/* SPDX-License-Identifier: GPL-2.0-or-later
 * Copyright 2001-2002 NaN Holding BV. All rights reserved. */

/** \file
 * \ingroup bli
 */

#include "BLI_utildefines.h"
#include "BLI_voxel.h"

#include "BLI_strict_flags.h"

BLI_INLINE float D(const float *data, const int res[3], int x, int y, int z)
{
  CLAMP(x, 0, res[0] - 1);
  CLAMP(y, 0, res[1] - 1);
  CLAMP(z, 0, res[2] - 1);
  return data[BLI_VOXEL_INDEX(x, y, z, res)];
}

/* *** nearest neighbor *** */

float BLI_voxel_sample_nearest(const float *data, const int res[3], const float co[3])
{
  int xi, yi, zi;

  xi = (int)(co[0] * (float)res[0]);
  yi = (int)(co[1] * (float)res[1]);
  zi = (int)(co[2] * (float)res[2]);

  return D(data, res, xi, yi, zi);
}

/* returns highest integer <= x as integer (slightly faster than floor()) */
BLI_INLINE int FLOORI(float x)
{
  const int r = (int)x;
  return ((x >= 0.0f) || (float)r == x) ? r : (r - 1);
}

/**
 * clamp function, cannot use the CLAMPIS macro,
 * it sometimes returns unwanted results apparently related to
 * gcc optimization flag `-fstrict-overflow` which is enabled at `-O2`
 *
 * this causes the test (x + 2) < 0 with int x == 2147483647 to return false (x being an integer,
 * x + 2 should wrap around to -2147483647 so the test < 0 should return true, which it doesn't).
 */
BLI_INLINE int64_t _clamp(int a, int b, int c)
{
  return (a < b) ? b : ((a > c) ? c : a);
}

float BLI_voxel_sample_trilinear(const float *data, const int res[3], const float co[3])
{
  if (data) {

    const float xf = co[0] * (float)res[0] - 0.5f;
    const float yf = co[1] * (float)res[1] - 0.5f;
    const float zf = co[2] * (float)res[2] - 0.5f;

    const int x = FLOORI(xf), y = FLOORI(yf), z = FLOORI(zf);

    const int64_t xc[2] = {
        _clamp(x, 0, res[0] - 1),
        _clamp(x + 1, 0, res[0] - 1),
    };
    const int64_t yc[2] = {
        _clamp(y, 0, res[1] - 1) * res[0],
        _clamp(y + 1, 0, res[1] - 1) * res[0],
    };
    const int64_t zc[2] = {
        _clamp(z, 0, res[2] - 1) * res[0] * res[1],
        _clamp(z + 1, 0, res[2] - 1) * res[0] * res[1],
    };

    const float dx = xf - (float)x;
    const float dy = yf - (float)y;
    const float dz = zf - (float)z;

    const float u[2] = {1.0f - dx, dx};
    const float v[2] = {1.0f - dy, dy};
    const float w[2] = {1.0f - dz, dz};

    return w[0] *
               (v[0] * (u[0] * data[xc[0] + yc[0] + zc[0]] + u[1] * data[xc[1] + yc[0] + zc[0]]) +
                v[1] * (u[0] * data[xc[0] + yc[1] + zc[0]] + u[1] * data[xc[1] + yc[1] + zc[0]])) +
           w[1] *
               (v[0] * (u[0] * data[xc[0] + yc[0] + zc[1]] + u[1] * data[xc[1] + yc[0] + zc[1]]) +
                v[1] * (u[0] * data[xc[0] + yc[1] + zc[1]] + u[1] * data[xc[1] + yc[1] + zc[1]]));
  }
  return 0.0f;
}

float BLI_voxel_sample_triquadratic(const float *data, const int res[3], const float co[3])
{
  if (data) {

    const float xf = co[0] * (float)res[0];
    const float yf = co[1] * (float)res[1];
    const float zf = co[2] * (float)res[2];
    const int x = FLOORI(xf), y = FLOORI(yf), z = FLOORI(zf);

