User:Chase-san/MovSim

This is the move simulator I created, for use in Precise Prediction, it was influenced by Albert's Precise Prediction code. Unlike his it doesn't handle distance, but that is a very complicated set of code (which I might add later if there is a need).

package chase.na.semove;

import robocode.Rules;
import robocode.util.Utils;

public class MovSim2 {
	//New DeAccel Rule, cannot go from -1 to 1, would go from -1 to 0.5
	public static final boolean useNewDeaccelRule = false;
	//For Dead Code
	@SuppressWarnings("all")
	public static final MovSim2Stat step(double x, double y, double velocity, double maxVelocity,
			int direction, double heading, double angleToTurn, double fieldW, double fieldH) {
		
		////////////////
		//Heading
		double lastHeading = heading;
		double turnRate = Rules.getTurnRateRadians(velocity);
		if(Math.abs(angleToTurn) < turnRate) heading += angleToTurn;
		else heading += turnRate * Math.signum(angleToTurn);
		heading = Utils.normalAbsoluteAngle(heading);
		
		////////////////
		//Movement
		if(direction != 0 || velocity != 0.0) {
			////////////////
			//Acceleration
			double acceleration = 0;
			double absVelocity = Math.abs(velocity);
			//Check if we are stopping!
			if(direction == 0) {
				//Slow to a stop!
				acceleration = Rules.DECELERATION;
				if(absVelocity < acceleration)
					acceleration = -velocity;
			} else {
				if(velocity == 0.0) {
					//We can only speed up from here
					acceleration = Rules.ACCELERATION;
					if(acceleration > maxVelocity)
						acceleration = maxVelocity;
				} else {
					//Check if we are speeding up
					if(Math.signum(velocity) == direction
					&& absVelocity < maxVelocity) {
						acceleration = Rules.ACCELERATION;
						if(absVelocity + acceleration > maxVelocity)
							acceleration = maxVelocity - absVelocity;
					} else {
						//We are slowing down, this is more complicated
						if(absVelocity < Rules.DECELERATION && useNewDeaccelRule) {
							double beyondZero = Math.abs(absVelocity - Rules.DECELERATION);
							acceleration = -((absVelocity - beyondZero) + beyondZero / 2.0);
						} else {
							acceleration = -Rules.DECELERATION;
							//If we are slowing down in the same direction
							if(Math.signum(velocity) == direction)
								acceleration = maxVelocity - absVelocity;
						}
					}
					
				}
			}
			acceleration *= direction;
			
			////////////////
			//Velocity
			velocity = Math.min(Math.max(-Rules.MAX_VELOCITY,
					velocity + acceleration), Rules.MAX_VELOCITY);
			
			////////////////
			//Position
			x += velocity * Math.sin(heading);
			y += velocity * Math.cos(heading);
			
			if (x < 18 || y < 18 || x > fieldW - 18 || y > fieldH - 18) {
				angleToTurn = 0;
				velocity = 0;
				x = Math.max(18, Math.min(fieldW - 18, x));
				y = Math.max(18, Math.min(fieldH - 18, y));
			}
		}
		return new MovSim2Stat(x,y,velocity,heading,Utils.normalRelativeAngle(heading - lastHeading));
	}
}

class MovSim2Stat {
	public double x, y;
	public double v, h, w; //w = heading change
	public MovSim2Stat(double x, double y, double v, double h, double w) {
		this.x = x;
		this.y = y;
		this.v = v;
		this.h = h;
		this.w = w;
	}
}