GlobeControls: Further Improvements

[gkjohnson]

Highest Priority

• Limit distance above ground. Orbiting is okay? But can't zoom out once beyond a certain point? Limit how far we can initiate rotation from?
• Force zooming in to a certain lat / lon?
• Normalize movement events using device pixel ratio and pixel distance rather than screen-space distance
• Reset the zoom pose if the wheel position shows a different pose
  • position the cursor, resize the window so the cursor changes pose, scroll again w/o moving the mouse

High Priority

• Retain a height when close to the surface? Ie snap back down when possible? The initial tiles are low res which pushes the tiles upward
• Enable two-finger drag, rotate, and zoom while keeping the positions under the fingers consistent
• Adjust the zoom speed to more accurately match the pinch speed
• Calculate the zoomed-out drag rotation angle based on the distance rather than magic numbers
• Auto orient the camera to a reasonable position based on initial position (ie tilt the camera angle as zooming in)
• Remove need for separate "pinchState"

Other

• Slow to a stop on zoom out to globe
• Trend camera towards rotation that guarantees camera visibility when updating the orientation
• There's an order of operations issue between tile update and controls update. You need to update the camera to update the tiles - but you also want to update the camera position based on the visible tiles.
• Fall back to intersection with WGS84 ellipse / plane for intersection
• Shift + scroll could adjust altitude
• Fade pivot icon in and out
• Add support for animating / physics based movement (ie momentum)
• Only perform zoom, rotation, pivot raycasts when the camera or tiles have changed