xref: /libCEED/include/ceed/jit-source/gallery/ceed-poisson2dbuild.h (revision c9c2c07970382857cc7b4a28d359710237b91a3e)
1a0154adeSJed Brown // Copyright (c) 2017-2022, Lawrence Livermore National Security, LLC and other CEED contributors.
2a0154adeSJed Brown // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3a0154adeSJed Brown //
4a0154adeSJed Brown // SPDX-License-Identifier: BSD-2-Clause
5a0154adeSJed Brown //
6a0154adeSJed Brown // This file is part of CEED:  http://github.com/ceed
7a0154adeSJed Brown 
8a0154adeSJed Brown /**
9a0154adeSJed Brown   @brief Ceed QFunction for building the geometric data for the 2D Poisson operator
10a0154adeSJed Brown **/
11a0154adeSJed Brown 
12a0154adeSJed Brown #ifndef poisson2dbuild_h
13a0154adeSJed Brown #define poisson2dbuild_h
14a0154adeSJed Brown 
15*c9c2c079SJeremy L Thompson #include <ceed.h>
16*c9c2c079SJeremy L Thompson 
17a0154adeSJed Brown CEED_QFUNCTION(Poisson2DBuild)(void *ctx, const CeedInt Q,
18a0154adeSJed Brown                                const CeedScalar *const *in,
19a0154adeSJed Brown                                CeedScalar *const *out) {
20a0154adeSJed Brown   // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store
21a0154adeSJed Brown   // the symmetric part of the result.
22a0154adeSJed Brown   // *INDENT-OFF*
23a0154adeSJed Brown   // in[0] is Jacobians with shape [2, nc=2, Q]
24a0154adeSJed Brown   // in[1] is quadrature weights, size (Q)
25a0154adeSJed Brown   const CeedScalar (*J)[2][CEED_Q_VLA] = (const CeedScalar(*)[2][CEED_Q_VLA])in[0],
26a0154adeSJed Brown                                     *w = in[1];
27a0154adeSJed Brown   // out[0] is qdata, size (3*Q)
28a0154adeSJed Brown   CeedScalar     (*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
29a0154adeSJed Brown   // *INDENT-ON*
30a0154adeSJed Brown 
31a0154adeSJed Brown   // Quadrature point loop
32a0154adeSJed Brown   CeedPragmaSIMD
33a0154adeSJed Brown   for (CeedInt i=0; i<Q; i++) {
34a0154adeSJed Brown     // Qdata stored in Voigt convention
35a0154adeSJed Brown     // J: 0 2   q_data: 0 2   adj(J):  J11 -J01
36a0154adeSJed Brown     //    1 3           2 1           -J10  J00
37a0154adeSJed Brown     const CeedScalar J00 = J[0][0][i];
38a0154adeSJed Brown     const CeedScalar J10 = J[0][1][i];
39a0154adeSJed Brown     const CeedScalar J01 = J[1][0][i];
40a0154adeSJed Brown     const CeedScalar J11 = J[1][1][i];
41a0154adeSJed Brown     const CeedScalar qw = w[i] / (J00*J11 - J10*J01);
42a0154adeSJed Brown     q_data[0][i] =   qw * (J01*J01 + J11*J11);
43a0154adeSJed Brown     q_data[1][i] =   qw * (J00*J00 + J10*J10);
44a0154adeSJed Brown     q_data[2][i] = - qw * (J00*J01 + J10*J11);
45a0154adeSJed Brown   } // End of Quadrature Point Loop
46a0154adeSJed Brown 
47a0154adeSJed Brown   return CEED_ERROR_SUCCESS;
48a0154adeSJed Brown }
49a0154adeSJed Brown 
50a0154adeSJed Brown #endif // poisson2dbuild_h
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