Flickering when a bitmap follows another in Allegro

Question

I'm developing a 2D game using C with Allegro 5. Right now, I'm coding the movement of an in-game enemy, a bitmap that follows the player (coordinates X and Y). While it works perfectly for the X axis, it often fails to go towards the player at the Y axis, having the bitmap flicker instead of move.

Here is the code I am using:

if(*xEnemy < *x){
    *xEnemy += 3;
}else if(*xEnemy > *x){
    *xEnemy -= 3;
}else if(*yEnemy < *y){
    *yEnemy += 3;
}else if (*yEnemy > *y){
    *yEnemy -= 3;
}

It would work just fine if I used ifs instead of else ifs , however, the enemy would walk on diagonal paths, and that is not something I'm planning for the game. It's clear that the problem lies with the elses , so what is a working alternative for them?

Answer 1

Can you look at the absolute value of the relative distance to decide to move in the x or y direction, for example;

xAbs = abs(*xEnemy - *x);
yAbs = abs(*yEnemy - *y);

   if (xAbs < yAbs)
   {
      // Move in the x direction since we're closer there
      if(*xEnemy < *x){
          *xEnemy += 3;
      } else if(*xEnemy > *x){
          *xEnemy -= 3;
      }
   }
   else
   {
      // Move in the y direction
      if(*yEnemy < *y){
          *yEnemy += 3;
      } else if (*yEnemy > *y){
          *yEnemy -= 3;
      }
   }