sdk/fidl/fuchsia.input.report/units.fidl

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.input.report;

/// This provides an easy, standardized way to specify units. New units can
/// be added as needed. Each UnitType should be named after a specific unit that
/// should be fully distinguished by the name (E.g: Use METERS instead of
/// DISTANCE). More complicated units that need to be differentiated should
/// begin with SI_ (for Internation System of Units) or ENGLISH_ (for English
/// System of Units).
enum UnitType : uint32 {
    /// The device did not specify units.
    NONE = 0;

    /// The device specified units that are not convertible to any of the other units.
    OTHER = 1;

    /// A measurement of distance in meters.
    METERS = 2;

    /// A measurement of mass in grams.
    GRAMS = 3;

    /// A measurement of rotation in degrees.
    DEGREES = 4;

    /// A measurement of angular velocity in degrees per second.
    ENGLISH_ANGULAR_VELOCITY = 5;

    /// A measurement of linear velocity in meters per second.
    SI_LINEAR_VELOCITY = 6;

    /// A measurement of acceleration in meters per second squared.
    SI_LINEAR_ACCELERATION = 7;

    /// A measure of magnetic flux in webers.
    WEBERS = 8;

    /// A measurement of luminous intensity in candelas.
    CANDELAS = 9;

    /// A measurement of pressure in pascals.
    PASCALS = 10;

    // A measurement of luminous flux in lumens per meter squared.
    LUX = 11;

    // A measurement of seconds.
    SECONDS = 12;
};

/// Describes a given unit by giving the unit and the unit's exponent.
/// E.g: Nanometers would have type METERS and exponent -9.
struct Unit {
    UnitType type;
    int32 exponent;
};

/// Describe a `Range` of values.
struct Range {
    int64 min;
    int64 max;
};

/// An `Axis` is defined as a `range` and a `unit`.
struct Axis {
    Range range;
    Unit unit;
};