Update fbneo.md

docs/library/fbneo.md

@@ -2,25 +2,49 @@
 
 ## Background
 
-FinalBurn Neo (also referred to as FBNeo or FBN) is a multi-system emulator (Arcade, consoles and computers) under active development, unlike MAME it's more focused on playability and advanced features than accuracy.
+FinalBurn Neo (also referred to as FBNeo or FBN) is a multi-system emulator (Arcade, consoles and computers) under active development. Unlike MAME it's more focused on playability and advanced features than preservation.
 It is the follow-up of FinalBurn and FinalBurn Alpha emulators.
 The libretro core provides wide compatibility with platforms and features supported by libretro.
 
-!!! Question "Focused on playability ? So FBNeo isn't accurate ?"
-    For the most part, it is just as accurate as current MAME, occasionally we even find out a few games are more faithful to the pcb videos. The main difference with MAME is that FBNeo doesn't mind including "quality of life" hacks, while MAME is about absolute preservation. "Quality of life" hacks include things like improving original game's sound, having control alternatives that didn't exist on original cabinet, or dramatically reducing hardware requirements by cutting what we deem as unnecessary corners in the emulation code.
+## Difference from MAME
+
+FBNeo strives for accuracy, just like MAME. There are some arcade boards where one or the other will be more accurate, but for the most part they should be equally accurate.
+The main difference with MAME is that FBNeo doesn't mind including "quality of life" hacks, while MAME is about absolute preservation. "Quality of life" hacks include things like :
+* improving original game's sound (some games like "Burger Time" have noise which was clearly unintended by their developpers, we are removing it)
+* implementing alternative colors for games where the colors don't look right (sometimes there are controversies about which colors are right for an arcade board, like "Tropical Angel", we implement alternative colors as dipswitches)
+* having control alternatives that didn't exist on original cabinet (play rotary stick games like twin-stick shooters, use lightguns in "Rambo 3", use simplified 8-way directional controls for "Battlezone", ...)
+* improving the gaming experience by cutting what we deem as unnecessary aspect of emulation (you won't have to spend 20 minutes "installing" CPS-3 games)
+* reducing hardware requirements by cutting what we deem as unnecessary corners in the emulation code
+* supporting popular romhacks 
+* ...
+
+Note: some of those "quality of life" hacks might be doable with programming skills and lua language on MAME
 
 ## License and changelog
 
-It's distributed under non-commercial license, see [LICENSE.md](https://github.com/finalburnneo/FBNeo/blob/master/LICENSE.md) and [whatsnew.html](https://github.com/finalburnneo/FBNeo/blob/master/whatsnew.html)
+It's distributed under non-commercial license, see [LICENSE.md](https://github.com/finalburnneo/FBNeo/blob/master/LICENSE.md) and [whatsnew.html](https://github.com/finalburnneo/FBNeo/blob/master/whatsnew.html).
 
 ## Extensions
 
 zip, 7z
 
+## Building this core manually
+
+From the root of the repository, run 
+```
+make -j5 -C src/burner/libretro generate-files
+make -j5 -C src/burner/libretro
+```
+Note : `-j5` is to optimize build time on cpus with 4 cores, you can rise or reduce that value to match your own, however a value too high will increase ram usage and might even cause your system to become instable.
+
+Note : if you need additional parameters, they must be added to both commands.
+
 ## Building romsets for FBNeo
 
 Arcade emulation won't work properly without the romsets matching the emulator. FBNeo being an emulator under active development, a given romset might change from time to time to stay in sync with the best dump available for that game. **All of this is to offer you the best gaming experience possible, because older bad dumps can prevent the game from working as it should**.
 
