More than just optimized

This week's second major update to Edddy brings a great performance improvement by limiting the number of block instances to the number of placed blocks, instead of creating one for every coordinate within the map. Another optimization is that block maps now keep track of the number of blocks being used from a certain set, thereby no longer requiring iteration over every instance to determine which blocksets it uses.

Other new features include:

• Previewing the removal of blocks
• The undo stack was reimplemented using Qt's undo framework
• Fill tool rotation filter by holding down Ctrl
• Switch between opened maps using Ctrl+(Shift+)Tab