Universalize draw-over API for EditorPlugins

- Now it is usable from both `CanvasItem` and `Spatial` editors.
- `EditorPlugin` API changes:
 - `forward_draw_over_canvas()` becomes `forward_draw_over_viewport()`.
 - `update_canvas()` becomes `update_overlays()`, which now triggers the update of every overlay on top of any 2D or 3D viewports present. Also now it returns the number of such viewports, which is useful whenever you need to know the number of draw-over calls you'll get.
 - New: `[set/is]_force_draw_over_forwarding_enabled()` to force overlaying regardless it handles the current object type, in a similar fashion as `[set/is]_input_event_forwarding_always_enabled`. This kind of overlay is also on top of those for regular handled node types.
 - New: `forward_force_draw_over_canvas()`, which is the callback that gets called for plugins that enable forced overlaying.

13 files changed, 44 insertions, 28 deletions

diff --git a/editor/plugins/abstract_polygon_2d_editor.cpp b/editor/plugins/abstract_polygon_2d_editor.cpp
index 736e176ab..1c4569d11 100644
--- a/editor/plugins/abstract_polygon_2d_editor.cpp
+++ b/editor/plugins/abstract_polygon_2d_editor.cpp
@@ -490,7 +490,7 @@ bool AbstractPolygon2DEditor::forward_gui_input(const Ref<InputEvent> &p_event)
 	return false;
 }
 
-void AbstractPolygon2DEditor::forward_draw_over_canvas(Control *p_canvas) {
+void AbstractPolygon2DEditor::forward_draw_over_viewport(Control *p_overlay) {
 	if (!_get_node())
 		return;
 
diff --git a/editor/plugins/abstract_polygon_2d_editor.h b/editor/plugins/abstract_polygon_2d_editor.h
index 915fe0803..545eff6ef 100644
--- a/editor/plugins/abstract_polygon_2d_editor.h
+++ b/editor/plugins/abstract_polygon_2d_editor.h
@@ -136,7 +136,7 @@ protected:
 
 public:
 	bool forward_gui_input(const Ref<InputEvent> &p_event);
-	void forward_draw_over_canvas(Control *p_canvas);
+	void forward_draw_over_viewport(Control *p_overlay);
 
 	void edit(Node *p_polygon);
 	AbstractPolygon2DEditor(EditorNode *p_editor, bool p_wip_destructive = true);
@@ -152,7 +152,7 @@ class AbstractPolygon2DEditorPlugin : public EditorPlugin {
 
 public:
 	virtual bool forward_canvas_gui_input(const Ref<InputEvent> &p_event) { return polygon_editor->forward_gui_input(p_event); }
-	virtual void forward_draw_over_canvas(Control *p_canvas) { polygon_editor->forward_draw_over_canvas(p_canvas); }
+	virtual void forward_draw_over_viewport(Control *p_overlay) { polygon_editor->forward_draw_over_viewport(p_overlay); }
 
 	bool has_main_screen() const { return false; }
 	virtual String get_name() const { return klass; }
diff --git a/editor/plugins/canvas_item_editor_plugin.cpp b/editor/plugins/canvas_item_editor_plugin.cpp
index 3940dd904..d18e97fe8 100644
--- a/editor/plugins/canvas_item_editor_plugin.cpp
+++ b/editor/plugins/canvas_item_editor_plugin.cpp
@@ -2955,8 +2955,13 @@ void CanvasItemEditor::_draw_viewport() {
 
 	EditorPluginList *over_plugin_list = editor->get_editor_plugins_over();
 	if (!over_plugin_list->empty()) {
-		over_plugin_list->forward_draw_over_canvas(viewport);
+		over_plugin_list->forward_draw_over_viewport(viewport);
 	}
+	EditorPluginList *force_over_plugin_list = editor->get_editor_plugins_force_over();
+	if (!force_over_plugin_list->empty()) {
+		force_over_plugin_list->forward_force_draw_over_viewport(viewport);
+	}
+
 	_draw_bones();
 }
 
diff --git a/editor/plugins/collision_shape_2d_editor_plugin.cpp b/editor/plugins/collision_shape_2d_editor_plugin.cpp
index 005de096c..029e3a558 100644
--- a/editor/plugins/collision_shape_2d_editor_plugin.cpp
+++ b/editor/plugins/collision_shape_2d_editor_plugin.cpp
@@ -414,7 +414,7 @@ void CollisionShape2DEditor::_get_current_shape_type() {
 	canvas_item_editor->get_viewport_control()->update();
 }
 
