/* SPDX-License-Identifier: GPL-2.0-or-later */

/** \file
 * \ingroup bli
 * \brief A KD-tree for nearest neighbor search.
 */

#include "BLI_compiler_attrs.h"
#include "BLI_sys_types.h"

#define _BLI_CONCAT_AUX(MACRO_ARG1, MACRO_ARG2) MACRO_ARG1##MACRO_ARG2
#define _BLI_CONCAT(MACRO_ARG1, MACRO_ARG2) _BLI_CONCAT_AUX(MACRO_ARG1, MACRO_ARG2)
#define BLI_kdtree_nd_(id) _BLI_CONCAT(KDTREE_PREFIX_ID, _##id)

#ifdef __cplusplus
extern "C" {
#endif

struct KDTree;
typedef struct KDTree KDTree;

typedef struct KDTreeNearest {
  int index;
  float dist;
  float co[KD_DIMS];
} KDTreeNearest;

KDTree *BLI_kdtree_nd_(new)(unsigned int maxsize);
void BLI_kdtree_nd_(free)(KDTree *tree);
void BLI_kdtree_nd_(balance)(KDTree *tree) ATTR_NONNULL(1);

void BLI_kdtree_nd_(insert)(KDTree *tree, int index, const float co[KD_DIMS]) ATTR_NONNULL(1, 3);
int BLI_kdtree_nd_(find_nearest)(const KDTree *tree,
                                 const float co[KD_DIMS],
                                 KDTreeNearest *r_nearest) ATTR_NONNULL(1, 2);

int BLI_kdtree_nd_(find_nearest_n)(const KDTree *tree,
                                   const float co[KD_DIMS],
                                   KDTreeNearest *r_nearest,
                                   uint nearest_len_capacity) ATTR_NONNULL(1, 2, 3);

int BLI_kdtree_nd_(range_search)(const KDTree *tree,
                                 const float co[KD_DIMS],
                                 KDTreeNearest **r_nearest,
                                 float range) ATTR_NONNULL(1, 2) ATTR_WARN_UNUSED_RESULT;

int BLI_kdtree_nd_(find_nearest_cb)(
    const KDTree *tree,
    const float co[KD_DIMS],
    int (*filter_cb)(void *user_data, int index, const float co[KD_DIMS], float dist_sq),
    void *user_data,
    KDTreeNearest *r_nearest);
void BLI_kdtree_nd_(range_search_cb)(
    const KDTree *tree,
    const float co[KD_DIMS],
    float range,
    bool (*search_cb)(void *user_data, int index, const float co[KD_DIMS], float dist_sq),
    void *user_data);

int BLI_kdtree_nd_(calc_duplicates_fast)(const KDTree *tree,
                                         float range,
                                         bool use_index_order,
                                         int *doubles);

int BLI_kdtree_nd_(deduplicate)(KDTree *tree);

/** Versions of find/range search that take a squared distance callback to support bias. */
int BLI_kdtree_nd_(find_nearest_n_with_len_squared_cb)(
    const KDTree *tree,
    const float co[KD_DIMS],
    KDTreeNearest *r_nearest,
    uint nearest_len_capacity,
    float (*len_sq_fn)(const float co_search[KD_DIMS],
                       const float co_test[KD_DIMS],
                       const void *user_data),
    const void *user_data) ATTR_NONNULL(1, 2, 3);
int BLI_kdtree_nd_(range_search_with_len_squared_cb)(
    const KDTree *tree,
    const float co[KD_DIMS],
    KDTreeNearest **r_nearest,
    float range,
    float (*len_sq_fn)(const float co_search[KD_DIMS],
                       const float co_test[KD_DIMS],
                       const void *user_data),
    const void *user_data) ATTR_NONNULL(1, 2) ATTR_WARN_UNUSED_RESULT;

#ifdef __cplusplus
}
#endif

#ifdef __cplusplus
template<typename Fn>
inline void BLI_kdtree_nd_(range_search_cb_cpp)(const KDTree *tree,
                                                const float co[KD_DIMS],
                                                float distance,
                                                const Fn &fn)
{
  BLI_kdtree_nd_(range_search_cb)(
      tree,
      co,
      distance,
      [](void *user_data, const int index, const float *co, const float dist_sq) {
        const Fn &fn = *static_cast<const Fn *>(user_data);
        return fn(index, co, dist_sq);
      },
      const_cast<Fn *>(&fn));
}
#endif

#undef _BLI_CONCAT_AUX
#undef _BLI_CONCAT
#undef BLI_kdtree_nd_