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#include "stl_triangle.h"

#include "../gmio_core/internal/vecgeom_utils.h"

GMIO_INLINE struct gmio_vec3f gmio_vec3f_sub(
        const struct gmio_vec3f* u, const struct gmio_vec3f* v)
{
    struct gmio_vec3f diff;
    diff.x = u->x - v->x;
    diff.y = u->y - v->y;
    diff.z = u->z - v->z;
    return diff;
}

void gmio_stl_triangle_compute_normal(struct gmio_stl_triangle* tri)
{
    const struct gmio_vec3f u = gmio_vec3f_sub(&tri->v2, &tri->v1);
    const struct gmio_vec3f v = gmio_vec3f_sub(&tri->v3, &tri->v1);
    gmio_vec3f_cross_product(&u, &v, &tri->n);
}