-void CollisionShape2DEditor::forward_draw_over_canvas(Control *p_canvas) {
+void CollisionShape2DEditor::forward_draw_over_viewport(Control *p_overlay) {
 
 	if (!node) {
 		return;
@@ -448,8 +448,8 @@ void CollisionShape2DEditor::forward_draw_over_canvas(Control *p_canvas) {
 			handles[0] = Point2(radius, -height);
 			handles[1] = Point2(0, -(height + radius));
 
-			p_canvas->draw_texture(h, gt.xform(handles[0]) - size);
-			p_canvas->draw_texture(h, gt.xform(handles[1]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[0]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[1]) - size);
 
 		} break;
 
@@ -459,7 +459,7 @@ void CollisionShape2DEditor::forward_draw_over_canvas(Control *p_canvas) {
 			handles.resize(1);
 			handles[0] = Point2(shape->get_radius(), 0);
 
-			p_canvas->draw_texture(h, gt.xform(handles[0]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[0]) - size);
 
 		} break;
 
@@ -478,8 +478,8 @@ void CollisionShape2DEditor::forward_draw_over_canvas(Control *p_canvas) {
 			handles[0] = shape->get_normal() * shape->get_d();
 			handles[1] = shape->get_normal() * (shape->get_d() + 30.0);
 
-			p_canvas->draw_texture(h, gt.xform(handles[0]) - size);
-			p_canvas->draw_texture(h, gt.xform(handles[1]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[0]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[1]) - size);
 
 		} break;
 
@@ -489,7 +489,7 @@ void CollisionShape2DEditor::forward_draw_over_canvas(Control *p_canvas) {
 			handles.resize(1);
 			handles[0] = Point2(0, shape->get_length());
 
-			p_canvas->draw_texture(h, gt.xform(handles[0]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[0]) - size);
 
 		} break;
 
@@ -501,8 +501,8 @@ void CollisionShape2DEditor::forward_draw_over_canvas(Control *p_canvas) {
 			handles[0] = Point2(ext.x, 0);
 			handles[1] = Point2(0, -ext.y);
 
-			p_canvas->draw_texture(h, gt.xform(handles[0]) - size);
-			p_canvas->draw_texture(h, gt.xform(handles[1]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[0]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[1]) - size);
 
 		} break;
 
@@ -513,8 +513,8 @@ void CollisionShape2DEditor::forward_draw_over_canvas(Control *p_canvas) {
 			handles[0] = shape->get_a();
 			handles[1] = shape->get_b();
 
-			p_canvas->draw_texture(h, gt.xform(handles[0]) - size);
-			p_canvas->draw_texture(h, gt.xform(handles[1]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[0]) - size);
+			p_overlay->draw_texture(h, gt.xform(handles[1]) - size);
 
 		} break;
 	}
diff --git a/editor/plugins/collision_shape_2d_editor_plugin.h b/editor/plugins/collision_shape_2d_editor_plugin.h
index d4fbe87fb..1e930ef37 100644
--- a/editor/plugins/collision_shape_2d_editor_plugin.h
+++ b/editor/plugins/collision_shape_2d_editor_plugin.h
@@ -74,7 +74,7 @@ protected:
 
 public:
 	bool forward_canvas_gui_input(const Ref<InputEvent> &p_event);
-	void forward_draw_over_canvas(Control *p_canvas);
+	void forward_draw_over_viewport(Control *p_overlay);
 	void edit(Node *p_node);
 
