<p>The altitude (in radians) of the transducer (e.g. pen/stylus), in the range [0,π/2]

— where 0 is parallel to the surface (X-Y plane), and π/2 is perpendicular to the surface.

For hardware and platforms that do not report tilt or angle, the value MUST be 0.</p>

<div class="note">

The default value defined here for <code>altitudeAngle</code> is 0.

This differs from the <a href="https://w3c.github.io/pointerevents/">Pointer Events - Level 3</a> [[POINTEREVENTS]] specification's

definition for the <code>altitudeAngle</code> property, which has a default value of π/2,

which positions the transducer as being perpendicular to the surface.

</div>

<figure id="figure_altitudeAngle">

<img src="images/altitudeAngle.png" alt="altitudeAngle explanation diagram">

<figcaption>Example <code>altitudeAngle</code> of π/4 (45 degrees from the X-Y plane).</figcaption>

</figure>

<p>The azimuth angle (in radians) of the transducer (e.g. pen/stylus),

in the range [0, 2π] — where 0 represents a transducer whose cap is pointing in the

direction of increasing X values (point to "3 o'clock" if looking straight down) on the X-Y plane,

and the values progressively increase when going clockwise

(π/2 at "6 o'clock", π at "9 o'clock", 3π/2 at "12 o'clock").

When the transducer is perfectly perpendicular to the surface (<code>altitudeAngle</code> of π/2), the value MUST be 0.

For hardware and platforms that do not report tilt or angle, the value should be 0.</p>

<figure id="figure_azimuthAngle">

<img src="images/azimuthAngle.png" alt="azimuthAngle explanation diagram">

<figcaption>Example <code>azimuthAngle</code> of π/6 ("4 o'clock").</figcaption>

</figure>