it is done

core/src/mindustry/net/Interpolator.java

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+package mindustry.net;
+
+import arc.math.*;
+import arc.math.geom.*;
+import arc.util.*;
+
+public class Interpolator{
+    //used for movement
+    public Vector2 target = new Vector2();
+    public Vector2 last = new Vector2();
+    public float[] targets = {};
+    public float[] lasts = {};
+    public long lastUpdated, updateSpacing;
+
+    //current state
+    public Vector2 pos = new Vector2();
+    public float[] values = {};
+
+    public void read(float cx, float cy, float x, float y, float... target1ds){
+        if(lastUpdated != 0) updateSpacing = Time.timeSinceMillis(lastUpdated);
+
+        lastUpdated = Time.millis();
+
+        targets = target1ds;
+        if(lasts.length != values.length){
+            lasts = new float[values.length];
+        }
+        for(int i = 0; i < values.length; i++){
+            lasts[i] = values[i];
+        }
+        last.set(cx, cy);
+        target.set(x, y);
+    }
+
+    public void reset(){
+        values = new float[0];
+        targets = new float[0];
+        target.setZero();
+        last.setZero();
+        lastUpdated = 0;
+        updateSpacing = 16; //1 frame
+        pos.setZero();
+    }
+
+    public void update(){
+        if(lastUpdated != 0 && updateSpacing != 0){
+            float timeSinceUpdate = Time.timeSinceMillis(lastUpdated);
+            float alpha = Math.min(timeSinceUpdate / updateSpacing, 2f);
+
+            pos.set(last).lerpPast(target, alpha);
+
+            if(values.length != targets.length){
+                values = new float[targets.length];
+            }
+
+            if(lasts.length != targets.length){
+                lasts = new float[targets.length];
+            }
+
+            for(int i = 0; i < values.length; i++){
+                values[i] = Mathf.slerp(lasts[i], targets[i], alpha);
+            }
+        }else{
+            pos.set(target);
+        }
+
+    }
+}