From 4354cd8d41e044fba2dc5b63324388e01a786049 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pedro=20J=2E=20Est=C3=A9banez?= Date: Tue, 4 Jul 2023 13:28:43 +0200 Subject: [PATCH] Reimplement scene change --- doc/classes/SceneTree.xml | 4 +-- scene/main/scene_tree.cpp | 60 ++++++++++++++++++++++++--------------- scene/main/scene_tree.h | 4 ++- 3 files changed, 42 insertions(+), 26 deletions(-) diff --git a/doc/classes/SceneTree.xml b/doc/classes/SceneTree.xml index 7b8eca22299..867314ebbf1 100644 --- a/doc/classes/SceneTree.xml +++ b/doc/classes/SceneTree.xml @@ -42,7 +42,7 @@ Changes the running scene to the one at the given [param path], after loading it into a [PackedScene] and creating a new instance. Returns [constant OK] on success, [constant ERR_CANT_OPEN] if the [param path] cannot be loaded into a [PackedScene], or [constant ERR_CANT_CREATE] if that scene cannot be instantiated. - [b]Note:[/b] The scene change is deferred, which means that the new scene node is added to the tree at the end of the frame. This ensures that both scenes aren't running at the same time, while still freeing the previous scene in a safe way similar to [method Node.queue_free]. As such, you won't be able to access the loaded scene immediately after the [method change_scene_to_file] call. + [b]Note:[/b] The new scene node is added to the tree at the end of the frame. This ensures that both scenes aren't running at the same time, while still freeing the previous scene in a safe way similar to [method Node.queue_free]. As such, you won't be able to access the loaded scene immediately after the [method change_scene_to_file] call. @@ -51,7 +51,7 @@ Changes the running scene to a new instance of the given [PackedScene] (which must be valid). Returns [constant OK] on success, [constant ERR_CANT_CREATE] if the scene cannot be instantiated, or [constant ERR_INVALID_PARAMETER] if the scene is invalid. - [b]Note:[/b] The scene change is deferred, which means that the new scene node is added to the tree at the end of the frame. You won't be able to access it immediately after the [method change_scene_to_packed] call. + [b]Note:[/b] The new scene node is added to the tree at the end of the frame. You won't be able to access it immediately after the [method change_scene_to_packed] call. diff --git a/scene/main/scene_tree.cpp b/scene/main/scene_tree.cpp index 9a7f34d277a..8a1778fd048 100644 --- a/scene/main/scene_tree.cpp +++ b/scene/main/scene_tree.cpp @@ -550,6 +550,10 @@ bool SceneTree::process(double p_time) { #endif // _3D_DISABLED #endif // TOOLS_ENABLED + if (unlikely(pending_new_scene)) { + _flush_scene_change(); + } + return _quit; } @@ -1378,27 +1382,16 @@ Node *SceneTree::get_current_scene() const { return current_scene; } -void SceneTree::_change_scene(Node *p_to) { - ERR_FAIL_COND_MSG(!Thread::is_main_thread(), "Changing scene can only be done from the main thread."); - if (current_scene) { - memdelete(current_scene); - current_scene = nullptr; - } - - // If we're quitting, abort. - if (unlikely(_quit)) { - if (p_to) { // Prevent memory leak. - memdelete(p_to); - } - return; - } - - if (p_to) { - current_scene = p_to; - root->add_child(p_to); - // Update display for cursor instantly. - root->update_mouse_cursor_state(); +void SceneTree::_flush_scene_change() { + if (prev_scene) { + memdelete(prev_scene); + prev_scene = nullptr; } + current_scene = pending_new_scene; + root->add_child(pending_new_scene); + pending_new_scene = nullptr; + // Update display for cursor instantly. + root->update_mouse_cursor_state(); } Error SceneTree::change_scene_to_file(const String &p_path) { @@ -1417,7 +1410,22 @@ Error SceneTree::change_scene_to_packed(const Ref &p_scene) { Node *new_scene = p_scene->instantiate(); ERR_FAIL_NULL_V(new_scene, ERR_CANT_CREATE); - call_deferred(SNAME("_change_scene"), new_scene); + // If called again while a change is pending. + if (pending_new_scene) { + queue_delete(pending_new_scene); + pending_new_scene = nullptr; + } + + prev_scene = current_scene; + + if (current_scene) { + // Let as many side effects as possible happen or be queued now, + // so they are run before the scene is actually deleted. + root->remove_child(current_scene); + } + DEV_ASSERT(!current_scene); + + pending_new_scene = new_scene; return OK; } @@ -1595,8 +1603,6 @@ void SceneTree::_bind_methods() { ClassDB::bind_method(D_METHOD("reload_current_scene"), &SceneTree::reload_current_scene); ClassDB::bind_method(D_METHOD("unload_current_scene"), &SceneTree::unload_current_scene); - ClassDB::bind_method(D_METHOD("_change_scene"), &SceneTree::_change_scene); - ClassDB::bind_method(D_METHOD("set_multiplayer", "multiplayer", "root_path"), &SceneTree::set_multiplayer, DEFVAL(NodePath())); ClassDB::bind_method(D_METHOD("get_multiplayer", "for_path"), &SceneTree::get_multiplayer, DEFVAL(NodePath())); ClassDB::bind_method(D_METHOD("set_multiplayer_poll_enabled", "enabled"), &SceneTree::set_multiplayer_poll_enabled); @@ -1835,6 +1841,14 @@ SceneTree::SceneTree() { } SceneTree::~SceneTree() { + if (prev_scene) { + memdelete(prev_scene); + prev_scene = nullptr; + } + if (pending_new_scene) { + memdelete(pending_new_scene); + pending_new_scene = nullptr; + } if (root) { root->_set_tree(nullptr); root->_propagate_after_exit_tree(); diff --git a/scene/main/scene_tree.h b/scene/main/scene_tree.h index 452fac7423f..24140ec7f1e 100644 --- a/scene/main/scene_tree.h +++ b/scene/main/scene_tree.h @@ -179,6 +179,8 @@ private: TypedArray _get_nodes_in_group(const StringName &p_group); Node *current_scene = nullptr; + Node *prev_scene = nullptr; + Node *pending_new_scene = nullptr; Color debug_collisions_color; Color debug_collision_contact_color; @@ -189,7 +191,7 @@ private: Ref collision_material; int collision_debug_contacts; - void _change_scene(Node *p_to); + void _flush_scene_change(); List> timers; List> tweens;