Implement Vector4, Vector4i, Projection

Implement built-in classes Vector4, Vector4i and Projection.

* Two versions of Vector4 (float and integer).
* A Projection class, which is a 4x4 matrix specialized in projection types.

These types have been requested for a long time, but given they were very corner case they were not added before.
Because in Godot 4, reimplementing parts of the rendering engine is now possible, access to these types (heavily used by the rendering code) becomes a necessity.

**Q**: Why Projection and not Matrix4?
**A**: Godot does not use Matrix2, Matrix3, Matrix4x3, etc. naming convention because, within the engine, these types always have a *purpose*. As such, Godot names them: Transform2D, Transform3D or Basis. In this case, this 4x4 matrix is _always_ used as a _Projection_, hence the naming.

8 files changed, 145 insertions, 4 deletions

diff --git a/modules/mono/csharp_script.cpp b/modules/mono/csharp_script.cpp
index 3dc26cfbe4..1e4d82ca30 100644
--- a/modules/mono/csharp_script.cpp
+++ b/modules/mono/csharp_script.cpp
@@ -481,11 +481,14 @@ static String variant_type_to_managed_name(const String &p_var_type_name) {
 		Variant::VECTOR3,
 		Variant::VECTOR3I,
 		Variant::TRANSFORM2D,
+		Variant::VECTOR4,
+		Variant::VECTOR4I,
 		Variant::PLANE,
 		Variant::QUATERNION,
 		Variant::AABB,
 		Variant::BASIS,
 		Variant::TRANSFORM3D,
+		Variant::PROJECTION,
 		Variant::COLOR,
 		Variant::STRING_NAME,
 		Variant::NODE_PATH,
diff --git a/modules/mono/editor/bindings_generator.cpp b/modules/mono/editor/bindings_generator.cpp
index 7cc195201b..2e628cb576 100644
--- a/modules/mono/editor/bindings_generator.cpp
+++ b/modules/mono/editor/bindings_generator.cpp
@@ -917,6 +917,8 @@ void BindingsGenerator::_generate_array_extensions(StringBuilder &p_output) {
 	ARRAY_ALL(Vector2i);
 	ARRAY_ALL(Vector3);
 	ARRAY_ALL(Vector3i);
+	ARRAY_ALL(Vector4);
+	ARRAY_ALL(Vector4i);
 
 #undef ARRAY_ALL
 #undef ARRAY_IS_EMPTY
@@ -3222,6 +3224,11 @@ bool BindingsGenerator::_arg_default_value_from_variant(const Variant &p_val, Ar
 			r_iarg.default_argument = "new %s" + r_iarg.default_argument;
 			r_iarg.def_param_mode = ArgumentInterface::NULLABLE_VAL;
 			break;
+		case Variant::VECTOR4:
+		case Variant::VECTOR4I:
+			r_iarg.default_argument = "new %s" + r_iarg.default_argument;
+			r_iarg.def_param_mode = ArgumentInterface::NULLABLE_VAL;
+			break;
 		case Variant::OBJECT:
 			ERR_FAIL_COND_V_MSG(!p_val.is_zero(), false,
 					"Parameter of type '" + String(r_iarg.type.cname) + "' can only have null/zero as the default value.");
@@ -3276,6 +3283,15 @@ bool BindingsGenerator::_arg_default_value_from_variant(const Variant &p_val, Ar
 			}
 			r_iarg.def_param_mode = ArgumentInterface::NULLABLE_VAL;
 		} break;
+		case Variant::PROJECTION: {
+			Projection transform = p_val.operator Projection();
+			if (transform == Projection()) {
+				r_iarg.default_argument = "Projection.Identity";
+			} else {
+				r_iarg.default_argument = "new Projection(new Vector4" + transform.matrix[0].operator String() + ", new Vector4" + transform.matrix[1].operator String() + ", new Vector4" + transform.matrix[2].operator String() + ", new Vector4" + transform.matrix[3].operator String() + ")";
+			}
+			r_iarg.def_param_mode = ArgumentInterface::NULLABLE_VAL;
+		} break;
 		case Variant::BASIS: {
 			Basis basis = p_val.operator Basis();
 			if (basis == Basis()) {
diff --git a/modules/mono/editor/bindings_generator.h b/modules/mono/editor/bindings_generator.h
index 1547d0ed2f..ee170e4558 100644
--- a/modules/mono/editor/bindings_generator.h
+++ b/modules/mono/editor/bindings_generator.h
@@ -590,6 +590,9 @@ class BindingsGenerator {
 		StringName type_Vector2 = StaticCString::create("Vector2");
 		StringName type_Rect2 = StaticCString::create("Rect2");
 		StringName type_Vector3 = StaticCString::create("Vector3");
+		StringName type_Vector3i = StaticCString::create("Vector3i");
+		StringName type_Vector4 = StaticCString::create("Vector4");
+		StringName type_Vector4i = StaticCString::create("Vector4i");
 
