RetroArch Roadmap for v1.7.0 and beyond

We don’t usually talk about all the behind the scenes development stuff that we do. We usually prefer to let the work speak for itself. Nevertheless, we feel compelled to share with you from now on a brief roadmap status update that basically shows what we are currently working on codebase-wise, where RA will go next, etc. We also hope this will be of use to existing upstream contributors.

Compatibility with OpenGL 1.x

From its inception, RetroArch’s OpenGL driver has targeted OpenGL 2.0 and/or later. There are a lot of people on ageing computers that don’t have a GL 2.x compliant driver. We have been putting a lot of work into modularizing the renderchain code, splitting it up from the main GL driver into their own files. This will pave the road towards a basic OpenGL 1.x renderchain which should at least work with OpenGL 1.3 and up. We might be able to target even lower versions later on, but time will tell.

Certain features this GL 1.x renderchain will not have:
* FBO support. FBOs wasn’t a thing with OpenGL until at least version 2.0 (not counting extensions). This also means no libretro GL support, so don’t expect hardware rendered cores with OpenGL 1.x.
* Shaders. Again, this is tied back to a couple of factors, one of them being the lack of FBO support which makes multi-pass shaders impossible to implement. But also, shaders are impossible in general for this 1.x mode. GL 1.x did not yet have shader support. Shaders didn’t become a thing until GL 2.x. GLSL/Cg/HLSL did not exist yet at this time and the entire rendering pipeline was fixed-function.
* There will be no fast framebuffer readback paths (in so far as that stuff is actually ‘fast’ with GL to begin with). No PBO support, which wasn’t a thing back in GL 1.x days. So expect slow screenshot taking and/or recording.
* VAOs (Vertex Array Object) and VBOs (Vertex Buffer Object) weren’t yet a thing until GL 3.x and GL 2.x respectively.

We have no idea yet when this will start working. The main issue is testing it on ancient GPUs that only have GL 1.x drivers.

Xbox OG/Xbox 360

For a long time, the Xbox OG and 360 versions of RetroArch and cores have been de-listed. This had several technical reasons, one of which being that it was a big maintenance burden and struggle to keep having to update all the separate Visual Studio solution files for these platforms. For all other platforms, we build cores using a universal Makefile, which typically contains one file (called Makefile.common) which conditionally defines which files are to be compiled in. By having to maintain some separate solution file, we need to update two files instead of one, and worse, having to start IDEs in order to edit them (or even worse), having to manually edit them with a text editor, which can tend to be error prone on top.

In order to do away with these issues, we have now reverse-engineered how we can still have a Makefile target for MSVC that uses MS’ compilers/linkers/assemblers from within the confines of a Makefile-based solution. Note that this solution does not depend on Microsoft’s nmake and uses plain make.

Now that we have accomplished being able to compile and link cores with MSVC without any MSVC solution file, we now feel the time is right to start reintroducing the Xbox OG and 360 ports.

The Xbox port work also feeds into several other things we have been working on concurrently, such as :

  • Better Direct3D support. Xbox OG will need Direct3D 8, whereas Xbox 360 needs Direct3D 9 + HLSL.
  • The latest compiler that can be used for Xbox OG is Visual Studio 2003, whereas for Xbox 360 this is Visual Studio 2010 (right now). To this end, we have updated a lot of core Makefiles to include targets for these platforms, and not just for the Xbox platforms, but PC as well.

Direct3D work – supporting more versions, etc.

In the past, we have had two separate Direct3D drivers – one for XDK (shorthand for Xbox platforms), and one for PC (Direct3D9-based). Because we intend on supporting the Xbox platforms again, we no longer want the maintenance burden of having two video drivers that essentially are similar in lots of ways. To this end, we have started modularizing the Direct3D driver so that multiple backends are possible to be implemented.

Not only is it possible to have a Direct 3D 8 / 9 codepath, but it is also possible to have separate renderchains. For instance, the Xbox 360 will be able to use the HLSL renderchain, whereas on PC the user has the option to choose between Cg (which would use the Cg renderchain), and/or HLSL (which would use the HLSL renderchain).