    const int64_t xc[3] = {
        _clamp(x - 1, 0, res[0] - 1),
        _clamp(x, 0, res[0] - 1),
        _clamp(x + 1, 0, res[0] - 1),
    };
    const int64_t yc[3] = {
        _clamp(y - 1, 0, res[1] - 1) * res[0],
        _clamp(y, 0, res[1] - 1) * res[0],
        _clamp(y + 1, 0, res[1] - 1) * res[0],
    };
    const int64_t zc[3] = {
        _clamp(z - 1, 0, res[2] - 1) * res[0] * res[1],
        _clamp(z, 0, res[2] - 1) * res[0] * res[1],
        _clamp(z + 1, 0, res[2] - 1) * res[0] * res[1],
    };

    const float dx = xf - (float)x, dy = yf - (float)y, dz = zf - (float)z;
    const float u[3] = {dx * (0.5f * dx - 1.0f) + 0.5f, dx * (1.0f - dx) + 0.5f, 0.5f * dx * dx};
    const float v[3] = {dy * (0.5f * dy - 1.0f) + 0.5f, dy * (1.0f - dy) + 0.5f, 0.5f * dy * dy};
    const float w[3] = {dz * (0.5f * dz - 1.0f) + 0.5f, dz * (1.0f - dz) + 0.5f, 0.5f * dz * dz};

    return w[0] *
               (v[0] * (u[0] * data[xc[0] + yc[0] + zc[0]] + u[1] * data[xc[1] + yc[0] + zc[0]] +
                        u[2] * data[xc[2] + yc[0] + zc[0]]) +
                v[1] * (u[0] * data[xc[0] + yc[1] + zc[0]] + u[1] * data[xc[1] + yc[1] + zc[0]] +
                        u[2] * data[xc[2] + yc[1] + zc[0]]) +
                v[2] * (u[0] * data[xc[0] + yc[2] + zc[0]] + u[1] * data[xc[1] + yc[2] + zc[0]] +
                        u[2] * data[xc[2] + yc[2] + zc[0]])) +
           w[1] *
               (v[0] * (u[0] * data[xc[0] + yc[0] + zc[1]] + u[1] * data[xc[1] + yc[0] + zc[1]] +
                        u[2] * data[xc[2] + yc[0] + zc[1]]) +
                v[1] * (u[0] * data[xc[0] + yc[1] + zc[1]] + u[1] * data[xc[1] + yc[1] + zc[1]] +
                        u[2] * data[xc[2] + yc[1] + zc[1]]) +
                v[2] * (u[0] * data[xc[0] + yc[2] + zc[1]] + u[1] * data[xc[1] + yc[2] + zc[1]] +
                        u[2] * data[xc[2] + yc[2] + zc[1]])) +
           w[2] *
               (v[0] * (u[0] * data[xc[0] + yc[0] + zc[2]] + u[1] * data[xc[1] + yc[0] + zc[2]] +
                        u[2] * data[xc[2] + yc[0] + zc[2]]) +
                v[1] * (u[0] * data[xc[0] + yc[1] + zc[2]] + u[1] * data[xc[1] + yc[1] + zc[2]] +
                        u[2] * data[xc[2] + yc[1] + zc[2]]) +
                v[2] * (u[0] * data[xc[0] + yc[2] + zc[2]] + u[1] * data[xc[1] + yc[2] + zc[2]] +
                        u[2] * data[xc[2] + yc[2] + zc[2]]));
  }
  return 0.0f;
}

float BLI_voxel_sample_tricubic(const float *data,
                                const int res[3],
                                const float co[3],
                                int bspline)
{
  if (data) {

    const float xf = co[0] * (float)res[0] - 0.5f;
    const float yf = co[1] * (float)res[1] - 0.5f;
    const float zf = co[2] * (float)res[2] - 0.5f;
    const int x = FLOORI(xf), y = FLOORI(yf), z = FLOORI(zf);

