Add naive position smoothing

Author: borodust

client/src/game-client.lisp

@@ -21,6 +21,7 @@
         (rot (rotation-of player)))
     (run (-> (client :command :player-info
                      :name name
+                     :timestamp (real-time-seconds)
                      :position (list (x pos) (y pos))
                      :rotation (list (x rot) (y rot)))
              ()))))

client/src/game-server.lisp

@@ -15,17 +15,16 @@
   (with-slots (players) *connector*
     (with-message (name) message
       (with-instance-lock-held (*connector*)
-        (let ((player (make-instance 'player)))
+        (let ((player (make-instance 'proxy)))
           (setf (gethash name players) player)
           (post (make-player-added-event player) (events))))))
   nil)
 
 
 (defmethod process-command ((command (eql :player-info)) message)
   (with-slots (players) *connector*
-    (with-message (name position rotation) message
+    (with-message (name position rotation timestamp) message
       (with-instance-lock-held (*connector*)
         (when-let ((player (gethash name players)))
-          (setf (position-of player) (sequence->vec2 position)
-                (rotation-of player) (sequence->vec2 rotation))))))
+          (update-proxy player (sequence->vec2 position) (sequence->vec2 rotation) timestamp)))))
   nil)

client/src/main.lisp

@@ -2,7 +2,6 @@
 
 
 (define-constant +framestep+ 0.017)
-(define-constant +player-speed+ 20.0)
 (defvar *main-latch* (mt:make-latch))
 
 
@@ -187,7 +186,10 @@
   (with-slots (remote-server game-client game-server) this
     (dolist (server (list remote-server game-client game-server))
       (when server
-        (disconnect-from-server server)))))
+        (disconnect-from-server server)))
+    (setf remote-server nil
+          game-client nil
+          game-server nil)))
 
 
 (defun start (configuration-path)

client/src/player.lisp

@@ -1,9 +1,14 @@
 (in-package :mortar-combat)
 
+(define-constant +player-speed+ 20.0)
 
 (defvar *forward-gaze* (vec3 0.0 0.0 -1.0))
 
 
+(defgeneric position-of (player))
+(defgeneric rotation-of (player))
+
+
 (defclass player ()
   ((position :initform (vec2)) ; f(x,y) field space = f(x,-z) global space
    (rotation :initform (vec2) :accessor rotation-of)
@@ -27,12 +32,6 @@
     position))
 
 
-(defmethod (setf position-of) ((value vec2) (this player))
-  (with-slots (position updated-at) this
-    (setf position value
-          updated-at (real-time-seconds))))
-
-
 (defun gaze-of (player)
   "In global coords"
   (with-slots (rotation) player

client/src/proxy.lisp

@@ -0,0 +1,45 @@
+(in-package :mortar-combat)
+
+
+(defclass proxy ()
+  ((position :initform (vec2)) ; f(x,y) field space = f(x,-z) global space
+   (rotation :initform (vec2) :accessor rotation-of)
+   (updated-at :initform (real-time-seconds))
+
+   (next-position :initform (vec2))
+   (next-rotation :initform (vec2))
+   (next-at :initform (real-time-seconds))
+
+   (correction :initform 0.0)))
+
+
+(defun proxy-lerp-factor (proxy)
+  (with-slots (updated-at next-at correction) proxy
+    (let* ((now (- (real-time-seconds) correction))
+           (delta (- next-at updated-at)))
+      (if (= delta 0.0) 1.0 (/ (- now next-at) delta)))))
+
+
+(defmethod position-of ((this proxy))
+  (with-slots (position next-position) this
+    (lerp position next-position (proxy-lerp-factor this))))
+
+
+(defmethod rotation-of ((this proxy))
+  (with-slots (rotation next-rotation) this
+    (lerp rotation next-rotation (proxy-lerp-factor this))))
+
+
+(defun update-proxy (proxy pos rot timestamp)
+  (with-slots (next-position next-at position updated-at
+                             correction rotation next-rotation)
+      proxy
+    (setf correction (- (real-time-seconds) timestamp)
+
+          position (position-of proxy)
+          rotation (rotation-of proxy)
+          updated-at next-at
+
+          next-position pos
+          next-rotation rot
+          next-at timestamp)))

mortar-combat.asd

@@ -30,6 +30,7 @@
                (:file "utils")
                (:file "keymap")
                (:file "player")
+               (:file "proxy")
                (:file "events")
                (:file "camera")
                (:file "room")