Wind first pass

project.clj

@@ -4,7 +4,8 @@
   :license {:name "EPL-2.0 OR GPL-2.0-or-later WITH Classpath-exception-2.0"
             :url "https://www.eclipse.org/legal/epl-2.0/"}
   :dependencies [[org.clojure/clojure "1.11.1"]
-                 [seesaw "1.5.0"]]
+                 [seesaw "1.5.0"]
+                 [com.formdev/flatlaf "3.2.5"]]
   :main ^:skip-aot age-of-sail.core
   :target-path "target/%s"
   :profiles {:uberjar {:aot :all

scratches/bootstrap.clj

@@ -8,12 +8,10 @@
 
 (def revenge (ref {:position [0. 0.]
                    :name "Revenge"
-                   :heading (normalize [1.0 1.0])
+                   :heading (normalize [0. 1.0])
                    :slots [{:type :downwind-sail :length 2 :furl 1.0}]
                    :velocity [1. 0.]}))
 
 (reset! ships [virginia-woolfe revenge])
 
 (show-ui)
-
-@tracked-ship

src/age_of_sail/core.clj

@@ -1,11 +1,22 @@
 (ns age-of-sail.core
-  (:require [age-of-sail.vec2 :refer :all]
+  (:require [age-of-sail.simulation :refer :all]
+            [age-of-sail.vec2 :refer :all]
             [seesaw.core :refer :all]
-            [seesaw.bind :as b]
-            [clojure.math :as math]))
-
-(def tickrate 100)
-(def hardcoded-wind [0.1 3.0]) ;; A strong easternly wind!
+            [seesaw.bind :as b])
+  (:import com.formdev.flatlaf.FlatDarculaLaf))
+;; Wind
+(def hardcoded-winds '({:strength [0.1 3.0] :position [0. 0.]})) ;; A strong easternly wind!
+(defn sum-wind
+  "Wind at x is the sum of each wind force divided by its distance away" 
+  [x winds]
+  (reduce (fn [sum wind]
+            (let [dist (len (sub x (:position wind)))]
+              (if (> dist 1.0)
+                (add sum (scale (:strength wind) (/ (len (sub x (:position wind))))))
+                (add sum (:strength wind)))))
+          (zero)
+          winds))
+;; Ships
 (defonce ships (atom []))
 
 (defn ship-names
@@ -35,67 +46,53 @@
       force)))
 
 (defn physics-step
-  [ship wind]
+  [ship winds]
   (dosync
-   ;; Update position
-   (alter ship update :position add (scale (:velocity @ship) (/ tickrate)))
-   ;; linear dampening
-   (alter ship update :velocity scale (- 1.0 (/ 0.5 tickrate)))
-   ;; wind force
-   (alter ship update :velocity add (scale (downwind-sails-force @ship wind) (/ tickrate)))))
+   (let [wind (sum-wind (:position @ship) winds)]
+     ;; Update position
+     (alter ship update :position add (scale (:velocity @ship) (/ tickrate)))
+     ;; linear dampening
+     (alter ship update :velocity scale (- 1.0 (/ 0.5 tickrate)))
+     ;; wind force
+     (alter ship update :velocity add (scale (downwind-sails-force @ship wind) (/ tickrate))))))
 
 (defn tick
   [ships]
   (doseq [ship ships]
-    (-> ship (physics-step hardcoded-wind))))
+    (-> ship (physics-step hardcoded-winds))))
 
-;; Simulation controls
-(defonce program (atom :stopped))
-(defn game-loop
-  []
-  (while (#{:running :paused} @program)
-    (when (= :running @program)
-      (tick @ships))
-    (Thread/sleep (quot 1000 tickrate)))
-  (when-not (compare-and-set! program :killed :stopped)
-    (throw "Error: tried to stop a program that wasn't killed!")))
-
-(defn pause-program
-  []
-  (compare-and-set! program :running :paused))
-
-(defn kill-program
-  []
-  (compare-and-set! program :running :paused)
-  (compare-and-set! program :paused :killed))
-
-(defn start-program
-  []
-  (when (= (first (reset-vals! program :running)) :stopped)
-    (.start (Thread. game-loop))))
+(subscribe! #(tick @ships))
 