 		// Object not included as it must be checked for all derived classes
 		static constexpr int nullable_types_count = 17;
diff --git a/modules/mono/mono_gd/gd_mono_cache.cpp b/modules/mono/mono_gd/gd_mono_cache.cpp
index fd78fae4ad..69d8c7edc9 100644
--- a/modules/mono/mono_gd/gd_mono_cache.cpp
+++ b/modules/mono/mono_gd/gd_mono_cache.cpp
@@ -108,9 +108,12 @@ void CachedData::clear_godot_api_cache() {
 	class_Transform2D = nullptr;
 	class_Vector3 = nullptr;
 	class_Vector3i = nullptr;
+	class_Vector4 = nullptr;
+	class_Vector4i = nullptr;
 	class_Basis = nullptr;
 	class_Quaternion = nullptr;
 	class_Transform3D = nullptr;
+	class_Projection = nullptr;
 	class_AABB = nullptr;
 	class_Color = nullptr;
 	class_Plane = nullptr;
@@ -239,9 +242,12 @@ void update_godot_api_cache() {
 	CACHE_CLASS_AND_CHECK(Transform2D, GODOT_API_CLASS(Transform2D));
 	CACHE_CLASS_AND_CHECK(Vector3, GODOT_API_CLASS(Vector3));
 	CACHE_CLASS_AND_CHECK(Vector3i, GODOT_API_CLASS(Vector3i));
+	CACHE_CLASS_AND_CHECK(Vector4, GODOT_API_CLASS(Vector4));
+	CACHE_CLASS_AND_CHECK(Vector4i, GODOT_API_CLASS(Vector4i));
 	CACHE_CLASS_AND_CHECK(Basis, GODOT_API_CLASS(Basis));
 	CACHE_CLASS_AND_CHECK(Quaternion, GODOT_API_CLASS(Quaternion));
 	CACHE_CLASS_AND_CHECK(Transform3D, GODOT_API_CLASS(Transform3D));
+	CACHE_CLASS_AND_CHECK(Projection, GODOT_API_CLASS(Projection));
 	CACHE_CLASS_AND_CHECK(AABB, GODOT_API_CLASS(AABB));
 	CACHE_CLASS_AND_CHECK(Color, GODOT_API_CLASS(Color));
 	CACHE_CLASS_AND_CHECK(Plane, GODOT_API_CLASS(Plane));
diff --git a/modules/mono/mono_gd/gd_mono_cache.h b/modules/mono/mono_gd/gd_mono_cache.h
index b3b0865608..e9cc26899e 100644
--- a/modules/mono/mono_gd/gd_mono_cache.h
+++ b/modules/mono/mono_gd/gd_mono_cache.h
@@ -79,9 +79,12 @@ struct CachedData {
 	GDMonoClass *class_Transform2D = nullptr;
 	GDMonoClass *class_Vector3 = nullptr;
 	GDMonoClass *class_Vector3i = nullptr;
+	GDMonoClass *class_Vector4 = nullptr;
+	GDMonoClass *class_Vector4i = nullptr;
 	GDMonoClass *class_Basis = nullptr;
 	GDMonoClass *class_Quaternion = nullptr;
 	GDMonoClass *class_Transform3D = nullptr;
+	GDMonoClass *class_Projection = nullptr;
 	GDMonoClass *class_AABB = nullptr;
 	GDMonoClass *class_Color = nullptr;
 	GDMonoClass *class_Plane = nullptr;
diff --git a/modules/mono/mono_gd/gd_mono_field.cpp b/modules/mono/mono_gd/gd_mono_field.cpp
index 333a06c94a..cb025fc67a 100644
--- a/modules/mono/mono_gd/gd_mono_field.cpp
+++ b/modules/mono/mono_gd/gd_mono_field.cpp
@@ -140,6 +140,18 @@ void GDMonoField::set_value_from_variant(MonoObject *p_object, const Variant &p_
 				break;
 			}
 
