Improve the 3D light gizmos

OmniLight and SpotLight gizmos were tweaked to better represent
their depth in the 3D world.

The default light gizmo color was changed to match the gizmo
icon color closely.

editor/spatial_editor_gizmos.cpp

@@ -783,9 +783,10 @@ Vector3 EditorSpatialGizmo::get_handle_pos(int p_idx) const {
 
 LightSpatialGizmoPlugin::LightSpatialGizmoPlugin() {
 
-	Color gizmo_color = EDITOR_DEF("editors/3d_gizmos/gizmo_colors/light", Color(1, 1, 0.2));
+	Color gizmo_color = EDITOR_DEF("editors/3d_gizmos/gizmo_colors/light", Color(1, 1, 0.7));
 
-	create_material("lines", gizmo_color);
+	create_material("lines_primary", gizmo_color);
+	create_material("lines_secondary", gizmo_color * Color(1, 1, 1, 0.35));
 	create_material("lines_billboard", gizmo_color, true);
 
 	create_icon_material("light_directional_icon", SpatialEditor::get_singleton()->get_icon("GizmoDirectionalLight", "EditorIcons"));
@@ -937,7 +938,7 @@ void LightSpatialGizmoPlugin::redraw(EditorSpatialGizmo *p_gizmo) {
 
 	if (Object::cast_to<DirectionalLight>(light)) {
 
-		Ref<Material> material = get_material("lines", p_gizmo);
+		Ref<Material> material = get_material("lines_primary", p_gizmo);
 		Ref<Material> icon = get_material("light_directional_icon", p_gizmo);
 
 		const int arrow_points = 7;
@@ -975,31 +976,39 @@ void LightSpatialGizmoPlugin::redraw(EditorSpatialGizmo *p_gizmo) {
 
 	if (Object::cast_to<OmniLight>(light)) {
 
-		Ref<Material> material = get_material("lines_billboard", p_gizmo);
-		Ref<Material> icon = get_material("light_omni_icon", p_gizmo);
+		// Use both a billboard circle and 3 non-billboard circles for a better sphere-like representation
+		const Ref<Material> lines_material = get_material("lines_secondary", p_gizmo);
+		const Ref<Material> lines_billboard_material = get_material("lines_billboard", p_gizmo);
+		const Ref<Material> icon = get_material("light_omni_icon", p_gizmo);
 
 		OmniLight *on = Object::cast_to<OmniLight>(light);
-
-		float r = on->get_param(Light::PARAM_RANGE);
-
+		const float r = on->get_param(Light::PARAM_RANGE);
 		Vector<Vector3> points;
+		Vector<Vector3> points_billboard;
 
-		for (int i = 0; i <= 360; i++) {
+		for (int i = 0; i < 120; i++) {
 
-			float ra = Math::deg2rad((float)i);
-			float rb = Math::deg2rad((float)i + 1);
-			Point2 a = Vector2(Math::sin(ra), Math::cos(ra)) * r;
-			Point2 b = Vector2(Math::sin(rb), Math::cos(rb)) * r;
+			// Create a circle
+			const float ra = Math::deg2rad((float)(i * 3));
+			const float rb = Math::deg2rad((float)((i + 1) * 3));
+			const Point2 a = Vector2(Math::sin(ra), Math::cos(ra)) * r;
+			const Point2 b = Vector2(Math::sin(rb), Math::cos(rb)) * r;
 
-			/*points.push_back(Vector3(a.x,0,a.y));
-			points.push_back(Vector3(b.x,0,b.y));
-			points.push_back(Vector3(0,a.x,a.y));
-			points.push_back(Vector3(0,b.x,b.y));*/
+			// Draw axis-aligned circles
+			points.push_back(Vector3(a.x, 0, a.y));
+			points.push_back(Vector3(b.x, 0, b.y));
+			points.push_back(Vector3(0, a.x, a.y));
+			points.push_back(Vector3(0, b.x, b.y));
 			points.push_back(Vector3(a.x, a.y, 0));
 			points.push_back(Vector3(b.x, b.y, 0));
+
+			// Draw a billboarded circle
+			points_billboard.push_back(Vector3(a.x, a.y, 0));
+			points_billboard.push_back(Vector3(b.x, b.y, 0));
 		}
 
