diff --git a/server/gameserver/app.cc b/server/gameserver/app.cc
index c17bfe9..d69db25 100755
--- a/server/gameserver/app.cc
+++ b/server/gameserver/app.cc
@@ -60,11 +60,10 @@ static void SavePerfLog()
 
 void App::Init(int argc, char* argv[])
 {
-    #if 0
+    #if 1
     {
-        Vector2D v1(1, 1);
-        v1.Rotate(-0.25);
-        TestGlm();
+        Vector2D v1(0.0f, 12.0f);
+        v1.Rotate2(-45 / 360.f);
         int i = 0;
     }
     #endif
diff --git a/server/gameserver/player.cc b/server/gameserver/player.cc
index fd32109..b374478 100644
--- a/server/gameserver/player.cc
+++ b/server/gameserver/player.cc
@@ -269,6 +269,15 @@ void Player::Shot()
         return;
     }
 
+    Vector2D bullet_born_offset = Vector2D(0, 12.0f);
+    #if 0
+    Vector2D bullet_born_dir = Vector2D(0, 12.0f);
+    bullet_born_dir.Normalize();
+    bullet_born_offset = bullet_born_dir * bullet_born_offset.Norm();
+    #else
+    bullet_born_offset.Rotate2(attack_dir.Angle(Vector2D::UP));
+    #endif
+    Vector2D bullet_born_pos = pos + bullet_born_offset;
     {
         cs::MFShot* shot = room->frame_data.shots.Add();
         shot->set_player_id(entity_uniid);
@@ -280,7 +289,7 @@ void Player::Shot()
         cs::MFBullet* bullet = room->frame_data.bullets.Add();
         bullet->set_player_id(entity_uniid);
         bullet->set_bullet_id(curr_weapon->meta->i->use_bullet());
-        pos.ToPB(bullet->mutable_pos());
+        bullet_born_pos.ToPB(bullet->mutable_pos());
         attack_dir.ToPB(bullet->mutable_dir());
         bullet->set_bulletskin(10001);
         bullet->set_gun_id(curr_weapon->meta->i->id());
@@ -292,9 +301,9 @@ void Player::Shot()
         bullet->room = room;
         bullet->gun_meta = curr_weapon->meta;
         bullet->meta = MetaMgr::Instance()->GetEquip(curr_weapon->meta->i->use_bullet());
-        bullet->pos = pos;
+        bullet->pos = bullet_born_pos;
         bullet->dir = attack_dir;
-        bullet->born_pos = pos;
+        bullet->born_pos = bullet_born_pos;
         bullet->born_dir = attack_dir;
         bullet->fly_distance = fly_distance;
         bullet->entity_uniid = bullet->room->AllocUniid();
diff --git a/server/gameserver/types.cc b/server/gameserver/types.cc
index 763b26c..5d6f74c 100644
--- a/server/gameserver/types.cc
+++ b/server/gameserver/types.cc
@@ -104,6 +104,39 @@ void Vector2D::Rotate(float angle)
     y = v[1];
 }
 
+void Vector2D::Rotate2(float angle)
+{
+    #if 1
+    Eigen::Vector3f v(x, y, 0);
+    v = Eigen::AngleAxisf(angle * 3.1415926f, Eigen::Vector3f::UnitZ()) * v;
+    x = v[0];
+    y = v[1];
+    #else
+    float newx = x * cos(angle) - y * sin(angle);
+    float newy = x * sin(angle) + y * cos(angle);
+    x = newx;
+    y = newy;
+    int i = 0;
+    #endif
+}
+
+float Vector2D::Angle(const Vector2D& b)
+{
+    float a1 = acos(Dot(b) / Norm() / b.Norm());
+    float a2 = atan2(y, x);
+    float a3 = atan2(y, x) / 0.017 - 90.0f;
+    #if 0
+    return a2;
+    #else
+    bool at_right_side = Vector2D::RIGHT.Dot(*this) > 0.0001f;
+    if (at_right_side) {
+        a1 = -a1;
+    }
+    return a1 / 3.14;
+    //    return a3 / 360.0f;
+    #endif
+}
+
 Vector2D Vector2D::Perp()
 {
     return Vector2D(y, -x);
@@ -114,7 +147,7 @@ float Vector2D::Dot(const Vector2D& v) const
     return x*v.x + y*v.y;
 }
 
-float Vector2D::Norm()
+float Vector2D::Norm() const
 {
     return fabs(sqrt(x*x + y*y));
 }
diff --git a/server/gameserver/types.h b/server/gameserver/types.h
index 375592f..3b14cff 100755
--- a/server/gameserver/types.h
+++ b/server/gameserver/types.h
@@ -26,6 +26,8 @@ struct Vector2D
     void FromPB(const cs::MFVector2D* pb_obj);
     void Normalize();
     void Rotate(float angle);
+    void Rotate2(float angle);
+    float Angle(const Vector2D& b);
 
     bool operator == (const Vector2D& b) const;
     Vector2D operator + (const Vector2D& b) const;
@@ -34,7 +36,7 @@ struct Vector2D
     Vector2D operator / (float scale) const;
     Vector2D Perp();
     float Dot(const Vector2D& v) const;
-    float Norm();
+    float Norm() const;
 
     static const Vector2D UP;
     static const Vector2D DOWN;