Snes9x Lua Y's III

-- Y's III (SNES) Collision box viewer
-- Snes9x 1.43-rr/1.51-rr
-- Author: Pasky

local camx
local camy

function findbit(p)
    return 2 ^ (p - 1)
end

function hasbit(x, p)
    return x % (p + p) >= p
end

local function hex(val)
    val = string.format("%X",val)
    if string.len(val) == 1 then
        val = "0" .. val
    end
    return val
end

local function camera()
    camx = memory.readword(0x12D8)
    camy = memory.readword(0x12E0)
end

local function player()
    local x = memory.readbyte(0x1274)
    local y = memory.readbyte(0x1276)
    local x1 = x
    local y1 = y
    local x2 = 0
    local y2 = 0
    if memory.readbyte(0x1273) == 3 then
        x1 = x1 - 4
        x2= x1 + 0x18
        y1= y1 + 0x12
        y2= y1 + 0x10
    else
        x2 = x1 + 0x10
        y1 = y1 + 0x08
        y2 = y1 + 0x18
    end

    gui.box(x1,y1,x2,y2,"#0000FF30","#0000FFFF")
    -- cheat
    -- memory.writebyte(0x1294,0x90) -- infinite hp
    -- memory.writeword(0x1299,0x400) -- experience

    -- Attacking
    if memory.readbyte(0x1283) ~= 0 then
        local offset1 = bit.band(memory.readbyte(0x1287),0x3)
        offset1 = offset1 + memory.readbyte(0x1278) + memory.readbyte(0x127A) - 0x10
        offset1 = bit.lshift(offset1,1)
        local offset2 = bit.band(memory.readbyte(0x127C),0x40)
        offset2 = bit.rshift(offset2,6)
        offset2 = bit.bor(offset2,offset1)
        offset2 = bit.lshift(offset2,2)
        local ax1 = bit.band(x + memory.readbyte(0x17A4BE + offset2),0xFF)
        local ay1 = bit.band(y + memory.readbyte(0x17A4BF + offset2),0xFF)
        local ax2 = bit.band(x + memory.readbyte(0x17A4BC + offset2),0xFF)
        local ay2 = bit.band(y + memory.readbyte(0x17A4BD + offset2),0xFF)
        gui.box(ax1,ay1,ax2,ay2)
    end
end

local function enemies()
    local start = 0x17FB - 0x22
    for i =0,15,1 do
        local base = start + (i * 0x22)
        local x = memory.readword(base) - camx
        local y = memory.readword(base + 2) - camy
        local facing = memory.readbyte(base + 0xf)
        local offset = memory.readbyte(base + 0xD) * 2
        local pointer = memory.readword(0x179a25 + offset)
        local hp = memory.readbyte(base + 0x8)
        local active = memory.readbyte(base + 0x1D)

        if active ~= 0 then
            if bit.band(facing,0x40) ~= 0 then
                -- left
                pointer = pointer + 4
            else
                -- right
            end
            local x1 = x + memory.readbyte(0x179A26 + pointer)
            local y1 = y + memory.readbyte(0x179A27 + pointer)
            local x2 = x + memory.readbyte(0x179A28 + pointer)
            local y2 = y + memory.readbyte(0x179A29 + pointer)

            gui.text(x,y,"HP: " .. hp)
            gui.box(x1,y1,x2,y2,"#0xFF000030","#FF0000FF")
            end
    end
end

while true do
    camera()
    player()
    enemies()
    emu.frameadvance()
end