Style: Partially apply clang-tidy's `cppcoreguidelines-pro-type-member-init`

Didn't commit all the changes where it wants to initialize a struct
with `{}`. Should be reviewed in a separate PR.

Option `IgnoreArrays` enabled for now to be conservative, can be
disabled to see if it proposes more useful changes.

Also fixed manually a handful of other missing initializations / moved
some from constructors.

7 files changed, 22 insertions, 27 deletions

diff --git a/scene/2d/area_2d.h b/scene/2d/area_2d.h
index 68047ccebf..a42e7722b0 100644
--- a/scene/2d/area_2d.h
+++ b/scene/2d/area_2d.h
@@ -49,7 +49,7 @@ public:
 private:
 	SpaceOverride gravity_space_override = SPACE_OVERRIDE_DISABLED;
 	Vector2 gravity_vec;
-	real_t gravity;
+	real_t gravity = 0.0;
 	bool gravity_is_point = false;
 	real_t gravity_distance_scale = 0.0;
 
diff --git a/scene/2d/cpu_particles_2d.h b/scene/2d/cpu_particles_2d.h
index 7ae51e3966..51d58723b4 100644
--- a/scene/2d/cpu_particles_2d.h
+++ b/scene/2d/cpu_particles_2d.h
@@ -137,7 +137,7 @@ private:
 	real_t randomness_ratio = 0.0;
 	double lifetime_randomness = 0.0;
 	double speed_scale = 1.0;
-	bool local_coords;
+	bool local_coords = false;
 	int fixed_fps = 0;
 	bool fractional_delta = true;
 
diff --git a/scene/2d/gpu_particles_2d.cpp b/scene/2d/gpu_particles_2d.cpp
index 04518dff97..35f1ae5421 100644
--- a/scene/2d/gpu_particles_2d.cpp
+++ b/scene/2d/gpu_particles_2d.cpp
@@ -666,9 +666,6 @@ GPUParticles2D::GPUParticles2D() {
 	set_speed_scale(1);
 	set_fixed_fps(30);
 	set_collision_base_size(collision_base_size);
-#ifdef TOOLS_ENABLED
-	show_visibility_rect = false;
-#endif
 }
 
 GPUParticles2D::~GPUParticles2D() {
diff --git a/scene/2d/gpu_particles_2d.h b/scene/2d/gpu_particles_2d.h
index 852270dd3c..3c7f4cd9b5 100644
--- a/scene/2d/gpu_particles_2d.h
+++ b/scene/2d/gpu_particles_2d.h
@@ -47,20 +47,20 @@ public:
 private:
 	RID particles;
 
-	bool one_shot;
-	int amount;
-	double lifetime;
-	double pre_process_time;
-	real_t explosiveness_ratio;
-	real_t randomness_ratio;
-	double speed_scale;
+	bool one_shot = false;
+	int amount = 0;
+	double lifetime = 0.0;
+	double pre_process_time = 0.0;
+	real_t explosiveness_ratio = 0.0;
+	real_t randomness_ratio = 0.0;
+	double speed_scale = 0.0;
 	Rect2 visibility_rect;
-	bool local_coords;
-	int fixed_fps;
-	bool fractional_delta;
+	bool local_coords = false;
+	int fixed_fps = 0;
+	bool fractional_delta = false;
 	bool interpolate = true;
 #ifdef TOOLS_ENABLED
-	bool show_visibility_rect;
+	bool show_visibility_rect = false;
 #endif
 	Ref<Material> process_material;
 
diff --git a/scene/2d/light_occluder_2d.cpp b/scene/2d/light_occluder_2d.cpp
index c4e57b375d..14188d7120 100644
--- a/scene/2d/light_occluder_2d.cpp
+++ b/scene/2d/light_occluder_2d.cpp
@@ -285,7 +285,6 @@ void LightOccluder2D::_bind_methods() {
 
 LightOccluder2D::LightOccluder2D() {
 	occluder = RS::get_singleton()->canvas_light_occluder_create();
-	mask = 1;
 
 	set_notify_transform(true);
 	set_as_sdf_collision(true);
diff --git a/scene/2d/light_occluder_2d.h b/scene/2d/light_occluder_2d.h
index 4f8c6d20df..4acfeaf781 100644
--- a/scene/2d/light_occluder_2d.h
+++ b/scene/2d/light_occluder_2d.h
@@ -81,10 +81,9 @@ class LightOccluder2D : public Node2D {
 	GDCLASS(LightOccluder2D, Node2D);
 
 	RID occluder;
-	bool enabled;
-	int mask;
+	int mask = 1;
 	Ref<OccluderPolygon2D> occluder_polygon;
-	bool sdf_collision;
+	bool sdf_collision = false;
 	void _poly_changed();
 
 protected:
diff --git a/scene/2d/navigation_agent_2d.h b/scene/2d/navigation_agent_2d.h
index 2fb6fab91c..1447e25e8c 100644
--- a/scene/2d/navigation_agent_2d.h
+++ b/scene/2d/navigation_agent_2d.h
@@ -45,17 +45,17 @@ class NavigationAgent2D : public Node {
 	uint32_t navigable_layers = 1;
 
 	real_t target_desired_distance = 1.0;
-	real_t radius;
-	real_t neighbor_dist;
-	int max_neighbors;
-	real_t time_horizon;
-	real_t max_speed;
+	real_t radius = 0.0;
+	real_t neighbor_dist = 0.0;
+	int max_neighbors = 0;
+	real_t time_horizon = 0.0;
+	real_t max_speed = 0.0;
 
 	real_t path_max_distance = 3.0;
 
 	Vector2 target_location;
 	Vector<Vector2> navigation_path;
-	int nav_path_index;
+	int nav_path_index = 0;
 	bool velocity_submitted = false;
 	Vector2 prev_safe_velocity;
 	/// The submitted target velocity
@@ -63,7 +63,7 @@ class NavigationAgent2D : public Node {
 	bool target_reached = false;
 	bool navigation_finished = true;
 	// No initialized on purpose
-	uint32_t update_frame_id;
+	uint32_t update_frame_id = 0;
 
 protected:
 	static void _bind_methods();