Rework GraphEdit connections (drawing, API, optimizations)

core/math/geometry_2d.h

@@ -119,6 +119,10 @@ class Geometry2D {
 		}
 	}
 
+	static real_t get_distance_to_segment(const Vector2 &p_point, const Vector2 *p_segment) {
+		return p_point.distance_to(get_closest_point_to_segment(p_point, p_segment));
+	}
+
 	static bool is_point_in_triangle(const Vector2 &s, const Vector2 &a, const Vector2 &b, const Vector2 &c) {
 		Vector2 an = a - s;
 		Vector2 bn = b - s;
@@ -249,6 +253,28 @@ class Geometry2D {
 		return -1;
 	}
 
+	static bool segment_intersects_rect(const Vector2 &p_from, const Vector2 &p_to, const Rect2 &p_rect) {
+		if (p_rect.has_point(p_from) || p_rect.has_point(p_to)) {
+			return true;
+		}
+
+		const Vector2 rect_points[4] = {
+			p_rect.position,
+			p_rect.position + Vector2(p_rect.size.x, 0),
+			p_rect.position + p_rect.size,
+			p_rect.position + Vector2(0, p_rect.size.y)
+		};
+
+		// Check if any of the rect's edges intersect the segment.
+		for (int i = 0; i < 4; i++) {
+			if (segment_intersects_segment(p_from, p_to, rect_points[i], rect_points[(i + 1) % 4], nullptr)) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	enum PolyBooleanOperation {
 		OPERATION_UNION,
 		OPERATION_DIFFERENCE,

doc/classes/GraphEdit.xml

@@ -143,7 +143,22 @@
 				[b]Note:[/b] This method suppresses any other connection request signals apart from [signal connection_drag_ended].
 			</description>
 		</method>
-		<method name="get_connection_line">
+		<method name="get_closest_connection_at_point" qualifiers="const">
+			<return type="Dictionary" />
+			<param index="0" name="point" type="Vector2" />
+			<param index="1" name="max_distance" type="float" default="4.0" />
+			<description>
+				Returns the closest connection to the given point in screen space. If no connection is found within [param max_distance] pixels, an empty [Dictionary] is returned.
+				A connection consists in a structure of the form [code]{ from_port: 0, from_node: "GraphNode name 0", to_port: 1, to_node: "GraphNode name 1" }[/code].
+				For example, getting a connection at a given mouse position can be achieved like this:
+				[codeblocks]
+				[gdscript]
+				var connection = get_closest_connection_at_point(mouse_event.get_position())
+				[/gdscript]
+				[/codeblocks]
+			</description>
+		</method>
+		<method name="get_connection_line" qualifiers="const">
 			<return type="PackedVector2Array" />
 			<param index="0" name="from_node" type="Vector2" />
 			<param index="1" name="to_node" type="Vector2" />
@@ -154,7 +169,14 @@
 		<method name="get_connection_list" qualifiers="const">
 			<return type="Dictionary[]" />
 			<description>
-				Returns an Array containing the list of connections. A connection consists in a structure of the form [code]{ from_port: 0, from_node: "GraphNode name 0", to_port: 1, to_node: "GraphNode name 1" }[/code].
+				Returns an [Array] containing the list of connections. A connection consists in a structure of the form [code]{ from_port: 0, from_node: "GraphNode name 0", to_port: 1, to_node: "GraphNode name 1" }[/code].
+			</description>
+		</method>
+		<method name="get_connections_intersecting_with_rect" qualifiers="const">
+			<return type="Dictionary[]" />
+			<param index="0" name="rect" type="Rect2" />
+			<description>
+				Returns an [Array] containing the list of connections that intersect with the given [Rect2]. A connection consists in a structure of the form [code]{ from_port: 0, from_node: "GraphNode name 0", to_port: 1, to_node: "GraphNode name 1" }[/code].
 			</description>
 		</method>
 		<method name="get_menu_hbox">
@@ -233,7 +255,7 @@
 		<member name="connection_lines_curvature" type="float" setter="set_connection_lines_curvature" getter="get_connection_lines_curvature" default="0.5">
 			The curvature of the lines between the nodes. 0 results in straight lines.
 		</member>
-		<member name="connection_lines_thickness" type="float" setter="set_connection_lines_thickness" getter="get_connection_lines_thickness" default="2.0">
+		<member name="connection_lines_thickness" type="float" setter="set_connection_lines_thickness" getter="get_connection_lines_thickness" default="4.0">
 			The thickness of the lines between the nodes.
 		</member>
 		<member name="focus_mode" type="int" setter="set_focus_mode" getter="get_focus_mode" overrides="Control" enum="Control.FocusMode" default="2" />
@@ -417,7 +439,16 @@
 	</constants>
 	<theme_items>
 		<theme_item name="activity" data_type="color" type="Color" default="Color(1, 1, 1, 1)">
-			Color of the connection's activity (see [method set_connection_activity]).
+			Color the connection line is interpolated to based on the activity value of a connection (see [method set_connection_activity]).
+		</theme_item>
+		<theme_item name="connection_hover_tint_color" data_type="color" type="Color" default="Color(0, 0, 0, 0.3)">
+			Color which is blended with the connection line when the mouse is hovering over it.
+		</theme_item>
+		<theme_item name="connection_rim_color" data_type="color" type="Color" default="Color(0.1, 0.1, 0.1, 0.6)">
+			Color of the rim around each connection line used for making intersecting lines more distinguishable.
+		</theme_item>
+		<theme_item name="connection_valid_target_tint_color" data_type="color" type="Color" default="Color(1, 1, 1, 0.4)">
+			Color which is blended with the connection line when the currently dragged connection is hovering over a valid target port.
 		</theme_item>
 		<theme_item name="grid_major" data_type="color" type="Color" default="Color(1, 1, 1, 0.2)">
 			Color of major grid lines/dots.

