Homing Bullet Current Setup

///Homing Bullet Create Event
homing = false;
current_speed = 0;
max_speed = 0;
target = noone;

alarm[1] = 0.5 * room_speed;

///Homing Bullet Step Event
speed = current_speed;

if instance_exists(target) and homing
{
    direction = scr_angle_rotate(direction, point_direction(x, y, target.x, target.y - target.sprite_height/2), current_speed);
    image_angle = direction;
}

else
{
    direction = direction;
    image_angle = image_angle;
}

///Homing Bullet Alarm #1 Event
homing = true;

///Homing Bullet Draw Event
draw_self();
//draw_line_color(x, y, target.x, target.y, c_red, c_red);
draw_sprite_ext(spr_crosshair, 0, target.x, target.y - target.sprite_height/2,
                scr_wave(0.5, 2.0, 1.0, 0.0), scr_wave(0.5, 2.0, 1.0, 0.0), 0, c_white, 0.5);

///scr_angle_rotate
/// scr_angle_rotate(angle, target, speed)
/// @arg angle
/// @arg target
/// @arg speed


var diff;
// 180 is to be replaced by "pi" for radians
diff = scr_cycle(argument1 - argument0, -180, 180);
// clamp rotations by speed:
if (diff < -argument2) return argument0 - argument2;
if (diff > argument2) return argument0 + argument2;
// if difference within speed, rotation's done:
return argument1;