Scripting 101
*************

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    <span style="color:blue"> 
 
	
 
Transform
=========

.. |barre| raw:: html

    <s>transform.position.x</s>
	

	
.. warning:: Writing *transform.position = P;* is ok. But it is not allowed to set only one parameter: |barre| = 4

 

Coordinates
-----------

World
^^^^^

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   * - |b|  Vector3 P = transform.position;
     - Get position
   * - |b|  float x = transform.position.x;  
     - Get X-coordinate
   * - |b|  transform.position = P;  
     - Set position  
   * - |b|  transform.rotation = Quaternion.Euler(0f, 90f, 0f);  
     - Rotation relative to the world axis

Local
^^^^^

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   * - |b|  Vector3 P = transform.localPosition;
   * - |b|  transform.localrotation =

 
	

Moving
------

World
^^^^^

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   * - |b|  transform.Translate(dirVector3)
     - Translate by a given vector
   * - |b|  transform.Translate(x, y, z)
     - Translate by x, y, z values
   * - |b|  transform.Rotate(rotAngle3);
     - Rotate using a Vector3 angle
   * - |b|  transform.Rotate(rx, ry, rz);
     - Rotate using individual angles on each axis

Local
^^^^^

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   * - |b|  transform.Translate(dirVector3, Space.Self)
   * - |b|  transform.Rotate(rotAngle3, Space.Self);


Built-In Properties 
===================
 
There are predefined properties and methods that are automatically available in a MonoBehaviour script.
Since they are not explicitly defined in the code, this can lead to some confusion.

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   * - |b| gameObject
     - GameObject
     - The current GameObject this script is attached to
   * - |b| transform
     - Transform 
     - The transform of the current gameObject
   * - |b| tag
     - string
     - The tag of the GameObject
   * - |b| name
     - string
     - The name of the GameObject
   * - |b|  Instantiate(Class,pos,rot);
     - given Class
     - Create new gameObject in the scene	 

 
.. warning: The keyword this is a reference to the script (GameComponent)

Lifecycle Methods
=================

MonoBehavior functions automatically called by Unity


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   * - |b| Start()
     - Used to initialize objects, variables, or references before the first frame update.
   * - |b| Update()
     - Every frame, handles non-physics updates: user input, animations and  logic
   * - |b| FixedUpdate()
     - At fixed intervals (0.02s), used for physics-related logic and Rigidbody interactions
   * - |b| void OnTriggerEnter(Collider other)
     - Detect an object entering the collider set in trigger mode
   * - |b| void OnTriggerExit(Collider other)
     - 
   * - |b| void OnMouseOver()
     - Mouse pointer passes over the object
   * - |b| void OnMouseDown()
     - Mouse click on the object
	 

    
	 

    
	 
Useful helper class
===================

Some utility classes, imported by *using UnityEngine*, may be handy:

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   * - |b| Debug.Log(..)
     - Debug
     - Display logs, warnings, and errors
   * - |b| Mathf.Abs(..)
     - Mathf
     - Mathematical functions: sin, cos, clamp, lerp, etc.
   * - |b| Random.Range(0, 3)
     - Random (int)
     - Integer random value among 0, 1, 2
   * - |b| Random.Range(0f, 3f)
     - Random (float)
     - Float random value like 0.4, 2.5...
   * - |b| Time.time
     - Time
     - Time since the start of the scene
   * - |b| Time.deltaTime
     - 
     - Time passed since the last frame
   * - |b| Input.GetKey(..)
     - Input
     - Reading keyboard
   * - |b| Input.mousePosition
     - 
     - Reading mouse
   * - |b| Input.GetAxis("Horizontal")
     - 
     - Reading joystick
   * - |b| SceneManager.LoadScene(..)
     - SceneManagement
     - Load or add a scene
   * - |b| PlayerPrefs.Set/Get
     - PlayerPrefs
     - Persistent data storage
   * - |b| Physics.Raycast(ray, ..)
     - Physics
     - Raycasting technique
   * - |b| Selection.activeGameObject
     - Selection
     - current selected gameObject in the scene view


	 
Hierarchy
=========

GameObject
----------


All parent/child relationship are stored in the *transform* parameter of a gameobject:

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   * - |b| GameObject obj = GameObject.Find('Name');
     - find an object by name
   * - |b| GameObject parent = obj.transform.parent.gameObject;
     - select its parent gameObject
   * - |b| foreach (Transform T in obj.transform) { }
     - parse its child gameObject
   * - |b| newobj.transform.SetParent(parentTransform)
     - set parent of a new object



Component
---------

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   * - |b| g.GetComponent<Rigidbody>()
     - Find a specific component of a GameObject      






Misc
====
 
Raycasting
----------

	.. code-block::
	
		RaycastHit hit;
		if (Physics.Raycast(position, vecDir, out hit, maxDist)) // throw a ray
		{
			GameObject touchedObject = hit.collider.gameObject;
			Debug.Log("Hit: " + touchedObject.name);
		}

Add a function in the Editor
----------------------------

	.. code-block::

		using UnityEngine;
		using UnityEditor;

		public class NameOfMyClass
		{
			[MenuItem("Tools/Generate 32 Materials")]   // new entry in the Tools menu
			public static void Go()  {...}
		}

Coroutine
---------

A coroutine if a function running asynchronously - use only for small process.

	.. code-block::
	
		public class test : MonoBehaviour
		{
    
			void Start()
			{
				StartCoroutine(MyCoroutine());  // Start the coroutine when the scene starts
			}

			IEnumerator MyCoroutine()
			{
				Debug.Log("Start");
				
				yield return new WaitForSeconds(3f); // Wait for 3 seconds

				Debug.Log("3 seconds later...");
			}
   
Lerp
----

Lerp stands for: Linear interpolation - Useful for animation:

	.. code-block::
	
		// rotate smoothly
		Quaternion targetRotation = Quaternion.Euler(0f, 180f, 0f);
		transform.rotation = Quaternion.Lerp(transform.rotation, targetRotation, Time.deltaTime);