using UnityEngine;
[AddComponentMenu("Exploration/Cannon")]
public class Cannon : MonoBehaviour
{
// Cannonball prefab
public GameObject cannonballPrefab;
// Initial velocity applied to the cannon ball's rigidbody
public float initialVelocity = 15f;
// Maximum pitch that can be applied to each shot
public float maxPitch = 25f;
// Maximum angle at which the cannon is able to fire
public float maxYaw = 45f;
// The firing direction will have this much deviation in degrees
public float maxAimDeviationAngle = 5f;
// Maximum possible delay that the cannon will fire after pressing the 'fire' button
public float reactionTime = 0.2f;
// How long it takes for the cannon to recharge
public float rechargeTime = 2f;
Transform mTrans;
GameShip mStats;
float mFireTime = 0f;
float mRechargeTime = 0f;
Collider[] mColliders;
Vector3 mFiringDir;
float mFiringPitch = 0f;
float mMaxRange = 1f;
/// <summary>
/// Calculated maximum range of the cannon based on max pitch and initial velocity.
/// </summary>
public float maxRange { get { return mMaxRange; } }
/// <summary>
/// Helper function that calculates the cannon's maximum firing range.
/// </summary>
float CalculateMaxRange ()
{
// Vertical velocity can be calculated using the pitch and initial full velocity:
float velocity = Mathf.Sin(Mathf.Deg2Rad * maxPitch) * initialVelocity;
// This is how long it will take the fired cannon ball to reach the sea level
float time = -velocity / (0.5f * Physics.gravity.y);
// Now let's calculate the distance traveled horizontally in the same amount of time
return Mathf.Cos(Mathf.Deg2Rad * maxPitch) * initialVelocity * time;
}
/// <summary>
/// Cache the transform and the ship controlling this cannon.
/// </summary>
void Start ()
{
TNManager.AddRCCs<Cannon> ();
mTrans = transform;
mStats = GameShip.Find(mTrans);
// Calculate the cannon's maximum range
mMaxRange = CalculateMaxRange();
if (mStats != null)
{
// Ship stats found -- use it as root node
mColliders = mStats.GetComponentsInChildren<Collider>();
}
else
{
// No ship stats present -- see if there is a rigidbody that can be used as root
Rigidbody rb = PirateTools.GetRigidbody(mTrans);
mColliders = (rb != null) ? rb.GetComponentsInChildren<Collider>() : GetComponentsInChildren<Collider>();
}
}
/// <summary>
/// Fire the cannon when ready.
/// </summary>
void Update()
{
float time = Time.time;
// We're ready to fire -- fire the cannon
if (mFireTime != 0f && mFireTime <= time)
{
// Recharge time varies from 80% to 120% of the intended duration just to add variety
mRechargeTime = time + rechargeTime * Mathf.Lerp(0.8f, 1.2f, Random.value);
mFireTime = 0f;
// Create the cannon ball
if (cannonballPrefab != null)
{
// Instantiate the prefab
GameObject go = TNManager.Instantiate("CreateCB", "Cannonball", true, pos, rot, velocity);
// Ensure that the newly instantiated object's collider won't collide with our colliders
if (mColliders != null)
{
Collider col = go.GetComponent<Collider>();
if (col != null)
{
foreach (Collider c in mColliders)
{
Physics.IgnoreCollision(c, col);
}
}
}
// It's usually a good idea to know who fired the cannon ball
Cannonball cb = go.GetComponent<Cannonball>();
if (cb != null) cb.owner = mStats.gameObject;
// Rigidbody is generally expected to be present
Rigidbody rb = go.GetComponent<Rigidbody>();
if (rb != null)
{
Vector2 deviation = Vector2.zero;
// Deviate the aim a little
if (maxAimDeviationAngle > 0f)
{
deviation
= new Vector2
(Random
.Range(-1f, 1f
), Random
.Range(-1f, 1f
)); deviation.Normalize();
deviation *= maxAimDeviationAngle;
}
// Calculate the initial velocity
Quaternion firingDir = Quaternion.LookRotation(mFiringDir);
Vector3 vel = (firingDir * Quaternion.Euler(-mFiringPitch + deviation.x, deviation.y, 0f)) *
Vector3.forward * initialVelocity;
// NOTE: For physics-accurate results we should append the ship's velocity as well,
// but this makes the auto-aiming logic fail unless the ship isn't moving.
rb.velocity = vel;
}
else
{
Debug.LogWarning("The cannon ball is missing its rigidbody");
}
}
}
}
/// <summary>
/// Start the firing process.
/// </summary>
public void Fire (Vector3 dir, float distance)
{
float time = Time.time;
if (mRechargeTime < time && mFireTime == 0f)
{
Vector3 cannonDir = mTrans.rotation * Vector3.forward;
// We only want this cannon to fire if the specified direction is close enough.
// It wouldn't make sense to fire guns that are on the opposite side of the ship.
if (Vector3.Angle(dir, cannonDir) < maxYaw)
{
mFireTime = time + Random.value * reactionTime;
mFiringDir = dir;
mFiringPitch = Mathf.Clamp01(distance / mMaxRange) * maxPitch;
}
}
}
}
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