// 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 "lib/jxl/chroma_from_luma.h"

#include <jxl/memory_manager.h>

#include <cstddef>

#include <cstdint>

#include <cstdlib>  // abs

#include <limits>

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

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

#include "lib/jxl/dec_bit_reader.h"

#include "lib/jxl/fields.h"

#include "lib/jxl/image.h"

#include "lib/jxl/image_ops.h"

namespace jxl {

Status ColorCorrelation::DecodeDC(BitReader* br) {

  if (br->ReadFixedBits<1>() == 1) {

    // All default.

    return true;

  }

  SetColorFactor(U32Coder::Read(kColorFactorDist, br));

  JXL_RETURN_IF_ERROR(F16Coder::Read(br, &base_correlation_x_));

  if (std::abs(base_correlation_x_) > 4.0f) {

    return JXL_FAILURE("Base X correlation is out of range");

  }

  JXL_RETURN_IF_ERROR(F16Coder::Read(br, &base_correlation_b_));

  if (std::abs(base_correlation_b_) > 4.0f) {

    return JXL_FAILURE("Base B correlation is out of range");

  }

  ytox_dc_ = static_cast<int>(br->ReadFixedBits<kBitsPerByte>()) +

             std::numeric_limits<int8_t>::min();

  ytob_dc_ = static_cast<int>(br->ReadFixedBits<kBitsPerByte>()) +

             std::numeric_limits<int8_t>::min();

  RecomputeDCFactors();

  return true;

}

StatusOr<ColorCorrelationMap> ColorCorrelationMap::Create(

    JxlMemoryManager* memory_manager, size_t xsize, size_t ysize, bool XYB) {

  ColorCorrelationMap result;

  size_t xblocks = DivCeil(xsize, kColorTileDim);

  size_t yblocks = DivCeil(ysize, kColorTileDim);

  JXL_ASSIGN_OR_RETURN(result.ytox_map,

                       ImageSB::Create(memory_manager, xblocks, yblocks));

  JXL_ASSIGN_OR_RETURN(result.ytob_map,

                       ImageSB::Create(memory_manager, xblocks, yblocks));

  ZeroFillImage(&result.ytox_map);

  ZeroFillImage(&result.ytob_map);

  if (!XYB) {

    result.base_.base_correlation_b_ = 0;

  }

  result.base_.RecomputeDCFactors();

  return result;

}

}  // namespace jxl