FiniteStateMachine

C# Fluent Finite State Machine for Unity3D

Installation

Copy StateMachine.cs to your Assets folder

Example

      StateMachine sm = new StateMachine("main");
      sm
        .State("decide")
            .Condition(() => transform.position.y - _moveTo.y > 50, "descending")
            .Condition(() => transform.position.y - _moveTo.y < -50, "ascending")
            .Condition(() => true, "alignAngle")
        .State("ascending")
            .OnEntry(() =>
            {
                originalPos = transform.position;
                tempTarget = new Vector3(transform.position.x, _moveTo.y, transform.position.z);
                percent = 0;
            })
            .OnState(() =>
            {
                speed = percent.HillSlope(1, 0.5f, 4);
                percent = Mathf.Min(percent + AscendingSpeed * Time.deltaTime, 2f);

                transform.position = Vector3.Lerp(originalPos, tempTarget, speed);
            })
            .Condition(() => Vector3.Distance(transform.position, tempTarget) <= 5, "moveTo")
        .State("descending")
            .Reset()
            .OnEntry(() =>
            {
                originalPos = transform.position;
                percent = 0;

                RaycastHit hitInfo;
                if (Physics.Raycast(transform.position, Vector3.down, out hitInfo))
                    tempTarget = new Vector3(transform.position.x, hitInfo.point.y, transform.position.z);
            })
            .OnState(() =>
            {
                speed = percent.HillSlope(1, 0.5f, 4);
                percent = Mathf.Min(percent + DescendingSpeed * Time.deltaTime, 2f);
                transform.position = Vector3.Lerp(originalPos, tempTarget, speed);
            })
            .Condition(() => Vector3.Distance(transform.position, tempTarget) <= 1, "moveTo")
        .State("alignAngle")
            .OnEntry(() =>
            {
            })
            .OnState(() =>
            {
                var dir = _moveTo - transform.position;
                dir.y = 0;
                var newRot = Quaternion.LookRotation(dir);
                transform.rotation = Quaternion.Slerp(transform.rotation, newRot, TurningSpeed * Time.deltaTime);

                transform.Translate(Vector3.forward * MoveSpeed * Time.deltaTime);

                if (transform.position.y < _moveTo.y-0.5)
                    transform.Translate(Vector3.up * MoveSpeed * Time.deltaTime);
                if (transform.position.y > _moveTo.y + 0.5)
                    transform.Translate(Vector3.down * MoveSpeed * Time.deltaTime);

            })
            .Condition(() =>
            {
                var dir = _moveTo - transform.position;
                dir.y = 0;
                var angle = Vector3.Angle(transform.forward, dir);
                if (angle < 15)
                    return true;

                if (Vector3.Distance(_moveTo, transform.position) <= 1)
                    return true;

                return false;
            }, "moveTo")
        .State("moveTo")
            .OnEntry(() =>
            {
                originalPos = transform.position;
                percent = 0;
            })
            .OnState(() =>
            {
                var dir = (_moveTo - transform.position).normalized;

                dir.y = 0;
                var newRot = Quaternion.LookRotation(dir);
                transform.rotation = Quaternion.Slerp(transform.rotation, newRot, TurningSpeed * Time.deltaTime);

                transform.Translate(Vector3.forward * MoveSpeed * Time.deltaTime);

                if (transform.position.y < _moveTo.y - 0.5)
                    transform.Translate(Vector3.up * MoveSpeed * Time.deltaTime);
                if (transform.position.y > _moveTo.y + 0.5)
                    transform.Translate(Vector3.down * MoveSpeed * Time.deltaTime);
            })
            .Condition(() =>
            {
                var result = Vector3.Distance(transform.position, _moveTo) <= 1;
                if (result)
                {
                    _patrolIndex = (_patrolIndex + 1) % PatrolCheckPoints.Length;
                    _moveTo = PatrolCheckPoints[_patrolIndex];
                }
                return result;
            }, "decide");