Finish multiplayer support #248
Conversation
MAC addresses can be derived from the libretro username, read from a file or read from firmware.
|
Thank you so much! This week I'll do a code review and test it personally, then I'll get back to you with any notes I have. |
JesseTG
added
bug
LanMultiplayer.md
Outdated
|
|
||
| Now, the Nintendo DS local Wi-Fi isn't the normal Wi-Fi in your house, it is a [mesh network that uses specialized hardware](https://melonds.kuribo64.net/comments.php?id=25). This means that games expect extremely low latency, which is achievable between two consoles directly connected with special hardware, but harder to achieve with two computers with a router in-between, and simply **impossible** to achieve through the Internet. **LAN multiplayer does not work through the Internet and neither with VPNs or tunnels such as Hamachi**. This is not something that can be fixed easily. **The only way to use emulated LAN Multiplayer is on an actual, low latency LAN connection**. | ||
|
|
||
| The latency requirements are so extreme that even in LAN, you might still have issues. If your sibling is watching Netflix and using the same router, it won't work. If the router is too far away, it won't work. If the router does not have a powerful enough CPU, it won't work. The recommended way to use the emulated Wi-Fi LAN connection is with a wired LAN connection between the computers. |
There was a problem hiding this comment.
The tests you've conducted so far...have they been in this kind of environment? When I tested your last PR, I did so with two Ethernet-connected devices on the same switch. Same network, but I don't think the packets have to go all the way to the router and back.
There was a problem hiding this comment.
The initial tests were in localhost, with two instances of RetroArch on the same computer. When I confirmed that the basics were working, I tested extensively in a connection between my desktop computer (wired) and my phone (wireless, very close to router).
It worked but disconnects sometimes happened. Should I update this to say that the only way it works is with a wired connection?
Specify netplay can be started during a game and improve wording
Ended up about the same size as the hand-rolled parser.
There was a problem hiding this comment.
All right, I've finally gotten around to adding the docs page for melonDS DS, and it's live! Could you move this writeup to that doc page? This link will take you directly to the in-browser editor for that file.
I do ask that you mark the ensuing PR (in the docs repo, not this one) as a draft until 1.2.0 is released, at which point I'll have it merged. Otherwise a hapless player may see this writeup go live before the functionality is ready, then get confused and upset when they don't see it in the core.
There was a problem hiding this comment.
Would you like me to remove the write-up in the repository?
|
Looks good to me (minus some minor notes I just left), but before I merge this I'd like to build and test it myself. I should have a chance to do that tomorrow. I'd also like to fix an unrelated bug in the build pipeline itself -- it turns out that PRs are being built against the wrong commit, and I didn't notice until I gave some poor bastard (what I thought was) a build of this PR to test! Thanks for your hard work and your patience. |
Allow multiplayer for more than 2 players by adding options to change MAC addresses and relevant documentation. Also add warning to not use VPNs or tunnels as well as copyright notices.
Changing MAC addresses can be done either through libretro usernames or dropping a text file on the "system" folder. Deriving MAC addresses from usernames is done with compiler-independent algorithms to guarantee portability.
Note that trying to run 3 instances of melonDS DS was too much for my CPU (on software renderer) and the game lagged too much that disconnects were frequent. I'd recommend using at least a second device to test 3 players so the CPU doesn't get overwhelmed trying to deal with both multiplayer and rendering.
With direct mode, things are a bit confusing as the DS thinks it's sending frames with a certain MAC address, but it's actually using your computer's MAC address instead. However, since direct mode is about Internet connection, it all works fine.
Should fix issues #246 #247 and #225