 ;; UI
+(FlatDarculaLaf/setup)
 (defn ignore-args
   [f]
   (fn [& _] (f)))
 
 (def tracked-ship (atom nil))
+(def ship-pos (b/notify-later))
+(defn update-pos
+  []
+  (let [ship @tracked-ship]
+    (when ship
+      (b/notify ship-pos (:position @ship)))))
+(subscribe! update-pos)
 
 (defn simulation-controls
   []
   (let [start-button (button :text "Start" :listen [:mouse-clicked (ignore-args start-program)])
         pause-button (button :text "Pause" :listen [:mouse-clicked (ignore-args pause-program)])
-        kill-button (button :text "Kill" :listen [:mouse-clicked (ignore-args kill-program)])]
+        kill-button  (button :text "Kill"  :listen [:mouse-clicked (ignore-args kill-program)])]
     (letfn [(start-enabled? [state] (contains? #{:stopped :paused} state))
             (pause-enabled? [state] (= :running state))
-            (kill-enabled? [state] (contains? #{:running :paused} state))]
+            (kill-enabled?  [state] (contains? #{:running :paused} state))]
       (b/bind program (b/tee
                        (b/bind (b/transform start-enabled?) (b/property start-button :enabled?))
                        (b/bind (b/transform pause-enabled?) (b/property pause-button :enabled?))
-                       (b/bind (b/transform kill-enabled?) (b/property kill-button :enabled?))))
+                       (b/bind (b/transform kill-enabled?)  (b/property kill-button :enabled?))))
       (config! start-button :enabled? (start-enabled? @program))
       (config! pause-button :enabled? (pause-enabled? @program))
-      (config! kill-button :enabled? (kill-enabled? @program))
+      (config! kill-button  :enabled? (kill-enabled? @program))
       (horizontal-panel :items [start-button pause-button kill-button]))))
 
 (defn ship-chooser
@@ -106,16 +103,14 @@
     (flow-panel :items ["Ship Name" name])))
 
 (defn format-position
-  [ship]
-  (apply format "X: %.2f Y: %.2f" (:position @ship)))
+  [[x y]]
+  (format "X: %.2f Y: %.2f" x y))
 
 (defn ship-info
   []
   (let [panel (vertical-panel :visible? false)
         position (label)]
-    (b/bind tracked-ship (b/some identity)
-            (b/tee
-             (b/bind (b/transform format-position) (b/value position))))
+    (b/bind ship-pos (b/transform format-position) (b/property position :text))
     (add! panel (flow-panel :items ["Position" position]))
     panel))
 
@@ -134,6 +129,7 @@
       show!)))
 
 (defn -main
-  [args]
+  []
   (start-program)
   (show-ui))
+

src/age_of_sail/simulation.clj

@@ -0,0 +1,34 @@
+(ns age-of-sail.simulation)
+
+(def tickrate 100)
+(def hooks (atom '()))
+(defn subscribe!
+  "Adds a hook to the hooks"
+  [f]
+  (swap! hooks conj f))
+
+(defonce program (atom :stopped))
+
+(defn game-loop
+  []
+  (while (#{:running :paused} @program)
+    (when (= :running @program)
+      (doseq [hook @hooks]
+        (hook)))
+    (Thread/sleep (quot 1000 tickrate)))
+  (when-not (compare-and-set! program :killed :stopped)
+    (throw "Error: tried to stop a program that wasn't killed!")))
+
+(defn pause-program
+  []
+  (compare-and-set! program :running :paused))
+
+(defn kill-program
+  []
+  (compare-and-set! program :running :paused)
+  (compare-and-set! program :paused :killed))
+
+(defn start-program
+  []
+  (when (= (first (reset-vals! program :running)) :stopped)
+    (.start (Thread. game-loop))))

src/age_of_sail/vec2.clj

@@ -9,6 +9,10 @@
   [v1 v2]
   (mapv + v1 v2))
 
+(defn sub
+  [v1 v2]
+  (mapv - v1 v2))
+
 (defn scale
   [v & scalars]
   (mapv #(* (apply * scalars) %) v))