.java @@ -69,7 +69,27 @@ public class Sensor { */ public static final int TYPE_PROXIMITY = 8; - + /** + * A constant describing a gravity sensor type. + * See {@link android.hardware.SensorEvent SensorEvent} + * for more details. + */ + public static final int TYPE_GRAVITY = 9; + + /** + * A constant describing a linear acceleration sensor type. + * See {@link android.hardware.SensorEvent SensorEvent} + * for more details. + */ + public static final int TYPE_LINEAR_ACCELERATION = 10; + + /** + * A constant describing a rotation vector sensor type. + * See {@link android.hardware.SensorEvent SensorEvent} + * for more details. + */ + public static final int TYPE_ROTATION_VECTOR = 11; + /** * A constant describing all sensor types. */ diff --git a/core/java/android/hardware/SensorEvent.java b/core/java/android/hardware/SensorEvent.java index 9a9f0bf..bba59a4 100644 --- a/core/java/android/hardware/SensorEvent.java +++ b/core/java/android/hardware/SensorEvent.java @@ -119,6 +119,16 @@ public class SensorEvent { * All values are in micro-Tesla (uT) and measure the ambient magnetic * field in the X, Y and Z axis. * + *

{@link android.hardware.Sensor#TYPE_GYROSCOPE Sensor.TYPE_GYROSCOPE}:

+ * All values are in radians/second and measure the rate of rotation + * around the X, Y and Z axis. The coordinate system is the same as is + * used for the acceleration sensor. Rotation is positive in the counter-clockwise + * direction. That is, an observer looking from some positive location on the x, y. + * or z axis at a device positioned on the origin would report positive rotation + * if the device appeared to be rotating counter clockwise. Note that this is the + * standard mathematical definition of positive rotation and does not agree with the + * definition of roll given earlier. + * *

{@link android.hardware.Sensor#TYPE_LIGHT Sensor.TYPE_LIGHT}:

* *

values[0]: Ambient light level in SI lux units @@ -130,7 +140,29 @@ public class SensorEvent { *

Note that some proximity sensors only support a binary "close" or "far" measurement. * In this case, the sensor should report its maxRange value in the "far" state and a value * less than maxRange in the "near" state. + * + *

{@link android.hardware.Sensor#TYPE_GRAVITY Sensor.TYPE_GRAVITY}:

+ * A three dimensional vector indicating the direction and magnitude of gravity. Units + * are m/s^2. The coordinate system is the same as is used by the acceleration sensor. + * + *

{@link android.hardware.Sensor#TYPE_LINEAR_ACCELERATION Sensor.TYPE_LINEAR_ACCELERATION}:

+ * A three dimensional vector indicating acceleration along each device axis, not including + * gravity. All values have units of m/s^2. The coordinate system is the same as is used by the + * acceleration sensor. + * + *

{@link android.hardware.Sensor#TYPE_ROTATION_VECTOR Sensor.TYPE_ROTATION_VECTOR}:

+ * The rotation vector represents the orientation of the device as a combination of an angle + * and an axis, in which the device has rotated through an angle theta around an axis + * . The three elements of the rotation vector are + * , such that the magnitude of the rotation + * vector is equal to sin(theta/2), and the direction of the rotation vector is equal to the + * direction of the axis of rotation. The three elements of the rotation vector are equal to + * the last three components of a unit quaternion + * . Elements of the rotation + * vector are unitless. The x,y, and z axis are defined in the same way as the acceleration + * sensor. */ + public final float[] values; /** diff --git a/core/java/android/hardware/SensorManager.java b/core/java/android/hardware/SensorManager.java index 98172e6..31bdc0c 100644 --- a/core/java/android/hardware/SensorManager.java +++ b/core/java/android/hardware/SensorManager.java @@ -1555,7 +1555,184 @@ public class SensorManager } } - + + /** Helper function to compute the angle change between two rotation matrices. + * Given a current rotation matrix (R) and a previous rotation matrix + * (prevR) computes the rotation around the x,y, and z axes which + * transforms prevR to R. + * outputs a 3 element vector containing the x,y, and z angle + * change at indexes 0, 1, and 2 respectively. + *

Each input matrix is either as a 3x3 or 4x4 row-major matrix + * depending on the length of the passed array: + *

If the array length is 9, then the array elements represent this matrix + * 

+     *   /  R[ 0]   R[ 1]   R[ 2]   \
+     *   |  R[ 3]   R[ 4]   R[ 5]   |
+     *   \  R[ 6]   R[ 7]   R[ 8]   /
+     *
+ *

