Port member initialization from constructor to declaration (C++11)

Using `clang-tidy`'s `modernize-use-default-member-init` check and
manual review of the changes, and some extra manual changes that
`clang-tidy` failed to do.

Also went manually through all of `core` to find occurrences that
`clang-tidy` couldn't handle, especially all initializations done
in a constructor without using initializer lists.

12 files changed, 101 insertions, 169 deletions

diff --git a/servers/audio/effects/audio_effect_record.h b/servers/audio/effects/audio_effect_record.h
index 09101033be..68d968c04b 100644
--- a/servers/audio/effects/audio_effect_record.h
+++ b/servers/audio/effects/audio_effect_record.h
@@ -49,7 +49,7 @@ class AudioEffectRecordInstance : public AudioEffectInstance {
 
 	bool is_recording;
 	Thread *io_thread;
-	bool thread_active;
+	bool thread_active = false;
 
 	Vector<AudioFrame> ring_buffer;
 	Vector<float> recording_data;
@@ -71,8 +71,7 @@ public:
 	virtual void process(const AudioFrame *p_src_frames, AudioFrame *p_dst_frames, int p_frame_count);
 	virtual bool process_silence() const;
 
-	AudioEffectRecordInstance() :
-			thread_active(false) {}
+	AudioEffectRecordInstance() {}
 	~AudioEffectRecordInstance();
 };
 
diff --git a/servers/audio/effects/reverb.cpp b/servers/audio/effects/reverb.cpp
index ea2174f1d4..02565f4516 100644
--- a/servers/audio/effects/reverb.cpp
+++ b/servers/audio/effects/reverb.cpp
@@ -31,7 +31,9 @@
 // Author: Juan Linietsky <reduzio@gmail.com>, (C) 2006
 
 #include "reverb.h"
+
 #include "core/math/math_funcs.h"
+
 #include <math.h>
 
 const float Reverb::comb_tunings[MAX_COMBS] = {
@@ -338,11 +340,8 @@ Reverb::Reverb() {
 	params.predelay = 150;
 	params.predelay_fb = 0.4;
 	params.hpf = 0;
-	hpf_h1 = 0;
-	hpf_h2 = 0;
 
 	input_buffer = memnew_arr(float, INPUT_BUFFER_MAX_SIZE);
-	echo_buffer = nullptr;
 
 	configure_buffers();
 	update_parameters();
diff --git a/servers/audio/effects/reverb.h b/servers/audio/effects/reverb.h
index 92e4aed435..ed8c824148 100644
--- a/servers/audio/effects/reverb.h
+++ b/servers/audio/effects/reverb.h
@@ -58,44 +58,34 @@ private:
 
 	struct Comb {
 
-		int size;
-		float *buffer;
-		float feedback;
-		float damp; //lowpass
-		float damp_h; //history
-		int pos;
-		int extra_spread_frames;
-
-		Comb() {
-			size = 0;
-			buffer = 0;
-			feedback = 0;
-			damp_h = 0;
-			pos = 0;
-		}
+		int size = 0;
+		float *buffer = nullptr;
+		float feedback = 0;
+		float damp = 0; //lowpass
+		float damp_h = 0; //history
+		int pos = 0;
+		int extra_spread_frames = 0;
+
+		Comb() {}
 	};
 
 	struct AllPass {
 
-		int size;
-		float *buffer;
-		int pos;
-		int extra_spread_frames;
-		AllPass() {
-			size = 0;
-			buffer = 0;
-			pos = 0;
-		}
+		int size = 0;
+		float *buffer = nullptr;
+		int pos = 0;
+		int extra_spread_frames = 0;
+		AllPass() {}
 	};
 
 	Comb comb[MAX_COMBS];
 	AllPass allpass[MAX_ALLPASS];
 	float *input_buffer;
-	float *echo_buffer;
+	float *echo_buffer = nullptr;
 	int echo_buffer_size;
 	int echo_buffer_pos;
 
-	float hpf_h1, hpf_h2;
+	float hpf_h1, hpf_h2 = 0;
 
 	struct Parameters {
 
diff --git a/servers/physics_3d/body_3d_sw.cpp b/servers/physics_3d/body_3d_sw.cpp
index fea5aed6ad..2f2525bb75 100644
--- a/servers/physics_3d/body_3d_sw.cpp
+++ b/servers/physics_3d/body_3d_sw.cpp
@@ -764,7 +764,7 @@ void Body3DSW::set_kinematic_margin(real_t p_margin) {
 
