Add gl macro

doclet/resources/classes.edn

@@ -92,7 +92,8 @@
                "grid-point-2!" :methods}
  "GridPoint3" {"grid-point-3" :methods
                "grid-point-3!" :methods}
- "GL20" {"gl!" :methods}
+ "GL20" {"gl!" :methods
+         "gl" :static-fields}
  "HexagonalTiledMapRenderer" {"hexagonal-tiled-map" :methods
                               "hexagonal-tiled-map!" :methods}
  "HorizontalGroup" {"horizontal" :methods

src/play_clj/core_basics.clj

@@ -60,6 +60,13 @@
   [k & options]
   `(u/call! ^GL20 (Gdx/gl20) ~k ~@options))
 
+(defmacro gl
+  "Returns a static field from [Gdx.gl20](http://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/graphics/GL20.html).
+
+    (gl :gl-triangles)"
+  [k]
+  `~(u/gdx-field :graphics :GL20 (u/key->upper k)))
+
 (defmacro graphics!
   "Calls a single method on [Gdx.graphics](http://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/Graphics.html).