1 // Copyright (c) 2017-2026, Lawrence Livermore National Security, LLC and other CEED contributors.
2 // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3 //
4 // SPDX-License-Identifier: BSD-2-Clause
5 //
6 // This file is part of CEED: http://github.com/ceed
7
8 /**
9 @brief Ceed QFunction for building the geometric data for the 2D Poisson operator
10 **/
11 #include <ceed/types.h>
12
Poisson2DBuild(void * ctx,const CeedInt Q,const CeedScalar * const * in,CeedScalar * const * out)13 CEED_QFUNCTION(Poisson2DBuild)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
14 // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store
15 // the symmetric part of the result.
16 // in[0] is Jacobians with shape [2, nc=2, Q]
17 // in[1] is quadrature weights, size (Q)
18 const CeedScalar(*J)[2][CEED_Q_VLA] = (const CeedScalar(*)[2][CEED_Q_VLA])in[0], *w = in[1];
19 // out[0] is qdata, size (3*Q)
20 CeedScalar(*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
21
22 // Quadrature point loop
23 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
24 // Qdata stored in Voigt convention
25 // J: 0 2 q_data: 0 2 adj(J): J11 -J01
26 // 1 3 2 1 -J10 J00
27 const CeedScalar J00 = J[0][0][i];
28 const CeedScalar J10 = J[0][1][i];
29 const CeedScalar J01 = J[1][0][i];
30 const CeedScalar J11 = J[1][1][i];
31 const CeedScalar qw = w[i] / (J00 * J11 - J10 * J01);
32
33 q_data[0][i] = qw * (J01 * J01 + J11 * J11);
34 q_data[1][i] = qw * (J00 * J00 + J10 * J10);
35 q_data[2][i] = -qw * (J00 * J01 + J10 * J11);
36 } // End of Quadrature Point Loop
37 return CEED_ERROR_SUCCESS;
38 }
39