UNITY | PROJECT | 2D PlatFormer | 1. Project Set Up

Claim variable for Player movement
- playerSpeed
- facingRight as flag
- playerJumpPower
- movementX
in “Update()” method
- get input to move horizontally by using “Input.GetAxis()”
- get “RigidBody2D” component by using “GetComponent()”
  - call “velocity” propery to move “Player” with continuous input
- create “if Statement” for Player’s movment
  - when pressing left and facing right
    - activate “FlipPlayer()” method
  - when pressing right and facing left
    - activate “FlipPlayer()” method
- Create a Function, “FlipPlayer()”,
  - set the flag, “facingRight” to opposite
  - get the “localScale” property
    - multiply -1 to reverse the direction
  - Don’t forget to update “localScale”

Create a function, “Jump()’,
- use “AddForce()” to give force upwards to “Player”
in “PlayerMove()” method,
- when “Jump” button is pressed, activate “Jump()” method

UNITY | PROJECT | SPACE SHOOTER 2D | 6. Explosion Animation

For the Sprite of Explosion in the Inspector
- Set the Sprite Mode into “Multiple”
- Set the Filter Mode into “Point(no filter)”
- Set the Max Sie into “1024”

“Explosion” Animation works well except that the last frame of the animation lasts in the scene

Create Variables for “speed”, “direction”, “flag”
Create a Function to set the Bullet’s Direction, “SetTheDirection(Vector2 direction)”
- Be careful not to be confused with the names of variable “direction”
  - to differentiate them, put “this.” in front of “direction”(not the argument)
- normalize the vector to get purely a direction (to make the computing correct and simple)
- set the flag(the boolean variable) as “True” to activate the codes in “Update()” method
In “Update()” method
- the codes will be activated when the flag is set to “True”
- the position of the bullet is updated every frame by calculating “transform.position” with “direction(Vector2, the result from “SetDirection()”)’
- if a bullet goes out of the screen, Destroy it
In “Awake()”
- every code in “Awake()” is activated before the game starts
- before the game starts, set “speed” and “ready” with default values

Add a public GameObject variable to use EnemyBullet prefab as a component
Create a Function to fire bullets from Enemy, “FireEnemyBullet()”
- get a reference of “Player” by using “GameObject.Find()”
- the way of detecting a GameObject, “if(gameObject != null)”
- if “Player” is detected, a bullet is instantiated and its initial position is set
- how to calculate an aiming direction: Vector – Vector
- to use “SetDirection()” method of “EnemyBullet” Class, use “GetComponent()” towards “bullet”
In “Start()” method
- make “FireEnemyBullet()” activated after 1 second, by using “Invoke()”

To apply changes on the prefab, Don’t forget to push “Apply” button in the Inspector

by selecting multiple Sprites and adding them in the scene, Create “EnemyAnimation”

Set the speed of Enemy with a float variable “speed”
in “Update()” method
- change the position of “enemy” GameObject with “transform.position” every frame
- for memory usage, destroy “enemy” when it goes out of the screen

To use “Enemy Prefab” in the script as a component
- add “Public GameObject” variable
- Don’t forget to add the reference in the inspector
Create a custom Function, SpawnEnemy()
- Instantiate()
- after instantiating, set the position of Enemy in a random position by using random range of “x” value
To make it spawn in 5 seconds
- in “Start()”, write “Invoke(string methodName, float time)”
- set the “maxSpawnRateInSeconds” as 5 seconds

Create a function, “ScheduleNextEnemySpawn()” to spawn multiple times
- by using, “Invoke()” and putting “ScheduleNextEnemySpawn()” inside “SpawnEnemy()”
  - without using “loop”, we can make enemy spawned continuously
To increase the difficulty of the game, Create a function, “IncreaseSpawnRate()”
- in “Start()”
  - by using “InvokeRepeating(sting methodName, float time, float repeatRate)”
    - every 30 mins, the Spawnrate will be increased(Spawning gets faster)
    - In “InvokeRepeating()”, “time” is 0 and “repeatRate” is 30, meaning every 30 secs, “IncreaseSpawnRate()” is invoked

by using “Sprite Editor”, slice “Bullets” sprites into 2 sprites
- when slicing, set the type into “Grid By Cell Size”
- when slicing, set the Pixel Size as 24×24

for the bullet sprite in the inspector
- deselect “Generate Physics Shape”
- Filter Mode into “Point(no filter)”
- Max Size into “1024”

set the public variable “speed” for the speed of the bullet
In “Update()” method
- get the bullet’s current position by using “transform.position”
- computing the bullet’s new position = the change of position when we shoot the bullet
  - only need to change the “y” value
- to smooth the shooting, use “Time.deltaTime”
- Don’t forget to update the position into “transform.position”
for the memory usage, destroy the bullets going outside the screen
- when setting the screen range, only consider “y” value or “height”
- “Camera.main.ViewPortToWorlPoint()”