Knockback following bullet direction (#5313)

core/src/mindustry/entities/bullet/BulletType.java

@@ -56,6 +56,8 @@ public abstract class BulletType extends Content{
     public float splashDamage = 0f;
     /** Knockback in velocity. */
     public float knockback;
+    /** Should knockback the bullet's direction */
+    public boolean impact;
     /** Status effect applied on hit. */
     public StatusEffect status = StatusEffects.none;
     /** Intensity of applied status effect in terms of duration. */
@@ -191,7 +193,9 @@ public abstract class BulletType extends Content{
         }
 
         if(entity instanceof Unit unit){
-            unit.impulse(Tmp.v3.set(unit).sub(b.x, b.y).nor().scl(knockback * 80f));
+            Tmp.v3.set(unit).sub(b.x, b.y).nor().scl(knockback * 80f);
+            if(impact) Tmp.v3.setAngle(b.rotation());
+            unit.impulse(Tmp.v3);
             unit.apply(status, statusDuration);
         }
     }

core/src/mindustry/entities/bullet/ContinuousLaserBulletType.java

@@ -35,6 +35,7 @@ public class ContinuousLaserBulletType extends BulletType{
         incendSpread = 5;
         incendChance = 0.4f;
         lightColor = Color.orange;
+        impact = true;
         keepVelocity = false;
         collides = false;
         pierce = true;

core/src/mindustry/entities/bullet/LaserBulletType.java

@@ -30,6 +30,7 @@ public class LaserBulletType extends BulletType{
         smokeEffect = Fx.none;
         hitSize = 4;
         lifetime = 16f;
+        impact = true;
         keepVelocity = false;
         collides = false;
         pierce = true;

core/src/mindustry/entities/bullet/SapBulletType.java

@@ -26,6 +26,7 @@ public class SapBulletType extends BulletType{
         hitEffect = Fx.hitLiquid;
         status = StatusEffects.sapped;
         statusDuration = 60f * 3f;
+        impact = true;
     }
 
     @Override