Merge pull request #20 from Minestom/smooth-pathfinding

Smooth pathfinding

src/main/java/fr/themode/demo/commands/SimpleCommand.java

@@ -53,7 +53,7 @@ public class SimpleCommand implements CommandProcessor {
 
         Instance instance = player.getInstance();
 
-        ChickenCreature chickenCreature = new ChickenCreature(new Position(-10, 40, -10));
+        ChickenCreature chickenCreature = new ChickenCreature(new Position(-10, 43, -10));
         chickenCreature.setInstance(instance);
 
         chickenCreature.setPathTo(player.getPosition());

src/main/java/net/minestom/server/entity/Entity.java

@@ -428,7 +428,7 @@ public abstract class Entity implements Viewable, EventHandler, DataContainer {
                 sendSynchronization();
 
                 if (shouldSendVelocityUpdate(time)) {
-                    sendPacketToViewersAndSelf(getVelocityPacket());
+                    sendVelocityPacket();
                     lastVelocityUpdateTime = time;
                 }
             }
@@ -482,6 +482,13 @@ public abstract class Entity implements Viewable, EventHandler, DataContainer {
         }
     }
 
+    /**
+     * Equivalent to <code>sendPacketsToViewers(getVelocityPacket());</code>
+     */
+    public void sendVelocityPacket() {
+        sendPacketsToViewers(getVelocityPacket());
+    }
+
     /**
      * Get the number of ticks this entity has been active for
      *

src/main/java/net/minestom/server/entity/EntityCreature.java

@@ -2,6 +2,7 @@ package net.minestom.server.entity;
 
 import com.extollit.gaming.ai.path.HydrazinePathFinder;
 import com.extollit.gaming.ai.path.model.PathObject;
+import net.minestom.server.MinecraftServer;
 import net.minestom.server.attribute.Attribute;
 import net.minestom.server.collision.CollisionUtils;
 import net.minestom.server.entity.pathfinding.PFPathingEntity;
@@ -50,8 +51,6 @@ public abstract class EntityCreature extends LivingEntity {
 
     @Override
     public void update(long time) {
-        super.update(time);
-
         // Path finding
         path = pathFinder.update();
         if (path != null) {
@@ -61,12 +60,11 @@ public abstract class EntityCreature extends LivingEntity {
             } else {
                 final float speed = getAttributeValue(Attribute.MOVEMENT_SPEED);
                 Position targetPosition = pathingEntity.getTargetPosition();
-                //targetPosition = new Position(-5.5f, 40f, -5.5f);
-                //System.out.println("target: " + targetPosition + " : " + (System.currentTimeMillis() - time));
-                //System.out.println("current: " + getPosition());
                 moveTowards(targetPosition, speed);
             }
         }
+
+        super.update(time);
     }
 
     @Override
@@ -82,6 +80,7 @@ public abstract class EntityCreature extends LivingEntity {
      * @param updateView should the entity move its head toward the position?
      */
     public void move(float x, float y, float z, boolean updateView) {
+        // TODO: remove ? Entity#tick already performs this behaviour, and syncs it properly
         final Position position = getPosition();
         Position newPosition = new Position();
         // Calculate collisions boxes
@@ -296,6 +295,7 @@ public abstract class EntityCreature extends LivingEntity {
     /**
      * Used to move the entity toward {@code direction} in the X and Z axis
      * Gravity is still applied but the entity will not attempt to jump
+     * Also update the yaw/pitch of the entity to look along 'direction'
      *
      * @param direction the targeted position
      * @param speed     define how far the entity will move
@@ -306,12 +306,34 @@ public abstract class EntityCreature extends LivingEntity {
         final float currentZ = position.getZ();
         final float targetX = direction.getX();
         final float targetZ = direction.getZ();
+        final float dz = targetZ - currentZ;
+        final float dx = targetX - currentX;
 
-        final float radians = (float) Math.atan2(targetZ - currentZ, targetX - currentX);
+        // the purpose of these few lines is to slow down entities when they reach their destination
+        float distSquared = dx * dx + dz * dz;
+        if(speed > distSquared) {
+            speed = distSquared;
+        }
+
+        final float radians = (float) Math.atan2(dz, dx);
         final float speedX = (float) (Math.cos(radians) * speed);
         final float speedZ = (float) (Math.sin(radians) * speed);
 
-        move(speedX, 0, speedZ, true);
+        lookAlong(dx, direction.getY(), dz);
+
+        // TODO: is a hard set an issue if there are other external forces at play?
+        final float tps = MinecraftServer.TICK_PER_SECOND;
+        velocity.setX(speedX * tps);
+        velocity.setZ(speedZ * tps);
+    }
+
+    private void lookAlong(float dx, float dy, float dz) {
+        final float horizontalAngle = (float) Math.atan2(dz, dx);
+        final float yaw = (float) (horizontalAngle * (180.0 / Math.PI)) - 90;
+        final float pitch = (float) Math.atan2(dy, Math.max(Math.abs(dx), Math.abs(dz)));
+
+        getPosition().setYaw(yaw);
+        getPosition().setPitch(pitch);
     }
 
     private ItemStack getEquipmentItem(ItemStack itemStack, ArmorEquipEvent.ArmorSlot armorSlot) {