+Uint16Pair AtlasPacker::GroupPack( const Dali::Vector<Uint16Pair>& blockSizes, Dali::Vector<Uint16Pair>& packPositions )
+{
+ uint16_t count = blockSizes.Count();
+ packPositions.Resize( count );
+
+ // Sort the blocks according to its maximum dimension. The bigger blocks are packed first.
+ Dali::Vector<Uint16Pair> packOrder;
+ packOrder.Resize( count );
+ for( uint16_t i = 0; i < count; i++ )
+ {
+ packOrder[i].SetX( MaxDimension( blockSizes[i] ) );
+ packOrder[i].SetY( i );
+ }
+ for( uint16_t i = 0; i < count-1; i++ )
+ for( uint16_t j = 0; j < count-i-1; j++ )
+ {
+ if( packOrder[j].GetX() < packOrder[j+1].GetX() )
+ {
+ Swap( packOrder[j], packOrder[j+1] );
+ }
+ }
+
+ int index = packOrder[0].GetY();
+ AtlasPacker packer( blockSizes[index].GetWidth(), blockSizes[index].GetHeight() );
+
+ SizeType packPositionX, packPositionY;
+ // pack the blocks one by one with descending size, grows as necessary to accommodate each subsequent block.
+ for( uint16_t i = 0; i < count; i++ )
+ {
+ index = packOrder[i].GetY();
+ packer.GrowPack( blockSizes[index].GetWidth(), blockSizes[index].GetHeight(),
+ packPositionX, packPositionY );
+ packPositions[index].SetX( packPositionX );
+ packPositions[index].SetY( packPositionY );
+ }
+
+ return Uint16Pair( packer.mRoot->rectArea.width, packer.mRoot->rectArea.height );
+}
+
+void AtlasPacker::GrowPack( SizeType blockWidth, SizeType blockHeight,
+ SizeType& packPositionX, SizeType& packPositionY )
+{
+ Node* firstFit = InsertNode( mRoot, blockWidth, blockHeight );
+ if( firstFit == NULL )
+ {
+ // Could fit in the current left space, grow the partition tree to get more space.
+ GrowNode( blockWidth, blockHeight );
+ firstFit = InsertNode( mRoot->child[1], blockWidth, blockHeight );
+ }
+
+ DALI_ASSERT_ALWAYS( firstFit != NULL && "It should never happen!")
+
+ firstFit->occupied = true;
+ packPositionX = firstFit->rectArea.x;
+ packPositionY = firstFit->rectArea.y;
+}
+
+void AtlasPacker::GrowNode( SizeType blockWidth, SizeType blockHeight )
+{
+ // Attempts to maintain a roughly square ratio when choosing the growing direction: right or down
+ bool canGrowRight = blockWidth <= mRoot->rectArea.width;
+ bool canGrowDown = blockHeight <= mRoot->rectArea.height;
+
+ bool shouldGrowRight = canGrowRight && mRoot->rectArea.height >= mRoot->rectArea.width+blockWidth;
+ bool shouldGrowDown = canGrowDown && mRoot->rectArea.width >= mRoot->rectArea.height+blockHeight;
+
+ if( canGrowRight && canGrowDown )
+ {
+ shouldGrowRight = mRoot->rectArea.width+blockWidth <= mRoot->rectArea.height+blockHeight;
+ shouldGrowDown = !shouldGrowRight;
+ }
+
+ if( shouldGrowRight || ( canGrowRight && !shouldGrowDown ) )
+ {
+ Node* newRoot = new Node( NULL, 0u, 0u, mRoot->rectArea.width+blockWidth, mRoot->rectArea.height );
+ newRoot->occupied = true;
+ newRoot->child[0] = mRoot;
+ newRoot->child[1] = new Node( newRoot, mRoot->rectArea.width, 0u, blockWidth, mRoot->rectArea.height );
+
+ mRoot = newRoot;
+ }
+ else if( shouldGrowDown || ( canGrowDown && !shouldGrowRight ) )
+ {
+ Node* newRoot = new Node( NULL, 0u, 0u, mRoot->rectArea.width, mRoot->rectArea.height+blockHeight );
+ newRoot->occupied = true;
+ newRoot->child[0] = mRoot;
+ newRoot->child[1] = new Node( newRoot, 0u, mRoot->rectArea.height, mRoot->rectArea.width, blockHeight );
+
+ mRoot = newRoot;
+ }
+ else
+ {
+ DALI_LOG_ERROR( " Atlas Packer failed to grow: make sure the packing order is sorted with the block size to avoid this happening");
+ }
+}
+