Super Melee for stock PC/CE maps for SAPP

-- Super Melee for stock PC/CE maps for SAPP
-- by H® Shaft

-- Allows players to melee enemy players AND enemy players in vehicles.
-- Melee to enemy players is instant kill, does not harm yourself or team
-- Melee to enemy players in vehicles causes vehicle to spill and causes some damage to riders.
-- WILL work with custom CE maps which have stock weapon sets

-- don't edit --
api_version = "1.8.0.0"
melee = {}
game_started = false

function OnScriptLoad()
    local tick_counter_sig = sig_scan("8B2D????????807D0000C644240600")
    if (tick_counter_sig ~= 0) then
        tick_counter_address = read_dword(read_dword(tick_counter_sig + 2)) + 0xC
        register_callback(cb['EVENT_TICK'],"OnTick")
    end
    register_callback(cb['EVENT_GAME_START'], "OnNewGame")
    register_callback(cb['EVENT_GAME_END'], "OnGameEnd")
    register_callback(cb['EVENT_JOIN'], "OnPlayerJoin")
    register_callback(cb['EVENT_LEAVE'], "OnPlayerLeave")
    if get_var(0, "$gt") ~= "n/a" then
        for i=1,16 do
            if player_present(i) then
                melee[i] = 0
            end
        end
    end
end

function OnScriptUnload() end

function OnPlayerJoin(PlayerIndex)
    melee[PlayerIndex] = 0
    rprint(PlayerIndex, "|c Super Melee is active!")
end

function OnPlayerLeave(PlayerIndex)
    melee[PlayerIndex] = nil
end

function OnNewGame()
    game_started = true
end

function OnGameEnd()
    game_started = false
    melee = {}
end

function SuperMelee(PlayerIndex, x, y, z)
    if PlayerIndex ~= nil and x ~= nil and y ~= nil and z ~= nil then
        local player_object = get_dynamic_player(PlayerIndex)
        local player_obj_id = read_dword(get_player(PlayerIndex) + 0x34)
        if player_object ~= 0 then
            local grunt = generategrunt(grunt)
            local melee_id = spawn_object("proj", "weapons\\rocket launcher\\rocket", x, y, z+0.7)
            local melee_object = get_object_memory(melee_id)
            if melee_object ~= 0 then
                write_dword(melee_object + 0xC4, player_obj_id)
                write_float(melee_object + 0x74, -0.996)
                write_float(melee_object + 0x70, -5)
            end
            rprint(PlayerIndex, "|c".. grunt)
        end
    end
end

function OnTick()
    if game_started then
        -- damage attributes
        local tick_id = read_dword(tick_counter_address)
        local tag_address = read_dword(0x40440000)
        local tag_count = read_word(0x4044000C)
        for A=0,tag_count-1 do
            local tag_id = tag_address + A * 0x20
            if (read_dword(tag_id) == 1785754657) then
                local tag_data = read_dword(tag_id + 0x14)
                if tag_data ~= nil then
                    if (read_word(tag_data + 0x1C6) == 4) then -- rocket/explosion damage: values below are based on this
                        write_bit(tag_data + 0x1C8, 0, 1) -- doesn't hurt self: 1 = true, 0 = false
                        write_bit(tag_data + 0x1C8, 3, 1) -- doesn't hurt team: 1 = true, 0 = false
                        write_float(tag_data + 0x1D8, 0.5) -- damage amount: passed to enemy players
                        write_float(tag_data + 0x1DC, 0.275) -- damage enemy vehicle riders - 0 damages, 1 = no damage
                        write_float(tag_data + 0x1F4, 3) -- force amount: amount of outward force
                    elseif (read_word(tag_data + 0x1C6) == 6) then -- melee damage
                        write_bit(tag_data + 0x1C8, 7, 1) -- flaming death/instant kill melee
                    end
                end
            end
        end
        -- melee detection and activation of super melee
        for PlayerIndex=1,16 do
            if player_alive(PlayerIndex) then
                local player_object = get_dynamic_player(PlayerIndex)
                local player_obj_id = read_dword(get_player(PlayerIndex) + 0x34)
                local x,y,z = read_vector3d(player_object + 0x5C)
                if (player_object ~= 0) then
                    -- melee detection
                    if not isinvehicle(PlayerIndex) then
                        if melee[PlayerIndex] == nil then melee[PlayerIndex] = 0 end
                        if melee[PlayerIndex] > 0 then melee[PlayerIndex] = melee[PlayerIndex] - 1 end
                        if (melee[PlayerIndex] == 0) and (read_bit(player_object + 0x208, 7) == 1) then
                            SuperMelee(PlayerIndex, x, y, z)
                            melee[PlayerIndex] = math.floor(1.7*30)
                        end
                    end
                end
            end
        end
    end
end

function isinvehicle(PlayerIndex)
    local player_object = get_dynamic_player(PlayerIndex)
    local vehicleId = read_dword(player_object + 0x11C)
    if vehicleId == 0xFFFFFFFF then
        return false
    else
        return true
    end
end

-- when a player melees, this short message is shown to them
function generategrunt(grunt)
    local grunt = {"Uhn!", "Hiyah!", "Umph!", "Doh!", "Fuuuh!", "Efff!", "Nuh!", "Arrg!", "Ack!", "Smack!", "Thwack!", "Nuh!", "whack!", "Pow!"}
    local gruntcount = #grunt
    local rand_grunt = rand(1, gruntcount+1)
    local grunt_type = string.format("%s",  grunt[rand_grunt])
    if grunt_type then
        return grunt_type
    else
        return "Uhn!"
    end
end

-- Created by H® Shaft
-- Visit http://halorace.org/forum/index.php