From f719c27f5725f34b072e5abc42a78bbea9327150 Mon Sep 17 00:00:00 2001
From: Struma <strix@struma.me>
Date: Wed, 10 Feb 2021 00:04:34 -0500
Subject: [PATCH] Move RGSS1 viewport elements to new parent when 'viewport='
 is called

---
 binding/disposable-binding.h      | 30 ++++++++++++++++++++++++++++--
 binding/viewportelement-binding.h |  8 ++++++++
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/binding/disposable-binding.h b/binding/disposable-binding.h
index bfe6b9c6..7c249e2a 100644
--- a/binding/disposable-binding.h
+++ b/binding/disposable-binding.h
@@ -31,16 +31,42 @@
 inline void
 disposableAddChild(VALUE disp, VALUE child)
 {
+    if (NIL_P(disp) || NIL_P(child))
+        return;
+    
 	VALUE children = rb_iv_get(disp, "children");
+    
+    bool exists = false;
 
 	if (NIL_P(children))
 	{
 		children = rb_ary_new();
 		rb_iv_set(disp, "children", children);
 	}
+    else {
+        exists = RTEST(rb_funcall(children, rb_intern("include?"), 1, child));
+    }
 
-	/* Assumes children are never removed until destruction */
-	rb_ary_push(children, child);
+	if (!exists)
+        rb_ary_push(children, child);
+}
+
+inline void
+disposableRemoveChild(VALUE disp, VALUE child)
+{
+    if (NIL_P(disp) || NIL_P(child))
+        return;
+    
+    VALUE children = rb_iv_get(disp, "children");
+    if (NIL_P(children))
+        return;
+    
+    VALUE index = rb_funcall(children, rb_intern("index"), 1, child);
+    if (NIL_P(index))
+        return;
+    
+    rb_funcall(children, rb_intern("delete_at"), 1, index);
+    
 }
 
 inline void
diff --git a/binding/viewportelement-binding.h b/binding/viewportelement-binding.h
index 9f450574..b0571554 100644
--- a/binding/viewportelement-binding.h
+++ b/binding/viewportelement-binding.h
@@ -26,6 +26,7 @@
 #include "sharedstate.h"
 #include "binding-util.h"
 #include "binding-types.h"
+#include "debugwriter.h"
 
 #include "sceneelement-binding.h"
 #include "disposable-binding.h"
@@ -54,6 +55,12 @@ RB_METHOD(viewportElementSetViewport)
 
 	if (!NIL_P(viewportObj))
 		viewport = getPrivateDataCheck<Viewport>(viewportObj, ViewportType);
+    
+    if (rgssVer == 1) {
+        VALUE vp = viewportElementGetViewport<C>(0, 0, self);
+        disposableRemoveChild(vp, self);
+        disposableAddChild(viewportObj, self);
+    }
 
 	GUARD_EXC( ve->setViewport(viewport); );
 
@@ -83,6 +90,7 @@ viewportElementInitialize(int argc, VALUE *argv, VALUE self)
 	/* Construct object */
 	C *ve = new C(viewport);
 
+    
 	/* Set property objects */
 	rb_iv_set(self, "viewport", viewportObj);