+Don't expect things to work properly if you didn't build valid romsets, and don't report issues because your romsets are invalid.
+
 ### Step 1: Obtaining an XML DAT
 
 You can download the dat files for the latest version of the core from the [dats](https://github.com/libretro/FBNeo/tree/master/dats/) directory. Note that some devices (Nintendo 3DS) are running a "light" build with fewer supported games due to memory limitation, the dat files for that build are available from the [light](https://github.com/libretro/FBNeo/tree/master/dats/light/) subdirectory.
@@ -42,6 +66,8 @@ Refer to a [clrmamepro tutorial](https://docs.libretro.com/guides/arcade-getting
 | Saves             | ✔         |
 | States            | ✔         |
 | Rewind            | ✔         |
+| Run-Ahead         | ✔         |
+| Preemptive Frames | ✔         |
 | Netplay           | ✔         |
 | RetroAchievements | ✔         |
 | RetroArch Cheats  | ✔         |
@@ -140,11 +166,11 @@ Samples should be put under `SYSTEM_DIRECTORY/fbneo/samples`
 
 ## Hiscores
 
-Copy [hiscore.dat](https://github.com/libretro/FBNeo/tree/master/metadata/hiscore.dat) to `SYSTEM_DIRECTORY/fbneo/` and have the hiscore core option enabled. It doesn't guarantee hiscores will work for a specific game though, sometimes a driver could just be missing the necessary support code for hiscores (or hiscore.dat might not be listing that romset). You can request support in the issue tracker as long as the request is reasonable (avoid making a list of several dozens/hundreds of games if you don't want to be ignored). Runahead now works with hiscores, it'll require fairly recent version of the core AND RetroArch though (support was added after 1.10.3 and is still only available through nightlies as of 2022-09-05).
+Copy [hiscore.dat](https://github.com/libretro/FBNeo/tree/master/metadata/hiscore.dat) to `SYSTEM_DIRECTORY/fbneo/` and have the hiscore core option enabled. It doesn't guarantee hiscores will work for a specific game though, sometimes a driver could just be missing the necessary support code for hiscores, or `hiscore.dat` might have a missing or broken entry for that romset. You can request support in the issue tracker. Runahead now works with hiscores, it'll require fairly recent version of the core AND RetroArch though (support was added after 1.10.3 and is still only available through nightlies as of 2022-09-05).
 
-## Run Ahead input lag reduction
+## Input lag reduction
 
-This core widely supports the RetroArch "Run Ahead" input latency reduction feature, with **single instance** being the recommended method. Support for `Second Instance` won't be guaranteed anymore as of [2022-06-25](https://github.com/libretro/FBNeo/commit/7ea5708565955658eeaf49da2be4a9905409bb35).
+This core widely supports the RetroArch input latency reduction features, with **runahead single instance** and **preemptive frames** being the recommended methods. Support for **runahead second instance** is not guaranteed because it doesn't exist in standalone FBNeo unlike the other methods.
 
 ## RetroAchievements
 
@@ -156,11 +182,104 @@ They are either directly available from `Quick Menu > Core Options`, or from the
 