 Body3DSW::Body3DSW() :
 		CollisionObject3DSW(TYPE_BODY),
-		locked_axis(0),
+
 		active_list(this),
 		inertia_update_list(this),
 		direct_state_query_list(this) {
diff --git a/servers/physics_3d/body_3d_sw.h b/servers/physics_3d/body_3d_sw.h
index a67894b64b..0308d8689e 100644
--- a/servers/physics_3d/body_3d_sw.h
+++ b/servers/physics_3d/body_3d_sw.h
@@ -54,7 +54,7 @@ class Body3DSW : public CollisionObject3DSW {
 	real_t angular_damp;
 	real_t gravity_scale;
 
-	uint16_t locked_axis;
+	uint16_t locked_axis = 0;
 
 	real_t kinematic_safe_margin;
 	real_t _inv_mass;
diff --git a/servers/physics_3d/gjk_epa.cpp b/servers/physics_3d/gjk_epa.cpp
index db37f261ce..aaa7de7531 100644
--- a/servers/physics_3d/gjk_epa.cpp
+++ b/servers/physics_3d/gjk_epa.cpp
@@ -513,16 +513,16 @@ struct	GJK
 		};
 		struct	sList
 		{
-			sFace*		root;
-			U			count;
-			sList() : root(nullptr),count(0)	{}
+			sFace*		root = nullptr;
+			U			count = 0;
+			sList() 	{}
 		};
 		struct	sHorizon
 		{
-			sFace*		cf;
-			sFace*		ff;
-			U			nf;
-			sHorizon() : cf(nullptr),ff(nullptr),nf(0)	{}
+			sFace*		cf = nullptr;
+			sFace*		ff = nullptr;
+			U			nf = 0;
+			sHorizon() 	{}
 		};
 		struct	eStatus { enum _ {
 			Valid,
diff --git a/servers/physics_3d/joints/jacobian_entry_3d_sw.h b/servers/physics_3d/joints/jacobian_entry_3d_sw.h
index 7e605ab173..1737c21b3d 100644
--- a/servers/physics_3d/joints/jacobian_entry_3d_sw.h
+++ b/servers/physics_3d/joints/jacobian_entry_3d_sw.h
@@ -54,7 +54,7 @@ subject to the following restrictions:
 
 class JacobianEntry3DSW {
 public:
-	JacobianEntry3DSW(){};
+	JacobianEntry3DSW() {}
 	//constraint between two different rigidbodies
 	JacobianEntry3DSW(
 			const Basis &world2A,
diff --git a/servers/physics_server_2d.h b/servers/physics_server_2d.h
index 8c833b390f..7f73a50b34 100644
--- a/servers/physics_server_2d.h
+++ b/servers/physics_server_2d.h
@@ -640,11 +640,9 @@ typedef PhysicsServer2D *(*CreatePhysicsServer2DCallback)();
 class PhysicsServer2DManager {
 	struct ClassInfo {
 		String name;
-		CreatePhysicsServer2DCallback create_callback;
+		CreatePhysicsServer2DCallback create_callback = nullptr;
 
-		ClassInfo() :
-				name(""),
-				create_callback(nullptr) {}
+		ClassInfo() {}
 
 		ClassInfo(String p_name, CreatePhysicsServer2DCallback p_create_callback) :
 				name(p_name),
diff --git a/servers/physics_server_3d.h b/servers/physics_server_3d.h
index 8ea8b22455..6900da1393 100644
--- a/servers/physics_server_3d.h
+++ b/servers/physics_server_3d.h
@@ -781,11 +781,9 @@ typedef PhysicsServer3D *(*CreatePhysicsServer3DCallback)();
 class PhysicsServer3DManager {
 	struct ClassInfo {
 		String name;
-		CreatePhysicsServer3DCallback create_callback;
+		CreatePhysicsServer3DCallback create_callback = nullptr;
 
-		ClassInfo() :
-				name(""),
-				create_callback(nullptr) {}
+		ClassInfo() {}
 
