Group sprites following other sprites

CS Discoveries Coding and Debugging Help
1

(Game Lab - Code.org)
My student is trying to create sprites in a group following another sprite, neither of us have any clue on how to create this behavior
We have tried whatever we could think of, nothing has worked.

2

Hello @su8scri88le,

I would recommend checking out this topic if this thread does not satisfy what you are looking for feel free to update the thread to give a more specific case of what type of following you are looking for

Varrience

3

This is not the type of behavior we are looking for, I apologize for not being more clear in my previous post. What we are looking for is code to make a sprite move toward another one, as an attacking enemy.

4

You could try this:

  
  var dx = targetX+randomNumber(10,30) - creature.x;
  var dy = targetY+randomNumber(10,30) - creature.y;
  var angle = Math.atan2(dx,dy);
  creature.x += speed*Math.sin(angle);
  creature.y += speed*Math.cos(angle);

where targetX and targetY are the points your enemy wants to move toward. dx is the distance x and dy is the distance y, this takes those values and finds the angle to the target and moves in that direction

1 Like
5

i need this to work with groups so i can spawn multiple of them. Is there any way to do that?

6

Use the for statement and add each sprite to the group, then every frame loop through every sprite in that group and apply the movement script to it.


var sprites = createGroup();
var spriteAmount = 10;
var defaultSpeed = 2;
for (var i = 0; i < spriteAmount; i++){
  
  var sprite = createSprite(randomNumber(0,400),randomNumber(0,400)); // makes a sprite at a random position at the screen
  sprite.scale = 0.5;
  sprites.add(sprite); //adds it to the group
  
}


function draw() {
  background("white");
  for (var i = 0; i < sprites.length; i++){ // starts i at 0 and as long as i < the amount of sprites in the group increases i.
     
    var thisSprite = sprites.get(i); //makes a variable for the current sprite in the group
    
    move(thisSprite, camera.mouseX, camera.mouseY, defaultSpeed); //calls the movement script 
    
  }
  
  
  drawSprites();
}
//previous code:
function move(sprite, targetX, targetY, speed){
  var dx = targetX+randomNumber(10,30) - sprite.x;
  var dy = targetY+randomNumber(10,30) - sprite.y;
  var angle = Math.atan2(dx,dy);
  sprite.x += speed*Math.sin(angle);
  sprite.y += speed*Math.cos(angle);
  
  
}