// Copyright (c) the JPEG XL Project Authors. All rights reserved.

//

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

#include <atomic>

#include "lib/jxl/base/rect.h"

#include "lib/jxl/base/status.h"

#include "lib/jxl/convolve-inl.h"

#include "lib/jxl/convolve.h"

namespace jxl {

//------------------------------------------------------------------------------

// Kernels

// 4 instances of a given literal value, useful as input to LoadDup128.

#define JXL_REP4(literal) literal, literal, literal, literal

// Concentrates energy in low-frequency components (e.g. for antialiasing).

const WeightsSymmetric3& WeightsSymmetric3Lowpass() {

  // Computed by research/convolve_weights.py's cubic spline approximations of

  // prolate spheroidal wave functions.

  constexpr float w0 = 0.36208932f;

  constexpr float w1 = 0.12820096f;

  constexpr float w2 = 0.03127668f;

  static constexpr WeightsSymmetric3 weights = {

      {JXL_REP4(w0)}, {JXL_REP4(w1)}, {JXL_REP4(w2)}};

  return weights;

}

const WeightsSeparable5& WeightsSeparable5Lowpass() {

  constexpr float w0 = 0.41714928f;

  constexpr float w1 = 0.25539268f;

  constexpr float w2 = 0.03603267f;

  static constexpr WeightsSeparable5 weights = {

      {JXL_REP4(w0), JXL_REP4(w1), JXL_REP4(w2)},

      {JXL_REP4(w0), JXL_REP4(w1), JXL_REP4(w2)}};

  return weights;

}

const WeightsSymmetric5& WeightsSymmetric5Lowpass() {

  static constexpr WeightsSymmetric5 weights = {

      {JXL_REP4(0.1740135f)}, {JXL_REP4(0.1065369f)}, {JXL_REP4(0.0150310f)},

      {JXL_REP4(0.0652254f)}, {JXL_REP4(0.0012984f)}, {JXL_REP4(0.0092025f)}};

  return weights;

}

const WeightsSeparable5& WeightsSeparable5Gaussian1() {

  constexpr float w0 = 0.38774f;

  constexpr float w1 = 0.24477f;

  constexpr float w2 = 0.06136f;

  static constexpr WeightsSeparable5 weights = {

      {JXL_REP4(w0), JXL_REP4(w1), JXL_REP4(w2)},

      {JXL_REP4(w0), JXL_REP4(w1), JXL_REP4(w2)}};

  return weights;

}

const WeightsSeparable5& WeightsSeparable5Gaussian2() {

  constexpr float w0 = 0.250301f;

  constexpr float w1 = 0.221461f;

  constexpr float w2 = 0.153388f;

  static constexpr WeightsSeparable5 weights = {

      {JXL_REP4(w0), JXL_REP4(w1), JXL_REP4(w2)},

      {JXL_REP4(w0), JXL_REP4(w1), JXL_REP4(w2)}};

  return weights;

}

#undef JXL_REP4

//------------------------------------------------------------------------------

// Slow

namespace {

template <class WrapX, class WrapY>

float SlowSymmetric3Pixel(const ImageF& in, const int64_t ix, const int64_t iy,

                          const int64_t xsize, const int64_t ysize,

                          const WeightsSymmetric3& weights) {

  float sum = 0.0f;

  // ix: image; kx: kernel

  for (int64_t ky = -1; ky <= 1; ky++) {

    const int64_t y = WrapY()(iy + ky, ysize);

    const float* JXL_RESTRICT row_in = in.ConstRow(static_cast<size_t>(y));

    const float wc = ky == 0 ? weights.c[0] : weights.r[0];

    const float wlr = ky == 0 ? weights.r[0] : weights.d[0];

    const int64_t xm1 = WrapX()(ix - 1, xsize);

    const int64_t xp1 = WrapX()(ix + 1, xsize);

    sum += row_in[ix] * wc + (row_in[xm1] + row_in[xp1]) * wlr;

  }

  return sum;

}

Unexecuted instantiation: convolve_slow.cc:float jxl::(anonymous namespace)::SlowSymmetric3Pixel<jxl::WrapMirror, jxl::WrapMirror>(jxl::Plane<float> const&, long, long, long, long, jxl::WeightsSymmetric3 const&)

Unexecuted instantiation: convolve_slow.cc:float jxl::(anonymous namespace)::SlowSymmetric3Pixel<jxl::WrapUnchanged, jxl::WrapMirror>(jxl::Plane<float> const&, long, long, long, long, jxl::WeightsSymmetric3 const&)

Unexecuted instantiation: convolve_slow.cc:float jxl::(anonymous namespace)::SlowSymmetric3Pixel<jxl::WrapMirror, jxl::WrapUnchanged>(jxl::Plane<float> const&, long, long, long, long, jxl::WeightsSymmetric3 const&)