 		ClassInfo(String p_name, CreatePhysicsServer3DCallback p_create_callback) :
 				name(p_name),
diff --git a/servers/rendering/rasterizer_rd/rasterizer_canvas_rd.h b/servers/rendering/rasterizer_rd/rasterizer_canvas_rd.h
index 4d47b3e13b..48467cbd8c 100644
--- a/servers/rendering/rasterizer_rd/rasterizer_canvas_rd.h
+++ b/servers/rendering/rasterizer_rd/rasterizer_canvas_rd.h
@@ -489,7 +489,7 @@ public:
 
 	void canvas_render_items(RID p_to_render_target, Item *p_item_list, const Color &p_modulate, Light *p_light_list, const Transform2D &p_canvas_transform);
 
-	void canvas_debug_viewport_shadows(Light *p_lights_with_shadow){};
+	void canvas_debug_viewport_shadows(Light *p_lights_with_shadow) {}
 
 	void draw_window_margins(int *p_margins, RID *p_margin_textures) {}
 
diff --git a/servers/rendering/shader_language.h b/servers/rendering/shader_language.h
index 314e4a5fba..c78d850e21 100644
--- a/servers/rendering/shader_language.h
+++ b/servers/rendering/shader_language.h
@@ -328,7 +328,7 @@ public:
 	};
 
 	struct Node {
-		Node *next;
+		Node *next = nullptr;
 
 		enum Type {
 			TYPE_SHADER,
@@ -352,7 +352,6 @@ public:
 		virtual String get_datatype_name() const { return ""; }
 
 		Node(Type t) :
-				next(nullptr),
 				type(t) {}
 		virtual ~Node() {}
 	};
@@ -368,41 +367,35 @@ public:
 	Node *nodes;
 
 	struct OperatorNode : public Node {
-		DataType return_cache;
-		DataPrecision return_precision_cache;
-		Operator op;
+		DataType return_cache = TYPE_VOID;
+		DataPrecision return_precision_cache = PRECISION_DEFAULT;
+		Operator op = OP_EQUAL;
 		StringName struct_name;
 		Vector<Node *> arguments;
 		virtual DataType get_datatype() const { return return_cache; }
 		virtual String get_datatype_name() const { return String(struct_name); }
 
 		OperatorNode() :
-				Node(TYPE_OPERATOR),
-				return_cache(TYPE_VOID),
-				return_precision_cache(PRECISION_DEFAULT),
-				op(OP_EQUAL),
-				struct_name("") {}
+				Node(TYPE_OPERATOR) {}
 	};
 
 	struct VariableNode : public Node {
-		DataType datatype_cache;
+		DataType datatype_cache = TYPE_VOID;
 		StringName name;
 		StringName struct_name;
 		virtual DataType get_datatype() const { return datatype_cache; }
 		virtual String get_datatype_name() const { return String(struct_name); }
-		bool is_const;
+		bool is_const = false;
 
 		VariableNode() :
-				Node(TYPE_VARIABLE),
-				datatype_cache(TYPE_VOID),
-				is_const(false) {}
+				Node(TYPE_VARIABLE) {}
 	};
 
 	struct VariableDeclarationNode : public Node {
-		DataPrecision precision;
-		DataType datatype;
+		DataPrecision precision = PRECISION_DEFAULT;
+		DataType datatype = TYPE_VOID;
 		String struct_name;
-		bool is_const;
+		bool is_const = false;
 
 		struct Declaration {
 			StringName name;
@@ -413,47 +406,38 @@ public:
 		virtual DataType get_datatype() const { return datatype; }
 
 		VariableDeclarationNode() :
-				Node(TYPE_VARIABLE_DECLARATION),
-				precision(PRECISION_DEFAULT),
-				datatype(TYPE_VOID),
-				is_const(false) {}
+				Node(TYPE_VARIABLE_DECLARATION) {}
 	};
 
 	struct ArrayNode : public Node {
-		DataType datatype_cache;
+		DataType datatype_cache = TYPE_VOID;
 		StringName struct_name;
 		StringName name;
-		Node *index_expression;
-		Node *call_expression;
-		bool is_const;
+		Node *index_expression = nullptr;
+		Node *call_expression = nullptr;
+		bool is_const = false;
 
 		virtual DataType get_datatype() const { return datatype_cache; }
 		virtual String get_datatype_name() const { return String(struct_name); }
 
