From e04f1d9dd570c6a3fe81d1fd7fb19f16ab7e64ce Mon Sep 17 00:00:00 2001
From: James Seibel <jeseibel@gondtc.com>
Date: Wed, 13 Jul 2022 07:54:34 -0500
Subject: [PATCH] Start adding a event API system

---
 .../external/events/DhApiEventRegister.java   | 37 +++++++++++++++++++
 .../lod/core/api/external/events/Readme.md    |  1 +
 .../events/interfaces/IDhApiEvent.java        | 13 +++++++
 .../events/interfaces/IDhApiRenderEvent.java  | 31 ++++++++++++++++
 4 files changed, 82 insertions(+)
 create mode 100644 src/main/java/com/seibel/lod/core/api/external/events/DhApiEventRegister.java
 create mode 100644 src/main/java/com/seibel/lod/core/api/external/events/Readme.md
 create mode 100644 src/main/java/com/seibel/lod/core/api/external/events/interfaces/IDhApiEvent.java
 create mode 100644 src/main/java/com/seibel/lod/core/api/external/events/interfaces/IDhApiRenderEvent.java

diff --git a/src/main/java/com/seibel/lod/core/api/external/events/DhApiEventRegister.java b/src/main/java/com/seibel/lod/core/api/external/events/DhApiEventRegister.java
new file mode 100644
index 000000000..cd1a70dca
--- /dev/null
+++ b/src/main/java/com/seibel/lod/core/api/external/events/DhApiEventRegister.java
@@ -0,0 +1,37 @@
+package com.seibel.lod.core.api.external.events;
+
+import com.seibel.lod.core.api.external.events.interfaces.IDhApiEvent;
+import com.seibel.lod.core.api.external.sharedObjects.DhApiResult;
+
+/**
+ * Handles adding/removing event handlers.
+ * Based off of JQuery's event system.
+ *
+ * @author James Seibel
+ * @version 2022-7-13
+ */
+public class DhApiEventRegister
+{
+	/**
+	 * Registers the given event handler. <Br>
+	 * Only one eventHandler of a specific class can be added at a time.
+	 * If multiple of the same eventHandler are added DhApiResult will return
+	 * the name of the already added handler and success = false.
+	 */
+	public static DhApiResult on(IDhApiEvent eventHandler)
+	{
+		throw new UnsupportedOperationException();
+	}
+	
+	/**
+	 * Removes the given event handler for this event if one has been registered. <br>
+	 * If no eventHandler of the given class has been registered the result will return
+	 * success = false.
+	 */
+	public static DhApiResult off(IDhApiEvent eventHandler)
+	{
+		throw new UnsupportedOperationException();
+	}
+	
+	
+}
diff --git a/src/main/java/com/seibel/lod/core/api/external/events/Readme.md b/src/main/java/com/seibel/lod/core/api/external/events/Readme.md
new file mode 100644
index 000000000..d11110896
--- /dev/null
+++ b/src/main/java/com/seibel/lod/core/api/external/events/Readme.md
@@ -0,0 +1 @@
+The events api package holds objects and methods for listening to events fired by Distant Horizons'.
\ No newline at end of file
diff --git a/src/main/java/com/seibel/lod/core/api/external/events/interfaces/IDhApiEvent.java b/src/main/java/com/seibel/lod/core/api/external/events/interfaces/IDhApiEvent.java
new file mode 100644
index 000000000..9d2518c38
--- /dev/null
+++ b/src/main/java/com/seibel/lod/core/api/external/events/interfaces/IDhApiEvent.java
@@ -0,0 +1,13 @@
+package com.seibel.lod.core.api.external.events.interfaces;
+
+/**
+ * All Api event handlers should implement this, so
+ * they can be more easily organized.
+ *
+ * @author James Seibel
+ * @version 2022-7-13
+ */
+public interface IDhApiEvent
+{
+
+}
diff --git a/src/main/java/com/seibel/lod/core/api/external/events/interfaces/IDhApiRenderEvent.java b/src/main/java/com/seibel/lod/core/api/external/events/interfaces/IDhApiRenderEvent.java
new file mode 100644
index 000000000..bc828878a
--- /dev/null
+++ b/src/main/java/com/seibel/lod/core/api/external/events/interfaces/IDhApiRenderEvent.java
@@ -0,0 +1,31 @@
+package com.seibel.lod.core.api.external.events.interfaces;
+
+import com.seibel.lod.core.objects.math.Mat4f;
+import com.seibel.lod.core.wrapperInterfaces.world.ILevelWrapper;
+
+/**
+ * Event handler for when Distant Horizons
+ * starts and finishes rendering
+ *
+ * @author James Seibel
+ * @version 2022-7-13
+ */
+public interface IDhApiRenderEvent extends IDhApiEvent
+{
+	// TODO should we allow editing the levelWrapper MVM matrix, etc.?
+	// TODO make sure to document it either way.
+	
+	/**
+	 * Called before Distant Horizons starts rendering. <Br>
+	 * If this methods returns false DH's rendering will be skipped for that frame.
+	 */
+	public boolean beforeRender(ILevelWrapper levelWrapper, Mat4f mcModelViewMatrix, Mat4f mcProjectionMatrix, float partialTicks);
+	
+	/**
+	 * Called after Distant Horizons finishes rendering.
+	 * If DH has rendering disabled or beforeRender //TODO Link
+	 * canceled the rendering this event will not fire.
+	 */
+	public void afterRender(ILevelWrapper levelWrapper, Mat4f mcModelViewMatrix, Mat4f mcProjectionMatrix, float partialTicks);
+	
+}
\ No newline at end of file