From 32cf4937f862c27c3bb385113ca484d9a8e54059 Mon Sep 17 00:00:00 2001
From: Josha von Gizycki <mail@joshavg.de>
Date: Thu, 12 Sep 2019 11:00:58 +0200
Subject: [PATCH] some codestyle

---
 src/cljs/topdown2d/core.cljs      | 46 ++++++++++---------------------
 src/cljs/topdown2d/demoscene.cljs | 14 ++++++----
 2 files changed, 22 insertions(+), 38 deletions(-)

diff --git a/src/cljs/topdown2d/core.cljs b/src/cljs/topdown2d/core.cljs
index c5d0687..53dc872 100644
--- a/src/cljs/topdown2d/core.cljs
+++ b/src/cljs/topdown2d/core.cljs
@@ -8,7 +8,6 @@
 (def gamestate
   {:canvas (by-id "gamecanvas")
    :ctx (.getContext (by-id "gamecanvas") "2d")
-   :target-fps 60
    :continue? true
    :timing {;; msecs of previous frame
             :prev 0
@@ -40,7 +39,7 @@
 (defn set-fps
   "calculates the current fps using the elapsed time"
   [state]
-  (let [elapsed (get-in state [:timing :elapsed])
+  (let [elapsed (-> state :timing :elapsed)
         fps (/ 1 elapsed)]
     (assoc-in state [:timing :fps] fps)))
 
@@ -98,15 +97,13 @@
   [gamestate]
   (let [ctx (:ctx gamestate)]
     (aset ctx "fillStyle" "white")
-    (.fillRect
-     ctx
-     0 0 13 13)
+    (.fillRect ctx
+               0 0 13 13)
     (aset ctx "fillStyle" "black")
     (aset ctx "font" "10px monospace")
-    (.fillText
-     (:ctx gamestate)
-     (int (get-in gamestate [:timing :fps]))
-     0 10)))
+    (.fillText (:ctx gamestate)
+               (int (get-in gamestate [:timing :fps]))
+               0 10)))
 
 (defn draw-step
   "clears the canvas, draws fps and invokes the scene draw function"
@@ -116,44 +113,29 @@
               (get-in gamestate [:dimensions :w])
               (get-in gamestate [:dimensions :h]))
   (let [scenekey (:scene gamestate)
-        {:keys [draw] :as scene} (get-in gamestate [:scenes scenekey])]
+        {:keys [draw] :as scene} (-> 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]
-  (let [update-elapsed (- (.now js/performance)
-                          (get-in gamestate [:timing :now]))]
-    (if (:continue? gamestate)
-      (/ (- 1000 update-elapsed)
-         (: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.
-  then, it calls itself again with a delay according to the target fps"
+  then, it calls itself again using requestAnimationFrame"
   [gamestate]
   (let [newstate (update-step gamestate)]
     (set! (.-imageSmoothingEnabled (:ctx gamestate)) false)
     (draw-step newstate)
     (when-not @reloaded
-      (.setTimeout js/window
-                   (fn []
-                     (.requestAnimationFrame
-                      js/window
-                      #(mainloop newstate)))
-                   (timeout newstate)))))
+      (.requestAnimationFrame js/window
+                              #(mainloop newstate)))))
 
 (defn init-scenes
   "initiates the scene data maps using their respective init functions"
   []
-  (set! (.-width (:canvas gamestate)) (get-in gamestate [:dimensions :w]))
-  (set! (.-height (:canvas gamestate)) (get-in gamestate [:dimensions :h]))
+  (set! (.-width (:canvas gamestate))
+        (-> gamestate :dimensions :w))
+  (set! (.-height (:canvas gamestate))
+        (-> gamestate :dimensions :h))
   (update gamestate
           :scenes
           #(reduce
diff --git a/src/cljs/topdown2d/demoscene.cljs b/src/cljs/topdown2d/demoscene.cljs
index 4000544..92cf2c7 100644
--- a/src/cljs/topdown2d/demoscene.cljs
+++ b/src/cljs/topdown2d/demoscene.cljs
@@ -81,11 +81,13 @@
         (update-in [:player :y] - (* zoom (/ th 2)))
         (assoc-in [:player :animation :tileset-def]
                   (tileset/map-def->tileset map-def
-                                            (get-in scenestate
-                                                    [:player :animation :tileset]))))))
+                                            (-> scenestate
+                                                :player
+                                                :animation
+                                                :tileset))))))
 
 (defn init-map-def [scenestate]
-  (if (and (not (get-in scenestate [:map-def :def]))
+  (if (and (not (-> scenestate :map-def :def))
            (some? @map-def))
     (let [loaded-def (walk/keywordize-keys @map-def)
           zoom (get-in scenestate [:map-def :zoom])
@@ -104,7 +106,7 @@
   (let [new-scenestate (init-map-def scenestate)
         player (:player new-scenestate)
         viewport (:viewport new-scenestate)
-        dir (get-in gamestate [:input :dir])]
+        dir (-> gamestate :input :dir)]
     (assoc new-scenestate
            :player (update-player gamestate player dir)
            :viewport (update-viewport gamestate viewport dir))))
@@ -113,12 +115,12 @@
   (let [viewport (:viewport scenestate)
         {:keys [x y w h background]} viewport
         ctx (:ctx gamestate)]
-    (when (get-in scenestate [:map-def :def])
+    (when (-> scenestate :map-def :def)
       (tileset/draw-viewport (:map-def scenestate)
                              ctx
                              viewport)
       (let [{:keys [tileset-def curr-id image]}
-            (get-in scenestate [:player :animation])]
+            (-> scenestate :player :animation)]
         (tileset/draw-tile ctx
                            tileset-def
                            image