Prevent errors when using ViewportTexture

doc/classes/Node.xml

@@ -500,6 +500,13 @@
  Returns [code]true[/code] if the local system is the multiplayer authority of this node.
  </description>
  </method>
+ <method name="is_node_ready" qualifiers="const">
+ <return type="bool" />
+ <description>
+ Returns [code]true[/code] if the node is ready, i.e. it's inside scene tree and all its children are initialized.
+ [method request_ready] resets it back to [code]false[/code].
+ </description>
+ </method>
  <method name="is_physics_processing" qualifiers="const">
  <return type="bool" />
  <description>

doc/classes/ViewportTexture.xml

@@ -6,7 +6,7 @@
  <description>
  Displays the content of a [Viewport] node as a dynamic [Texture2D]. This can be used to mix controls, 2D, and 3D elements in the same scene.
  To create a ViewportTexture in code, use the [method Viewport.get_texture] method on the target viewport.
- [b]Note:[/b] When local to scene, this texture uses [method Resource.setup_local_to_scene] to set the proxy texture and flags in the local viewport.
+ [b]Note:[/b] When local to scene, this texture uses [method Resource.setup_local_to_scene] to set the proxy texture and flags in the local viewport. Local to scene viewport textures will return incorrect data until the scene root is ready (see [signal Node.ready]).
  </description>
  <tutorials>
  <link title="GUI in 3D Demo">https://godotengine.org/asset-library/asset/127</link>

scene/main/node.cpp

@@ -2786,6 +2786,10 @@ bool Node::is_displayed_folded() const {
  return data.display_folded;
 }
 
+bool Node::is_ready() const {
+ return !data.ready_first;
+}
+
 void Node::request_ready() {
  data.ready_first = true;
 }
@@ -2932,6 +2936,7 @@ void Node::_bind_methods() {
  ClassDB::bind_method(D_METHOD("queue_free"), &Node::queue_free);
 
  ClassDB::bind_method(D_METHOD("request_ready"), &Node::request_ready);
+ ClassDB::bind_method(D_METHOD("is_node_ready"), &Node::is_ready);
 
  ClassDB::bind_method(D_METHOD("set_multiplayer_authority", "id", "recursive"), &Node::set_multiplayer_authority, DEFVAL(true));
  ClassDB::bind_method(D_METHOD("get_multiplayer_authority"), &Node::get_multiplayer_authority);

scene/main/node.h

@@ -500,6 +500,7 @@ class Node : public Object {
  bool can_process_notification(int p_what) const;
  bool is_enabled() const;
 
+ bool is_ready() const;
  void request_ready();
 
  static void print_orphan_nodes();

scene/main/viewport.cpp

@@ -61,6 +61,10 @@
 #include "servers/rendering/rendering_server_globals.h"
 
 void ViewportTexture::setup_local_to_scene() {
+ if (vp_pending) {
+ return;
+ }
+
  Node *loc_scene = get_local_scene();
  if (!loc_scene) {
  return;
@@ -72,22 +76,11 @@ void ViewportTexture::setup_local_to_scene() {
 
  vp = nullptr;
 
- Node *vpn = loc_scene->get_node(path);
- ERR_FAIL_COND_MSG(!vpn, "ViewportTexture: Path to node is invalid.");
-
- vp = Object::cast_to<Viewport>(vpn);
-
- ERR_FAIL_COND_MSG(!vp, "ViewportTexture: Path to node does not point to a viewport.");
-
- vp->viewport_textures.insert(this);
-
- ERR_FAIL_NULL(RenderingServer::get_singleton());
- if (proxy_ph.is_valid()) {
- RS::get_singleton()->texture_proxy_update(proxy, vp->texture_rid);
- RS::get_singleton()->free(proxy_ph);
+ if (loc_scene->is_ready()) {
+ _setup_local_to_scene(loc_scene);
  } else {
- ERR_FAIL_COND(proxy.is_valid()); // Should be invalid.
- proxy = RS::get_singleton()->texture_proxy_create(vp->texture_rid);
+ loc_scene->connect(SNAME("ready"), callable_mp(this, &ViewportTexture::_setup_local_to_scene).bind(loc_scene), CONNECT_ONE_SHOT);
+ vp_pending = true;
  }
 }
 
@@ -108,17 +101,32 @@ NodePath ViewportTexture::get_viewport_path_in_scene() const {
 }
 
 int ViewportTexture::get_width() const {
- ERR_FAIL_COND_V_MSG(!vp, 0, "Viewport Texture must be set to use it.");
+ if (!vp) {
+ if (!vp_pending) {
+ ERR_PRINT("Viewport Texture must be set to use it.");
+ }
+ return 0;
+ }
  return vp->size.width;
 }
 
 int ViewportTexture::get_height() const {
- ERR_FAIL_COND_V_MSG(!vp, 0, "Viewport Texture must be set to use it.");
+ if (!vp) {
+ if (!vp_pending) {
+ ERR_PRINT("Viewport Texture must be set to use it.");
+ }
+ return 0;
+ }
  return vp->size.height;
 }
 
 Size2 ViewportTexture::get_size() const {
- ERR_FAIL_COND_V_MSG(!vp, Size2(), "Viewport Texture must be set to use it.");
+ if (!vp) {
+ if (!vp_pending) {
+ ERR_PRINT("Viewport Texture must be set to use it.");
+ }
+ return Size2();
+ }
  return vp->size;
 }
 
@@ -135,10 +143,36 @@ bool ViewportTexture::has_alpha() const {
 }
 
 Ref<Image> ViewportTexture::get_image() const {
- ERR_FAIL_COND_V_MSG(!vp, Ref<Image>(), "Viewport Texture must be set to use it.");
+ if (!vp) {
+ if (!vp_pending) {
+ ERR_PRINT("Viewport Texture must be set to use it.");
+ }
+ return Ref<Image>();
+ }
  return RS::get_singleton()->texture_2d_get(vp->texture_rid);
 }
 
+void ViewportTexture::_setup_local_to_scene(const Node *p_loc_scene) {
+ Node *vpn = p_loc_scene->get_node(path);
+ ERR_FAIL_COND_MSG(!vpn, "ViewportTexture: Path to node is invalid.");
+
+ vp = Object::cast_to<Viewport>(vpn);
+
+ ERR_FAIL_COND_MSG(!vp, "ViewportTexture: Path to node does not point to a viewport.");
+
+ vp->viewport_textures.insert(this);
+
+ ERR_FAIL_NULL(RenderingServer::get_singleton());
+ if (proxy_ph.is_valid()) {
+ RS::get_singleton()->texture_proxy_update(proxy, vp->texture_rid);
+ RS::get_singleton()->free(proxy_ph);
+ } else {
+ ERR_FAIL_COND(proxy.is_valid()); // Should be invalid.
+ proxy = RS::get_singleton()->texture_proxy_create(vp->texture_rid);
+ }
+ vp_pending = false;
+}
+
 void ViewportTexture::_bind_methods() {
  ClassDB::bind_method(D_METHOD("set_viewport_path_in_scene", "path"), &ViewportTexture::set_viewport_path_in_scene);
  ClassDB::bind_method(D_METHOD("get_viewport_path_in_scene"), &ViewportTexture::get_viewport_path_in_scene);

scene/main/viewport.h

@@ -59,6 +59,9 @@ class ViewportTexture : public Texture2D {
 
  friend class Viewport;
  Viewport *vp = nullptr;
+ bool vp_pending = false;
+
+ void _setup_local_to_scene(const Node *p_loc_scene);
 
  mutable RID proxy_ph;
  mutable RID proxy;