WIP point laser turret

core/src/mindustry/world/blocks/defense/turrets/ContinuousTurret.java

@@ -3,6 +3,7 @@ package mindustry.world.blocks.defense.turrets;
 import arc.math.*;
 import arc.struct.*;
 import arc.util.*;
+import arc.util.io.*;
 import mindustry.content.*;
 import mindustry.entities.bullet.*;
 import mindustry.gen.*;
@@ -12,6 +13,8 @@ import mindustry.world.meta.*;
 /** A turret that fires a continuous beam bullet with no reload or coolant necessary. The bullet only disappears when the turret stops shooting. */
 public class ContinuousTurret extends Turret{
     public BulletType shootType = Bullets.placeholder;
+    /** Speed at which the turret can change its bullet "aim" distance. This is only used for point laser bullets. */
+    public float aimChangeSpeed = Float.POSITIVE_INFINITY;
 
     public ContinuousTurret(String name){
         super(name);
@@ -33,6 +36,7 @@ public class ContinuousTurret extends Turret{
     //TODO LaserTurret shared code
     public class ContinuousTurretBuild extends TurretBuild{
         public Seq<BulletEntry> bullets = new Seq<>();
+        public float lastLength = size * 4f;
 
         @Override
         protected void updateCooling(){
@@ -85,6 +89,18 @@ public class ContinuousTurret extends Turret{
                     entry.bullet.rotation(angle);
                     entry.bullet.set(bulletX, bulletY);
 
+                    //target length of laser
+                    float shootLength = Math.min(dst(targetPos), range);
+                    //current length of laser
+                    float curLength = dst(entry.bullet.aimX, entry.bullet.aimY);
+                    //resulting length of the bullet (smoothed)
+                    float resultLength = Mathf.approachDelta(curLength, shootLength, aimChangeSpeed);
+                    //actual aim end point based on length
+                    Tmp.v1.trns(rotation, lastLength = resultLength).add(x, y);
+
+                    entry.bullet.aimX = Tmp.v1.x;
+                    entry.bullet.aimY = Tmp.v1.y;
+
                     if(isShooting() && hasAmmo()){
                         entry.bullet.time = entry.bullet.lifetime * entry.bullet.type.optimalLifeFract * shootWarmup;
                         entry.bullet.keepAlive = true;
@@ -122,6 +138,11 @@ public class ContinuousTurret extends Turret{
         protected void handleBullet(@Nullable Bullet bullet, float offsetX, float offsetY, float angleOffset){
             if(bullet != null){
                 bullets.add(new BulletEntry(bullet, offsetX, offsetY, angleOffset, 0f));
+
+                //make sure the length updates to the last set value
+                Tmp.v1.trns(rotation, shootY + lastLength).add(x, y);
+                bullet.aimX = Tmp.v1.x;
+                bullet.aimY = Tmp.v1.y;
             }
         }
 
@@ -129,5 +150,26 @@ public class ContinuousTurret extends Turret{
         public boolean shouldActiveSound(){
             return bullets.any();
         }
+
+        @Override
+        public byte version(){
+            return 3;
+        }
+
+        @Override
+        public void write(Writes write){
+            super.write(write);
+
+            write.f(lastLength);
+        }
+
+        @Override
+        public void read(Reads read, byte revision){
+            super.read(read, revision);
+
+            if(revision >= 3){
+                lastLength = read.f();
+            }
+        }
     }
 }