We also intend for there to be a fallback path to Direct 3D 8 in case your GPU and its drivers do not support Direct 3D 9 for whatever reason. Backwards compatibility is very important to us and it’s increasingly getting harder to keep supporting all of these various versions in one single codebase. These are unique challenges to which there is often not a clear-cut solution, so we have to improvise a little on the fly and do unconventional things in order to make this happen.

Windows 95

Brad Parker likes extending backwards compatibility of RetroArch to older versions of Windows, and this in turn makes our codebase more flexible so that we can keep the Xbox OG and 360 ports alive.

People might mistake this for taking up resources and time that could be better spent elsewhere, but the opposite is true – by setting up the foundation in our codebase just once, it will be automated and take care of itself from that point on. Also, there is lots of overlap between platforms. For instance,
the latest compiler that can still churn out binaries for Windows 95 is Visual Studio 2003. This incidentally happens to be the last compiler that can create binaries for Xbox OG. So already here we have overlap whenever we need to make a core compatible with MSVC 2003 and we have to create the necessary Makefile targets for it.

For Windows 95, we are thinking of defaulting to the GDI video driver instead of Direct3D since we assume that the kind of machines running Windows 95 typically would not have either a video driver with Direct 3D 9 support or a GPU that supports it to begin with. Windows 95 still supported DirectX so we should be able to default to ‘DirectInput’ as the input driver. Windows NT 3.5 will pose more of a problem here though – back then, NT did not have any DirectX support at all, so a DirectInput driver is not possible and we lack any other input driver that we could use. Windows Raw Input driver cannot work on this ancient NT version. We are not sure yet what approach we will take there.

Nevertheless, Windows 95 will be first out of the starting gates.

New hardware platforms we intend to support

We have obtained some new hardware over the past few months:

  1. NES/SNES Classic
  2. GCW Zero
  3. SteamLink

It is our intention to have this be part of our main release schedule in future releases. We understand that for a system like SNES Classic, a different approach will be required vs. just the usual ‘full fat’ version of RetroArch that people have grown accustomed to, and we will certainly be taking a long hard look at RetroArch Clover for inspiration on what we will do. Our first approach is likely going to be something similar to RetroArch Clover that ultimately piggybacks off Hakchi and which complements the main UI of the platform rather than trying to replace it.

RetroArch 1.6.9 -Released!

RetroArch 1.6.9 has just been released! Grab it here.

This latest version has also been uploaded to the Google Play Store.

