Distance?

[pig132]

Okay i'm going to start working on something and it requires a distance formula between a player and another player(or npc). When I mess around with one distances come up as negatives sometimes depending where the player is. I have ran into one a few times a while back but I can't seem to find it.

Any help would be appreciated, thank you


EDIT: I did a quick mockup of what my end goal is to be (with players only. npc was just to test)
Pretty much the further a player is from another player the less alpha the player has. I just have no idea how I could accomplish this. GANIs? Add a weapon to everyone that has it?

PHP Code:

//#CLIENTSIDE
function onCreated() {
  setshape(1, 32, 32);
  setTimer(0.05);
}

function onTimeout() {
  temp.np = findnearestplayer(this.x, this.y);
  temp.dx = this.x - player.x;
  temp.dy = this.y - player.y;
  this.chat = temp.np @ ": " @ temp.dx @ "," @ temp.dy;
  
  if (temp.dx && temp.dy <= 3) {
    this.alpha = 1;
  }
  
  if (temp.dx && temp.dy > 3) {
    if (temp.dx && temp.dy <= 6) {
      this.alpha = 0.75;
    }
  }
  
  if (temp.dx && temp.dy > 6) {
    if (temp.dx && temp.dy <= 9) {
      this.alpha = 0.5;
    }
  }
  
  if (temp.dx && temp.dy > 9) {
    if (temp.dx && temp.dy <= 12) {
      this.alpha = 0.25;
    }
  }
  
  if (temp.dx && temp.dy > 12) {
    if (temp.dx && temp.dy <= 15) {
      this.alpha = 0;
    }
  }
  setTimer(0.05);
} 


[cbk1994]

PHP Code:

function getDistance(temp.x1, temp.y1, temp.x2, temp.y2) {
  return ((temp.x1 - temp.x2) ^ 2) + ((temp.y1 - temp.y2) ^ 2)) ^ 0.5;
} 


[pig132]

EDIT: Scratch that didn't need to use it.

Ran into another problem. It works great, but its pretty much doing the opposite. I've messed with the math in temp.done but its still not right. The closer I am to the player, the lower the alpha. Which is the opposite and I'm not sure how I can flip it? Also I think the distance needs to be converted to less than 1 (decimals under 1) but i'm stumped!

PHP Code:

//#CLIENTSIDE
function onCreated() {
  setTimer(0.05);
}

function onTimeout() {
  for (temp.pl: allplayers) {
    if (pl.level.name == null) continue;
    //define distance formula
    temp.a = (pl.x - player.x) ^ 2;
    temp.b = (pl.y - player.y) ^ 2;
    temp.c = (temp.a + temp.b) ^ 0.5;
    
    temp.done = temp.c;
    
    player.chat = temp.done;
    temp.pl.alpha = temp.done;
  }
  setTimer(0.05);
} 


Sorry!

There's got to be an easier way of doing this:

PHP Code:

//#CLIENTSIDE
function onCreated() {
  setTimer(0.05);
  player.alpha = 1;
}

function onTimeout() {
  for (temp.pl: allplayers) {
    if (pl.level.name == null) continue;
    //define distance formula
    temp.a = (pl.x - player.x) ^ 2;
    temp.b = (pl.y - player.y) ^ 2;
    temp.c = (temp.a + temp.b) ^ 0.5;
    
    temp.done = temp.c;
    
    //player.chat = temp.done;
    
    if (temp.c < 5) {
      pl.alpha = 1;
    }
    
    if (temp.c > 5 && temp.c <= 10) {
      pl.alpha = 0.75;
    }
    
    if (temp.c > 10 && temp.c <= 15) {
      pl.alpha = 0.5;
    }
    
    if (temp.c > 15 && temp.c <= 20) {
      pl.alpha = 0.25;
    }
    
    if (temp.c > 20) {
      pl.alpha = 0;
    }
  }
  setTimer(0.05);
} 


[cbk1994]

something like...

PHP Code:

temp.range = 20; // 20 tiles away would be 0 alpha
pl.alpha = max(0, (temp.range - temp.done) / temp.range); 


You should probably also just use players instead of allplayers for this.

[pig132]

Awesome! Thank you that works so much better & smoother.

To use just 'players' would it be:

PHP Code:

for (temp.pl: players) 


?

[cbk1994]

Originally Posted by pig132

Awesome! Thank you that works so much better & smoother.

To use just 'players' would it be:

PHP Code:

for (temp.pl: players) 


?

Yes.

[pig132]

Okay cool, thank you very much for your help

[fowlplay4]

You can also use vectordist() to calculate distance. I.e:

temp.distance = vectordist({player.x, player.y, player.z}, {pl.x, pl.y, pl.z});