 ## Cheats
 
-You can either use the RetroArch cheat feature, or download a pack of FBNeo native cheats from [here](https://github.com/finalburnneo/FBNeo-cheats/archive/master.zip) and uncompress them into the `SYSTEM_DIRECTORY/fbneo/cheats/` folder, then they'll become available through core options (`Quick Menu > Options`, **NOT** `Quick Menu > Cheats`), using a MAME `cheat.dat` file should also work.
+This core supports the RetroArch cheat feature with the `.cht` files. However it is recommended to use FBNeo's native cheat support instead :
+* download the pack of cheats from [here](https://github.com/finalburnneo/FBNeo-cheats/archive/master.zip)
+* uncompress **all of them** into the `SYSTEM_DIRECTORY/fbneo/cheats/` folder (which is **NOT** the same folder as the RetroArch feature with the `.cht` files)
+* cheats will become available through core options (`Quick Menu > Options`, **NOT** `Quick Menu > Cheats`) afterward.
+
+## Frequently asked questions
+
+### Where can i find the XXX roms ?
+As far as we are concerned, you are supposed to dump your own games, so we can't help you with acquiring romsets.
+
+### Game XXX is not launching, why ?
+It is either not supported or you have a bad rom, your logs will give you more details. Build a valid romset with clrmamepro as said above.
+There are also a few games marked as not working, try one of their clones.
+
+### I patched game XXX and can't run it, why ?
+Because it's considered a bad rom since the crcs won't match, however there is a method to use a patched romset, if you put the patched version of the romset into `SYSTEM_DIRECTORY/fbneo/patched` it will work (NB: you can strip it of any file that don't differ from non-patched romset if you want). **The romset you must launch is still the original non-patched romset though (its content will be overrided by the content of the patched one)**, you can disable that override by toggling off the `Allow patched romsets` core option.
+
+### I bought unibios from http://unibios.free.fr/ and can't run it, why ?
+Same answer as above.
+
+### Game XXX has graphical glitches, why ?
+Write a report with details on the issue and your platform.
+
+### Game XXX runs slowly, why ?
+Your hardware is probably too slow to run the game with your current settings. Try the following :
+* Check if there is a speedhack dipswitch in the core options, set it to "yes".
+* Try disabling rewind, runahead, pre-emptive frames, shaders, or any other retroarch setting known for increasing requirements.
+* Try enabling "Threaded Video" in retroarch settings.
+* Try changing "Max swapchain images" in retroarch settings (higher values gave a small performance benefit on my setup).
+* Try setting a value for frameskip in core options (note : "Fixed" frameskip is recommended, the other methods don't seem to be nearly as reliable).
+* Try lowering CPU clock in core options (note : some games don't support this feature).
+* Try lowering audio settings in the core options.
+* With m68k games (most boards from the late 80s and early 90s) on arm platforms, you can try enabling cyclone in core options, however this is really a last resort since some games won't work properly with this, furthermore it's causing savestates incompatibilities.
+* If it is not enough, upgrade/overclock your hardware, or use another core.
+
+We won't accept requests for "making the core faster", as far as we are concerned this core has a good balance between accuracy & speed, and for the most part will already run really well on low-end devices (rpi3, ...).
+
+### Game XXX has choppy sound, why ?
+Most likely for the same reason as above.
+
+### Game XXX runs faster in MAME2003/MAME2010, why ?
+Overall, FBNeo is slower than old MAME version, because it's more accurate, meaning graphics, sound and gameplay are more likely to be faithful to the real machine.
+This libretro port also supports various features which are usually buggy or totally absent in MAME cores (runahead, netplay, rewind, retroachievements, ...), those features might use additional resources.
+
+### Neogeo CD doesn't work, why ?
+There are several things to know :
+* You need a copy of neocdz.zip and neogeo.zip in your bios folder
+* You need to add `--subsystem neocd` to the command line, or to place your games in a `neocd` folder
+* Supported format are ccd/sub/img (trurip), and single file MODE1/2352 cue/bin (use utilities like "CDmage" to convert your iso if needed), **they must not be compressed**
+
+You can convert your unsupported isos by following this tutorial :
+* Get [CDMage 1.02.1 (beta)](https://www.videohelp.com/software/CDMage) (freeware & no ads). **Don't get CDMage 1.01.5, it doesn't have the "Save As" function**
+* File > Open > select your iso (NB : for multi-track, select the .cue file, not the .iso file)
