The azimuthAngle read-only property of the PointerEvent interface represents the angle between the Y-Z plane and the plane containing both the transducer (pointer or stylus) axis and the Y axis.
Depending on the specific hardware and platform, user agents will likely only receive one set of values for the transducer orientation relative to the screen plane — either tiltX and tiltY or altitudeAngle and azimuthAngle.
For an additional illustration of this property, see Figure 5 in the specification.
An angle in radians between 0 and 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 perpendicular to the surface (altitudeAngle of π/2), the value is 0. For hardware and platforms that do not report tilt or angle, the value is 0.
someElement.addEventListener("pointerdown", (event) => {
process_angles(event.altitudeAngle, event.azimuthAngle);
});