-		p_gizmo->add_lines(points, material, true);
+		p_gizmo->add_lines(points, lines_material, true);
+		p_gizmo->add_lines(points_billboard, lines_billboard_material, true);
 		p_gizmo->add_unscaled_billboard(icon, 0.05);
 
 		Vector<Vector3> handles;
@@ -1009,40 +1018,44 @@ void LightSpatialGizmoPlugin::redraw(EditorSpatialGizmo *p_gizmo) {
 
 	if (Object::cast_to<SpotLight>(light)) {
 
-		Ref<Material> material = get_material("lines", p_gizmo);
-		Ref<Material> icon = get_material("light_spot_icon", p_gizmo);
+		const Ref<Material> material_primary = get_material("lines_primary", p_gizmo);
+		const Ref<Material> material_secondary = get_material("lines_secondary", p_gizmo);
+		const Ref<Material> icon = get_material("light_spot_icon", p_gizmo);
 
-		Vector<Vector3> points;
+		Vector<Vector3> points_primary;
+		Vector<Vector3> points_secondary;
 		SpotLight *sl = Object::cast_to<SpotLight>(light);
 
 		float r = sl->get_param(Light::PARAM_RANGE);
 		float w = r * Math::sin(Math::deg2rad(sl->get_param(Light::PARAM_SPOT_ANGLE)));
 		float d = r * Math::cos(Math::deg2rad(sl->get_param(Light::PARAM_SPOT_ANGLE)));
 
-		for (int i = 0; i < 360; i++) {
-
-			float ra = Math::deg2rad((float)i);
-			float rb = Math::deg2rad((float)i + 1);
-			Point2 a = Vector2(Math::sin(ra), Math::cos(ra)) * w;
-			Point2 b = Vector2(Math::sin(rb), Math::cos(rb)) * w;
+		for (int i = 0; i < 120; i++) {
 
-			points.push_back(Vector3(a.x, a.y, -d));
-			points.push_back(Vector3(b.x, b.y, -d));
+			// Draw a circle
+			const float ra = Math::deg2rad((float)(i * 3));
+			const float rb = Math::deg2rad((float)((i + 1) * 3));
+			const Point2 a = Vector2(Math::sin(ra), Math::cos(ra)) * w;
+			const Point2 b = Vector2(Math::sin(rb), Math::cos(rb)) * w;
 
-			if (i % 90 == 0) {
+			points_primary.push_back(Vector3(a.x, a.y, -d));
+			points_primary.push_back(Vector3(b.x, b.y, -d));
 
-				points.push_back(Vector3(a.x, a.y, -d));
-				points.push_back(Vector3());
+			if (i % 15 == 0) {
+				// Draw 8 lines from the cone origin to the sides of the circle
+				points_secondary.push_back(Vector3(a.x, a.y, -d));
+				points_secondary.push_back(Vector3());
 			}
 		}
 
-		points.push_back(Vector3(0, 0, -r));
-		points.push_back(Vector3());
+		points_primary.push_back(Vector3(0, 0, -r));
+		points_primary.push_back(Vector3());
 
-		p_gizmo->add_lines(points, material);
+		p_gizmo->add_lines(points_primary, material_primary);
+		p_gizmo->add_lines(points_secondary, material_secondary);
 
-		float ra = 16 * Math_PI * 2.0 / 64.0;
-		Point2 a = Vector2(Math::sin(ra), Math::cos(ra)) * w;
+		const float ra = 16 * Math_PI * 2.0 / 64.0;
+		const Point2 a = Vector2(Math::sin(ra), Math::cos(ra)) * w;
 
 		Vector<Vector3> handles;
 		handles.push_back(Vector3(0, 0, -r));