editor/themes/editor_theme_manager.cpp

@@ -1367,6 +1367,10 @@ void EditorThemeManager::_populate_standard_styles(const Ref<Theme> &p_theme, Th
 		p_theme->set_color("selection_stroke", "GraphEdit", p_theme->get_color(SNAME("box_selection_stroke_color"), EditorStringName(Editor)));
 		p_theme->set_color("activity", "GraphEdit", p_config.accent_color);
 
+		p_theme->set_color("connection_hover_tint_color", "GraphEdit", p_config.dark_theme ? Color(0, 0, 0, 0.3) : Color(1, 1, 1, 0.3));
+		p_theme->set_color("connection_valid_target_tint_color", "GraphEdit", p_config.dark_theme ? Color(1, 1, 1, 0.4) : Color(0, 0, 0, 0.4));
+		p_theme->set_color("connection_rim_color", "GraphEdit", p_config.tree_panel_style->get_bg_color());
+
 		p_theme->set_icon("zoom_out", "GraphEdit", p_theme->get_icon(SNAME("ZoomLess"), EditorStringName(EditorIcons)));
 		p_theme->set_icon("zoom_in", "GraphEdit", p_theme->get_icon(SNAME("ZoomMore"), EditorStringName(EditorIcons)));
 		p_theme->set_icon("zoom_reset", "GraphEdit", p_theme->get_icon(SNAME("ZoomReset"), EditorStringName(EditorIcons)));

misc/extension_api_validation/4.2-stable.expected

@@ -59,3 +59,10 @@ Validate extension JSON: Error: Field 'classes/TileMap/methods/get_collision_vis
 Validate extension JSON: Error: Field 'classes/TileMap/methods/get_navigation_visibility_mode': is_const changed value in new API, from false to true.
 
 Two TileMap getters were made const. No adjustments should be necessary.
+
+
+GH-86158
+--------
+Validate extension JSON: Error: Field 'classes/GraphEdit/methods/get_connection_line': is_const changed value in new API, from false to true.
+
+get_connection_line was made const.

scene/gui/graph_edit.compat.inc

@@ -38,9 +38,14 @@ void GraphEdit::_set_arrange_nodes_button_hidden_bind_compat_81582(bool p_enable
 	set_show_arrange_button(!p_enable);
 }
 
+PackedVector2Array GraphEdit::_get_connection_line_bind_compat_86158(const Vector2 &p_from, const Vector2 &p_to) {
+	return get_connection_line(p_from, p_to);
+}
+
 void GraphEdit::_bind_compatibility_methods() {
 	ClassDB::bind_compatibility_method(D_METHOD("is_arrange_nodes_button_hidden"), &GraphEdit::_is_arrange_nodes_button_hidden_bind_compat_81582);
 	ClassDB::bind_compatibility_method(D_METHOD("set_arrange_nodes_button_hidden", "enable"), &GraphEdit::_set_arrange_nodes_button_hidden_bind_compat_81582);
+	ClassDB::bind_compatibility_method(D_METHOD("get_connection_line", "from_node", "to_node"), &GraphEdit::_get_connection_line_bind_compat_86158);
 }
 
 #endif