From 26c952bf61b5c079a7bce7e1cdddc877df1da737 Mon Sep 17 00:00:00 2001 From: Pierre Fite-Georgel Date: Mon, 20 May 2019 17:27:23 -0700 Subject: [PATCH] Clarify documentation for AINFO_SENSOR_PLACEMENT Specify units of location vector and define the direction of the rotation matrix translation as Android device frame to local sensor frame. Fixes: 133264933 Test: n/a, comment update only Change-Id: I76dae7a6fae3c8f44a4dcd1fcc6b790abff86420 --- current.txt | 1 + sensors/1.0/types.hal | 38 ++++++++++++++++++++++++++++++++++---- 2 files changed, 35 insertions(+), 4 deletions(-) diff --git a/current.txt b/current.txt index d572f21600..5742d667d0 100644 --- a/current.txt +++ b/current.txt @@ -412,6 +412,7 @@ ed9da80ec0c96991fd03f0a46107815d0e50f764656e49dba4980fa5c31d5bc3 android.hardwar cd1757867a5e3a3faa362e785239515870d1a3c9ce756c6f0cf0f0fd8aac2547 android.hardware.radio@1.2::types 722b3595548ed7f1953b6e0143dc842d4d6e290ff009a134eb518d7c17a09347 android.hardware.radio@1.2::types # b/112486807 e78cf871f9fd1c072874e481e06e18e2681763cf2aa38c1fd777d53bab4eb69b android.hardware.sensors@1.0::types +c28859a334c1f540dea0a7d4f0baef0551ba76a3232f53c936196543ee35bc4d android.hardware.sensors@1.0::types # b/133264933 3d01e29e8129186f7567c4f9c8bee7480a0768e587b1be9b28adb0a6cbec6bf2 android.hardware.tv.cec@1.0::types 1722ad002317b1fae1400de709e90f442d94ef22864e05f7a12af48c32e8edc8 android.hardware.usb@1.1::types 29c8da7a13c40d488f569c812441d5754ee45bdcdb8ce6564f524b708d10a057 android.hardware.vibrator@1.1::types diff --git a/sensors/1.0/types.hal b/sensors/1.0/types.hal index e91820c377..cbbe92f6f7 100644 --- a/sensors/1.0/types.hal +++ b/sensors/1.0/types.hal @@ -1008,10 +1008,40 @@ enum AdditionalInfoType : uint32_t { AINFO_VEC3_CALIBRATION, /** - * Location and orientation of sensor element in the device frame: origin is - * the geometric center of the mobile device screen surface; the axis - * definition corresponds to Android sensor definitions. - * float[12]: 3x4 matrix in row major order + * Provides the orientation and location of the sensor element in terms of + * the Android coordinate system. This data is given as a 3x4 matrix + * consisting of a 3x3 rotation matrix (R) concatenated with a 3x1 location + * vector (t). The rotation matrix provides the orientation of the Android + * device coordinate frame relative to the local coordinate frame of the + * sensor. Note that assuming the axes conventions of the sensor are the + * same as Android, this is the inverse of the matrix applied to raw + * samples read from the sensor to convert them into the Android + * representation. The location vector represents the translation from the + * origin of the Android sensor coordinate system to the geometric center + * of the sensor, specified in millimeters (mm). + * + * float[12]: 3x4 matrix in row major order [R; t] + * + * Example: + * This raw buffer: {0, 1, 0, 0, -1, 0, 0, 10, 0, 0, 1, -2.5} + * Corresponds to this 3x4 matrix: + * 0 1 0 0 + * -1 0 0 10 + * 0 0 1 -2.5 + * The sensor is oriented such that: + * - the device X axis corresponds to the sensor's local -Y axis + * - the device Y axis corresponds to the sensor's local X axis + * - the device Z axis and sensor's local Z axis are equivalent + * In other words, if viewing the origin of the Android coordinate + * system from the positive Z direction, the device coordinate frame is + * to be rotated 90 degrees counter-clockwise about the Z axis to align + * with the sensor's local coordinate frame. Equivalently, a vector in + * the Android coordinate frame may be multiplied with R to rotate it + * 90 degrees clockwise (270 degrees counter-clockwise), yielding its + * representation in the sensor's coordinate frame. + * Relative to the origin of the Android coordinate system, the physical + * center of the sensor is located 10mm in the positive Y direction, and + * 2.5mm in the negative Z direction. */ AINFO_SENSOR_PLACEMENT,