feat(libmeanfield): centrifugal + pressure

libmeanfield/interface/operators/gravity_field_jacobian.cppm

@@ -0,0 +1,38 @@
+module;
+#include <mfem.hpp>
+
+export module mean_field:operators.gravity_field_jacobian;
+export import :fem;
+export import :mapping.domain_mapper;
+export import :operators.context.gravity_field;
+
+export namespace mean_field::operators {
+    class GravityFieldJacobianOperator final : public mfem::Operator {
+    public:
+        GravityFieldJacobianOperator(
+            fem::FEM &f,
+            const mapping::DomainMapperStateless &domain_mapper,
+            const context::gravity_field::GravityFieldLinearizationContext
+                &linearization_context,
+            const mfem::Array<int> &state_true_offsets,
+            const mfem::Array<int> &residual_true_offsets
+        );
+
+        void Mult(
+            const mfem::Vector &direction,
+            mfem::Vector &action
+        ) const override;
+
+        [[nodiscard]] const context::gravity_field::
+            GravityFieldLinearizationContext &
+            GetLinearizationContext() const noexcept;
+
+    private:
+        fem::FEM &m_fem;
+        const mapping::DomainMapperStateless &m_domain_mapper;
+        const context::gravity_field::GravityFieldLinearizationContext
+            &m_linearization_context;
+        mfem::Array<int> m_state_true_offsets;
+        mfem::Array<int> m_residual_true_offsets;
+    };
+} // namespace mean_field::operators