If the array length is 16, then the array elements represent this matrix + * 

+     *   /  R[ 0]   R[ 1]   R[ 2]   R[ 3]  \
+     *   |  R[ 4]   R[ 5]   R[ 6]   R[ 7]  |
+     *   |  R[ 8]   R[ 9]   R[10]   R[11]  |
+     *   \  R[12]   R[13]   R[14]   R[15]  /
+     *
+ * @param R current rotation matrix see {@link android.hardware.Sensor#TYPE_ROTATION_MATRIX}. + * @param prevR previous rotation matrix + * @param angleChange an array of floats in which the angle change is stored + */ + + public static void getAngleChange( float[] angleChange, float[] R, float[] prevR) { + float rd1=0,rd4=0, rd6=0,rd7=0, rd8=0; + float ri0=0,ri1=0,ri2=0,ri3=0,ri4=0,ri5=0,ri6=0,ri7=0,ri8=0; + float pri0=0, pri1=0, pri2=0, pri3=0, pri4=0, pri5=0, pri6=0, pri7=0, pri8=0; + int i, j, k; + + if(R.length == 9) { + ri0 = R[0]; + ri1 = R[1]; + ri2 = R[2]; + ri3 = R[3]; + ri4 = R[4]; + ri5 = R[5]; + ri6 = R[6]; + ri7 = R[7]; + ri8 = R[8]; + } else if(R.length == 16) { + ri0 = R[0]; + ri1 = R[1]; + ri2 = R[2]; + ri3 = R[4]; + ri4 = R[5]; + ri5 = R[6]; + ri6 = R[8]; + ri7 = R[9]; + ri8 = R[10]; + } + + if(prevR.length == 9) { + pri0 = R[0]; + pri1 = R[1]; + pri2 = R[2]; + pri3 = R[3]; + pri4 = R[4]; + pri5 = R[5]; + pri6 = R[6]; + pri7 = R[7]; + pri8 = R[8]; + } else if(prevR.length == 16) { + pri0 = R[0]; + pri1 = R[1]; + pri2 = R[2]; + pri3 = R[4]; + pri4 = R[5]; + pri5 = R[6]; + pri6 = R[8]; + pri7 = R[9]; + pri8 = R[10]; + } + + // calculate the parts of the rotation difference matrix we need + // rd[i][j] = pri[0][i] * ri[0][j] + pri[1][i] * ri[1][j] + pri[2][i] * ri[2][j]; + + rd1 = pri0 * ri1 + pri3 * ri4 + pri6 * ri7; //rd[0][1] + rd4 = pri1 * ri1 + pri4 * ri4 + pri7 * ri7; //rd[1][1] + rd6 = pri2 * ri0 + pri5 * ri3 + pri8 * ri6; //rd[2][0] + rd7 = pri2 * ri1 + pri5 * ri4 + pri8 * ri7; //rd[2][1] + rd8 = pri2 * ri2 + pri5 * ri5 + pri8 * ri8; //rd[2][2] + + angleChange[0] = (float)Math.atan2(rd1, rd4); + angleChange[1] = (float)Math.asin(-rd7); + angleChange[2] = (float)Math.atan2(-rd6, rd8); + + } + + /** Helper function to convert a rotation vector to a rotation matrix. + * Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a + * 9 or 16 element rotation matrix in the array R. R must have length 9 or 16. + * If R.length == 9, the following matrix is returned: + * 
+     *   /  R[ 0]   R[ 1]   R[ 2]   \
+     *   |  R[ 3]   R[ 4]   R[ 5]   |
+     *   \  R[ 6]   R[ 7]   R[ 8]   /
+     *
+ * If R.length == 16, the following matrix is returned: + * 
+     *   /  R[ 0]   R[ 1]   R[ 2]   0  \
+     *   |  R[ 4]   R[ 5]   R[ 6]   0  |
+     *   |  R[ 8]   R[ 9]   R[10]   0  |
+     *   \  0       0       0       1  /
+     *
+ * @param rotationVector the rotation vector to convert + * @param R an array of floats in which to store the rotation matrix + */ + public static void getRotationMatrixFromVector(float[] R, float[] rotationVector) { + float q0 = (float)Math.sqrt(1 - rotationVector[0]*rotationVector[0] - + rotationVector[1]*rotationVector[1] - + rotationVector[2]*rotationVector[2]); + float q1 = rotationVector[0]; + float q2 = rotationVector[1]; + float q3 = rotationVector[2]; + + float sq_q1 = 2 * q1 * q1; + float sq_q2 = 2 * q2 * q2; + float sq_q3 = 2 * q3 * q3; + float q1_q2 = 2 * q1 * q2; + float q3_q0 = 2 * q3 * q0; + float q1_q3 = 2 * q1 * q3; + float q2_q0 = 2 * q2 * q0; + float q2_q3 = 2 * q2 * q3; + float q1_q0 = 2 * q1 * q0; + + if(R.length == 9) { + R[0] = 1 - sq_q2 - sq_q3; + R[1] = q1_q2 - q3_q0; + R[2] = q1_q3 + q2_q0; + + R[3] = q1_q2 + q3_q0; + R[4] = 1 - sq_q1 - sq_q3; + R[5] = q2_q3 - q1_q0; + + R[6] = q1_q3 - q2_q0; + R[7] = q2_q3 + q1_q0; + R[8] = 1 - sq_q1 - sq_q2; + } else if (R.length == 16) { + R[0] = 1 - sq_q2 - sq_q3; + R[1] = q1_q2 - q3_q0; + R[2] = q1_q3 + q2_q0; + R[3] = 0.0f; + + R[4] = q1_q2 + q3_q0; + R[5] = 1 - sq_q1 - sq_q3; + R[6] = q2_q3 - q1_q0; + R[7] = 0.0f; + + R[8] = q1_q3 - q2_q0; + R[9] = q2_q3 + q1_q0; + R[10] = 1 - sq_q1 - sq_q2; + R[11] = 0.0f; + + R[12] = R[13] = R[14] = 0.0f; + R[15] = 1.0f; + } + } + + /** Helper function to convert a rotation vector to a normalized quaternion. + * Given a rotation vector (presumably from a ROTATION_VECTOR sensor), returns a normalized + * quaternion in the array Q. The quaternion is stored as [w, x, y, z] + * @param rv the rotation vector to convert + * @param Q an array of floats in which to store the computed quaternion + */ + public static void getQuaternionFromVector(float[] Q, float[] rv) { + float w = (float)Math.sqrt(1 - rv[0]*rv[0] - rv[1]*rv[1] - rv[2]*rv[2]); + //In this case, the w component of the quaternion is known to be a positive number + + Q[0] = w; + Q[1] = rv[0]; + Q[2] = rv[1]; + Q[3] = rv[2]; + } + private static native void nativeClassInit(); private static native int sensors_module_init(); -- cgit v1.1