General changelog

– Audio: Fix the Audio DSP picker
– CHEEVOS: Add support for Atari Lynx cheevos.
– CHEEVOS: Add support for RetroAchievements Leaderboards.
– GUI: (MaterialUI) Fix crash that happened on context reset with Vulkan.
– GUI: (MaterialUI) Skip querying and drawing items that are not visible; Cache content height and bbox calculation.
– GUI: (MaterialUI) Fix entry box highlight calculation.
– GUI: (XMB) Skip drawing the fading list when it is already transparent. Optimization.
– GUI: (XMB) Comment out visible item calculation in xmb_draw_items().
– GUI: (RGUI) Prevent crashes when using a non-English language reliant on UTF8.
– GUI: Add menu option for OSD background color.
– GUI: Add menu option for OSD text color.
– GUI: Add menu option to remove frame count from OSD.
– GUI: Allow wraparound of int/float settings when pressing the left key
– INPUT/LIBRETRO: Add support for more mouse buttons (buttons 4/5)
– INPUT/LIBRETRO: Add support for analog buttons
– INPUT: Always show the controls menu even if descriptors are not set
– INPUT: Fix input descriptors not being set on cores that don’t implement the controllers interface
– INPUT: Apply descriptors only for the amount of cores the core supports
– INPUT: Implement keyboard to gamepad input remapping (limited to one gamepad device for now)
– INPUT: Fix absolute mouse move handling on the winraw driver
– INPUT: Ignore keyboard input if window is not active on udev driver
– INPUT: Sanitize the filenames of autoconfig profiles before saving
– LOBBIES: Fix crash on navigating left / right from the lobby menu
– LOCALIZATION: Update Dutch translation
– LOCALIZATION: Update Italian translation.
– LOCALIZATION: Update Japanese translation.
– LOCALIZATION: Update Portuguese-Brazilian translation.
– LOCALIZATION: Update Russian translation.
– LINUX/ARMHF: Set buildbot updater URL to armhf location instead of blank string
– LINUX/PI: Broadcom VC4: Add Videocore config option
– LINUX/UDEV: Fix – RetroArch reads keyboard input when not focused with the udev input driver.
– NETPLAY: Fix disconnection not fully deinitializing Netplay.
– NETPLAY: Fix lan rooms when there is more than one room
– NETPLAY: Fix lan rooms on systems where all addresses are treated as IPv6
– COMMON: Fix clear/free loop conditionals in playlists.
– WINDOWS/GDI: Fix flickering of text.
– WINDOWS/GDI: Fix graphics corruption on Windows 98
– WINDOWS/GDI: Allow compiling without DirectInput8 for NT support
– WINDOWS/WGL: Try to use wglSwapLayerBuffers instead of SwapBuffers if possible (for more optimal performance).
– WINDOWS: Fix menubar text corruption on Japanese locale systems
– WINDOWS: Support Unicode file I/O (can now display CJK characters in file browser for example).
– WINDOWS: Support Windows 95, NT3.51, NT4
– WINDOWS: add Makefile.griffin targets for msvc6,2003,2005,2010,2012,2013
– WII: Use custom, embedded libogc SDK.
– WIIU: Initial touchscreen support for WiiU gamepad.
– WIIU: Add Cheevos support.
– SCANNER: Fix archive scanning.
– SCANNER: Support CHD files.
– SCANNER: Support Gamecube ISO scanning.
– SCANNER: Use primary data track of disc images for CRC lookups rather than cue files. This is slower but finds matches more reliably, and is necessary for CHD files to work at all. Update your databases!
– SCANNER: Fall back on looking inside archives when matching MAME/FBA content (most recent cores only). If you had difficulty with content being detected before, you may have better luck now. Update your databases and core info!

Highlights

Scanner system supports more formats

CHD and Gamecube ISO files can now be scanned. A lot of libretro cores have gained the ability to use CHD image files, some of them being all the Mednafen-derived cores (also known as Beetle cores). There is also a new fallback used for scanning MAME/FBA content which looks inside an archive for matching files. If you had trouble having the scanner detect your content before, you might be more usccessful now.

Retro Achievements – Leaderboard support

Unicode support for Windows users

Unicode is now supported for file I/O (Input/Output). What this means, is that game content that uses CJK characters and/or other non-ASCII characters can now be read by RetroArch. These files will also show up from within the filebrowser. Useful for our Japanese users.

NOTE: MaterialUI (the default UI on Android) might still exhibit issues displaying Japanese on Android. This is due to a font renderer that will need to be improved in a future version in order to display these extra characters properly.

Kiosk Mode and more


You can now tailor RetroArch’s UI even more to your own personal preferences. You can choose which submenus to hide, and which to show.

There’s also a special mode called ‘Kiosk Mode’. When enabled, you won’t be able to access any settings, and/or install/upgrade any cores. The guy who implemented this feature likely intended it as a parental control feature to make sure that kids don’t get to mess with any of the internal settings by accident that could end up breaking something. There’s also a password lock you can enable so that any access to settings can still be curtailed.

See the PDF article here for a more detailed breakdown of Kiosk Mode –

https://github.com/libretro/RetroArch/files/1320429/RetroArch.Kiosk.Mode.v4.pdf

Input enhancements


The libretro API has been enhanced by David Walters in the following ways:

  • Button input was previously all-digital, now button input can be analog as well. As a proof of concept, this has already been implemented for the Beetle Saturn core. Analog triggers now work as expected. This feature will be necessary for future systems like PlayStation2, where each face button on the gamepad was an analogue button.
  • Mouse buttons 4 and 5 were added. A proof of concept has already been implemented for Beetle Saturn. The mouse on the Sega Saturn had at least 5 buttons instead of the PlayStation mouse’s 2.


