Add ability to inject custom rendering code, open GLFW subsystem

windowing/glfw/src/main/java/de/staropensource/engine/windowing/glfw/implementation/GlfwWindow.java

@@ -34,6 +34,7 @@ import de.staropensource.engine.windowing.implementable.Window;
 import de.staropensource.engine.windowing.type.window.VsyncMode;
 import de.staropensource.engine.windowing.type.window.WindowMode;
 import lombok.Getter;
+import lombok.Setter;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -73,6 +74,20 @@ public final class GlfwWindow extends Window {
     @Getter
     private long identifierLong;
 
+    /**
+     * Contains the code to execute in {@link #render()}.
+     *
+     * @since v1-alpha8
+     * -- GETTER --
+     * Returns the code to execute in {@link #render()}.
+     *
+     * @return rendering code
+     * @since v1-alpha8
+     */
+    @Getter
+    @Setter
+    private @NotNull Runnable renderCode = () -> glfwSwapBuffers(identifierLong);
+
     /**
      * Contains the {@link GLFWKeyCallback} used for emitting {@link InputEvent}s.
      *
@@ -279,7 +294,7 @@ public final class GlfwWindow extends Window {
         if (!Miscellaneous.onMainThread())
             throw new NotOnMainThreadException();
 
-        glfwSwapBuffers(identifierLong);
+        renderCode.run();
     }
 
     // ------------------------------------------------ [ GLFW handling ] ------------------------------------------------ //

windowing/glfw/src/main/java/module-info.java

@@ -17,7 +17,9 @@ module sosengine.windowing.glfw {
 
     // API access
     exports de.staropensource.engine.windowing.glfw;
+    exports de.staropensource.engine.windowing.glfw.implementation;
 
     // Reflection access
     opens de.staropensource.engine.windowing.glfw;
+    opens de.staropensource.engine.windowing.glfw.implementation;
 }