Arcade.Events.WORLD_STEP is a new event you can listen to. It is emitted by the Arcade Physics World every time the world steps once. It is emitted _after_ the bodies and colliders have been updated. Fix phaserjs#4289

Author: photonstorm

CHANGELOG.md

@@ -110,6 +110,7 @@ The following changes took place in the Pointer class:
 * `Phaser.Sound.Events#DECODED_ALL` is a new event emitted by the Web Audio Sound Manager when it has finished decoding all of the audio data files passed to the `decodeAudio` method.
 * `Phaser.Utils.Objects.Pick` is a new function that will take an object and an array of keys and return a new object containing just the keys provided in the array.
 * `Text.align` and `Text.setAlign` can now accept `justify` as a type. It will apply basic justification to multi-line text, adding in extra spaces in order to justify the content. Fix #4291 (thanks @andrewbaranov @Donerkebap13 @dude78GH)
+* `Arcade.Events.WORLD_STEP` is a new event you can listen to. It is emitted by the Arcade Physics World every time the world steps once. It is emitted _after_ the bodies and colliders have been updated. Fix #4289 (thanks @fant0m)
 
 ### Updates
 

src/physics/arcade/World.js

@@ -901,6 +901,7 @@ var World = new Class({
      *
      * @method Phaser.Physics.Arcade.World#update
      * @protected
+     * @fires Phaser.Physics.Arcade.Events#WORLD_STEP
      * @since 3.0.0
      *
      * @param {number} time - The current timestamp as generated by the Request Animation Frame or SetTimeout.
@@ -961,6 +962,8 @@ var World = new Class({
                     collider.update();
                 }
             }
+
+            this.emit(Events.WORLD_STEP);
         }
 
         //  Process any additional steps this frame
@@ -976,6 +979,7 @@ var World = new Class({
      * Advances the simulation by a time increment.
      *
      * @method Phaser.Physics.Arcade.World#step
+     * @fires Phaser.Physics.Arcade.Events#WORLD_STEP
      * @since 3.10.0
      *
      * @param {number} delta - The delta time amount, in seconds, by which to advance the simulation.
@@ -1018,6 +1022,8 @@ var World = new Class({
             }
         }
 
+        this.emit(Events.WORLD_STEP);
+
         this.stepsLastFrame++;
     },
 

src/physics/arcade/events/WORLD_STEP_EVENT.js

@@ -0,0 +1,20 @@
+/**
+ * @author       Richard Davey <rich@photonstorm.com>
+ * @copyright    2019 Photon Storm Ltd.
+ * @license      {@link https://opensource.org/licenses/MIT|MIT License}
+ */
+
+/**
+ * The Arcade Physics World Step Event.
+ * 
+ * This event is dispatched by an Arcade Physics World instance whenever a physics step is run.
+ * It is emitted _after_ the bodies and colliders have been updated.
+ * 
+ * In high framerate settings this can be multiple times per game frame.
+ * 
+ * Listen to it from a Scene using: `this.physics.world.on('worldstep', listener)`.
+ *
+ * @event Phaser.Physics.Arcade.Events#WORLD_STEP
+ * @since 3.18.0
+ */
+module.exports = 'worldstep';

src/physics/arcade/events/index.js

@@ -16,6 +16,7 @@ module.exports = {
     RESUME: require('./RESUME_EVENT'),
     TILE_COLLIDE: require('./TILE_COLLIDE_EVENT'),
     TILE_OVERLAP: require('./TILE_OVERLAP_EVENT'),
-    WORLD_BOUNDS: require('./WORLD_BOUNDS_EVENT')
+    WORLD_BOUNDS: require('./WORLD_BOUNDS_EVENT'),
+    WORLD_STEP: require('./WORLD_STEP_EVENT')
 
 };