code style, sprites calculate speed in cycles per second

shit's working now, i promise

src/cljs/topdown2d/core.cljs

@@ -31,8 +31,7 @@
 (defn set-timing
   "sets the current time at the given key"
   [state timingkey]
-  (assoc-in
-   state
+  (assoc-in state
             [:timing timingkey]
             (.now js/performance)))
 
@@ -46,12 +45,12 @@
 (defn set-elapsed-seconds
   "calculates and writes the elapsed seconds since the last frame"
   [gamestate]
-  (assoc-in
-   gamestate
-   [:timing :elapsed]
-   (/ (-(get-in gamestate [:timing :now])
-        (get-in gamestate [:timing :prev]))
-      1000)))
+  (update gamestate
+          :timing
+          #(let [{:keys [now prev]} %]
+             (assoc % :elapsed
+                    (/ (- now prev)
+                       1000)))))
 
 (defn update-scene
   "updates the current scene using its udpate function"
@@ -59,9 +58,9 @@
   (if-not (:continue? gamestate)
     gamestate
     (let [scenekey (:scene gamestate)
-          scenestate (get-in gamestate [:scenes scenekey])
-          updatefunc (:update scenestate)
-          newstate (updatefunc gamestate scenestate)]
+          {updatefunc :update
+           :as scene} (get-in gamestate [:scenes scenekey])
+          newstate (updatefunc gamestate scene)]
       (assoc-in gamestate [:scenes scenekey] newstate))))
 
 (defn continue-running?
@@ -74,14 +73,11 @@
      (cond
        (and continue?
             (input/keydown? :Digit2)
-            (input/keydown? :ControlLeft))
-       false
+            (input/keydown? :ControlLeft)) false
        (and (not continue?)
             (input/keydown? :Digit3)
-            (input/keydown? :ControlLeft))
-       true
-       :else
-       continue?))))
+            (input/keydown? :ControlLeft)) true
+       :else continue?))))
 
 (defn update-step
   "updates timing information and the current scene"
@@ -118,11 +114,22 @@
               (get-in gamestate [:dimensions :w])
               (get-in gamestate [:dimensions :h]))
   (let [scenekey (:scene gamestate)
-        scene (get-in gamestate [:scenes scenekey])
-        drawfunc (:draw scene)]
-    (drawfunc gamestate scene))
+        {:keys [draw] :as scene} (get-in gamestate [:scenes scenekey])]
+    (draw gamestate scene))
   (draw-fps gamestate))
 
+(defn timeout
+  "calculates the duration of update-step and draw-step.
+  substracts that from the wait time to reach target-fps
+  more accurately.
+  if continue? is true, wait for 5 seconds plain"
+  [gamestate]
+  (if (:continue? gamestate)
+    (/ (- 1000 (- (.now js/performance)
+                  (get-in gamestate [:timing :now])))
+       (:target-fps gamestate))
+    5000))
+
 (defn mainloop
   "transforms the given gamestate by invoking a series of update
   functions and draws it using the 2d context of the gamestate.
@@ -130,35 +137,21 @@
   [gamestate]
   (let [newstate (update-step gamestate)]
     (draw-step newstate)
-    ;; calculate the duration of update-step and draw-step
-    ;; substract that from the wait time to reach target-fps
-    ;; more accurately
-    (let [now (get-in newstate [:timing :now])
-          duration (- (.now js/performance) now)
-          timeout (if (:continue? newstate)
-                    (/
-                     (- 1000 duration)
-                     (:target-fps newstate))
-                    5000)]
     (.setTimeout js/window
                  (fn []
                    (.requestAnimationFrame
                     js/window
                     #(mainloop newstate)))
-                   timeout))))
+                 (timeout newstate))))
 
 (defn init-scenes
   "initiates the scene data maps using their respective init functions"
   []
-  (assoc
-   gamestate
+  (update gamestate
           :scenes
-   (reduce
-    (fn [scenes [scenekey scenestate]]
-      (let [initfunc (:init scenestate)
-            newstate (initfunc gamestate scenestate)]
-        (assoc scenes scenekey newstate)))
-    {}
-    (:scenes gamestate))))
+          #(reduce
+            (fn [carr [key scene]]
+              (assoc carr key ((:init scene) gamestate scene)))
+            {} %)))
 
 (mainloop (init-scenes))

src/cljs/topdown2d/demoscene.cljs

@@ -21,15 +21,15 @@
                       :from 1
                       :count 8
                       :last-cycle 0
-                      ;; seconds per cycle
-                      :spc 0.08}}}
+                      ;; cycles per second
+                      :cps 10}}}
     :viewport {:image (.getElementById js/document "demo-background")
                :keep-in {:x 0 :y 0
                          :w 2239 :h 2235}
                :x 1 :y 1
                :d :?
                ;; pixels per second
-               :pps 350
+               :pps 150
                :w (get-in gamestate [:dimensions :w])
                :h (get-in gamestate [:dimensions :h])}}))
 

src/cljs/topdown2d/sprites.cljs

@@ -3,36 +3,28 @@
 (defn- reset-cycle [obj]
   (let [cycle (get-in obj [:sprite :cycle])
         {:keys [pos from] maxpos :count} cycle
-        reset-position? (> (inc pos) maxpos)]
+        reset? (> (inc pos) maxpos)
+        new-pos (if reset? from (inc pos))]
     (-> obj
         ;; set position
-        (assoc-in
-         [:sprite :cycle :pos]
-         (if reset-position?
-           from
-           (inc pos)))
+        (assoc-in [:sprite :cycle :pos] new-pos)
         ;; timestamp of last cycle is 0
-        (assoc-in
-         [:sprite :cycle :last-cycle]
-         0))))
+        (assoc-in [:sprite :cycle :last-cycle] 0))))
 
 (defn proc [gamestate obj]
-  (let [sprite (:sprite obj)
-        sprite-cycle (:cycle sprite)
-        {:keys [spc last-cycle]} sprite-cycle
+  (let [cycle (get-in obj [:sprite :cycle])
+        {:keys [cps last-cycle]} cycle
         elapsed (get-in gamestate [:timing :elapsed])]
     ;; new sprite frame?
-    (if (> (+ last-cycle elapsed) spc)
+    (if (> (+ last-cycle elapsed) (/ 1 cps))
       (reset-cycle obj)
       ;; no new sprite, increase last-cycle
-      (update-in
-       obj
+      (update-in obj
                  [:sprite :cycle :last-cycle]
-       #(+ % elapsed)))))
+                 + elapsed))))
 
 (defn reset [obj]
-  (assoc-in
-   obj
+  (assoc-in obj
             [:sprite :cycle :pos]
             0))
 
@@ -43,13 +35,11 @@
     {:y (* row size) :x (* pos size)}))
 
 (defn draw [ctx obj]
-  (let [{:keys [x y w h d sprite]} obj
-        image (:image sprite)
-        sprite-size (:size sprite)
-        sprite-cycle (:cycle sprite)
+  (let [{:keys [x y w h d]
+         {:keys [image size cycle] :as sprite} :sprite} obj
         pos (pos-in-sprite sprite d)]
     (.drawImage
      ctx
      image
-     (:x pos) (:y pos) sprite-size sprite-size
-     x y sprite-size sprite-size)))
+     (:x pos) (:y pos) size size
+     x y size size)))