Mouse support and lightgun support has also been added to Beetle PSX, a much-requested feature. There are also some proposals on how to improve lightgun support in libretro so that it is more conducive to non-mouse based lightgun solutions. As ever, additions to the libretro API have to be backwards compatible and they should not break ABI, so that existing frontends will not be adversely affected but at the same time new frontends can reap the benefits of these new features all the same.

What’s coming next for RetroArch

We will have a separate blog post on this soon.

In the meantime, check out the addendum to this post –

https://www.libretro.com/index.php/core-updates-since-last-release/

This details all of the changes to the cores that have happened since the last release.

Core Updates Since Last Release (v1.6.7)

In anticipation of RetroArch 1.6.8, let’s detail all the work that has been performed on the libretro cores since the last frontend release (1.6.7).

higan

Themaister came out of retirement to collaborate with byuu on an upstream-friendly libretro-ization of higan. Currently, only the SNES emulator is available, but we hope to extend this to include all of his suite of emulators. Only the mainline ‘accuracy’ profile is available from the Online Updater currently, but we hope to add hex_usr’s ‘balanced’ profile soon. In the meantime, you can get it pre-compiled for Windows from his nSide github repo.
Notably, the higan core includes Super Game Boy support, including all special features, such as borders and music. Instructions for setting it up are here.

Yabause

raelgc has backported many commits from upstream, including a ton of accuracy and performance improvements.

Citra

j-selby has been keeping the libretro core up-to-date with upstream’s amazing progress. The version available in the online updater is lagging behind these updates a bit, since the buildbot is having trouble building it lately, but we hope to have this resolved soon. We also hope to get the recently announced network support hooked up to the libretro core, but no promises there.

PicoDrive

notaz provided a massive update to bring the libretro core up to date with upstream. This update included many accuracy improvements, along with some nice features like 68k overclocking.

mGBA

sergiobenrocha2 did the legwork to merge/update mgba-libretro to match the upstream 0.6.1 release, including a big pile of accuracy fixes from endrift.

Snes9x-git

hunterk backported qwertymodo’s MSU1 fixes, which should alleviate the crackling that some users reported, especially on Android devices, and he also added RTC support for the recently completed Tengai Makyo Zero (Far East of Eden: Zero) translation.

In addition to this, a hack got backported from Snes9x2010 which should prevent an annoying resolution flicker which occurs when switching from field mode to battle mode in the game Chrono Trigger.

Snes9x2010

Upstream Snes9x dev OV2 provided a patch to check for invalid VRAM access, which makes Hook work without massive artifacting.

ParaLLEl-N64

Massive amount of work from mudlord, AIO, bparker and Twinaphex to get the threaded angrylion RDP integrated. It started as a port of the angrylion-plus-rdp plugin, but the libretro version is now quite different, including being a true software renderer (that is, compatible with all video driver backends, including d3d). This plugin is very fast in Windows, reaching full speed on relatively modest CPUs, while Linux is only slightly faster than non-threaded angrylion. We hope to identify what’s holding back performance on non-MSVC compilers in the near future.

Beetle-Saturn

hiddenasbestos brought the libretro port up to parity with upstream v0.9.47 v0.9.48, which gives a few ton of nice accuracy improvements and the much-awaited savestate support (savestates made with the v0.9.47 version are not compatible with the v0.9.48 update, so beware if you made a bunch of states in the short time between updates). Tatsuya79 and retro-wertz provided a number of improvements to the overscan and cropping behavior.

Beetle-PSX

bkoropoff and simias did a lot of work on the CD reading code, including reduced stuttering during reading and a core option for increased CD loading speed. This *greatly* reduces the loading times on games, from the standard 15-30 seconds down to as low as 2-3 seconds. Do note that this is very much an experimental feature though, and it won’t work correctly for all games. r5 also added the ability to use unsupported BIOS files, which should make the core a little less picky about BIOSes. simias also backported new and improved triangle code from upstream, which unfortunately causes some issues with the PGXP features in some games. Zapeth also added support for CHD files.