Unexecuted instantiation: convolve_slow.cc:float jxl::(anonymous namespace)::SlowSymmetric3Pixel<jxl::WrapUnchanged, jxl::WrapUnchanged>(jxl::Plane<float> const&, long, long, long, long, jxl::WeightsSymmetric3 const&)

template <class WrapY>

void SlowSymmetric3Row(const ImageF& in, const int64_t iy, const int64_t xsize,

                       const int64_t ysize, const WeightsSymmetric3& weights,

                       float* JXL_RESTRICT row_out) {

  row_out[0] =

      SlowSymmetric3Pixel<WrapMirror, WrapY>(in, 0, iy, xsize, ysize, weights);

  for (int64_t ix = 1; ix < xsize - 1; ix++) {

    row_out[ix] = SlowSymmetric3Pixel<WrapUnchanged, WrapY>(in, ix, iy, xsize,

                                                            ysize, weights);

  }

  {

    const int64_t ix = xsize - 1;

    row_out[ix] = SlowSymmetric3Pixel<WrapMirror, WrapY>(in, ix, iy, xsize,

                                                         ysize, weights);

  }

}

Unexecuted instantiation: convolve_slow.cc:void jxl::(anonymous namespace)::SlowSymmetric3Row<jxl::WrapMirror>(jxl::Plane<float> const&, long, long, long, jxl::WeightsSymmetric3 const&, float*)

Unexecuted instantiation: convolve_slow.cc:void jxl::(anonymous namespace)::SlowSymmetric3Row<jxl::WrapUnchanged>(jxl::Plane<float> const&, long, long, long, jxl::WeightsSymmetric3 const&, float*)

}  // namespace

Status SlowSymmetric3(const ImageF& in, const Rect& rect,

                      const WeightsSymmetric3& weights, ThreadPool* pool,

                      ImageF* JXL_RESTRICT out) {

  const int64_t xsize = static_cast<int64_t>(rect.xsize());

  const int64_t ysize = static_cast<int64_t>(rect.ysize());

  const int64_t kRadius = 1;

  const auto process_row = [&](const uint32_t task,

                               size_t /*thread*/) -> Status {

    const int64_t iy = task;

    float* JXL_RESTRICT out_row = out->Row(static_cast<size_t>(iy));

    if (iy < kRadius || iy >= ysize - kRadius) {

      SlowSymmetric3Row<WrapMirror>(in, iy, xsize, ysize, weights, out_row);

    } else {

      SlowSymmetric3Row<WrapUnchanged>(in, iy, xsize, ysize, weights, out_row);

    }

    return true;

  };

  JXL_RETURN_IF_ERROR(RunOnPool(pool, 0, static_cast<uint32_t>(ysize),

                                ThreadPool::NoInit, process_row,

                                "SlowSymmetric3"));

  return true;

}

namespace {

// Separable kernels, any radius.

StatusOr<float> SlowSeparablePixel(const ImageF& in, const Rect& rect,

                                   const int64_t x, const int64_t y,

                                   const int64_t radius,

                                   const float* JXL_RESTRICT horz_weights,

                                   const float* JXL_RESTRICT vert_weights) {

  const size_t xsize = in.xsize();

  const size_t ysize = in.ysize();

  const WrapMirror wrap;

  float mul = 0.0f;

  for (int dy = -radius; dy <= radius; ++dy) {

    const float wy = vert_weights[std::abs(dy) * 4];

    const size_t sy = wrap(rect.y0() + y + dy, ysize);

    JXL_ENSURE(sy < ysize);

    const float* const JXL_RESTRICT row = in.ConstRow(sy);

    for (int dx = -radius; dx <= radius; ++dx) {

      const float wx = horz_weights[std::abs(dx) * 4];

      const size_t sx = wrap(rect.x0() + x + dx, xsize);

      JXL_ENSURE(sx < xsize);

      mul += row[sx] * wx * wy;

    }

  }

  return mul;

}

template <int R, typename Weights>

Status SlowSeparable(const ImageF& in, const Rect& in_rect,

                     const Weights& weights, ThreadPool* pool, ImageF* out,

                     const Rect& out_rect) {

  JXL_ENSURE(in_rect.xsize() == out_rect.xsize());

  JXL_ENSURE(in_rect.ysize() == out_rect.ysize());

  JXL_ENSURE(in_rect.IsInside(Rect(in)));

  JXL_ENSURE(out_rect.IsInside(Rect(*out)));

  const float* horz_weights = &weights.horz[0];

  const float* vert_weights = &weights.vert[0];

  const auto process_row = [&](const uint32_t task,

                               size_t /*thread*/) -> Status {

    const int64_t y = task;

    float* const JXL_RESTRICT row_out = out_rect.Row(out, y);

    for (size_t x = 0; x < in_rect.xsize(); ++x) {

      JXL_ASSIGN_OR_RETURN(row_out[x],

                           SlowSeparablePixel(in, in_rect, x, y, /*radius=*/R,

                                              horz_weights, vert_weights));

    }

    return true;

  };

  const size_t ysize = in_rect.ysize();

  JXL_RETURN_IF_ERROR(RunOnPool(pool, 0, static_cast<uint32_t>(ysize),

                                ThreadPool::NoInit, process_row,

                                "SlowSeparable"));

  return true;

}

}  // namespace

Status SlowSeparable5(const ImageF& in, const Rect& in_rect,

                      const WeightsSeparable5& weights, ThreadPool* pool,

                      ImageF* out, const Rect& out_rect) {

  return SlowSeparable<2>(in, in_rect, weights, pool, out, out_rect);

}

}  // namespace jxl