Fixed simulation step variation.

Author: ForNeVeR

src/hyperspace/game.clj

@@ -106,28 +106,34 @@
   (assoc world
     :exit true))
 
+(def simulation-step 10)
+
 (defn update-world
   [{missiles :missiles
     planets :planets
     fragments :fragments
     traces :traces
     :as world}
    delta-time]
-  (let [broken-particles (mapcat #(break-particle % planets)
-                                 (concat missiles fragments))
-        ;; FIXME: Duplicate code
-        new-missiles (->> missiles
-                          (filter #(circle-X-rectangle? % world))
-                          (remove #(circle-X-any-circle? % planets))
-                          (map #(update-particle % planets delta-time)))
-        new-fragments (->> fragments
-                           (concat broken-particles)
-                           (filter #(circle-X-rectangle? % world))
-                           (remove #(circle-X-any-circle? % planets))
-                           (map #(update-particle % planets delta-time)))
+  (if (<= delta-time simulation-step)
+    [world delta-time]
+    (let [broken-particles (mapcat #(break-particle % planets)
+                                   (concat missiles fragments))
+          ;; FIXME: Duplicate code
+          new-missiles (->> missiles
+                            (filter #(circle-X-rectangle? % world))
+                            (remove #(circle-X-any-circle? % planets))
+                            (map #(update-particle % planets simulation-step)))
+          new-fragments (->> fragments
+                             (concat broken-particles)
+                             (filter #(circle-X-rectangle? % world))
+                             (remove #(circle-X-any-circle? % planets))
+                             (map #(update-particle % planets simulation-step)))
 
-        new-traces  (reduce update-traces traces new-missiles)]
-    (assoc world
-      :missiles new-missiles
-      :fragments new-fragments
-      :traces new-traces)))
+          new-traces  (reduce update-traces traces new-missiles)]
+      (recur
+        (assoc world
+          :missiles new-missiles
+          :fragments new-fragments
+          :traces new-traces)
+        (- delta-time simulation-step)))))

src/hyperspace/ui.clj

@@ -133,20 +133,21 @@
 
 (defn ui-loop
   [initial-world]
-  (loop [time (get-time)
-         world initial-world]
+  (loop [initial-timestamp (get-time)
+         accumulated-time  0
+         world             initial-world]
     (if (or (Display/isCloseRequested)
             (:exit world))
       (Display/destroy)
-      (let [new-time (get-time)
-            delta-time (- new-time time)
-            new-world (-> world
-                          (update-world delta-time)
-                          process-input
-                          render-world)]
+
+      (let [new-timestamp (get-time)
+            delta-time    (+ (- new-timestamp initial-timestamp) accumulated-time)
+            [new-world remaining-time] (update-world world delta-time)
+            final-world (-> new-world process-input
+                                      render-world)]
         (Display/update)
         (Display/sync fps)
-        (recur new-time new-world)))))
+        (recur new-timestamp remaining-time final-world)))))
 
 (defn start-ui
   [world]