瞄准辅助系统 (Aim Assist System)

MagnetismRadius = BaseRadius * (1 + RangeFactor * (1 - NormalizedDistance))

其中:
- BaseRadius: 基础磁吸半径（屏幕空间像素）
- RangeFactor: 距离衰减系数（0-1）
- NormalizedDistance: 归一化距离（0 = 近距离, 1 = 最大射程）

AttractStrength = MaxStrength / (1 + e^(-k * (Distance - Threshold)))

参数说明:
- MaxStrength: 最大拉力系数（0-1）
- k: 曲线陡峭度（越大越陡）
- Distance: 准星与目标中心距离
- Threshold: 触发瞄准辅助的阈值

// 预测目标未来位置
Vector3 predictedPos = target.position + target.velocity * inputLatency;
Vector3 aimDirection = (predictedPos - player.position).normalized;

[System.Serializable]
public class AimAssistConfig
{
    [Header("磁吸参数")]
    [Tooltip("基础磁吸半径（屏幕空间）")]
    [Range(0, 200)]
    public float baseMagnetismRadius = 100f;
    
    [Tooltip("距离衰减系数")]
    [Range(0, 1)]
    public float rangeFalloff = 0.5f;
    
    [Header("强度控制")]
    [Tooltip("最大拉力系数")]
    [Range(0, 1)]
    public float maxAttractionStrength = 0.7f;
    
    [Tooltip("Sigmoid 曲线陡峭度")]
    [Range(1, 10)]
    public float sigmoidSteepness = 5f;
    
    [Header("输入补偿")]
    [Tooltip("预测延迟时间（秒）")]
    [Range(0, 0.2f)]
    public float predictionLatency = 0.08f;
    
    [Header("子弹磁吸")]
    [Tooltip("子弹偏转最大角度")]
    [Range(0, 30)]
    public float bulletMagnetismAngle = 10f;
    
    [Header("难度系数")]
    [Tooltip("当前难度等级 (1-4)")]
    [Range(1, 4)]
    public int difficultyLevel = 2;
}

public class AimAssistController : MonoBehaviour
{
    public AimAssistConfig config;
    private Camera mainCam;
    
    void Start()
    {
        mainCam = Camera.main;
    }
    
    /// <summary>
    /// 获取最佳磁吸目标
    /// </summary>
    public Transform GetBestTarget(Vector3 aimPoint, LayerMask targetLayer)
    {
        Collider[] targets = Physics.OverlapSphere(
            transform.position, 
            50f, // 最大检测距离
            targetLayer
        );
        
        Transform bestTarget = null;
        float minScore = float.MaxValue;
        
        foreach (var target in targets)
        {
            // 计算屏幕空间距离
            Vector2 screenPos = mainCam.WorldToScreenPoint(target.transform.position);
            Vector2 aimScreenPos = mainCam.WorldToScreenPoint(aimPoint);
            float screenDist = Vector2.Distance(screenPos, aimScreenPos);
            
            // 计算世界空间距离
            float worldDist = Vector3.Distance(transform.position, target.transform.position);
            
            // 动态磁吸半径（距离越远半径越小）
            float radius = CalculateMagnetismRadius(worldDist);
            
            // 不在磁吸范围内则跳过
            if (screenDist > radius) continue;
            
            // 评分：屏幕距离 + 优先级权重
            float priority = GetTargetPriority(target);
            float score = screenDist / radius + (1f - priority) * 100f;
            
            if (score < minScore)
            {
                minScore = score;
                bestTarget = target.transform;
            }
        }
        
        return bestTarget;
    }
    
    /// <summary>
    /// 计算动态磁吸半径
    /// </summary>
    float CalculateMagnetismRadius(float worldDistance)
    {
        float normalizedDist = Mathf.Clamp01(worldDistance / 50f); // 假设最大射程 50m
        return config.baseMagnetismRadius * (1 + config.rangeFalloff * (1 - normalizedDist));
    }
    
    /// <summary>
    /// 获取目标优先级（Boss > 精英 > 普通小怪）
    /// </summary>
    float GetTargetPriority(Collider target)
    {
        var enemy = target.GetComponent<EnemyController>();
        if (enemy == null) return 0.3f;
        
        return enemy.type switch
        {
            EnemyType.Boss => 1.0f,
            EnemyType.Elite => 0.7f,
            EnemyType.Normal => 0.5f,
            _ => 0.3f
        };
    }
}

/// <summary>
/// 应用磁吸到准星移动
/// </summary>
public Vector2 ApplyMagnetism(Vector2 rawInput, Transform target)
{
    if (target == null) return rawInput;
    
