Inputs applyPan needs to convert a pointer delta into a world-space
pan: the camera (perspective or orthographic), the current orbit distance
(scales perspective pan by frustum height at the target), the pan-speed
multiplier, whether panning is screen-space or world-up locked, and the DOM
element whose size normalizes pixel deltas.
Inputs applyPan needs to convert a pointer delta into a world-space pan: the camera (perspective or orthographic), the current orbit distance (scales perspective pan by frustum height at the target), the pan-speed multiplier, whether panning is screen-space or world-up locked, and the DOM element whose size normalizes pixel deltas.