+			if (tclass == CACHED_CLASS(Vector4)) {
+				GDMonoMarshal::M_Vector4 from = MARSHALLED_OUT(Vector4, p_value.operator ::Vector4());
+				mono_field_set_value(p_object, mono_field, &from);
+				break;
+			}
+
+			if (tclass == CACHED_CLASS(Vector4i)) {
+				GDMonoMarshal::M_Vector4i from = MARSHALLED_OUT(Vector4i, p_value.operator ::Vector4i());
+				mono_field_set_value(p_object, mono_field, &from);
+				break;
+			}
+
 			if (tclass == CACHED_CLASS(Basis)) {
 				GDMonoMarshal::M_Basis from = MARSHALLED_OUT(Basis, p_value.operator ::Basis());
 				mono_field_set_value(p_object, mono_field, &from);
@@ -158,6 +170,12 @@ void GDMonoField::set_value_from_variant(MonoObject *p_object, const Variant &p_
 				break;
 			}
 
+			if (tclass == CACHED_CLASS(Projection)) {
+				GDMonoMarshal::M_Projection from = MARSHALLED_OUT(Projection, p_value.operator ::Projection());
+				mono_field_set_value(p_object, mono_field, &from);
+				break;
+			}
+
 			if (tclass == CACHED_CLASS(AABB)) {
 				GDMonoMarshal::M_AABB from = MARSHALLED_OUT(AABB, p_value.operator ::AABB());
 				mono_field_set_value(p_object, mono_field, &from);
@@ -328,6 +346,14 @@ void GDMonoField::set_value_from_variant(MonoObject *p_object, const Variant &p_
 					GDMonoMarshal::M_Vector3i from = MARSHALLED_OUT(Vector3i, p_value.operator ::Vector3i());
 					mono_field_set_value(p_object, mono_field, &from);
 				} break;
+				case Variant::VECTOR4: {
+					GDMonoMarshal::M_Vector4 from = MARSHALLED_OUT(Vector4, p_value.operator ::Vector4());
+					mono_field_set_value(p_object, mono_field, &from);
+				} break;
+				case Variant::VECTOR4I: {
+					GDMonoMarshal::M_Vector4i from = MARSHALLED_OUT(Vector4i, p_value.operator ::Vector4i());
+					mono_field_set_value(p_object, mono_field, &from);
+				} break;
 				case Variant::TRANSFORM2D: {
 					GDMonoMarshal::M_Transform2D from = MARSHALLED_OUT(Transform2D, p_value.operator ::Transform2D());
 					mono_field_set_value(p_object, mono_field, &from);
@@ -352,6 +378,10 @@ void GDMonoField::set_value_from_variant(MonoObject *p_object, const Variant &p_
 					GDMonoMarshal::M_Transform3D from = MARSHALLED_OUT(Transform3D, p_value.operator ::Transform3D());
 					mono_field_set_value(p_object, mono_field, &from);
 				} break;
+				case Variant::PROJECTION: {
+					GDMonoMarshal::M_Projection from = MARSHALLED_OUT(Projection, p_value.operator ::Projection());
+					mono_field_set_value(p_object, mono_field, &from);
+				} break;
 				case Variant::COLOR: {
 					GDMonoMarshal::M_Color from = MARSHALLED_OUT(Color, p_value.operator ::Color());
 					mono_field_set_value(p_object, mono_field, &from);
diff --git a/modules/mono/mono_gd/gd_mono_marshal.cpp b/modules/mono/mono_gd/gd_mono_marshal.cpp
index 957abca37b..a860442764 100644
--- a/modules/mono/mono_gd/gd_mono_marshal.cpp
+++ b/modules/mono/mono_gd/gd_mono_marshal.cpp
@@ -99,6 +99,13 @@ Variant::Type managed_to_variant_type(const ManagedType &p_type, bool *r_nil_is_
 			if (vtclass == CACHED_CLASS(Vector3i)) {
 				return Variant::VECTOR3I;
 			}
+			if (vtclass == CACHED_CLASS(Vector4)) {
+				return Variant::VECTOR4;
+			}
+
+			if (vtclass == CACHED_CLASS(Vector4i)) {
+				return Variant::VECTOR4I;
+			}
 
