// 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.

#ifndef LIB_JXL_COEFF_ORDER_FWD_H_

#define LIB_JXL_COEFF_ORDER_FWD_H_

// Breaks circular dependency between ac_strategy and coeff_order.

#include <cstddef>

#include <cstdint>

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

namespace jxl {

// Needs at least 16 bits. A 32-bit type speeds up DecodeAC by 2% at the cost of

// more memory.

using coeff_order_t = uint32_t;

// Maximum number of orders to be used. Note that this needs to be multiplied by

// the number of channels. One per "size class" (plus one extra for DCT8),

// shared between transforms of size XxY and of size YxX.

constexpr uint8_t kNumOrders = 13;

// DCT coefficients are laid out in such a way that the number of rows of

// coefficients is always the smaller coordinate.

JXL_INLINE constexpr size_t CoefficientRows(size_t rows, size_t columns) {

  return rows < columns ? rows : columns;

}

JXL_INLINE constexpr size_t CoefficientColumns(size_t rows, size_t columns) {

  return rows < columns ? columns : rows;

}

JXL_INLINE void CoefficientLayout(size_t* JXL_RESTRICT rows,

                                  size_t* JXL_RESTRICT columns) {

  size_t r = *rows;

  size_t c = *columns;

  *rows = CoefficientRows(r, c);

  *columns = CoefficientColumns(r, c);

}

}  // namespace jxl

#endif  // LIB_JXL_COEFF_ORDER_FWD_H_