#pragma region CPL License
/*
Nuclex Native Framework
Copyright (C) 2002-2013 Nuclex Development Labs

This library is free software; you can redistribute it and/or
modify it under the terms of the IBM Common Public License as
published by the IBM Corporation; either version 1.0 of the
License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
IBM Common Public License for more details.

You should have received a copy of the IBM Common Public
License along with this library
*/
#pragma endregion // CPL License

// If the library is compiled as a DLL, this ensures symbols are exported
#define NUCLEX_INPUT_SOURCE 1

#include "Nuclex/Input/Devices/GamePadState.h"

namespace {

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

  /// <summary>Returns the number of bits set in an unsigned integer</summary>
  /// <param name="value">Value whose bits will be counted</param>
  /// <returns>The number of bits set in the unsigned integer</returns>
  template <int TIntegerSize> std::size_t countBits(std::size_t value);

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

  /// <summary>Returns the number of bits set in an unsigned integer</summary>
  /// <param name="value">Value whose bits will be counted</param>
  /// <returns>The number of bits set in the unsigned integer</returns>
  /// <remarks>
  ///   Based on a trick revealed here: http://stackoverflow.com/questions/109023
  /// </remarks>
  template <>
  std::size_t countBits<4>(std::size_t value) { // 32 bit version
    value = value - ((value >> 1) & 0x55555555);
    value = (value & 0x33333333) + ((value >> 2) & 0x33333333);
    return ((value + (value >> 4) & 0xF0F0F0F) * 0x1010101) >> 24;
  }

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

  /// <summary>Returns the number of bits set in an unsigned integer</summary>
  /// <param name="value">Value whose bits will be counted</param>
  /// <returns>The number of bits set in the unsigned integer</returns>
  /// <remarks>
  ///   Based on a trick revealed here: http://stackoverflow.com/questions/2709430
  /// </remarks>
  template <>
  std::size_t countBits<8>(std::size_t value) { // 64 bit version
    value = value - ((value >> 1) & 0x5555555555555555UL);
    value = (value & 0x3333333333333333UL) + ((value >> 2) & 0x3333333333333333UL);
    return (((value + (value >> 4)) & 0xF0F0F0F0F0F0F0FUL) * 0x101010101010101UL) >> 56;
  }

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

} // anonymous namespace

namespace Nuclex { namespace Input { namespace Devices {

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

  std::size_t GamePadState::CountSliders() const {
    return countBits<sizeof(std::size_t)>(this->SliderMask);
  }

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

  std::size_t GamePadState::CountAxes() const {
    return countBits<sizeof(std::size_t)>(this->AxisMask);
  }

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

  void GamePadState::Reset() {

    // Clear all buttons
    this->Buttons.reset();
    this->ButtonCount = 0;

    // Clear all sliders
    for(std::size_t index = 0; index < 8; ++index) {
      this->Sliders[index] = 0.0f;
    }
    this->SliderMask = static_cast<Sliders::Enum>(0);

    // Clear all axes
    for(std::size_t index = 0; index < 24; ++index) {
      this->Axes[index] = 0.0f;
    }
    this->AxisMask = static_cast<Axes::Enum>(0);

    // Clear all directional pads
    for(std::size_t index = 0; index < 4; ++index) {
      DirectionalPad &pad = this->DirectionalPads[index];
      pad.Up = pad.Down = pad.Left = pad.Right = false;
    }
    this->DirectionalPadCount = 0;

  }

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

}}} // namespace Nuclex::Input::Devices