Jigsaw.js

Required functions
  Snap
  Solve
  Jumble
  Possibly square pad

Plan
Multiple jigsaws on page?
Definition of start point for solve and jumble.
Definition of xBits and yBits and horizontal and vertical spacing.
Need array of all pieces.
Each piece needs to know
  it is a jigsaw piece
  it's correct row / column,
  it's tags
  snap lines
On drop, see if near other pieces, if so snap.
Function to position piece.
Button for solve.
  Look at java code.
Button for jumble.
  Look at java code.
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