{ 15パズル }
func main()
	assert @pieceSize % @piecePerFrame = 0 {この条件が満たされている前提で駒の移動処理を行います}
	var finishedFont: draw@Font :: draw@makeFont("Meiryo", @finishedFontSize, false, false, true, 0.0)

	{駒の初期化}
	do @pieces :: #[16]@Piece
	for i(0, 15)
		do @pieces[i] :: (#@Piece).init(i)
	end for
	do @voidPiece :: @pieces[15]
	do @shufflePieces()

	const wndSizeW: int :: @pieceSize * 4
	const wndSizeH: int :: @pieceSize * 4 + @finishedFontSize * 2
	var wndMain: wnd@Wnd :: wnd@makeWnd(null, %normal, wndSizeW, wndSizeH, "The 15 puzzle")
	var drawMain: wnd@Draw :: wnd@makeDraw(wndMain, 0, 0, wndSizeW, wndSizeH, %fix, %fix, false)
	while a(wnd@act())
		do draw@render(30)
		do drawPieces()
		if(@completeCheck())
			do finishedFont.draw(10.0, @pieceSize $ float * 4.0, "Congratulations!", 0xFFFFFFFF)
		end if
		for i(0, ^@pieces - 1) {移動アニメーション用のループです}
			var p: @Piece :: @pieces[i]
			if(p.dir <> %stay)
				do p.move(@piecePerFrame)
				skip a {移動中にマウス入力を受け付けないように、ここでwhileループの先頭に戻ります}
			end if
		end for

		do @setDirection(false)
		if(input@pad(0, %a) > 10) {スペースキー長押しでシャッフル}
			do @shufflePieces()
		end if
	end while

	func drawPieces()
		for i(0, ^@pieces - 1)
			var p: @Piece :: @pieces[i]
			if(p <>& @voidPiece)
				do p.draw()
			end if
		end for
	end func
end func

const pieceSize: int :: 100
const shuffleNum: int :: 1000
const piecePerFrame: int :: @pieceSize / 4
const fontSize: int :: 48
const finishedFontSize: int :: 20

enum Dir
	stay
	left :: 1
	right :: 2
	up :: 3
	down :: 4
end enum

class Piece()
	var id: int
	var num: int
	var font: draw@Font
	+var posId: int
	+var pos: Pos
	+var dir: @Dir

	+func init(id: int): @Piece
		do me.id :: id
		do me.num :: id + 1
		do me.font :: draw@makeFont("Meiryo", @fontSize, false, false, false, @fontSize $ float)
		do me.posId :: id
		do me.pos :: (#Pos).init(me.posId)
		do me.dir :: %stay
		ret me
	end func

	+func getId(): int
		ret me.id
	end func

	+func move(pixelPerFrame: int)
		if(me.dir = %left)
			do me.pos.x :- pixelPerFrame
		elif(me.dir = %right)
			do me.pos.x :+ pixelPerFrame
		elif(me.dir = %up)
			do me.pos.y :- pixelPerFrame
		elif(me.dir = %down)
			do me.pos.y :+ pixelPerFrame
		end if
		if(me.pos.x % @pieceSize = 0 & me.pos.y % @pieceSize = 0)
			do me.dir :: %stay
		end if
	end func

	+func draw()
		do draw@rect(me.pos.x $ float + 2.0, me.pos.y $ float + 2.0, @pieceSize $ float - 4.0, @pieceSize $ float - 4.0, 0xFF0000FF)
		do me.font.draw(me.pos.x $ float + (@pieceSize $ float - (^me.num.toStr() * @fontSize) $ float) / 2.0, me.pos.y $ float, me.num.toStr(), 0xFFFFFFFF)
	end func

	class Pos()
		+var x: int
		+var y: int
		+func init(posId: int): Pos
			do me.x :: @pieceSize * (posId % 4)
			do me.y :: @pieceSize * (posId / 4)
			ret me
		end func
	end class
end class

var pieces: []@Piece
var voidPiece: @Piece

{駒の位置情報を元にその駒のidを返します}
func findPieceId(posId: int): int
	for i(0, ^@pieces - 1)
		var p: @Piece :: @pieces[i]
		if(p.posId = posId)
			ret p.getId()
		end if
	end for
	assert false {駒が見つかりません。これはおかしいです。}
end func

func setDirection(shuffleMode: bool)
	var id: int
	var dir: @Dir :: %stay
	if(shuffleMode)
		do dir :: lib@rnd(1, 4) $ @Dir
	else
		if(input@pad(0, %left) % 15 = 1)
			do dir :: %left
		elif(input@pad(0, %right) % 15 = 1)
			do dir :: %right
		elif(input@pad(0, %up) % 15 = 1)
			do dir :: %up
		elif(input@pad(0, %down) % 15 = 1)
			do dir :: %down
		end if
	end if

	switch d(dir)
	case %left
		if(@voidPiece.posId % 4 <> 3)
			do id :: @findPieceId(@voidPiece.posId + 1)
			do @pieces[id].dir :: d
			do @voidPiece.posId :$ @pieces[id].posId
		end if
	case %right
		if(@voidPiece.posId % 4 <> 0)
			do id :: @findPieceId(@voidPiece.posId - 1)
			do @pieces[id].dir :: d
			do @voidPiece.posId :$ @pieces[id].posId
		end if
	case %up
		if(@voidPiece.posId / 4 <> 3)
			do id :: @findPieceId(@voidPiece.posId + 4)
			do @pieces[id].dir :: d
			do @voidPiece.posId :$ @pieces[id].posId
		end if
	case %down
		if(@voidPiece.posId / 4 <> 0)
			do id :: @findPieceId(@voidPiece.posId - 4)
			do @pieces[id].dir :: d
			do @voidPiece.posId :$ @pieces[id].posId
		end if
	end switch

	if(shuffleMode)
		do @pieces[id].move(@pieceSize)
	end if
end func

func shufflePieces()
	for i(1, @shuffleNum)
		do @setDirection(true)
	end for
end func

func completeCheck(): bool
	for i(0, ^@pieces - 1)
		var p: @Piece :: @pieces[i]
		if(p.getId() <> p.posId)
			ret false
		end if
	end for
	ret true
end func