Method _updateCoverGrid

Engine/source/T3D/fx/groundCover.cpp:1426–1560

}

void GroundCover::_updateCoverGrid( const Frustum &culler )
{
   PROFILE_SCOPE( GroundCover_UpdateCoverGrid );
   
   mGridSize = getMax( mGridSize, (U32)2 );

   // How many cells in the grid?
   const U32 cells = mGridSize * mGridSize;

   // Whats the max placement count for each cell considering 
   // the grid size and quality scale LOD value.
   const S32 placementCount = getMax( ( (F32)mMaxPlacement * smDensityScale ) / F32( mGridSize * mGridSize ), 0.0f );

   // If the cell grid isn't sized or the placement count
   // changed (most likely because of quality lod) then we
   // need to initialize the system again.
   if ( mCellGrid.empty() || placementCount != mLastPlacementCount )
   {
      _initialize( cells, placementCount );
      mLastPlacementCount = placementCount;
   }

   // Without a count... we don't function at all.
   if ( placementCount == 0 )
      return;

   // Clear the scratch grid.
   dMemset( mScratchGrid.address(), 0, mScratchGrid.memSize() );

   // Calculate the normal cell size here.
   const F32 cellSize = ( mRadius * 2.0f ) / (F32)(mGridSize - 1);

   // Figure out the root index of the new grid based on the camera position.
   Point2I index( (S32)mFloor( ( culler.getPosition().x - mRadius ) / cellSize  ),
                  (S32)mFloor( ( culler.getPosition().y - mRadius ) / cellSize ) );

   // Figure out the cell shift between the old and new grid positions.
   Point2I shift = mGridIndex - index;

   // If we've shifted more than one in either axis then we've warped.
   bool didWarp = shift.x > 1 || shift.x < -1 || 
                  shift.y > 1 || shift.y < -1 ? true : false;

   // Go thru the grid shifting each cell we find and
   // placing them in the scratch grid.
   for ( S32 i = 0; i < mCellGrid.size(); i++ )
   {
      GroundCoverCell* cell = mCellGrid[ i ];
      if ( !cell )
         continue;

      // Whats our new index?
      Point2I newIndex = cell->shiftIndex( shift );

      // Is this cell outside of the new grid?
      if (  newIndex.x < 0 || newIndex.x >= mGridSize ||
            newIndex.y < 0 || newIndex.y >= mGridSize )
      {