Pushback

Pushback consists of an object being pushed in the direction of a reference position for a certain distance.
It's a side effect of certain skills, like Jupitel Thunder.

src - current position
ref - reference position
range - how much to push
dx - push increment for the x coordinate
dy - push increment for the y coordinate

The implementation can push in 8 directions.
The direction is determined by the position of ref relative to src.

if( abs(ref.y-src.y) >= 3*abs(ref.x-src.x) )
{// vertical
  dx = 0;
  dy = (ref.y > src.y ? 1 : -1);
}
else if( abs(ref.x-src.x) >= 3*abs(ref.y-src.y) )
{// horizontal
  dx = (ref.x > src.x ? 1 : -1);
  dy = 0;
}
else
{// diagonal
  dx = (ref.x > src.x ? 1 : -1);
  dy = (ref.y > src.y ? 1 : -1);
}

It pushes until the target range is reached or an unmovable cell is found.

for( ; range > 0; --range )
{
  if( !is_movable(src.x+dx, src.y+dy) )
    break;// not movable
  src.x += dx;
  src.y += dy;
}

Based on a 11.2 zone.