 			if (vtclass == CACHED_CLASS(Basis)) {
 				return Variant::BASIS;
@@ -111,7 +118,9 @@ Variant::Type managed_to_variant_type(const ManagedType &p_type, bool *r_nil_is_
 			if (vtclass == CACHED_CLASS(Transform3D)) {
 				return Variant::TRANSFORM3D;
 			}
-
+			if (vtclass == CACHED_CLASS(Projection)) {
+				return Variant::PROJECTION;
+			}
 			if (vtclass == CACHED_CLASS(AABB)) {
 				return Variant::AABB;
 			}
@@ -539,6 +548,14 @@ MonoObject *variant_to_mono_object(const Variant &p_var) {
 			GDMonoMarshal::M_Transform2D from = MARSHALLED_OUT(Transform2D, p_var.operator ::Transform2D());
 			return mono_value_box(mono_domain_get(), CACHED_CLASS_RAW(Transform2D), &from);
 		}
+		case Variant::VECTOR4: {
+			GDMonoMarshal::M_Vector4 from = MARSHALLED_OUT(Vector4, p_var.operator ::Vector4());
+			return mono_value_box(mono_domain_get(), CACHED_CLASS_RAW(Vector4), &from);
+		}
+		case Variant::VECTOR4I: {
+			GDMonoMarshal::M_Vector4i from = MARSHALLED_OUT(Vector4i, p_var.operator ::Vector4i());
+			return mono_value_box(mono_domain_get(), CACHED_CLASS_RAW(Vector4i), &from);
+		}
 		case Variant::PLANE: {
 			GDMonoMarshal::M_Plane from = MARSHALLED_OUT(Plane, p_var.operator ::Plane());
 			return mono_value_box(mono_domain_get(), CACHED_CLASS_RAW(Plane), &from);
@@ -559,6 +576,10 @@ MonoObject *variant_to_mono_object(const Variant &p_var) {
 			GDMonoMarshal::M_Transform3D from = MARSHALLED_OUT(Transform3D, p_var.operator ::Transform3D());
 			return mono_value_box(mono_domain_get(), CACHED_CLASS_RAW(Transform3D), &from);
 		}
+		case Variant::PROJECTION: {
+			GDMonoMarshal::M_Projection from = MARSHALLED_OUT(Projection, p_var.operator ::Projection());
+			return mono_value_box(mono_domain_get(), CACHED_CLASS_RAW(Projection), &from);
+		}
 		case Variant::COLOR: {
 			GDMonoMarshal::M_Color from = MARSHALLED_OUT(Color, p_var.operator ::Color());
 			return mono_value_box(mono_domain_get(), CACHED_CLASS_RAW(Color), &from);
diff --git a/modules/mono/mono_gd/gd_mono_marshal.h b/modules/mono/mono_gd/gd_mono_marshal.h
index 778e52b6cb..b25e7c916c 100644
--- a/modules/mono/mono_gd/gd_mono_marshal.h
+++ b/modules/mono/mono_gd/gd_mono_marshal.h
@@ -256,6 +256,18 @@ enum {
 			offsetof(Vector3, y) == (sizeof(real_t) * 1) &&
 			offsetof(Vector3, z) == (sizeof(real_t) * 2)),
 
+	MATCHES_Vector4 = (MATCHES_real_t && (sizeof(Vector4) == (sizeof(real_t) * 4)) &&
+			offsetof(Vector4, x) == (sizeof(real_t) * 0) &&
+			offsetof(Vector4, y) == (sizeof(real_t) * 1) &&
+			offsetof(Vector4, z) == (sizeof(real_t) * 2) &&
+			offsetof(Vector4, w) == (sizeof(real_t) * 3)),
+
+	MATCHES_Vector4i = (MATCHES_int && (sizeof(Vector4i) == (sizeof(int32_t) * 4i)) &&
+			offsetof(Vector4i, x) == (sizeof(int32_t) * 0) &&
+			offsetof(Vector4i, y) == (sizeof(int32_t) * 1) &&
+			offsetof(Vector4i, z) == (sizeof(int32_t) * 2) &&
+			offsetof(Vector4i, w) == (sizeof(int32_t) * 3)),
+
 	MATCHES_Vector3i = (MATCHES_int && (sizeof(Vector3i) == (sizeof(int32_t) * 3)) &&
 			offsetof(Vector3i, x) == (sizeof(int32_t) * 0) &&
 			offsetof(Vector3i, y) == (sizeof(int32_t) * 1) &&
@@ -273,6 +285,8 @@ enum {
 			offsetof(Transform3D, basis) == 0 &&
 			offsetof(Transform3D, origin) == sizeof(Basis)),
 