    const int64_t xc[4] = {
        _clamp(x - 1, 0, res[0] - 1),
        _clamp(x, 0, res[0] - 1),
        _clamp(x + 1, 0, res[0] - 1),
        _clamp(x + 2, 0, res[0] - 1),
    };
    const int64_t yc[4] = {
        _clamp(y - 1, 0, res[1] - 1) * res[0],
        _clamp(y, 0, res[1] - 1) * res[0],
        _clamp(y + 1, 0, res[1] - 1) * res[0],
        _clamp(y + 2, 0, res[1] - 1) * res[0],
    };
    const int64_t zc[4] = {
        _clamp(z - 1, 0, res[2] - 1) * res[0] * res[1],
        _clamp(z, 0, res[2] - 1) * res[0] * res[1],
        _clamp(z + 1, 0, res[2] - 1) * res[0] * res[1],
        _clamp(z + 2, 0, res[2] - 1) * res[0] * res[1],
    };
    const float dx = xf - (float)x, dy = yf - (float)y, dz = zf - (float)z;

    float u[4], v[4], w[4];
    if (bspline) {  // B-Spline
      u[0] = (((-1.0f / 6.0f) * dx + 0.5f) * dx - 0.5f) * dx + (1.0f / 6.0f);
      u[1] = ((0.5f * dx - 1.0f) * dx) * dx + (2.0f / 3.0f);
      u[2] = ((-0.5f * dx + 0.5f) * dx + 0.5f) * dx + (1.0f / 6.0f);
      u[3] = (1.0f / 6.0f) * dx * dx * dx;
      v[0] = (((-1.0f / 6.0f) * dy + 0.5f) * dy - 0.5f) * dy + (1.0f / 6.0f);
      v[1] = ((0.5f * dy - 1.0f) * dy) * dy + (2.0f / 3.0f);
      v[2] = ((-0.5f * dy + 0.5f) * dy + 0.5f) * dy + (1.0f / 6.0f);
      v[3] = (1.0f / 6.0f) * dy * dy * dy;
      w[0] = (((-1.0f / 6.0f) * dz + 0.5f) * dz - 0.5f) * dz + (1.0f / 6.0f);
      w[1] = ((0.5f * dz - 1.0f) * dz) * dz + (2.0f / 3.0f);
      w[2] = ((-0.5f * dz + 0.5f) * dz + 0.5f) * dz + (1.0f / 6.0f);
      w[3] = (1.0f / 6.0f) * dz * dz * dz;
    }
    else {  // Catmull-Rom
      u[0] = ((-0.5f * dx + 1.0f) * dx - 0.5f) * dx;
      u[1] = ((1.5f * dx - 2.5f) * dx) * dx + 1.0f;
      u[2] = ((-1.5f * dx + 2.0f) * dx + 0.5f) * dx;
      u[3] = ((0.5f * dx - 0.5f) * dx) * dx;
      v[0] = ((-0.5f * dy + 1.0f) * dy - 0.5f) * dy;
      v[1] = ((1.5f * dy - 2.5f) * dy) * dy + 1.0f;
      v[2] = ((-1.5f * dy + 2.0f) * dy + 0.5f) * dy;
      v[3] = ((0.5f * dy - 0.5f) * dy) * dy;
      w[0] = ((-0.5f * dz + 1.0f) * dz - 0.5f) * dz;
      w[1] = ((1.5f * dz - 2.5f) * dz) * dz + 1.0f;
      w[2] = ((-1.5f * dz + 2.0f) * dz + 0.5f) * dz;
      w[3] = ((0.5f * dz - 0.5f) * dz) * dz;
    }

