Changes

src/clj/sekai/macros/components.clj

@@ -0,0 +1,29 @@
+(ns sekai.macros.components
+  (:require [clojure.string :refer [capitalize]]))
+
+(defmacro defcomponent [name fields & [generator constructor destructor]]
+  (let [kwname (keyword name)
+        compname (str "Component" (capitalize name))
+        this (gensym)
+        eid (gensym)]
+    `(do
+       (defrecord ~(symbol compname) ~fields
+         ~'IComponent
+         (~'attach! [~this ~eid]
+          (sekai.entity.entity/register-component! ~eid ~kwname ~this)
+          ~(when constructor
+             `(~constructor ~eid ~this)))
+
+         (~'_detach! [~this ~eid]
+          (sekai.entity.entity/deregister-component! ~eid ~kwname)
+          ~(when destructor
+             `(~destructor ~eid ~this))))
+
+       (defn ~name [~@fields]
+         (apply ~(symbol (str "->" compname))
+          ~(if generator
+             `(let [result# (~generator ~@fields)]
+                (if (sequential? result#)
+                  result#
+                  [result#]))
+             fields))))))