(module
	(import "console" "log" (func $log (param i32)))
	(import "js" "mem" (memory $mem 1))

	# n回の呼び出し毎にデバッグ値を出力する
	(global $dbgcnt (mut i32)
		i32.push	0
	)
	(func $dbgval (param $val i32)

		global.push	dbgcnt
		i32.push	0x3F
		i32.and
		if
		else									# dbgcnt & 0x3F == 0
			push		val
			call		log
		end

		global.push	dbgcnt
		i32.push	1
		i32.add
		global.pop	dbgcnt
	)

#	回転(拡大縮小)機能
	(func (export "rotnscl") (param $v i32) (param $w i32)
		(local $it i32)
		(local $rx16 i32)						# rxy: サンプリングxy開始点計算用
		(local $ry16 i32)
		(local $hx16 i32)						# hxy: 水平方向サンプリングxy間隔
		(local $hy16 i32)
		(local $vx16 i32)						# vxy: 垂直方向サンプリングxy間隔
		(local $vy16 i32)
		(local $dest_adr i32)
		(local $w16 i32)
		(local $x i32)
		(local $_vx16 i32)
		(local $_vy16 i32)
		(local $_hx16 i32)
		(local $_hy16 i32)

		# テーブルから cos, sin を得る 0x200000 - 0x2007FF: table (cos:4 sin:4) x 256
		push		v
		i32.push	3
		i32.shl									# [ (v << 3)
		pop_push	it
		push		it
		push		it							# [ (v << 3) (v << 3) (v << 3)

		# rxy: サンプリングxy開始点計算用
		i32.push	0x200400					# 0x200000 + PI:128 << 3
		i32.add									# [ (v << 3) (v << 3) ((v << 3) + (PI << 3))
		i32.push	0x2007F8
		i32.and									# [ (v << 3) (v << 3) *cos(v + 128)

		pop_push	it
		push		it
		i32.push	4
		i32.add									# [ (v << 3) (v << 3) *cos(v + 128) *sin(v + 128)

		i32.load
		pop			ry16						# ry16 = sin(v + 128) <16bit.16bit>
		i32.load
		pop			rx16						# rx16 = cos(v + 128) <16bit.16bit>

		# hxy: 水平方向サンプリングxy間隔
		i32.push	0x200000					# 0x200000
		i32.add									# [ (v << 3) (v << 3)
		i32.push	0x2007F8
		i32.and									# [ (v << 3) *cos(v)

		pop_push	it
		push		it
		i32.push	4
		i32.add									# [ (v << 3) *cos(v) *sin(v)

		i32.load
		pop			hy16						# hy16 = sin(v) <16bit.16bit>
		i32.load
		pop			hx16						# hx16 = cos(v) <16bit.16bit>	

		# vxy: 垂直方向サンプリングxy間隔
		i32.push	0x200200					# 0x200000 + (PI/2):64 << 3
		i32.add									# [ (v << 3) ((v << 3) + ((PI/2) << 3))
		i32.push	0x2007F8
		i32.and									# [ (v << 3) *cos(v + 64)

		pop_push	it
		push		it
		i32.push	4
		i32.add									# [ *cos(v + 64) *sin(v + 64)

		i32.load
		pop			vy16						# vy16 = sin(v + 64) <16bit.16bit>
		i32.load
		pop			vx16						# vx16 = cos(v + 64) <16bit.16bit>

		# 描画先アドレス
		push		w
		push		w
		i32.mul
		i32.push	2
		i32.shl
		pop			dest_adr					# dest_adr = (w * w) << 2

		# _vx16, _vy16: サンプリングxy開始点
		push		w
		i32.push	1
		i32.shr_u
		pop_push	it							# [ (dxy = w >> 1)
		push		it							# [ dxy dxy

		i32.push	65536
		push		rx16
		push		ry16						# [ dxy dxy 65536 rx16 ry16
		i32.sub
		i32.add
		i32.mul									# [ dxy dxy * (65536 + rx16 - ry16)
		pop			_vx16						# _vx16 = (dxy * rx16) - (dxy * ry16) + (dxy << 16) <16bit.16bit>

		i32.push	65536
		push		ry16
		push		rx16						# [ dxy 65536 ry16 rx16
		i32.add
		i32.add
		i32.mul									# [ dxy * (65536 + ry16 + rx16)
		pop			_vy16						# _vy16 = (dxy * ry16) + (dxy * rx16) + (dxy << 16) <16bit.16bit>

		# サンプリング範囲外チェック用に w16 を作っておく
		push		w
		i32.push	16
		i32.shl
		pop			w16							# w16 = w << 16

vloop:	loop									# 垂直方向ループ

		# 水平方向カウンタを初期化
		push		w
		pop			x							# x = w

		# サンプリング位置を垂直方向に進め、水平方向の初期位置としてセット
		push		_vx16
		push		vx16
		i32.add
		pop_push	_vx16						# _vx16 += vx16
		pop			_hx16						# _hx16 = _vx16

		push		_vy16
		push		vy16
		i32.add
		pop_push	_vy16						# _vy16 += vy16
		pop			_hy16						# _hy16 = _vy16

hloop:	loop									# 水平方向ループ

		push		dest_adr
		i32.push	4
		i32.sub
		pop_push	dest_adr					# [ (dest_adr -= 4)

sblock:	block		(result i32)				# [ dest_adr

		# 透過色を持つアドレス
		i32.push	0x200800					# [ dest_adr 0x200800

		# サンプリング位置を水平方向に進める
		push		_hx16
		push		hx16
		i32.add
		pop_push	_hx16						# [ dest_adr 0x200800 (_hx16 += hx16)

		push		_hy16
		push		hy16
		i32.add
		pop_push	_hy16						# [ dest_adr 0x200800 _hx16 (_hy16 += hy16)

		# サンプリング範囲外チェック
		i32.or									# [ dest_adr 0x200800 (_hx16 | _hy16)
		push		w16
		i32.ge_u								# [ dest_adr 0x200800 ((_hx16 | _hy16) >= (w << 16))
		br_if		sblock						# [ dest_adr break(0x200800)

		# 透過色を持つアドレスを捨てる
		drop									# [ dest_adr

		# サンプリングアドレス計算
		i32.push	0x100000					# [ dest_adr 0x100000

		push		_hy16
		i32.push	16
		i32.shr_u
		push		w
		i32.mul									# [ dest_adr 0x100000 (_hy16 >> 16 * w)

		push		_hx16
		i32.push	16
		i32.shr_u
		i32.add									# [ dest_adr 0x100000 ((_hy16 >> 16 * w) + (_hx16 >> 16))

		i32.push	2
		i32.shl									# [ dest_adr 0x100000 ((_hy16 >> 16 * w) + (_hx16 >> 16) << 2)

		i32.add									# [ dest_adr src_adr

		end			# sblock

		# サンプリング＆描画
		i32.load								# [ dest_adr color
		i32.store								# [

		push		x
		i32.push	1
		i32.sub
		pop_push	x
		jp_nz		hloop						# (x -= 1) != 0 and loop
		end

		push		dest_adr
		jp_nz		vloop						# dest_adr != 0 and loop
		end
	)
)

__END__