-- Super Metroid script for GGG Study [WIP]
-- written by gocha, for snes9x-rr 1.43 svn.
-- great thanks: http://drewseph.zophar.net/Kejardon/RAMMap.txt

-- [ startup ] -----------------------------------------------------------------

if emu then error("Unknown SNES EmuLua host.") end
emu = snes9x
if not emu then error("Unknown SNES EmuLua host.") end

-- require("bit")
local bit = {}
bit.band = AND
bit.bor  = OR
bit.bxor = XOR
function bit.lshift(num, shift) return SHIFT(num, -shift) end
function bit.rshift(num, shift) return SHIFT(num,  shift) end

-- Instant ROM check
function romCheck()
	if string.char(unpack(memory.readbyterange(0x80ffc0, 13))) ~= "Super Metroid" then
		return false
	end
	return true
end
if not romCheck() then
	error("Unsupported ROM: make sure if the current ROM is Super Metroid")
end

-- [ routines ] ----------------------------------------------------------------

local camera = {}
local samus = {}
local enemy = {}
local projectile = {}
local ingameFrame

-- xx seconds => h:mm:ss.ss
function formatseconds(seconds)
	local h, m, s
	s = seconds % 60
	m = math.floor(seconds / 60)
	h = math.floor(m / 60)
	m = m % 60
	return string.format("%d:%02d:%05.2f", h, m, s)
end

-- Lua version of win32 PtInRect
function ptInRect(rect, pt)
	if pt.x >= rect.left and pt.x <= rect.right and pt.y >= rect.top and pt.y <= rect.bottom then
		return true
	else
		return false
	end
end

function readMemory()
	ingameFrame = memory.readword(0x7e09da) + (60*memory.readword(0x7e09dc))
		+ (60*60*memory.readword(0x7e09de)) + (60*60*60*memory.readword(0x7e09e0))

	-- camera = {}
	camera.x = memory.readword(0x7e0911)
	camera.y = memory.readword(0x7e0915)
	camera.xsub = memory.readword(0x7e090f)
	camera.ysub = memory.readword(0x7e0913)

	-- samus = {}
	samus.x = memory.readword(0x7e0af6)
	samus.y = memory.readword(0x7e0afa)
	samus.xsub = memory.readword(0x7e0af8)
	samus.ysub = memory.readword(0x7e0afc)
	samus.width = memory.readword(0x7e0afe) * 2
	samus.height = memory.readword(0x7e0b00) * 2
	samus.speed = memory.readbyte(0x7e0b3f)
	samus.shineTimer = memory.readword(0x7e0a68)
	samus.left = samus.x - (samus.width/2)
	samus.top = samus.y - (samus.height/2)
	samus.right = samus.x + (samus.width/2)
	samus.bottom = samus.y + (samus.height/2)

	-- enemy = {}
	for id = 0, 31 do
		local i = id + 1
		enemy[i] = {
			hp = memory.readword(0x7e0f8c + 64*id),
			x = memory.readword(0x7e0f7a + 64*id),
			y = memory.readword(0x7e0f7e + 64*id),
			xsub = memory.readword(0x7e0f7c + 64*id),
			ysub = memory.readword(0x7e0f80 + 64*id),
			width = memory.readword(0x7e0f82 + 64*id) * 2,
			height = memory.readword(0x7e0f84 + 64*id) * 2
		}
		enemy[i].id = id
		enemy[i].left = enemy[i].x - (enemy[i].width/2)
		enemy[i].top = enemy[i].y - (enemy[i].height/2)
		enemy[i].right = enemy[i].x + (enemy[i].width/2)
		enemy[i].bottom = enemy[i].y + (enemy[i].height/2)
		enemy[i].active = (hp ~= 0)
	end

	-- projectile = {}
	for id = 0, 4 do
		local i = id + 1
		projectile[i] = {
			x = memory.readword(0x7e0b64 + 2*id),
			y = memory.readword(0x7e0b78 + 2*id),
			width = memory.readword(0x7e0bb4 + 2*id) * 2,
			height = memory.readword(0x7e0bc8 + 2*id) * 2,
			type = memory.readword(0x7e0c18 + 2*id)
		}
		projectile[i].id = id
		projectile[i].left = projectile[i].x - (projectile[i].width/2)
		projectile[i].top = projectile[i].y - (projectile[i].height/2)
		projectile[i].right = projectile[i].x + (projectile[i].width/2)
		projectile[i].bottom = projectile[i].y + (projectile[i].height/2)
		projectile[i].active = (bit.band(projectile[i].type, 0x8000) ~= 0)
	end
end
readMemory()

-- [ core ] -----------------------------------------------------------------

emu.registerbefore(function()
end)

emu.registerafter(function()
	readMemory()
end)

emu.registerexit(function()
	emu.registerbefore(nil)
	emu.registerafter(nil)
	emu.registerexit(nil)
	gui.register(nil)
end)

gui.register(function()
	gui.opacity(0.68)

	gui.box(samus.left - camera.x, samus.top - camera.y, samus.right - camera.x, samus.bottom - camera.y, "#808080")
	if samus.speed ~= 0 then
		gui.text(samus.x - camera.x - 5, samus.bottom - camera.y, string.format("%d/%d", samus.speed, samus.shineTimer))
	end
	for i = 1, 32 do
		if enemy[i].active and enemy[i].width ~= 0 and enemy[i].height ~= 0 then
			gui.box(enemy[i].left - camera.x, enemy[i].top - camera.y, enemy[i].right - camera.x, enemy[i].bottom - camera.y, "red")
			gui.text(enemy[i].x - camera.x - 5, enemy[i].bottom - camera.y, string.format("#%02d", enemy[i].id))
		end
	end
	for i = 1, 5 do
		if projectile[i].active and projectile[i].width ~= 0 and projectile[i].height ~= 0 then
			gui.box(projectile[i].left - camera.x, projectile[i].top - camera.y, projectile[i].right - camera.x, projectile[i].bottom - camera.y, "blue")
			gui.text(projectile[i].x - camera.x - 5, projectile[i].bottom - camera.y, string.format("#%02d", projectile[i].id))
		end
	end
	gui.text(151, 1, string.format("CAMERA:%04X.%04X,%04X.%04X", camera.x, camera.xsub, camera.y, camera.ysub))
	gui.text(151, 9, string.format(" SAMUS:%04X.%04X,%04X.%04X", samus.x, samus.xsub, samus.y, samus.ysub))
	gui.text(147, 17, string.format("Frame #%07d - %s", ingameFrame, formatseconds(ingameFrame/60.0)))
end)

while true do
	if not romCheck() then
		emu.registerbefore(nil)
		emu.registerafter(nil)
		emu.registerexit(nil)
		gui.register(nil)
		--emu.message("Script closed.")
		break
	end
	emu.frameadvance()
end