Wheel speeds from joystick positions

• Easier than it looks
• Sum and difference, min and max
• -1 <= x <= +1; -1 <= y <= +1
  • left = y+x, normalize to -1..+1 range
  • right = y-x, normalize to -1..+1 range
• Examples:
  • Stick centered: x = 0, y = 0 gives left = 0, right = 0, dead stop
  • Stick fully forward: x = 0, y = 1 gives left = 1, right = 1, full speed forward
  • Stick fully down: x = 0, y = -1 gives left = -1, right = -1, full speed backward
  • Stick full right: x = 1, y = 0 gives left = 1, right = -1, hard clockwise spin
  • Stick slightly right of full foward: x = 0.1, y = 1 gives left = 1, right = 0.9, slight right drift
• Continuous functions
• Easy to calculate with 8-bit integers
  • In fact, I boil it down to four-bit integers
• Mapped through curves
• Broken down into 8-bit speed and "backwards" bit

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