 		ArrayNode() :
-				Node(TYPE_ARRAY),
-				datatype_cache(TYPE_VOID),
-				index_expression(nullptr),
-				call_expression(nullptr),
-				is_const(false) {}
+				Node(TYPE_ARRAY) {}
 	};
 
 	struct ArrayConstructNode : public Node {
-		DataType datatype;
+		DataType datatype = TYPE_VOID;
 		String struct_name;
 		Vector<Node *> initializer;
 
 		ArrayConstructNode() :
-				Node(TYPE_ARRAY_CONSTRUCT),
-				datatype(TYPE_VOID) {
-		}
+				Node(TYPE_ARRAY_CONSTRUCT) {}
 	};
 
 	struct ArrayDeclarationNode : public Node {
-		DataPrecision precision;
-		DataType datatype;
+		DataPrecision precision = PRECISION_DEFAULT;
+		DataType datatype = TYPE_VOID;
 		String struct_name;
-		bool is_const;
+		bool is_const = false;
 
 		struct Declaration {
 			StringName name;
@@ -465,14 +449,11 @@ public:
 		virtual DataType get_datatype() const { return datatype; }
 
 		ArrayDeclarationNode() :
-				Node(TYPE_ARRAY_DECLARATION),
-				precision(PRECISION_DEFAULT),
-				datatype(TYPE_VOID),
-				is_const(false) {}
+				Node(TYPE_ARRAY_DECLARATION) {}
 	};
 
 	struct ConstantNode : public Node {
-		DataType datatype;
+		DataType datatype = TYPE_VOID;
 
 		union Value {
 			bool boolean;
@@ -485,15 +466,14 @@ public:
 		virtual DataType get_datatype() const { return datatype; }
 
 		ConstantNode() :
-				Node(TYPE_CONSTANT),
-				datatype(TYPE_VOID) {}
+				Node(TYPE_CONSTANT) {}
 	};
 
 	struct FunctionNode;
 
 	struct BlockNode : public Node {
-		FunctionNode *parent_function;
-		BlockNode *parent_block;
+		FunctionNode *parent_function = nullptr;
+		BlockNode *parent_block = nullptr;
 
 		enum BlockType {
 			BLOCK_TYPE_STANDART,
@@ -503,8 +483,8 @@ public:
 			BLOCK_TYPE_DEFAULT,
 		};
 
-		int block_type;
-		SubClassTag block_tag;
+		int block_type = BLOCK_TYPE_STANDART;
+		SubClassTag block_tag = SubClassTag::TAG_GLOBAL;
 
 		struct Variable {
 			DataType type;
@@ -517,52 +497,39 @@ public:
 
 		Map<StringName, Variable> variables;
 		List<Node *> statements;
-		bool single_statement;
+		bool single_statement = false;
 
 		BlockNode() :
-				Node(TYPE_BLOCK),
-				parent_function(nullptr),
-				parent_block(nullptr),
-				block_type(BLOCK_TYPE_STANDART),
-				block_tag(SubClassTag::TAG_GLOBAL),
-				single_statement(false) {}
+				Node(TYPE_BLOCK) {}
 	};
 
 	struct ControlFlowNode : public Node {
-		FlowOperation flow_op;
+		FlowOperation flow_op = FLOW_OP_IF;
 		Vector<Node *> expressions;
 		Vector<BlockNode *> blocks;
 
 		ControlFlowNode() :
-				Node(TYPE_CONTROL_FLOW),
-				flow_op(FLOW_OP_IF) {}
+				Node(TYPE_CONTROL_FLOW) {}
 	};
 
 	struct MemberNode : public Node {
-		DataType basetype;
-		bool basetype_const;
+		DataType basetype = TYPE_VOID;
+		bool basetype_const = false;
 		StringName base_struct_name;
 		DataPrecision precision;
-		DataType datatype;
-		int array_size;
+		DataType datatype = TYPE_VOID;
+		int array_size = 0;
 		StringName struct_name;
 		StringName name;
-		Node *owner;
-		Node *index_expression;
-		bool has_swizzling_duplicates;
+		Node *owner = nullptr;
+		Node *index_expression = nullptr;
+		bool has_swizzling_duplicates = false;
 
 		virtual DataType get_datatype() const { return datatype; }
 		virtual String get_datatype_name() const { return String(struct_name); }
 