+	MATCHES_Projection = (MATCHES_Vector4 && (sizeof(Projection) == (sizeof(Vector4) * 4))),
+
 	MATCHES_AABB = (MATCHES_Vector3 && (sizeof(AABB) == (sizeof(Vector3) * 2)) &&
 			offsetof(AABB, position) == (sizeof(Vector3) * 0) &&
 			offsetof(AABB, size) == (sizeof(Vector3) * 1)),
@@ -291,9 +305,9 @@ enum {
 // In the future we may force this if we want to ref return these structs
 #ifdef GD_MONO_FORCE_INTEROP_STRUCT_COPY
 /* clang-format off */
-static_assert(MATCHES_Vector2 && MATCHES_Rect2 && MATCHES_Transform2D && MATCHES_Vector3 &&
-				MATCHES_Basis && MATCHES_Quaternion && MATCHES_Transform3D && MATCHES_AABB && MATCHES_Color &&
-				MATCHES_Plane && MATCHES_Vector2i && MATCHES_Rect2i && MATCHES_Vector3i);
+static_assert(MATCHES_Vector2 && MATCHES_Rect2 && MATCHES_Transform2D && MATCHES_Vector3 && MATCHES_Vector4 &&
+				MATCHES_Basis && MATCHES_Quaternion && MATCHES_Transform3D && MATCHES_Projection && MATCHES_AABB && MATCHES_Color &&
+				MATCHES_Plane && MATCHES_Vector2i && MATCHES_Rect2i && MATCHES_Vector3i && MATCHES_Vector4i);
 /* clang-format on */
 #endif
 } // namespace InteropLayout
@@ -401,6 +415,32 @@ struct M_Vector3i {
 	}
 };
 
+struct M_Vector4 {
+	real_t x, y, z, w;
+
+	static _FORCE_INLINE_ Vector4 convert_to(const M_Vector4 &p_from) {
+		return Vector4(p_from.x, p_from.y, p_from.z, p_from.w);
+	}
+
+	static _FORCE_INLINE_ M_Vector4 convert_from(const Vector4 &p_from) {
+		M_Vector4 ret = { p_from.x, p_from.y, p_from.z, p_from.w };
+		return ret;
+	}
+};
+
+struct M_Vector4i {
+	int32_t x, y, z, w;
+
+	static _FORCE_INLINE_ Vector4i convert_to(const M_Vector4i &p_from) {
+		return Vector4i(p_from.x, p_from.y, p_from.z, p_from.w);
+	}
+
+	static _FORCE_INLINE_ M_Vector4i convert_from(const Vector4i &p_from) {
+		M_Vector4i ret = { p_from.x, p_from.y, p_from.z, p_from.w };
+		return ret;
+	}
+};
+
 struct M_Basis {
 	M_Vector3 elements[3];
 
@@ -447,6 +487,22 @@ struct M_Transform3D {
 	}
 };
 
+struct M_Projection {
+	M_Vector4 vec1;
+	M_Vector4 vec2;
+	M_Vector4 vec3;
+	M_Vector4 vec4;
+
+	static _FORCE_INLINE_ Projection convert_to(const M_Projection &p_from) {
+		return Projection(M_Vector4::convert_to(p_from.vec1), M_Vector4::convert_to(p_from.vec2), M_Vector4::convert_to(p_from.vec3), M_Vector4::convert_to(p_from.vec4));
+	}
+
+	static _FORCE_INLINE_ M_Projection convert_from(const Projection &p_from) {
+		M_Projection ret = { M_Vector4::convert_from(p_from.matrix[0]), M_Vector4::convert_from(p_from.matrix[1]), M_Vector4::convert_from(p_from.matrix[2]), M_Vector4::convert_from(p_from.matrix[3]) };
+		return ret;
+	}
+};
+
 struct M_AABB {
 	M_Vector3 position;
 	M_Vector3 size;
@@ -533,8 +589,11 @@ DECL_TYPE_MARSHAL_TEMPLATES(Transform2D)
 DECL_TYPE_MARSHAL_TEMPLATES(Vector3)
 DECL_TYPE_MARSHAL_TEMPLATES(Vector3i)
 DECL_TYPE_MARSHAL_TEMPLATES(Basis)
+DECL_TYPE_MARSHAL_TEMPLATES(Vector4)
+DECL_TYPE_MARSHAL_TEMPLATES(Vector4i)
 DECL_TYPE_MARSHAL_TEMPLATES(Quaternion)
 DECL_TYPE_MARSHAL_TEMPLATES(Transform3D)
+DECL_TYPE_MARSHAL_TEMPLATES(Projection)
 DECL_TYPE_MARSHAL_TEMPLATES(AABB)
 DECL_TYPE_MARSHAL_TEMPLATES(Color)
 DECL_TYPE_MARSHAL_TEMPLATES(Plane)