HEVC代码追踪（十一。九）:运动估计/补偿之xTZ2PointSearch

__inline Void TEncSearch::xTZ2PointSearch( TComPattern* pcPatternKey, IntTZSearchStruct& rcStruct, TComMv* pcMvSrchRngLT, TComMv* pcMvSrchRngRB )
{
  Int   iSrchRngHorLeft   = pcMvSrchRngLT->getHor();
  Int   iSrchRngHorRight  = pcMvSrchRngRB->getHor();
  Int   iSrchRngVerTop    = pcMvSrchRngLT->getVer();
  Int   iSrchRngVerBottom = pcMvSrchRngRB->getVer();
  
  // 2 point search,                   //   1 2 3
  // check only the 2 untested points  //   4 0 5
  // around the start point            //   6 7 8
//!< 注意到，这里的1,3,6,8实际上是搜索步长iDist==2的时候由iDist>>1进行赋值的，实际距离以1计算，
//!< 在前面经过xTZ8PointSearch确定最佳步长为1后，会在这里对以最佳点为中心、周围没搜索过的点进行运动估计
  Int iStartX = rcStruct.iBestX;
  Int iStartY = rcStruct.iBestY;
  switch( rcStruct.ucPointNr )//!< 主要思想是根据该最佳点的位置处理未搜索过的点
  {
    case 1:
    {
      if ( (iStartX - 1) >= iSrchRngHorLeft )
      {
        xTZSearchHelp( pcPatternKey, rcStruct, iStartX - 1, iStartY, 0, 2 );//!< 左
      }
      if ( (iStartY - 1) >= iSrchRngVerTop )
      {
        xTZSearchHelp( pcPatternKey, rcStruct, iStartX, iStartY - 1, 0, 2 );//!< 上
      }
    }
      break;
    case 2:
    {
      if ( (iStartY - 1) >= iSrchRngVerTop )
      {
        if ( (iStartX - 1) >= iSrchRngHorLeft )
        {
          xTZSearchHelp( pcPatternKey, rcStruct, iStartX - 1, iStartY - 1, 0, 2 );//!< 左上  
        }
        if ( (iStartX + 1) <= iSrchRngHorRight )
        {
          xTZSearchHelp( pcPatternKey, rcStruct, iStartX + 1, iStartY - 1, 0, 2 );//!< 右上  
        }
      }
    }
      break;
    case 3:
    {
      if ( (iStartY - 1) >= iSrchRngVerTop )
      {
        xTZSearchHelp( pcPatternKey, rcStruct, iStartX, iStartY - 1, 0, 2 );//!< 上
      }
      if ( (iStartX + 1) <= iSrchRngHorRight )
      {
        xTZSearchHelp( pcPatternKey, rcStruct, iStartX + 1, iStartY, 0, 2 );//!< 右
      }
    }
      break;
    case 4:
    {
      if ( (iStartX - 1) >= iSrchRngHorLeft )
      {
        if ( (iStartY + 1) <= iSrchRngVerBottom )
        {
          xTZSearchHelp( pcPatternKey, rcStruct, iStartX - 1, iStartY + 1, 0, 2 );//!< 左下  
        }
        if ( (iStartY - 1) >= iSrchRngVerTop )
        {
          xTZSearchHelp( pcPatternKey, rcStruct, iStartX - 1, iStartY - 1, 0, 2 );//!< 左上  
        }
      }
    }
      break;
    case 5:
    {
      if ( (iStartX + 1) <= iSrchRngHorRight )
      {
        if ( (iStartY - 1) >= iSrchRngVerTop )
        {
          xTZSearchHelp( pcPatternKey, rcStruct, iStartX + 1, iStartY - 1, 0, 2 );//!< 右上  
        }
        if ( (iStartY + 1) <= iSrchRngVerBottom )
        {
          xTZSearchHelp( pcPatternKey, rcStruct, iStartX + 1, iStartY + 1, 0, 2 );//!< 右下  
        }
      }
    }
      break;
    case 6:
    {
      if ( (iStartX - 1) >= iSrchRngHorLeft )
      {
        xTZSearchHelp( pcPatternKey, rcStruct, iStartX - 1, iStartY , 0, 2 );//!< 左
      }
      if ( (iStartY + 1) <= iSrchRngVerBottom )
      {
        xTZSearchHelp( pcPatternKey, rcStruct, iStartX, iStartY + 1, 0, 2 );//!< 下
      }
    }
      break;
    case 7:
    {
      if ( (iStartY + 1) <= iSrchRngVerBottom )
      {
        if ( (iStartX - 1) >= iSrchRngHorLeft )
        {
          xTZSearchHelp( pcPatternKey, rcStruct, iStartX - 1, iStartY + 1, 0, 2 );//!< 左下  
        }
        if ( (iStartX + 1) <= iSrchRngHorRight )
        {
          xTZSearchHelp( pcPatternKey, rcStruct, iStartX + 1, iStartY + 1, 0, 2 );//!< 右下  
        }
      }
    }
      break;
    case 8:
    {
      if ( (iStartX + 1) <= iSrchRngHorRight )
      {
        xTZSearchHelp( pcPatternKey, rcStruct, iStartX + 1, iStartY, 0, 2 );//!< 右
      }
      if ( (iStartY + 1) <= iSrchRngVerBottom )
      {
        xTZSearchHelp( pcPatternKey, rcStruct, iStartX, iStartY + 1, 0, 2 );//!< 下
      }
    }
      break;
    default:
    {
      assert( false );
    }
      break;
  } // switch( rcStruct.ucPointNr )
}