Explicitly use "Cartesian" in the name of algorithms

1 files changed, 126 insertions, 0 deletions

diff --git a/Source/FieldSolver/FiniteDifferenceSolver/FiniteDifferenceAlgorithms/CartesianNodalAlgorithm.H b/Source/FieldSolver/FiniteDifferenceSolver/FiniteDifferenceAlgorithms/CartesianNodalAlgorithm.H
new file mode 100644
index 000000000..ed75dedc1
--- /dev/null
+++ b/Source/FieldSolver/FiniteDifferenceSolver/FiniteDifferenceAlgorithms/CartesianNodalAlgorithm.H
@@ -0,0 +1,126 @@
+/* Copyright 2020 Remi Lehe
+ *
+ * This file is part of WarpX.
+ *
+ * License: BSD-3-Clause-LBNL
+ */
+
+#ifndef WARPX_FINITE_DIFFERENCE_ALGORITHM_CARTESIAN_NODAL_H_
+#define WARPX_FINITE_DIFFERENCE_ALGORITHM_CARTESIAN_NODAL_H_
+
+#include <AMReX_REAL.H>
+#include <AMReX_Array4.H>
+#include <AMReX_Gpu.H>
+
+struct CartesianNodalAlgorithm {
+
+    static void InitializeStencilCoefficients (
+        std::array<amrex::Real,3>& cell_size,
+        amrex::Gpu::ManagedVector<amrex::Real>& stencil_coefs_x,
+        amrex::Gpu::ManagedVector<amrex::Real>& stencil_coefs_y,
+        amrex::Gpu::ManagedVector<amrex::Real>& stencil_coefs_z ) {
+
+        // Store the inverse cell size along each direction in the coefficients
+        stencil_coefs_x.resize(1);
+        stencil_coefs_x[0] = 1./cell_size[0];
+        stencil_coefs_y.resize(1);
+        stencil_coefs_y[0] = 1./cell_size[1];
+        stencil_coefs_z.resize(1);
+        stencil_coefs_z[0] = 1./cell_size[2];
+    }
+
+    /**
+    /* Perform derivative along x
+    /* (For a solver on a staggered grid, `UpwardDx` and `DownwardDx` take into
+    /* account the staggering; but for `CartesianNodalAlgorithm`, they are equivalent) */
+    AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
+    static amrex::Real UpwardDx (
+        amrex::Array4<amrex::Real> const& F,
+        amrex::Real const * const coefs_x, int const n_coefs_x,
+        int const i, int const j, int const k ) {
+
+        amrex::Real const inv_dx = coefs_x[0];
+        return 0.5*inv_dx*( F(i+1,j,k) - F(i-1,j,k) );
+    };
+
+    /**
+    /* Perform derivative along x
+    /* (For a solver on a staggered grid, `UpwardDx` and `DownwardDx` take into
+    /* account the staggering; but for `CartesianNodalAlgorithm`, they are equivalent) */
+    AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
+    static amrex::Real DownwardDx (
+        amrex::Array4<amrex::Real> const& F,
+        amrex::Real const * const coefs_x, int const n_coefs_x,
+        int const i, int const j, int const k ) {
+
+        return UpwardDx( F, coefs_x, n_coefs_x, i, j, k );
+        // For CartesianNodalAlgorithm, UpwardDx and DownwardDx are equivalent
+    };
+
+    /**
+    /* Perform derivative along y
+    /* (For a solver on a staggered grid, `UpwardDy` and `DownwardDy` take into
+    /* account the staggering; but for `CartesianNodalAlgorithm`, they are equivalent) */
+    AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
+    static amrex::Real UpwardDy (
+        amrex::Array4<amrex::Real> const& F,
+        amrex::Real const * const coefs_y, int const n_coefs_y,
+        int const i, int const j, int const k ) {
+
+#if defined WARPX_DIM_3D
+            amrex::Real const inv_dy = coefs_y[0];
+            return 0.5*inv_dy*( F(i,j+1,k) - F(i,j-1,k) );
+#elif (defined WARPX_DIM_XZ)
+            return 0; // 2D Cartesian: derivative along y is 0
+#endif
+    };
+
+    /**
+    /* Perform derivative along y
+    /* (For a solver on a staggered grid, `UpwardDy` and `DownwardDy` take into
+    /* account the staggering; but for `CartesianNodalAlgorithm`, they are equivalent) */
+    AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
+    static amrex::Real DownwardDy (
+        amrex::Array4<amrex::Real> const& F,
+        amrex::Real const * const coefs_y, int const n_coefs_y,
+        int const i, int const j, int const k ) {
+
+        return UpwardDy( F, coefs_y, n_coefs_y, i, j, k );
+        // For CartesianNodalAlgorithm, UpwardDy and DownwardDy are equivalent
+    };
+
+    /**
+    /* Perform derivative along z
+    /* (For a solver on a staggered grid, `UpwardDz` and `DownwardDz` take into
+    /* account the staggering; but for `CartesianNodalAlgorithm`, they are equivalent) */
+    AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
+    static amrex::Real UpwardDz (
+        amrex::Array4<amrex::Real> const& F,
+        amrex::Real const * const coefs_z, int const n_coefs_z,
+        int const i, int const j, int const k ) {
+
+        amrex::Real const inv_dz = coefs_z[0];
+#if defined WARPX_DIM_3D
+            return 0.5*inv_dz*( F(i,j,k+1) - F(i,j,k-1) );
+#elif (defined WARPX_DIM_XZ)
+            return 0.5*inv_dz*( F(i,j+1,k) - F(i,j-1,k) );
+#endif
+    };
+
+    /**
+    /* Perform derivative along z
+    /* (For a solver on a staggered grid, `UpwardDz` and `DownwardDz` take into
+    /* account the staggering; but for `CartesianNodalAlgorithm`, they are equivalent) */
+    AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
+    static amrex::Real DownwardDz (
+        amrex::Array4<amrex::Real> const& F,
+        amrex::Real const * const coefs_z, int const n_coefs_z,
+        int const i, int const j, int const k ) {
+
+        return UpwardDz( F, coefs_z, n_coefs_z, i, j, k );
+        // For CartesianNodalAlgorithm, UpwardDz and DownwardDz are equivalent
+    };
+
+};
+
+#endif // WARPX_FINITE_DIFFERENCE_ALGORITHM_CARTESIAN_NODAL_H_