Can someone explain this code?

[mwtidd]

Here's what I've interpreted so far. The rotate left/right may be flipped.

This is a rather strange convention.
leftMotorSpeed = moveValue - rotateValue;
rightMotorSpeed = Math.max(moveValue, rotateValue);

It's probably trying to make sure the right motor is going faster than the left (i.e. turning left), but regardless this is probably not the ideal way to code this.

public class Drivetrain {

	//right speed controllers
	Talon talon1 = new Talon(1); //front
	Talon talon2 = new Talon(2); //middle
	Talon talon3 = new Talon(3); //rear
	
	//left speed controllers
	Talon talon4 = new Talon(4); //front
	Talon talon5 = new Talon(5); //middle
	Talon talon6 = new Talon(6); //rear
	
	DoubleSolenoid shifter = new DoubleSolenoid(1, 5, 6);
	
	Encoder leftEncoder = new Encoder(10, 11);
	Encoder rightEncoder = new Encoder(13, 14);
	
	public Drivetrain(){
		leftEncoder.start();
		rightEncoder.start();
	}
	
	//DigitalInput port14 = new DigitalInput(14);
	public void arcadeDrive(double moveValue, double rotateValue){
	double leftMotorSpeed = 0, rightMotorSpeed = 0;
	
	rotateValue = -rotateValue; //x axis value from joystick. inverted to get the correct rotation direction
	moveValue = limit(moveValue); //y axis value from joystick. make sure its between -1 and 1
	rotateValue = limit(rotateValue); //make sure the rotation value from before is between -1 and 1
	
	if (moveValue > 0.0) {
		//driving forward?
		if (rotateValue > 0.0) {
			//turning left?
			leftMotorSpeed = moveValue - rotateValue;
			rightMotorSpeed = Math.max(moveValue, rotateValue);
		} else {
			//stopped or turning right?
			leftMotorSpeed = Math.max(moveValue, -rotateValue);
			rightMotorSpeed = moveValue + rotateValue;
		}
	} else {
		//driving backward or stopped
		if (rotateValue > 0.0) {
			//turning left?
			leftMotorSpeed = -Math.max(-moveValue, rotateValue);
			rightMotorSpeed = moveValue + rotateValue;
		} else {
			//stopped or turning right?
			leftMotorSpeed = moveValue - rotateValue;
			rightMotorSpeed = -Math.max(-moveValue, -rotateValue);
		}
	}
	
	//Setting talon values
	talon1.set(-rightMotorSpeed); //invert the front right speed controller (probably because the leads were swapped)
	talon2.set(rightMotorSpeed);
	talon3.set(rightMotorSpeed);
	talon4.set(leftMotorSpeed); 
	talon5.set(-leftMotorSpeed); //invert the center left speed controller (probably because the leads were swapped)
	talon6.set(-leftMotorSpeed); //invert the rear left speed controller (probably because the leads were swapped)
	}
	
	protected static double limit(double num) {
		if (num > 1.0) {
			return 1.0;
		}
		if (num < -1.0) {
			return -1.0;
		}
		return num;
	}
	
	public void highGear(){
		//retract pneumatic
		shifter.set(DoubleSolenoid.Value.kReverse);
	}
	
	public void lowGear(){
		//extend pneumatic
		shifter.set(DoubleSolenoid.Value.kForward);
	}
	
	public void brake(){
	
	}
	
	public int getRightDistance(){
		return rightEncoder.get();
	}
	
	public int getLeftDistance(){
		return leftEncoder.get();
	}
	
	public void resetEncoders(){
		leftEncoder.reset();
		rightEncoder.reset();
	
	}
}