Unity2d horizontal game jump real-time response

If we move , Jumping and other operations are put in Update In the function, we will find that sometimes when we press the jump key, the character will not respond , It has a great impact on the feel , So we combine Update and FixedUpdate Achieve accurate jump response .

We know the movement of our characters , The jump operation is usually placed in the function to be executed in each frame , There are many functions executed in each frame , such as Update,LateUpdate,FixedUpdate etc. .LateUpdate Let's not mention , Briefly, the other two .

First of all Update, Every frame calls Update function , This is the main function of frame update , But we need to know , For different computers, the number of frames executed per second is different , For example, some older computers execute in one second 30 frame , A better computer executes in one second 40 frame , So in order to make different computers can also detect the response of keys in real time , We're going to use FixedUpdate function .

FixedUpdate It is executed at a fixed time , If there is no modification, it is 0.02 Once per second FixedUpdate function , That is to say, one second execution 50 Time , We can also modify the interval , But notice , This value is just a request , The machine may not reach this speed . therefore ,Update and FixedUpdate It's actually two completely independent functions . When Update When executed once ,FixedUpdate It may have been executed twice 、 Three times, not even once . According to the official manual , Everything related to physics will be put in FixedUpdate Inside , such as Rigidbody.

Let's introduce Update and FixedUpdate It is because these two functions are needed to realize the perfect jump , We put GetButtonDown Put it in Update It can ensure that when we press the jump button on different machines , The computer can give us a real-time feedback of calling this button at that frame . and FixedUpdate It will be executed at a fixed time , To detect whether the command pressed by the key is executed . So by combining Update and FixedUpdate To do this .

using UnityEngine;
 
public class Test:MonoBehaviour{
bool action = false;
private Rigidbody2D rb;
public float jumpForce; 
void Start(){
rb=GetComponent<Rigidbody2D>();
}
    void Update(){
         if(Input.GetKeyDown(KeyCode.Space)){
             action = true;
         }
    }
    void FixedUpdate(){
       if(action){
           rb.velocity=new Vector2(rb.velocity.x,jumpForce);
           action = false;
        }
    }
}

above , We use one boolean Value to control the switch . because Update Every frame calls , Therefore, it can ensure that all inputs can be responded .

Of course, this is just a pseudocode , Because we didn't consider the situation of ground or multi jump , So the specific code and specific situation analysis