Global Vehicle Meta-Ids for Sapp

-- Global Vehicle Meta-Ids  (Utility Script for scripting with SAPP, not a game-play script)
-- by H® Shaft

-- edited 11/26/2016 corrected an omitted map name

-- This script will display a list of vehicle meta-ids listed in the maps global tag
-- Works with BOTH protected and unprotected Halo PC/CE maps
-- This will display and log: 1) a meta-id list, or: 2) a single vehicle meta-id into sapps log file with the map name
-- see USAGE below.

-- Usage:
    -- to see and save a list of all global vehicle meta-ids, type: "all_vehicles" (without quotes)
    -- to see and save the meta-id of the vehicle you are IN, type "this_vehicle" (without quotes)

-- Sample Output (all_vehicles) Displayed on screen, and logged into sapp.log:
    -- There are 6 vehicles listed in the map bloodgulch (PC/CE):
    -- Vehicle # 1: Meta ID: 3822322272
    -- Vehicle # 2: Meta ID: 3837199171
    -- Vehicle # 3: Meta ID: 3830907619
    -- Vehicle # 4: Meta ID: 3846177740
    -- Vehicle # 5: Meta ID: 3899197173
    -- Vehicle # 6: Meta ID: 3842311057


-- Each map has a standard list of SIX vehicle 'slots', this is the "stock" slot list.
-- This slot list matches the multiplayer gametype 'vehicle options' screen, in the halo lobby 'Edit Gametypes' section:

-- Slot 1: Warthog
-- Slot 2: Ghost
-- Slot 3: Scorpion
-- Slot 4: Rocket Warthog
-- Slot 5: Banshee
-- Slot 6: Gun Turret

-- Notes:
-- 'Stock' PC/CE maps always follow the above order, BUT, - not all "custom" Halo CE maps follow the above order.
-- The Custom map's author may have 'mixed the slot order', or - may not have used all six slots, or
-- some vehicles in the map may have been spawned by a 'built-in' halo script. If so, they may NOT all be listed in the output
-- Slots 1, 2 & 4 are the vehicles typically setup for RACE gametypes, and others will not 'usually' spawn during race games.
-- Stock PC/CE maps use the same meta-ids for each slot for both PC and CE stock maps (Warthog meta-id for PC and CE is 3822322272)
-- "Custom Maps" use meta-ids that are unique to each map.

-- sapp api version
api_version = "1.9.0.0"

function OnScriptLoad()
    register_callback(cb['EVENT_CHAT'], "OnPlayerChat")
    vehicle_index = {}
end

function OnPlayerChat(PlayerIndex, Message)
    local response = nil
    local Message = string.lower(Message)
    map_name = get_var(0,"$map")

    -- | retrieve and show/save the meta-id list for map from globals tag
    if (Message == "all_vehicles") then
        response = false
        if (get_var(0, "$gt") ~= "n/a") then
            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 vehicles_count = read_dword(mp_info_data + 0x20)
            local vehicles_data = read_dword(mp_info_data + 0x24)
            vehicle_index[map_name] = {}
            if vehicles_count > 0 then
                local str1 = string.format("There are %s vehicles listed in the map %s:", tostring(vehicles_count),tostring(map_name))
                execute_command("log_note \""..str1.."\"")
                say(PlayerIndex,str1)
                local veh_index = 1
                for i=0,vehicles_count-1 do
                    local vehicle_metaid = read_dword(vehicles_data + i*16 + 0xC)
                    if (vehicle_metaid ~= 0) then
                        vehicle_index[map_name][1] = veh_index
                        vehicle_index[map_name][2] = vehicle_metaid
                        local str2 = string.format("Vehicle #%s: Meta ID: %s", tostring(vehicle_index[map_name][1]), tostring(vehicle_index[map_name][2]))
                        say(PlayerIndex, str2)
                        execute_command("log_note \""..str2.."\"")
                        veh_index = veh_index + 1
                    end
                end
                say(PlayerIndex, "This list was saved in the sapp log file.")
            else
                local str3 = string.format("There are no vehicles listed in %s, or there was an error.", tostring(map_name))
                say(PlayerIndex, str3)
                execute_command("log_note \""..str3.."\"")
            end
        end
    end

    -- | retrieve and show/save the meta-id for your current vehicle (you must be in a vehicle)
    if (Message == "this_vehicle") then
        response = false
        if isinvehicle(PlayerIndex) then
            local player_object = get_dynamic_player(PlayerIndex)
            local vehicle_id = read_dword(player_object + 0x11C)
            local veh_object = get_object_memory(vehicle_id)
            if (veh_object ~= 0) then
                local vehicle_metaid = read_dword(veh_object)
                if (vehicle_metaid ~= 0) then
                    local data = string.format("Map: %s  Vehicle MetaId: %s", tostring(map_name),tostring(vehicle_metaid))
                    execute_command("log_note \""..data.."\"")
                    say(PlayerIndex, data)
                    say(PlayerIndex, "This vehicle's meta-id was saved in the sapp log file.")
                else
                    say(PlayerIndex, "Sorry, there was an error, no meta-data available.")
                end
            end
        else
            say(PlayerIndex, "You must be in a vehicle to retrieve it's meta-data.")
        end
    end

    return response
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 OnScriptUnload()
    vehicle_index = {}
end

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

-- Created by H® Shaft, special thanks to Giraffe
-- Visit http://halorace.org/forum/index.php