Dynamic Vehicle Entry for SAPP

-- Dynamic Vehicle Entry for SAPP
-- by H® Shaft and Giraffe

-- Players only need to aim at a vehicle then press Action Key (E) to enter it.
-- if they are in range and on the same team (if it is occupied),  and if it is upright
-- they will be inserted into an available seat: 1) driver, 2) gunner, or 3) passenger
-- Compatible with all halo PC/CE maps, stock and custom, protected or not, any vehicle in range
-- Compatible with Multi-Team-Vehicles script for non-team games! http://pastebin.com/vq6HXEpA

-- max distance from a vehicle player can be to enter a vehicle (in world units)
-- recommended: 30 for most stock maps, 50-100 for extremely large custom maps (hugeass, extinction, etc)
MAX_DISTANCE = 30

-- if set to true, players will be shown the JOIN_MESSAGE below (how to use Dynamic Vehicle Entry)
ENABLE_MESSAGE = true

-- message given to joining players if ENABLE_MESSAGE (above) is set to true
-- should not be more than 3 entries, ensure the messages are within quotes,
-- and separated by a comma between each message
JOIN_MESSAGE = {
    "Dynamic Vehicle Entry is Enabled!",
    "Aim at a vehicle then press Action Key (E) to enter it.",
}

-- sapp api version
api_version = '1.10.0.0'

-- don't edit below here unless you know what you are doing --
function OnScriptLoad()
    register_callback(cb['EVENT_GAME_START'], "OnNewGame")
    register_callback(cb['EVENT_GAME_END'], "OnGameEnd")
    register_callback(cb['EVENT_TICK'], "OnTick")
    register_callback(cb['EVENT_JOIN'], "OnPlayerJoin")
    register_callback(cb['EVENT_LEAVE'], "OnPlayerLeave")
    register_callback(cb['EVENT_DIE'], "OnPlayerDeath")

    if get_var(0, "$gt") ~= "n/a" then
        OnNewGame()
    end

end

function OnNewGame()
    game_started = true
    LoadDefaults()
end

function OnGameEnd()
    game_started = false
end

function OnPlayerJoin(PlayerIndex)
    delay[PlayerIndex] = 0
    if ENABLE_MESSAGE then
        timer(12000, "Timed_Message", PlayerIndex)
    end
end

function Timed_Message(PlayerIndex)
    if game_started then
        if player_present(PlayerIndex) then
            for l,message in pairs(JOIN_MESSAGE) do
                say(PlayerIndex,message)
            end
        end
    end
    return false
end

function OnPlayerLeave(PlayerIndex)
    delay[PlayerIndex] = 0
end

function OnPlayerDeath(PlayerIndex, KillerIndex)
    if player_present(PlayerIndex) then
        delay[PlayerIndex] = 0
    end
end

function OnTick()
    if game_started then
        for i=1,16 do
            if player_alive(i) then
                local player_object = get_dynamic_player(i)

                -- entry delay default and decrement
                if (delay[i] == nil) then delay[i] = 0 end
                if (delay[i] > 0) then delay[i] = delay[i] - 1 end

                -- detect action key press - activate if no delay, and if player is not in a vehicle, check for vehicle intersect
                if not isinvehicle(i) and (read_bit(player_object + 0x208, 6) == 1) then
                    if (delay[i] == 0) then
                        delay[i] = math.floor(2*30)
                        Intersect_Vehicle(i)
                    end
                end
            end
        end
    end
end

function Intersect_Vehicle(PlayerIndex)
    if not game_started then return end
    local vehicle_id = 0
    local player_object = get_dynamic_player(PlayerIndex)
    local px, py, pz = read_vector3d(player_object + 0x5c)
    local cx, cy, cz = read_vector3d(player_object + 0x230)
    local ignore_this_pid = read_dword(get_player(PlayerIndex) + 0x34)
    local crouch_state = read_float(player_object + 0x50C)
    pz = pz + stand_height - (crouch_state * (stand_height - crouch_height))

    local success, x, y, z, target = intersect(px, py, pz, cx*1000, cy*1000, cz*1000, ignore_this_pid)

    if (success == true and target ~= 0xFFFFFFFF) then
        local target_object = get_object_memory(target)
        if (target_object ~= 0) then
            local obj_type = read_word(target_object + 0xB4)
            if (obj_type == 1) then -- target is a vehicle
                vehicle_id = target
                local distance = tonumber(math.sqrt(((x-px)*(x-px)) + ((y-py)*(y-py)) + ((z-pz)*(z-pz))))
                if (distance <= MAX_DISTANCE and vehicle_id ~= 0) then
                    enter_vehicle_empty_seat(vehicle_id, PlayerIndex)
                end
            end
        end
    end
end

