From 677e72d2f67ca13deb796d323367eb6c5a893721 Mon Sep 17 00:00:00 2001
From: toasteater <48371905+toasteater@users.noreply.github.com>
Date: Fri, 10 Jan 2020 11:55:49 +0000
Subject: [PATCH] Expose instance_from_id to GDNative

This function is available to GDScript but not to GDNative. When exposed, it
allows building more ergonomic safe abstractions over the GDNative APIs, and
covers the use cases of the original PR.

Close #28478. Supersedes #28791.

Co-authored-by: Markus Ewald <cygon@nuclex.org>
---
 modules/gdnative/gdnative/gdnative.cpp       | 4 ++++
 modules/gdnative/gdnative_api.json           | 7 +++++++
 modules/gdnative/include/gdnative/gdnative.h | 3 +++
 3 files changed, 14 insertions(+)

diff --git a/modules/gdnative/gdnative/gdnative.cpp b/modules/gdnative/gdnative/gdnative.cpp
index 6ef1f2f4b95..06334556d92 100644
--- a/modules/gdnative/gdnative/gdnative.cpp
+++ b/modules/gdnative/gdnative/gdnative.cpp
@@ -170,6 +170,10 @@ bool GDAPI godot_is_instance_valid(const godot_object *p_object) {
 	return ObjectDB::instance_validate((Object *)p_object);
 }
 
+godot_object GDAPI *godot_instance_from_id(godot_int p_instance_id) {
+	return (godot_object *)ObjectDB::get_instance((ObjectID)p_instance_id);
+}
+
 void *godot_get_class_tag(const godot_string_name *p_class) {
 	StringName class_name = *(StringName *)p_class;
 	ClassDB::ClassInfo *class_info = ClassDB::classes.getptr(class_name);
diff --git a/modules/gdnative/gdnative_api.json b/modules/gdnative/gdnative_api.json
index 7e2ca49f8d3..8ccb8d2286c 100644
--- a/modules/gdnative/gdnative_api.json
+++ b/modules/gdnative/gdnative_api.json
@@ -155,6 +155,13 @@
               ["const godot_object *", "p_object"],
               ["void *", "p_class_tag"]
             ]
+          },
+          {
+            "name": "godot_instance_from_id",
+            "return_type": "godot_object *",
+            "arguments": [
+              ["godot_int", "p_instance_id"]
+            ]
           }
         ]
       },
diff --git a/modules/gdnative/include/gdnative/gdnative.h b/modules/gdnative/include/gdnative/gdnative.h
index 2fe59b8a73e..e19a2ec149d 100644
--- a/modules/gdnative/include/gdnative/gdnative.h
+++ b/modules/gdnative/include/gdnative/gdnative.h
@@ -290,6 +290,9 @@ bool GDAPI godot_is_instance_valid(const godot_object *p_object);
 void GDAPI *godot_get_class_tag(const godot_string_name *p_class);
 godot_object GDAPI *godot_object_cast_to(const godot_object *p_object, void *p_class_tag);
 
+// equivalent of GDScript's instance_from_id
+godot_object GDAPI *godot_instance_from_id(godot_int p_instance_id);
+
 #ifdef __cplusplus
 }
 #endif