Beetle-SuperGrafx

retro-wertz aded support for cheevos/RetroAchievements.

MAME

r-type continued his fantastic stewardship of the up-to-date MAME core, keeping it in lockstep with upstream releases.

MAME2016

Oggom backported support for the awesome sidescrolling Cave shmup Akai Katana, support for which was just added to upstream mainline MAME.

MAME2003

gamez-fan has been backporting dozens of patches and drivers from later versions of MAME to make more games work (or work better) with this core. markwkidd also fixed up a lot of the core’s reporting to correctly distinguish between working and nonworking games.

MAME2003_Midway

gamez-fan added in some speedhacks and fixed Rampage World Tour for this low-power spinoff of mame2003.

Final Burn Alpha

barbudreadmon continued his stewardship of Final Burn Alpha, bringing in many fixes from upstream and fine-tuning controls for specific problematic games.

FBAlpha2012

sergiobenrocha2 backported many fixes from the mainline FBA core for this low-power spinoff.

VICE

tschak909 added support for loading VIC-20 games. r-type improved screen resizing and handling for PAL/NTSC regions.

MrBoom

frranck greatly improved the AI in MrBoom, making it possibly the most advanced Bomberman AI in existence.

blueMSX

meepingsnesroms added disk swapping and, along with Tatsuya79, provided some nice quality of life improvements for this core, including machine auto-selection.

NP2Kai

AZO234 added a number of improvements to this core, including support for more disk formats (floppy and SCSI HDD), sound fixes and new soundcards and better savestate support.

Genesis Plus GX

nukeykt added a fantastic, cycle-accurate sound core. The older, MAME-derived core is still available for low-power devices. bkoropoff also added support for overclocking and the ability to remove per-line sprite limits (i.e., the cause of sprite-flickering).

gw-libretro

leiradel fixed some issues with high scores not updating properly and controller popups appearing behind game sprites.

FCEUmm

retro-wertz continued his work on this core, providing many fixes and updates for the mapper code, as well as greatly improving the Zapper functionality.

SameBoy

radius worked with LIJI32 to get the libretro-ization upstreamed in this extremely accurate Game Boy emulator. radius also hooked up savestates and SRAM/in-game saves, along with a variety of options that weren’t previously exposed to the libretro port, such as audio and video tweaks and rumble, while leiradel added cheevos/RetroAchievements support.

melonDS

radius worked to keep this core in lockstep with upstream. hunterk fixed an issue that was causing the red and blue color channels to be swapped and also closed a significant memory leak.

DeSmuME

moose65468 fixed loading Dragon Quest 5.

Nestopia

meepingsnesroms added support for 2x overclocking, while rdanbrook added preliminary Famicom Mic support (get ready to yell at those Pols Voices) and Tatsuya79 provided some edge-case fixes for Zapper functionality.

Atari800

nanoant fixed building on Android and made the core look for BIOS ROMs in the libretro ‘system’ directory, which puts this core more in-line with good libretro behavior. Meanwhile, r-type added support for more keys.

PPSSPP

Twinaphex collaborated with hrydgard to get an updated PPSSPP core ported over and to upstream a few things that should make it easier for the libretro port to stay up-to-date.

PCSX-ReARMed

meepingsnesroms fixed some polygon issues and radius fixed building this core for Windows. However, it’s still not something people should use on non-ARM hardware for general purposes.

DOSBox

Tatsuya79 fixed an annoying key-repeat bug.

Across many cores, bparker added support for Travis continuous integration, so we can better determine whether commits will break building on the many platforms we support, yoshisuga added support for arm64 builds on iOS targets and radius added support for mapping cores’ keyboard keys to the retropad, which is very useful for classic computing cores. Also, retro-wertz fixed a bug that prevented the beetle-* cores from cleaning up after themselves when loading zipped ROMs.