 	CollisionShape2DEditor(EditorNode *p_editor);
@@ -88,7 +88,7 @@ class CollisionShape2DEditorPlugin : public EditorPlugin {
 
 public:
 	virtual bool forward_canvas_gui_input(const Ref<InputEvent> &p_event) { return collision_shape_2d_editor->forward_canvas_gui_input(p_event); }
-	virtual void forward_draw_over_canvas(Control *p_canvas) { return collision_shape_2d_editor->forward_draw_over_canvas(p_canvas); }
+	virtual void forward_draw_over_viewport(Control *p_overlay) { return collision_shape_2d_editor->forward_draw_over_viewport(p_overlay); }
 
 	virtual String get_name() const { return "CollisionShape2D"; }
 	bool has_main_screen() const { return false; }
diff --git a/editor/plugins/light_occluder_2d_editor_plugin.cpp b/editor/plugins/light_occluder_2d_editor_plugin.cpp
index 485657d2c..3febc9923 100644
--- a/editor/plugins/light_occluder_2d_editor_plugin.cpp
+++ b/editor/plugins/light_occluder_2d_editor_plugin.cpp
@@ -318,7 +318,7 @@ bool LightOccluder2DEditor::forward_gui_input(const Ref<InputEvent> &p_event) {
 	return false;
 }
 
-void LightOccluder2DEditor::forward_draw_over_canvas(Control *p_canvas) {
+void LightOccluder2DEditor::forward_draw_over_viewport(Control *p_overlay) {
 
 	if (!node || !node->get_occluder_polygon().is_valid())
 		return;
diff --git a/editor/plugins/light_occluder_2d_editor_plugin.h b/editor/plugins/light_occluder_2d_editor_plugin.h
index 068832d8e..dc3ff7405 100644
--- a/editor/plugins/light_occluder_2d_editor_plugin.h
+++ b/editor/plugins/light_occluder_2d_editor_plugin.h
@@ -82,7 +82,7 @@ protected:
 
 public:
 	Vector2 snap_point(const Vector2 &p_point) const;
-	void forward_draw_over_canvas(Control *p_canvas);
+	void forward_draw_over_viewport(Control *p_overlay);
 	bool forward_gui_input(const Ref<InputEvent> &p_event);
 	void edit(Node *p_collision_polygon);
 	LightOccluder2DEditor(EditorNode *p_editor);
@@ -97,7 +97,7 @@ class LightOccluder2DEditorPlugin : public EditorPlugin {
 
 public:
 	virtual bool forward_canvas_gui_input(const Ref<InputEvent> &p_event) { return light_occluder_editor->forward_gui_input(p_event); }
-	virtual void forward_draw_over_canvas(Control *p_canvas) { return light_occluder_editor->forward_draw_over_canvas(p_canvas); }
+	virtual void forward_draw_over_viewport(Control *p_overlay) { return light_occluder_editor->forward_draw_over_viewport(p_overlay); }
 
 	virtual String get_name() const { return "LightOccluder2D"; }
 	bool has_main_screen() const { return false; }
diff --git a/editor/plugins/path_2d_editor_plugin.cpp b/editor/plugins/path_2d_editor_plugin.cpp
index 2174f08e2..5e811bfa1 100644
--- a/editor/plugins/path_2d_editor_plugin.cpp
+++ b/editor/plugins/path_2d_editor_plugin.cpp
@@ -269,7 +269,7 @@ bool Path2DEditor::forward_gui_input(const Ref<InputEvent> &p_event) {
 	return false;
 }
 
-void Path2DEditor::forward_draw_over_canvas(Control *p_canvas) {
+void Path2DEditor::forward_draw_over_viewport(Control *p_overlay) {
 
 	if (!node)
 		return;
diff --git a/editor/plugins/path_2d_editor_plugin.h b/editor/plugins/path_2d_editor_plugin.h
index 516e48c47..638d93379 100644
--- a/editor/plugins/path_2d_editor_plugin.h
+++ b/editor/plugins/path_2d_editor_plugin.h
@@ -94,7 +94,7 @@ protected:
 
 public:
 	bool forward_gui_input(const Ref<InputEvent> &p_event);
-	void forward_draw_over_canvas(Control *p_canvas);
+	void forward_draw_over_viewport(Control *p_overlay);
 	void edit(Node *p_path2d);
 	Path2DEditor(EditorNode *p_editor);
 };
@@ -108,7 +108,7 @@ class Path2DEditorPlugin : public EditorPlugin {
 
 public:
 	virtual bool forward_canvas_gui_input(const Ref<InputEvent> &p_event) { return path2d_editor->forward_gui_input(p_event); }
-	virtual void forward_draw_over_canvas(Control *p_canvas) { return path2d_editor->forward_draw_over_canvas(p_canvas); }
+	virtual void forward_draw_over_viewport(Control *p_overlay) { return path2d_editor->forward_draw_over_viewport(p_overlay); }
 