 		MemberNode() :
-				Node(TYPE_MEMBER),
-				basetype(TYPE_VOID),
-				basetype_const(false),
-				datatype(TYPE_VOID),
-				array_size(0),
-				owner(nullptr),
-				index_expression(nullptr),
-				has_swizzling_duplicates(false) {}
+				Node(TYPE_MEMBER) {}
 	};
 
 	struct StructNode : public Node {
@@ -591,19 +558,15 @@ public:
 		};
 
 		StringName name;
-		DataType return_type;
+		DataType return_type = TYPE_VOID;
 		StringName return_struct_name;
-		DataPrecision return_precision;
+		DataPrecision return_precision = PRECISION_DEFAULT;
 		Vector<Argument> arguments;
-		BlockNode *body;
-		bool can_discard;
+		BlockNode *body = nullptr;
+		bool can_discard = false;
 
 		FunctionNode() :
-				Node(TYPE_FUNCTION),
-				return_type(TYPE_VOID),
-				return_precision(PRECISION_DEFAULT),
-				body(nullptr),
-				can_discard(false) {}
+				Node(TYPE_FUNCTION) {}
 	};
 
 	struct ShaderNode : public Node {
@@ -629,16 +592,12 @@ public:
 		};
 
 		struct Varying {
-			DataType type;
-			DataInterpolation interpolation;
-			DataPrecision precision;
-			int array_size;
+			DataType type = TYPE_VOID;
+			DataInterpolation interpolation = INTERPOLATION_FLAT;
+			DataPrecision precision = PRECISION_DEFAULT;
+			int array_size = 0;
 
-			Varying() :
-					type(TYPE_VOID),
-					interpolation(INTERPOLATION_FLAT),
-					precision(PRECISION_DEFAULT),
-					array_size(0) {}
+			Varying() {}
 		};
 
 		struct Uniform {
@@ -667,28 +626,19 @@ public:
 				SCOPE_GLOBAL,
 			};
 
-			int order;
-			int texture_order;
-			DataType type;
-			DataPrecision precision;
+			int order = 0;
+			int texture_order = 0;
+			DataType type = TYPE_VOID;
+			DataPrecision precision = PRECISION_DEFAULT;
 			Vector<ConstantNode::Value> default_value;
-			Scope scope;
-			Hint hint;
-			TextureFilter filter;
-			TextureRepeat repeat;
+			Scope scope = SCOPE_LOCAL;
+			Hint hint = HINT_NONE;
+			TextureFilter filter = FILTER_DEFAULT;
+			TextureRepeat repeat = REPEAT_DEFAULT;
 			float hint_range[3];
-			int instance_index;
-
-			Uniform() :
-					order(0),
-					texture_order(0),
-					type(TYPE_VOID),
-					precision(PRECISION_DEFAULT),
-					scope(SCOPE_LOCAL),
-					hint(HINT_NONE),
-					filter(FILTER_DEFAULT),
-					repeat(REPEAT_DEFAULT),
-					instance_index(0) {
+			int instance_index = 0;
+
+			Uniform() {
 				hint_range[0] = 0.0f;
 				hint_range[1] = 1.0f;
 				hint_range[2] = 0.001f;
@@ -768,12 +718,10 @@ public:
 	static void get_builtin_funcs(List<String> *r_keywords);
 
 	struct BuiltInInfo {
-		DataType type;
-		bool constant;
+		DataType type = TYPE_VOID;
+		bool constant = false;
 
-		BuiltInInfo() :
-				type(TYPE_VOID),
-				constant(false) {}
+		BuiltInInfo() {}
 
 		BuiltInInfo(DataType p_type, bool p_constant = false) :
 				type(p_type),
diff --git a/servers/xr/xr_interface.cpp b/servers/xr/xr_interface.cpp
index c1233ae810..5ffe50894a 100644
--- a/servers/xr/xr_interface.cpp
+++ b/servers/xr/xr_interface.cpp
@@ -122,7 +122,7 @@ XRInterface::XRInterface() {
 	tracking_state = XR_UNKNOWN_TRACKING;
 };
 
-XRInterface::~XRInterface(){};
+XRInterface::~XRInterface() {}
 
 // optional render to external texture which enhances performance on those platforms that require us to submit our end result into special textures.
 unsigned int XRInterface::get_external_texture_for_eye(XRInterface::Eyes p_eye) {