+* File > Save As > write the name of your new file
+* Make sure you select MODE1/2352 in the second drop-down
+* Press OK, wait for the process to finish (a few seconds on my computer), and it’s done !
+
+### Killer instinct won't work, why ?
+That driver was disabled for now, it doesn't meet our quality criteria.
+
+~~There are several things to know :~~
+* ~~It is only running at playable speed on x86_64 (other arch will basically need a cpu at 4Ghz because they lack a mips3 dynarec), and the core needs to be built like this to enable this dynarec : `make -j5 -C src/burner/libretro USE_X64_DRC=1`~~
+* ~~If your rom is at `ROM_DIRECTORY/kinst.zip`, you'll need the uncompressed disc image at `ROM_DIRECTORY/kinst/kinst.img`~~
+* ~~To get the uncompressed disc image, you'll need to use the chdman tool from MAME on the chd from mame, the command looks like this : `chdman extracthd -i kinst.chd -o kinst.img`~~
+
+### Vertical games don't work properly, why ?
+2 settings are required when running vertical games in FBNeo :
+* `Settings > Core > Allow rotation` must be enabled  (`video_allow_rotate = "true"` in `retroarch.cfg`)
+* `Settings > Video > Scaling > Aspect Ratio` should be set to `Core Provided` (`aspect_ratio_index = "22"` in `retroarch.cfg`)
+
+If you are wondering why this isn't required for the MAME core, you can find more information about it [here](https://github.com/libretro/mame/issues/261)
+
+Additionally :
+* If you are playing on a vertical screen, you'll want to use the `Vertical Mode` core option to rotate the display for your needs, while it's also possible to rotate display from `Settings > Video > Output > Video Rotation`, that method is not recommended because it doesn't rotate the aspect ratio.
+* If you are using a bezel pack, it seems you need to enable `Settings > On-Screen Display > On-Screen Overlay > Auto-Scale Overlay` (`input_overlay_auto_scale = "true"` in `retroarch.cfg`)
+
+### Music is high-pitched, too fast and/or different from FBNeo standalone, why ?
+For better or worse, it was decided to use different default audio settings from standalone in the libretro port. By default standalone has 44100 samplerate and both interpolations off and that's what you should set in libretro's core options if you want the same audio output.
+
+You might also want to make sure you are running the game at the correct speed, most crt games don't run at 60Hz and if you want the proper refresh rate to be emulated you'll need to make sure `Force 60Hz` isn't enabled in core options and `Settings > Video > Synchronization > Sync to Exact Content Framerate` is enabled (`vrr_runloop_enable = "true"` in `retroarch.cfg`). Please note that your screen might not handle well the correct refresh rate, in which case you'll have to make a choice between smoothness and correct refresh rate.
+
+### I have a black screen in neogeo games, why ?
+Most likely because you have an incomplete `neogeo` romset and you changed the bios in core options for some reason. `MVS Asia/Europe ver. 6 (1 slot)` is the default bios and the only one that will cause a "white screen of death" if missing from your `neogeo` romset. If you select another neogeo bios while not having the corresponding file, you won't get the "white screen of death", instead you'll have a black screen with some sound playing. This issue will only happen if you didn't follow the instructions about romsets.
+
+### My favorite combo button is not available, why ?
+Retroarch doesn't allow cores to declare buttons and map them later, meaning the number of different "actions" available is limited by the number of buttons available on the retropad model.
+
+Removing that limitation was asked in https://github.com/libretro/RetroArch/issues/6718, then again in https://github.com/libretro/RetroArch/issues/11273, i won't add more macros as long as this limitation hasn't been removed. If you want more macros, go spam those issues, preferably the later.
+
+The currently available neogeo combos were decided in https://github.com/libretro/FBNeo/issues/51, i won't replace them, but i'll seriously consider removing all of them if i keep having users complaining about them every month.
+
+Note that there was also a request to add a retroarch macro mapper in https://github.com/libretro/RetroArch/issues/8209.
 
-## F.A.Q
+### I can't enable hardcore mode in RetroAchievements, why ?
+This feature doesn't accept achievements made with a romhack, so you need to disable the `Allow patched romsets` core option.
 
-There is a F.A.Q available from [the FBNeo libretro readme](https://github.com/libretro/FBNeo/blob/master/src/burner/libretro/README.md)
+### Where is SYSTEM_DIRECTORY ?
+Open your `retroarch.cfg` file and look for `system_directory`, or check `Settings > Directory > System/BIOS`.
 
 ## External Links