xref: /libCEED/examples/fluids/qfunctions/setupgeo.h (revision bdee0278611904727ee35fcc2d0d7c3bf83db4c4)
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 /// @file
9 /// Geometric factors (3D) for Navier-Stokes example using PETSc
10 #include <ceed/types.h>
11 #ifndef CEED_RUNNING_JIT_PASS
12 #include <math.h>
13 #endif
14 
15 #include "setupgeo_helpers.h"
16 #include "utils.h"
17 
18 // *****************************************************************************
19 // This QFunction sets up the geometric factors required for integration and coordinate transformations
20 //
21 // Reference (parent) coordinates: X
22 // Physical (current) coordinates: x
23 // Change of coordinate matrix: dxdX_{i,j} = x_{i,j} (indicial notation)
24 // Inverse of change of coordinate matrix: dXdx_{i,j} = (detJ^-1) * X_{i,j}
25 //
26 // All quadrature data is stored in 10 field vector of quadrature data.
27 //
28 // We require the determinant of the Jacobian to properly compute integrals of the form: int( v u )
29 //
30 // Determinant of Jacobian:
31 //   detJ = J11*A11 + J21*A12 + J31*A13
32 //     Jij = Jacobian entry ij
33 //     Aij = Adjugate ij
34 //
35 // Stored: w detJ
36 //   in q_data[0]
37 //
38 // We require the transpose of the inverse of the Jacobian to properly compute integrals of the form: int( gradv u )
39 //
40 // Inverse of Jacobian:
41 //   dXdx_i,j = Aij / detJ
42 //
43 // Stored: Aij / detJ
44 //   in q_data[1:9] as
45 //   (detJ^-1) * [A11 A12 A13]
46 //               [A21 A22 A23]
47 //               [A31 A32 A33]
48 // *****************************************************************************
49 CEED_QFUNCTION(Setup)(void *ctx, CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
50   const CeedScalar(*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[0];
51   const CeedScalar(*w)                = in[1];
52   CeedScalar(*q_data)                 = out[0];
53 
54   CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
55     CeedScalar detJ, dXdx[3][3];
56     InvertMappingJacobian_3D(Q, i, J, dXdx, &detJ);
57     const CeedScalar wdetJ = w[i] * detJ;
58 
59     StoredValuesPack(Q, i, 0, 1, &wdetJ, q_data);
60     StoredValuesPack(Q, i, 1, 9, (const CeedScalar *)dXdx, q_data);
61   }
62   return 0;
63 }
64 
65 // *****************************************************************************
66 // This QFunction sets up the geometric factor required for integration when reference coordinates are in 2D and the physical coordinates are in 3D
67 //
68 // Reference (parent) 2D coordinates: X
69 // Physical (current) 3D coordinates: x
70 // Change of coordinate matrix:
71 //   dxdX_{i,j} = dx_i/dX_j (indicial notation) [3 * 2]
72 // Inverse change of coordinate matrix:
73 //   dXdx_{i,j} = dX_i/dx_j (indicial notation) [2 * 3]
74 //
75 // (J1,J2,J3) is given by the cross product of the columns of dxdX_{i,j}
76 //
77 // detJb is the magnitude of (J1,J2,J3)
78 //
79 // dXdx is calculated via Moore–Penrose inverse:
80 //
81 //   dX_i/dx_j = (dxdX^T dxdX)^(-1) dxdX
82 //             = (dx_l/dX_i * dx_l/dX_k)^(-1) dx_j/dX_k
83 //
84 // All quadrature data is stored in 10 field vector of quadrature data.
85 //
86 // We require the determinant of the Jacobian to properly compute integrals of
87 //   the form: int( u v )
88 //
89 // Stored: w detJb
90 //   in q_data_sur[0]
91 //
92 // Normal vector = (J1,J2,J3) / detJb
93 //
94 //   - TODO Could possibly remove normal vector, as it could be calculated in the Qfunction from dXdx
95 //    See https://github.com/CEED/libCEED/pull/868#discussion_r871979484
96 // Stored: (J1,J2,J3) / detJb
97 //   in q_data_sur[1:3] as
98 //   (detJb^-1) * [ J1 ]
99 //                [ J2 ]
100 //                [ J3 ]
101 //
102 // Stored: dXdx_{i,j}
103 //   in q_data_sur[4:9] as
104 //    [dXdx_11 dXdx_12 dXdx_13]
105 //    [dXdx_21 dXdx_22 dXdx_23]
106 // *****************************************************************************
107 CEED_QFUNCTION(SetupBoundary)(void *ctx, CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
108   const CeedScalar(*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[0];
109   const CeedScalar(*w)                = in[1];
110   CeedScalar(*q_data_sur)             = out[0];
111 
112   CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
113     CeedScalar detJb, normal[3], dXdx[2][3];
114 
115     NormalVectorFromdxdX_3D(Q, i, J, normal, &detJb);
116     InvertBoundaryMappingJacobian_3D(Q, i, J, dXdx);
117     const CeedScalar wdetJ = w[i] * detJb;
118 
119     StoredValuesPack(Q, i, 0, 1, &wdetJ, q_data_sur);
120     StoredValuesPack(Q, i, 1, 3, normal, q_data_sur);
121     StoredValuesPack(Q, i, 4, 6, (const CeedScalar *)dXdx, q_data_sur);
122   }
123   return 0;
124 }
125