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.

4 files changed, 29 insertions, 27 deletions

diff --git a/servers/physics_3d/gjk_epa.cpp b/servers/physics_3d/gjk_epa.cpp
index 23c8079538..ba362740b2 100644
--- a/servers/physics_3d/gjk_epa.cpp
+++ b/servers/physics_3d/gjk_epa.cpp
@@ -113,7 +113,7 @@ struct	MinkowskiDiff {
 	real_t margin_A = 0.0;
 	real_t margin_B = 0.0;
 
-	Vector3 (*get_support)(const GodotShape3D*, const Vector3&, real_t);
+	Vector3 (*get_support)(const GodotShape3D*, const Vector3&, real_t) = nullptr;
 
 	void Initialize(const GodotShape3D* shape0, const Transform3D& wtrs0, const real_t margin0,
 		const GodotShape3D* shape1, const Transform3D& wtrs1, const real_t margin1) {
@@ -191,13 +191,13 @@ struct	GJK
 		/* Fields		*/
 		tShape			m_shape;
 		Vector3		m_ray;
-		real_t		m_distance;
+		real_t		m_distance = 0.0f;
 		sSimplex		m_simplices[2];
 		sSV				m_store[4];
 		sSV*			m_free[4];
-		U				m_nfree;
-		U				m_current;
-		sSimplex*		m_simplex;
+		U				m_nfree = 0;
+		U				m_current = 0;
+		sSimplex*		m_simplex = nullptr;
 		eStatus::_		m_status;
 		/* Methods		*/
 		GJK()
@@ -548,12 +548,12 @@ struct	GJK
 		struct	sFace
 		{
 			Vector3	n;
-			real_t	d;
+			real_t	d = 0.0f;
 			sSV*		c[3];
 			sFace*		f[3];
 			sFace*		l[2];
 			U1			e[3];
-			U1			pass;
+			U1			pass = 0;
 		};
 		struct	sList
 		{
@@ -583,10 +583,10 @@ struct	GJK
 			eStatus::_		m_status;
 			GJK::sSimplex	m_result;
 			Vector3		m_normal;
-			real_t		m_depth;
+			real_t		m_depth = 0.0f;
 			sSV				m_sv_store[EPA_MAX_VERTICES];
 			sFace			m_fc_store[EPA_MAX_FACES];
-			U				m_nextsv;
+			U				m_nextsv = 0;
 			sList			m_hull;
 			sList			m_stock;
 			/* Methods		*/
diff --git a/servers/physics_3d/godot_collision_solver_3d.cpp b/servers/physics_3d/godot_collision_solver_3d.cpp
index 0adfabef78..afc74df166 100644
--- a/servers/physics_3d/godot_collision_solver_3d.cpp
+++ b/servers/physics_3d/godot_collision_solver_3d.cpp
@@ -29,6 +29,7 @@
 /*************************************************************************/
 
 #include "godot_collision_solver_3d.h"
+
 #include "godot_collision_solver_3d_sat.h"
 #include "godot_soft_body_3d.h"
 
@@ -276,19 +277,20 @@ bool GodotCollisionSolver3D::solve_soft_body(const GodotShape3D *p_shape_A, cons
 }
 
 struct _ConcaveCollisionInfo {
-	const Transform3D *transform_A;
-	const GodotShape3D *shape_A;
-	const Transform3D *transform_B;
-	GodotCollisionSolver3D::CallbackResult result_callback;
-	void *userdata;
-	bool swap_result;
-	bool collided;
-	int aabb_tests;
-	int collisions;
-	bool tested;
-	real_t margin_A;
-	real_t margin_B;
-	Vector3 close_A, close_B;
+	const Transform3D *transform_A = nullptr;
+	const GodotShape3D *shape_A = nullptr;
+	const Transform3D *transform_B = nullptr;
+	GodotCollisionSolver3D::CallbackResult result_callback = nullptr;
+	void *userdata = nullptr;
+	bool swap_result = false;
+	bool collided = false;
+	int aabb_tests = 0;
+	int collisions = 0;
+	bool tested = false;
+	real_t margin_A = 0.0f;
+	real_t margin_B = 0.0f;
+	Vector3 close_A;
+	Vector3 close_B;
 };
 
 bool GodotCollisionSolver3D::concave_callback(void *p_userdata, GodotShape3D *p_convex) {
diff --git a/servers/physics_3d/godot_collision_solver_3d_sat.cpp b/servers/physics_3d/godot_collision_solver_3d_sat.cpp
index ca429040f5..7b7a09f31d 100644
--- a/servers/physics_3d/godot_collision_solver_3d_sat.cpp
+++ b/servers/physics_3d/godot_collision_solver_3d_sat.cpp
@@ -68,7 +68,7 @@
  *************************************************************************/
 
 struct _CollectorCallback {
-	GodotCollisionSolver3D::CallbackResult callback;
+	GodotCollisionSolver3D::CallbackResult callback = nullptr;
 	void *userdata = nullptr;
 	bool swap = false;
 	bool collided = false;
diff --git a/servers/physics_3d/godot_shape_3d.cpp b/servers/physics_3d/godot_shape_3d.cpp
index 21595c9612..63ba28258f 100644
--- a/servers/physics_3d/godot_shape_3d.cpp
+++ b/servers/physics_3d/godot_shape_3d.cpp
@@ -1438,7 +1438,7 @@ Vector3 GodotConcavePolygonShape3D::get_moment_of_inertia(real_t p_mass) const {
 struct _Volume_BVH_Element {
 	AABB aabb;
 	Vector3 center;
-	int face_index;
+	int face_index = 0;
 };
 
 struct _Volume_BVH_CompareX {
@@ -1461,10 +1461,10 @@ struct _Volume_BVH_CompareZ {
 
 struct _Volume_BVH {
 	AABB aabb;
-	_Volume_BVH *left;
-	_Volume_BVH *right;
+	_Volume_BVH *left = nullptr;
+	_Volume_BVH *right = nullptr;
 
-	int face_index;
+	int face_index = 0;
 };
 
 _Volume_BVH *_volume_build_bvh(_Volume_BVH_Element *p_elements, int p_size, int &count) {