    return w[0] *
               (v[0] * (u[0] * data[xc[0] + yc[0] + zc[0]] + u[1] * data[xc[1] + yc[0] + zc[0]] +
                        u[2] * data[xc[2] + yc[0] + zc[0]] + u[3] * data[xc[3] + yc[0] + zc[0]]) +
                v[1] * (u[0] * data[xc[0] + yc[1] + zc[0]] + u[1] * data[xc[1] + yc[1] + zc[0]] +
                        u[2] * data[xc[2] + yc[1] + zc[0]] + u[3] * data[xc[3] + yc[1] + zc[0]]) +
                v[2] * (u[0] * data[xc[0] + yc[2] + zc[0]] + u[1] * data[xc[1] + yc[2] + zc[0]] +
                        u[2] * data[xc[2] + yc[2] + zc[0]] + u[3] * data[xc[3] + yc[2] + zc[0]]) +
                v[3] * (u[0] * data[xc[0] + yc[3] + zc[0]] + u[1] * data[xc[1] + yc[3] + zc[0]] +
                        u[2] * data[xc[2] + yc[3] + zc[0]] + u[3] * data[xc[3] + yc[3] + zc[0]])) +
           w[1] *
               (v[0] * (u[0] * data[xc[0] + yc[0] + zc[1]] + u[1] * data[xc[1] + yc[0] + zc[1]] +
                        u[2] * data[xc[2] + yc[0] + zc[1]] + u[3] * data[xc[3] + yc[0] + zc[1]]) +
                v[1] * (u[0] * data[xc[0] + yc[1] + zc[1]] + u[1] * data[xc[1] + yc[1] + zc[1]] +
                        u[2] * data[xc[2] + yc[1] + zc[1]] + u[3] * data[xc[3] + yc[1] + zc[1]]) +
                v[2] * (u[0] * data[xc[0] + yc[2] + zc[1]] + u[1] * data[xc[1] + yc[2] + zc[1]] +
                        u[2] * data[xc[2] + yc[2] + zc[1]] + u[3] * data[xc[3] + yc[2] + zc[1]]) +
                v[3] * (u[0] * data[xc[0] + yc[3] + zc[1]] + u[1] * data[xc[1] + yc[3] + zc[1]] +
                        u[2] * data[xc[2] + yc[3] + zc[1]] + u[3] * data[xc[3] + yc[3] + zc[1]])) +
           w[2] *
               (v[0] * (u[0] * data[xc[0] + yc[0] + zc[2]] + u[1] * data[xc[1] + yc[0] + zc[2]] +
                        u[2] * data[xc[2] + yc[0] + zc[2]] + u[3] * data[xc[3] + yc[0] + zc[2]]) +
                v[1] * (u[0] * data[xc[0] + yc[1] + zc[2]] + u[1] * data[xc[1] + yc[1] + zc[2]] +
                        u[2] * data[xc[2] + yc[1] + zc[2]] + u[3] * data[xc[3] + yc[1] + zc[2]]) +
                v[2] * (u[0] * data[xc[0] + yc[2] + zc[2]] + u[1] * data[xc[1] + yc[2] + zc[2]] +
                        u[2] * data[xc[2] + yc[2] + zc[2]] + u[3] * data[xc[3] + yc[2] + zc[2]]) +
                v[3] * (u[0] * data[xc[0] + yc[3] + zc[2]] + u[1] * data[xc[1] + yc[3] + zc[2]] +
                        u[2] * data[xc[2] + yc[3] + zc[2]] + u[3] * data[xc[3] + yc[3] + zc[2]])) +
           w[3] *
               (v[0] * (u[0] * data[xc[0] + yc[0] + zc[3]] + u[1] * data[xc[1] + yc[0] + zc[3]] +
                        u[2] * data[xc[2] + yc[0] + zc[3]] + u[3] * data[xc[3] + yc[0] + zc[3]]) +
                v[1] * (u[0] * data[xc[0] + yc[1] + zc[3]] + u[1] * data[xc[1] + yc[1] + zc[3]] +
                        u[2] * data[xc[2] + yc[1] + zc[3]] + u[3] * data[xc[3] + yc[1] + zc[3]]) +
                v[2] * (u[0] * data[xc[0] + yc[2] + zc[3]] + u[1] * data[xc[1] + yc[2] + zc[3]] +
                        u[2] * data[xc[2] + yc[2] + zc[3]] + u[3] * data[xc[3] + yc[2] + zc[3]]) +
                v[3] * (u[0] * data[xc[0] + yc[3] + zc[3]] + u[1] * data[xc[1] + yc[3] + zc[3]] +
                        u[2] * data[xc[2] + yc[3] + zc[3]] + u[3] * data[xc[3] + yc[3] + zc[3]]));
  }
  return 0.0f;
}