[Neftali [Germán.Estévez]]

Una posible rtuina de colisiones podría ser algo así:

Código Delphi [-]
// Calcular colisión entre dos objetos
function TForm1._CalculateColision(sh1, sh2:TShape): boolean;
var
  r1, r2, b1, b2:Integer;
begin

  Result := False;

  r1 := (sh1.Left + sh1.Width);
  r2 := (sh2.Left + sh2.Width);
  b1 := (sh1.Top + sh1.Height);
  b2 := (sh2.Top + sh2.Height);

  // COLISION?
  if (((sh1.Left < sh2.Left) and (r1 > sh2.Left)) and
      ((sh1.Top < sh2.Top) and (b1 > sh2.Top))) or

     (((sh2.Left < sh1.Left) and (r2 > sh1.Left)) and
      ((sh2.Top < sh1.Top) and (b2 > sh1.Top))) or

     (((sh1.Left < sh2.Left) and (r1 > sh2.Left)) and
      ((sh2.Top < sh1.Top) and (b2 > sh1.Top))) or

     (((sh2.Left < sh1.Left) and (r2 > sh1.Left)) and
      ((sh1.Top < sh2.Top) and (b1 > sh2.Top))) then begin


    Result := True;
  end;

end;

Está en Delphi y usa TShapes, pero es fácil de entender y creo que puedes pasarla a Builder y cambiar los TShape por TButton sin grandes problemas.