[yom]

Well, it's working perfect for me, so i think you use it wrong.

Test cases:

pawn Код:

new Float:coords[][] =
{
  { 0.0, 0.0},
  { 0.0, 1.0},
  { 0.0, -1.0},
  { 1.0, 0.0},
  { 1.0, 1.0},
  { 1.0, -1.0},
  {-1.0, 0.0},
  {-1.0, 1.0},
  {-1.0, -1.0}
};
    
for (new i = 0; i < sizeof coords; i++)
  for (new j = 0; j < sizeof coords; j++)
    if (i != j)
      printf("Angle between {%2.1f, %2.1f} and {%2.1f, %2.1f} : %4.2f", coords[i][0], coords[i][1], coords[j][0], coords[j][1], Angle2D(coords[i], coords[j]));

Edit: fix for negative angles (gta fix negative angles for us, but for displaying in messages or whatever, its better to fix them here)

pawn Код:

Float:Angle2D(Float:PointA[], Float:PointB[])
{
  new
    Float:Dist[2],
    Float:Angle
  ;

  Dist[0] = PointA[0] < PointB[0] ? PointB[0] - PointA[0] : PointA[0] - PointB[0];
  Dist[1] = PointA[1] < PointB[1] ? PointB[1] - PointA[1] : PointA[1] - PointB[1];

  Angle = atan2(Dist[1], Dist[0]);
  Angle = PointA[0] < PointB[0] ? 270.0 + Angle : 90.0 - Angle;
  Angle = PointA[1] < PointB[1] ? Angle : 180.0 - Angle;
  
  return Angle < 0.0 ? Angle + 360.0 : Angle;
}