 	virtual String get_name() const { return "Path2D"; }
 	bool has_main_screen() const { return false; }
diff --git a/editor/plugins/spatial_editor_plugin.cpp b/editor/plugins/spatial_editor_plugin.cpp
index 20dda8b69..c8a7ad45a 100644
--- a/editor/plugins/spatial_editor_plugin.cpp
+++ b/editor/plugins/spatial_editor_plugin.cpp
@@ -2332,6 +2332,16 @@ static void draw_indicator_bar(Control &surface, real_t fill, Ref<Texture> icon)
 
 void SpatialEditorViewport::_draw() {
 
+	EditorPluginList *over_plugin_list = EditorNode::get_singleton()->get_editor_plugins_over();
+	if (!over_plugin_list->empty()) {
+		over_plugin_list->forward_draw_over_viewport(surface);
+	}
+
+	EditorPluginList *force_over_plugin_list = editor->get_editor_plugins_force_over();
+	if (!force_over_plugin_list->empty()) {
+		force_over_plugin_list->forward_force_draw_over_viewport(surface);
+	}
+
 	if (surface->has_focus()) {
 		Size2 size = surface->get_size();
 		Rect2 r = Rect2(Point2(), size);
diff --git a/editor/plugins/spatial_editor_plugin.h b/editor/plugins/spatial_editor_plugin.h
index 58c464c3e..ab26a70f7 100644
--- a/editor/plugins/spatial_editor_plugin.h
+++ b/editor/plugins/spatial_editor_plugin.h
@@ -311,6 +311,7 @@ protected:
 	static void _bind_methods();
 
 public:
+	void update_surface() { surface->update(); }
 	void update_transform_gizmo_view();
 
 	void set_can_preview(Camera *p_preview);
@@ -389,6 +390,8 @@ class SpatialEditor : public VBoxContainer {
 	GDCLASS(SpatialEditor, VBoxContainer);
 
 public:
+	static const unsigned int VIEWPORTS_COUNT = 4;
+
 	enum ToolMode {
 
 		TOOL_MODE_SELECT,
@@ -403,8 +406,6 @@ public:
 	};
 
 private:
-	static const unsigned int VIEWPORTS_COUNT = 4;
-
 	EditorNode *editor;
 	EditorSelection *editor_selection;
 
diff --git a/editor/plugins/tile_map_editor_plugin.cpp b/editor/plugins/tile_map_editor_plugin.cpp
index 4092fd399..e552e24c1 100644
--- a/editor/plugins/tile_map_editor_plugin.cpp
+++ b/editor/plugins/tile_map_editor_plugin.cpp
@@ -1183,7 +1183,7 @@ bool TileMapEditor::forward_gui_input(const Ref<InputEvent> &p_event) {
 	return false;
 }
 
-void TileMapEditor::forward_draw_over_canvas(Control *p_canvas) {
+void TileMapEditor::forward_draw_over_viewport(Control *p_overlay) {
 
 	if (!node)
 		return;
diff --git a/editor/plugins/tile_map_editor_plugin.h b/editor/plugins/tile_map_editor_plugin.h
index c7a5bf0cc..ce58cc970 100644
--- a/editor/plugins/tile_map_editor_plugin.h
+++ b/editor/plugins/tile_map_editor_plugin.h
@@ -184,7 +184,7 @@ public:
 	HBoxContainer *get_toolbar() const { return toolbar; }
 
 	bool forward_gui_input(const Ref<InputEvent> &p_event);
-	void forward_draw_over_canvas(Control *p_canvas);
+	void forward_draw_over_viewport(Control *p_overlay);
 
 	void edit(Node *p_tile_map);
 
@@ -200,7 +200,7 @@ class TileMapEditorPlugin : public EditorPlugin {
 
 public:
 	virtual bool forward_canvas_gui_input(const Ref<InputEvent> &p_event) { return tile_map_editor->forward_gui_input(p_event); }
-	virtual void forward_draw_over_canvas(Control *p_canvas) { tile_map_editor->forward_draw_over_canvas(p_canvas); }
+	virtual void forward_draw_over_viewport(Control *p_overlay) { tile_map_editor->forward_draw_over_viewport(p_overlay); }
 
 	virtual String get_name() const { return "TileMap"; }
 	bool has_main_screen() const { return false; }