-
Notifications
You must be signed in to change notification settings - Fork 0
/
retroarch_api_faker.lua
137 lines (124 loc) · 5.88 KB
/
retroarch_api_faker.lua
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
-- SPDX-FileCopyrightText: 2023 Wilhelm Schürmann <[email protected]>
--
-- SPDX-License-Identifier: MIT
-- This script attempts to implement the basic functionality needed in order for
-- the LADXR Archipelago client to be able to talk to BizHawk instead of RetroArch
-- by reproducing the RetroArch API with BizHawk's Lua interface.
--
-- RetroArch UDP API: https://github.com/libretro/RetroArch/blob/master/command.c
--
-- Only
-- VERSION
-- GET_STATUS
-- READ_CORE_MEMORY
-- WRITE_CORE_MEMORY
-- commands are supported right now.
--
-- USAGE:
-- Load this script in BizHawk ("Tools" -> "Lua Console" -> "Script" -> "Open Script")
--
-- All inconsistencies (like missing newlines for some commands) of the RetroArch
-- UDP API (network_cmd_enable) are reproduced as-is in order for clients written to work with
-- RetroArch's current API to "just work"(tm).
--
-- This script has only been tested on GB(C). If you have made sure it works for N64 or other
-- cores supported by BizHawk, please let me know. Note that GET_STATUS, at the very least, will
-- have to be adjusted.
--
--
-- NOTE:
-- BizHawk's Lua API is very trigger-happy on throwing exceptions.
-- Emulation will continue fine, but the RetroArch API layer will stop working. This
-- is indicated only by an exception visible in the Lua console, which most players
-- will probably not have in the foreground.
--
-- pcall(), the usual way to catch exceptions in Lua, doesn't appear to be supported at all,
-- meaning that error/exception handling is not easily possible.
--
-- This means that a lot more error checking would need to happen before e.g. reading/writing
-- memory. Since the end goal, according to AP's Discord, seems to be SNI integration of GB(C),
-- no further fault-proofing has been done on this.
--
local socket = require("socket")
local udp = socket.udp()
udp:setsockname('127.0.0.1', 55355)
udp:settimeout(0)
while true do
-- Attempt to lessen the CPU load by only polling the UDP socket every x frames.
-- x = 10 is entirely arbitrary, very little thought went into it.
-- We could try to make use of client.get_approx_framerate() here, but the values returned
-- seemed more or less arbitrary as well.
--
-- NOTE: Never mind the above, the LADXR Archipelago client appears to run into problems with
-- interwoven GET_STATUS calls, leading to stopped communication.
-- For GB(C), polling the socket on every frame is OK-ish, so we just do that.
--
--while emu.framecount() % 10 ~= 0 do
-- emu.frameadvance()
--end
local data, msg_or_ip, port_or_nil = udp:receivefrom()
if data then
-- "data" format is "COMMAND [PARAMETERS] [...]"
local command = string.match(data, "%S+")
if command == "VERSION" then
-- 1.14 is the latest RetroArch release at the time of writing this, no other reason
-- for choosing this here.
udp:sendto("1.14.0\n", msg_or_ip, port_or_nil)
elseif command == "GET_STATUS" then
local status = "PLAYING"
if client.ispaused() then
status = "PAUSED"
end
if emu.getsystemid() == "GBC" then
-- Actual reply from RetroArch's API:
-- "GET_STATUS PLAYING game_boy,AP_62468482466172374046_P1_Lonk,crc32=3ecb7b6f"
-- CRC32 isn't readily available through the Lua API. We could calculate
-- it ourselves, but since LADXR doesn't make use of this field it is
-- simply replaced by the hash that BizHawk _does_ make available.
udp:sendto(
"GET_STATUS " .. status .. " game_boy," ..
string.gsub(gameinfo.getromname(), "[%s,]", "_") ..
",romhash=" ..
gameinfo.getromhash() .. "\n",
msg_or_ip, port_or_nil
)
else -- No ROM loaded
-- NOTE: No newline is intentional here for 1:1 RetroArch compatibility
udp:sendto("GET_STATUS CONTENTLESS", msg_or_ip, port_or_nil)
end
elseif command == "READ_CORE_MEMORY" then
local _, address, length = string.match(data, "(%S+) (%S+) (%S+)")
address = tonumber(address, 16)
length = tonumber(length)
-- NOTE: mainmemory.read_bytes_as_array() would seem to be the obvious choice
-- here instead, but it isn't. At least for Sameboy and Gambatte, the "main"
-- memory differs (ROM vs WRAM).
-- Using memory.read_bytes_as_array() and explicitly using the System Bus
-- as the active memory domain solves this incompatibility, allowing us
-- to hopefully use whatever GB(C) emulator we want.
local mem = memory.read_bytes_as_array(address, length, "System Bus")
local hex_string = ""
for _, v in ipairs(mem) do
hex_string = hex_string .. string.format("%02X ", v)
end
hex_string = hex_string:sub(1, -2) -- Hang head in shame, remove last " "
local reply = string.format("%s %02x %s\n", command, address, hex_string)
udp:sendto(reply, msg_or_ip, port_or_nil)
elseif command == "WRITE_CORE_MEMORY" then
local _, address = string.match(data, "(%S+) (%S+)")
address = tonumber(address, 16)
local to_write = {}
local i = 1
for byte_str in string.gmatch(data, "%S+") do
if i > 2 then
table.insert(to_write, tonumber(byte_str, 16))
end
i = i + 1
end
memory.write_bytes_as_array(address, to_write, "System Bus")
local reply = string.format("%s %02x %d\n", command, address, i - 3)
udp:sendto(reply, msg_or_ip, port_or_nil)
end
end
emu.frameadvance()
end