Following Paths

This section covers how to build autonomous routines with clean syntax. Apex is extremely easy to integrate into FSMs, command libraries and action systems, enabling you to choose the method that best fits your team’s needs.

FSM Integration

There are multiple ways to integrate Apex into a Finite State Machine (FSM) style autonomous routine. The first is to use the hasStarted() and hasEnded() methods of the FollowerMovement class to determine when to start and stop following a path.


while (opModeIsActive()) {
    follower.update();
    switch (state) {
        case 0:
            if (!path1.hasStarted()) follower.follow(path1);
            if (path1.hasEnded()) state = 1;
            break;
        case 1:
            if (!path2.hasStarted()) follower.follow(path2);
            if (path2.hasEnded()) state = 2;
            break;
        case 2:
            follower.stop();
            telemetry.addLine("Auto Complete!");
            break;
    }
}

The second option is to use the isBusy() method of the Follower class to determine when the follower is done with a path. This method may be more familiar to some teams.


while (opModeIsActive()) {
    follower.update();
    switch (state) {
        case 0:
            follower.follow(path1);
            state = 2;
            break;
        case 2:
            if (!follower.isBusy()) {
                follower.follow(path2);
                state = 3;
            }
            break;
        case 3:
            if (!follower.isBusy()) {
                follower.stop();
                telemetry.addLine("Auto Complete!");
            }
            break;
    }
}

Sequential Iterator Integration

Another option is to put your paths in an array and iterate through them. This is a great option if you use only callbacks and don’t need to do anything else in your loop. It keeps the auto clean and simple.


while (opModeIsActive()) {
    follower.update();
    if (iterator < paths.length - 1) {
        if (!follower.isBusy()) {
            iterator++;
            follower.follow(paths[iterator]);
        }
    } else {
        follower.stop();
        telemetry.addLine("Auto Complete!");
    }
}

Command System Integration

We also provide commands and examples for integrating Apex into the most popular command libraries in FTC. These can be adapted to work with your specific command library.

FTCLib

We recommend using this command class to integrate Apex into FTCLib’s command system. It is a simple command that takes in a Follower and a FollowerMovement.


package org.firstinspires.ftc.teamcode.commands; // Change this for your setup
 
import com.arcrobotics.ftclib.command.CommandBase;
// Import Follower and FollowerMovement classes from Apex
 
public class FollowPathCommand extends CommandBase {
    private final Follower follower;
    private final FollowerMovement movement;
 
    public FollowPathCommand(Follower follower, FollowerMovement movement) {
        this.follower = follower;
        this.movement = movement;
    }
 
    @Override
    public void initialize() { follower.follow(movement); }
 
    @Override
    public void execute() { follower.update(); }
 
    @Override
    public boolean isFinished() { return !follower.isBusy(); }
 
    @Override
    public void end(boolean interrupted) {
        if (interrupted) follower.stop();
    }
}

This command can then be used like any other command, for example in a SequentialCommandGroup:


schedule(new SequentialCommandGroup(
    new FollowPathCommand(follower, path1),
    new FollowPathCommand(follower, path2),
    new InstantCommand(() -> {
        follower.stop();
        telemetry.addLine("Auto Complete!");
        telemetry.update();
    })
));

NextFTC

We recommend using the following command method to integrate Apex Pathing into NextFTC’s command system. It is a simple command that takes in a Follower and a FollowerMovement.


public static Command follow(Follower follower, FollowerMovement movement) {
    return new LambdaCommand()
        .setStart(() -> { follower.follow(movement); })
        .setUpdate(() -> { follower.update(); })
        .setStop(interrupted -> { if (interrupted) follower.stop(); })
        .setIsDone(() -> !follower.isBusy())
        .named("Apex Pathing Follow Command");
    }

This command can then be used like any other command, for example in a SequentialGroup:


new SequentialGroup(
    follow(follower, path1),
    follow(follower, path2),
    instant(() -> {
        follower.stop();
        telemetry.addLine("Auto Complete!");
        telemetry.update();
    })
).schedule();

Solverslib

We recommend using this command class to integrate Apex into Solverslib’s command system. It is a simple command that takes in a Follower and a FollowerMovement.


package org.firstinspires.ftc.teamcode.commands; // Change this for your setup
 
import com.seattlesolvers.solverslib.command.CommandBase;
// Import Follower and FollowerMovement classes from Apex
 
public class FollowPathCommand extends CommandBase {
    private final Follower follower;
    private final FollowerMovement movement;
 
    public FollowPathCommand(Follower follower, FollowerMovement movement) {
        this.follower = follower;
        this.movement = movement;
    }
 
    @Override
    public void initialize() { follower.follow(movement); }
 
    @Override
    public void execute() { follower.update(); }
 
    @Override
    public boolean isFinished() { return !follower.isBusy(); }
 
    @Override
    public void end(boolean interrupted) {
        if (interrupted) follower.stop();
    }
}

This command can then be used like any other command, for example in a SequentialCommandGroup:


schedule(new SequentialCommandGroup(
    new FollowPathCommand(follower, path1),
    new FollowPathCommand(follower, path2),
    new InstantCommand(() -> {
        follower.stop();
        telemetry.addLine("Auto Complete!");
        telemetry.update();
    })
));

Ivy

We recommend using this command method to integrate Apex into Ivy’s command system. It is a simple command that takes in a Follower and a FollowerMovement.


public static Command follow(Follower follower, FollowerMovement movement) {
    return Command.build()
        .setStart(() -> follower.follow(movement))
        .setExecute(() -> follower.update())
        .setDone(() -> !follower.isBusy())
        .setEnd(endCondition -> follower.stop());
}

This command can then be used like any other command, for example in a sequential:


Scheduler.schedule(sequential(
    follow(follower, path1),
    follow(follower, path2),
    instant(() -> {
        follower.stop();
        telemetry.addLine("Auto Complete!");
        telemetry.update();
    })
));