function enter_vehicle_empty_seat(ObjectID, PlayerIndex)
    if not game_started then return end
    local vehicle = get_object_memory(ObjectID)
    local vehicle_metaid = read_dword(vehicle)
    local vehicle_tag = lookup_tag(vehicle_metaid)
    local vehicle_data = read_dword(vehicle_tag + 0x14)
    if (read_bit(vehicle + 0x8B, 7) == 1) then return false end -- do nothing if vehicle is flipped
    local seats = {}
    for i=1,16 do
        if (player_alive(i)) then
            local player = get_dynamic_player(i)
            if (ObjectID == read_dword(player + 0x11C)) then
                -- using this method of reading team to enable use with multi-team vehicles
                if (read_word(get_player(PlayerIndex) + 0x20) ~= read_word(get_player(i) + 0x20)) then
                    return false
                end
                seats[read_word(player + 0x2F0)] = i
            end
        end
    end

    local driver_seat = nil
    local gunner_seat = nil

    local seat_count = read_dword(vehicle_data + 0x2E4)
    local seat_data = read_dword(vehicle_data + 0x2E8)
    for i=0,seat_count-1 do
        local label = read_string32(seat_data + i*284 + 0x4)
        if (biped_seat_labels[label] == true) then
            if (read_bit(seat_data + i*284, 2) == 1) then -- check if driver
                driver_seat = i
            elseif (read_bit(seat_data + i*284, 3) == 1) then -- check if gunner
                gunner_seat = i
            end
        else
            cprint(label)
            seats[i] = 0
        end
    end

    if (driver_seat ~= nil and seats[driver_seat] == nil) then
        enter_vehicle(ObjectID, PlayerIndex, driver_seat)
        return true
    end

    if (gunner_seat ~= nil and seats[gunner_seat] == nil) then
        enter_vehicle(ObjectID, PlayerIndex, gunner_seat)
        return true
    end

    for i=0,seat_count-1 do
        if (seats[i] == nil) then
            enter_vehicle(ObjectID, PlayerIndex, i)
            return true
        end
    end

    return false
end

function LoadDefaults()

    -- tables
    delay = {}
    biped_seat_labels = {}

    -- default globals
    stand_height = nil
    crouch_height = nil

    -- player values
    for i = 1,16 do
        if player_present(i) then
            delay[i] = 0
        end
    end

    if get_var(0, "$gt") ~= "n/a" then

        -- biped data - don't edit anything here
        -- checks if unit type is biped, and sets stand & crouch heights
        -- crosschecks biped_animation data against vehicle seat labels
        local globals_tag = lookup_tag("matg", "globals\\globals")
        local globals_data = read_dword(globals_tag + 0x14)
        local mp_info_data = read_dword(globals_data + 0x168)
        local player_unit_type = read_dword(mp_info_data + 0x10)
        if (player_unit_type == 0x62697064) then
            local biped_metaid = read_dword(mp_info_data + 0x1C)
            if (biped_metaid ~= 0xFFFFFFFF) then
                local biped_tag = lookup_tag(biped_metaid)
                local biped_data = read_dword(biped_tag + 0x14)
                stand_height = read_float(biped_data + 0x400)
                crouch_height = read_float(biped_data + 0x404)
                local biped_animation_metaid = read_dword(biped_data + 0x44)
                if (biped_animation_metaid ~= 0xFFFFFFFF) then
                    local animation_tag = lookup_tag(biped_animation_metaid)
                    local animation_data = read_dword(animation_tag + 0x14)
                    local unit_seat_count = read_dword(animation_data + 0xC)
                    local unit_seat_data = read_dword(animation_data + 0x10)
                    for i=0,unit_seat_count-1 do
                        local label = read_string32(unit_seat_data + i*100)
                        biped_seat_labels[label] = true
                    end
                end
            end
        end
    end
end

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

function read_string32(ReadAddress)
    local str = read_string(ReadAddress)
    if (str:len() > 32) then
        str = str:sub(1, 32)
    end
    return str
end

function OnScriptUnload() end

function OnError(Message)
    print(debug.traceback())
end

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

-- The player -db-GoNe/Juhleek - a well spoken liar, cheat.
-- -db- is: "diverging from the believable" - How ironic. A race clan where admins use rcon to favor themselves to win.