tensor_field.c

#include "tensor_field.h"
#include <math.h>
#include <stdlib.h>
#include <assert.h>

bool tensor_field_consistant_spatial_size_tensor_field(tensor_field lhs, tensor_field rhs) {
    return (rhs.nx == lhs.nx && rhs.ny == lhs.ny && rhs.nz == lhs.nz);
}

bool tensor_field_consistant_size_tensor_field(tensor_field lhs, tensor_field rhs) {
    return (rhs.nx == lhs.nx && rhs.ny == lhs.ny && rhs.nz == lhs.nz && rhs.q == lhs.q);
}

bool tensor_field_consistant_size_scalar_field(tensor_field lhs, scalar_field rhs) {
    return (rhs.nx == lhs.nx && rhs.ny == lhs.ny && rhs.nz == lhs.nz);
}

tensor_field tensor_field_allocate(fint nx, fint ny, fint nz, fint q) {
    tensor_field field;
    field.nx = nx;
    field.ny = ny;
    field.nz = nz;
    field.q  = q;
    field.dim = 3;
    
    field.data = malloc(sizeof(T) * nx * ny * nz * q);
    field.grid = malloc(sizeof(T ***) * nx);
    for (fint ix = 0; ix < nx; ++ix) {
        field.grid[ix] = malloc(sizeof(T **) * ny);
        for (fint iy = 0; iy < ny; ++iy) {
            field.grid[ix][iy] = malloc(sizeof(T *) * nz);
            for (fint iz = 0; iz < nz; ++iz) {
                field.grid[ix][iy][iz] = field.data + q * (iz + nz * (iy + ny * ix));
            }
        }
    }
    return field;
}

void tensor_field_deallocate(tensor_field field) {
    free(field.data);

    for (fint ix = 0; ix < field.nx; ++ix) {
        for (fint iy = 0; iy < field.ny; ++iy) {
            free(field.grid[ix][iy]);
        }
        free(field.grid[ix]);
    }
    free(field.grid);
}

void tensor_field_from_futhark_f32_4d_inplace(struct futhark_f32_4d *f, struct futhark_context *ctx, tensor_field field) {
    int64_t *shape = futhark_shape_f32_4d(ctx, f);
    fint nx = shape[0];
    fint ny = shape[1];
    fint nz = shape[2];
    fint q = shape[3];

    assert(nx == field.nx);
    assert(ny == field.ny);
    assert(nz == field.nz);
    assert(q == field.q);

    futhark_values_f32_4d(ctx, f, field.data);
}

void tensor_field_compute_norm_inplace(tensor_field field, scalar_field norm) {
    assert(norm.nx == field.nx);
    assert(norm.ny == field.ny);
    assert(norm.nz == field.nz);

    for (int ix = 0; ix < field.nx; ++ix) {
        for (int iy = 0; iy < field.ny; ++iy) {
            for (int iz = 0; iz < field.nz; ++iz) {
                T n = 0.0;
                for (int id = 0; id < field.q; ++id) {
                    n += field.grid[ix][iy][iz][id] * field.grid[ix][iy][iz][id];
                }
                norm.grid[ix][iy][iz] = sqrt(n);
            }
        }
    }
}

tensor_field tensor_field_from_futhark_f32_4d(struct futhark_f32_4d *f, struct futhark_context *ctx) {
    int64_t *shape = futhark_shape_f32_4d(ctx, f);
    fint nx = shape[0];
    fint ny = shape[1];
    fint nz = shape[2];
    fint q = shape[3];

    tensor_field field = tensor_field_allocate(nx, ny, nz, q);

    tensor_field_from_futhark_f32_4d_inplace(f, ctx, field);

    return field;
}

struct futhark_f32_4d *tensor_field_to_futhark_f32_4d(tensor_field field, struct futhark_context *ctx) {
    
    struct futhark_f32_4d *f = futhark_new_f32_4d(ctx,
                                          field.data, field.nx, field.ny, field.nz, field.q);
    return f;
}

scalar_field tensor_field_compute_norm(tensor_field field) {
    scalar_field norm = scalar_field_allocate(field.nx, field.ny, field.nz);

    tensor_field_compute_norm_inplace(field, norm);

    return norm;
}