    // 计算目标在屏幕空间的方向
    Vector2 targetScreenPos = mainCam.WorldToScreenPoint(target.position);
    Vector2 currentCrosshair = new Vector2(Screen.width / 2, Screen.height / 2);
    Vector2 toTarget = (targetScreenPos - currentCrosshair).normalized;
    
    // 计算距离
    float distance = Vector2.Distance(targetScreenPos, currentCrosshair);
    
    // Sigmoid 强度计算
    float strength = CalculateSigmoidStrength(distance);
    
    // 混合原始输入和磁吸向量
    Vector2 assistedInput = Vector2.Lerp(rawInput, toTarget, strength * config.maxAttractionStrength);
    
    return assistedInput;
}

/// <summary>
/// Sigmoid 强度曲线
/// </summary>
float CalculateSigmoidStrength(float distance)
{
    float threshold = config.baseMagnetismRadius * 0.5f; // 磁吸半径的一半为中心点
    float x = config.sigmoidSteepness * (distance - threshold) / threshold;
    return 1f / (1f + Mathf.Exp(x)); // 距离越近，强度越大
}

public class BulletMagnetism : MonoBehaviour
{
    public float magnetismAngle = 10f; // 最大偏转角度
    public LayerMask targetLayer;
    
    void FixedUpdate()
    {
        // 检测前方锥形范围内的敌人
        Collider[] hits = Physics.OverlapSphere(transform.position, 5f, targetLayer);
        
        Transform closestTarget = null;
        float minAngle = magnetismAngle;
        
        foreach (var hit in hits)
        {
            Vector3 toTarget = (hit.transform.position - transform.position).normalized;
            float angle = Vector3.Angle(transform.forward, toTarget);
            
            if (angle < minAngle)
            {
                minAngle = angle;
                closestTarget = hit.transform;
            }
        }
        
        if (closestTarget != null)
        {
            // 平滑转向目标
            Vector3 newDirection = Vector3.RotateTowards(
                transform.forward,
                (closestTarget.position - transform.position).normalized,
                magnetismAngle * Mathf.Deg2Rad * Time.fixedDeltaTime,
                0f
            );
            
            transform.rotation = Quaternion.LookRotation(newDirection);
        }
    }
}

public class TouchAimController : MonoBehaviour
{
    [Header("触屏死区")]
    public float deadZoneRadius = 30f; // 中心死区半径（像素）
    public AnimationCurve sensitivityCurve; // 灵敏度曲线
    
    Vector2 ProcessTouchInput(Vector2 touchDelta)
    {
        float magnitude = touchDelta.magnitude;
        
        // 死区内忽略输入
        if (magnitude < deadZoneRadius)
            return Vector2.zero;
        
        // 减去死区后重新归一化
        float adjustedMagnitude = (magnitude - deadZoneRadius) / (Screen.width * 0.5f - deadZoneRadius);
        
        // 应用灵敏度曲线
        float sensitivity = sensitivityCurve.Evaluate(adjustedMagnitude);
        
        return touchDelta.normalized * sensitivity;
    }
}

public class GyroscopeAim : MonoBehaviour
{
    public float gyroSensitivity = 2f;
    private Quaternion gyroInitialRotation;
    
    void Start()
    {
        Input.gyro.enabled = true;
        gyroInitialRotation = Input.gyro.attitude;
    }
    
    void Update()
    {
        if (!Input.gyro.enabled) return;
        
        // 获取陀螺仪相对旋转
        Quaternion gyroRotation = Quaternion.Inverse(gyroInitialRotation) * Input.gyro.attitude;
        
        // 转换为欧拉角（仅使用 Yaw 和 Pitch）
        Vector3 euler = gyroRotation.eulerAngles;
        
        // 应用到相机旋转（微调瞄准）
        transform.Rotate(new Vector3(-euler.x, euler.y, 0) * gyroSensitivity * Time.deltaTime);
    }
}

[CreateAssetMenu(fileName = "AimAssistPreset", menuName = "Vampirefall/Aim Assist Preset")]
public class AimAssistPreset : ScriptableObject
{
    public string presetName = "Default";
    public AimAssistConfig config;
    
    [Header("难度适配表")]
    public AimAssistConfig easyConfig;
    public AimAssistConfig normalConfig;
    public AimAssistConfig hardConfig;
    public AimAssistConfig expertConfig;
    
    public AimAssistConfig GetConfigForDifficulty(int difficulty)
    {
        return difficulty switch
        {
            1 => easyConfig,
            2 => normalConfig,
            3 => hardConfig,
            4 => expertConfig,
            _ => normalConfig
        };
    }
}