Shader Changes

Abstract

GLSL shaders now preferred over Cg when possible
Update to latest RetroArch for compatibility with updated GLSL shaders

Cg shaders demoted, GLSL promoted to first-class

Portability and compatibility are major goals for RetroArch and libretro, so we invested heavily in Nvidia’s Cg shader language, which worked natively anywhere their Cg Toolkit framework was available (that is, Windows, Linux and Mac OS X), as well as on PS3 and Vita, and could be machine-compiled to messy-but-usable GLSL (lacking a few features, such as runtime parameters) for platforms that lacked the framework (primarily ARM / mobile platforms). Cg was also so close to Microsoft’s HLSL shader language that many Cg shaders will compile successfully with HLSL compilers, such as those available with Windows’ D3D driver and on Xbox 360.

This was great for us because we could write shaders once and have them work pretty much everywhere.
Sadly, Nvidia deprecated the Cg language in 2012, which left us in a bad spot. Since then, we’ve been limping along with the same strategy as before, but with the uneasy understanding that Nvidia could stop supplying their Cg Toolkit framework at any time. Rather than sit idly by, waiting for that other shoe to drop, we took it upon ourselves to hand-convert the vast majority of our Cg shaders to native GLSL with all of the bells and whistles. TroggleMonkey’s monstrous masterpiece, CRT-Royale, still has a couple of bugs but is mostly working, along with its popular BVM-styled variant from user Kurozumi. Additionally, before this conversion, many of our Cg shaders were flaky or completely unusable on libretro-gl cores, such as Beetle-PSX-HW’s OpenGL renderer, but these native GLSL conversions should work reliably and consistently with any core/context except for those that require Vulkan (namely, ParaLLEl-N64’s and Beetle-PSX-HW’s Vulkan renderers).

With the GLSL shaders brought up to speed, we can finally join Nvidia in deprecating Cg, though it will still remain as an option–that is, we’re not *removing* support for Cg shaders or contexts at this point–and we will continue to use it where there is no other choice; namely, Windows’ D3D driver and the Xbox 360, PS3 and Vita ports. Moving forward, our focus for shaders will be on native GLSL and our slang/Vulkan formats, though we will likely still port some to Cg from time to time.

RetroArch now correctly handles #version directives in GLSL shaders; GLSL shader repo updated to match

There have been a number of updates to the GLSL shader language/spec over its long life, and shader authors can use #version directives (that is, a line at the top of the shader that says #version 130 or whatever) to tell compilers which flavor/version of GLSL is required for that shader. However, RetroArch has long had a strange behavior whereby it injected a couple of lines at the beginning of all GLSL shader files at compile time, and this broke any shader that attempted to use a #version directive, since those directives must be on the first line of the shader. This meant that our shaders couldn’t use #version directives at all, and all of our shaders lacked #version directives until very recently for this reason. These #version-less GLSL shaders are still perfectly compliant GLSL because GLSL v1.10 didn’t support directives, either, but the necessity of leaving off the #version started to cause some problems as we whipped our GLSL shader library into shape.

The error caused by adding a #version directive under the old behavior.

On AMD and Nvidia GPUs, the compilers would just toss up a warning about the missing directive and still expose whatever GLSL features were available to the GPU, which worked out great. On Intel IGPs, however, the compiler tosses the error and then reverts to only exposing the features available in ancient GLSL v1.10 (released way back in 2004). As a stopgap, we gave many shaders fallback codepaths that would still work in these circumstances, but a number of other shaders were either impossible to make compatible or even the compatible result was imperfect.

So, as of this commit (courtesy of aliaspider), RetroArch will no longer reject shaders with explicit #version directives, and we have added those directives to any shaders that require them at the lowest version that still compiles/functions properly. That is, if the shader doesn’t use any features that require greater than #version 110, they will still have no #version specified, and any shader that requires #version 120 but not #version 130 will not have its requirements increased to the higher version for no reason. This should keep our GLSL shaders as compatible as possible with older hardware, and including the #versions explicitly when needed will also make it easier for other programs/developers to utilize our shaders without any unnecessary guesswork due to behind-the-scenes magic.

This change does require a clean break, insofar as older versions of RetroArch will choke on the new #version directives (that is, they’ll fail to compile with the “#version must occur before any other program statement” error pictured above), so users with Nvidia or AMD GPUs must update their RetroArch installation if they want to use the updated shaders. Users with Intel IGPs will be no worse off if they don’t update, since those shaders were already broken for them, but they’ll probably *want* to update to gain access to the many fancy shaders that now work properly on their machines.

Mobile GPUs using GLES had many of the same issues that Intel IGPs had, with many shaders refusing to work without #version directives, but GLES compatibility added in a further complication: GLES requires its own separate #version directives, either #version 100 es or #version 300 es, which are different from and incompatible with desktop GL’s #versions. To get around this, we added a trick in RetroArch to change any #version of 120 or below to #version 100, which is roughly comparable in features to 120, and any #version 130 or above to #version 300 es whenever a GLES context is used. This should get everything working as effectively and consistently as possible on mobile GPUs, but if anything slipped through the cracks, be sure to file an issue report at the GLSL shader repo.

RetroArch 1.4.1 Open Beta – Released! Highlights

Half a year after RetroArch 1.3.6 was released, now comes the next big stable! Version 1.4.1 is by any yardstick a big massive advance on the previous version. There are about 5000 commits or more to sift through, so let’s focus on a few big main standout features that we want to emphasize for this release.

Where to get it

https://buildbot.libretro.com/stable/1.4.1/

We are calling this release an ‘Open Beta’ because we want people to put the massively improved Netplay features through its paces! All of your feedback and issues will be taken onboard so that 1.5.0 (which we intend to ship somewhere beginning of March) will deliver on all the promises we have made for netplay.

Netplay

Netplay has seen a big massive improvement since version 1.3.6.

To set up a netplay game, you have two options: Manual or automatic connection.

Naturally, the automatic way is easier:

To host, just load a core and launch some content as usual and, once the game is running, go back into the ‘quick menu’ (the default keyboard shortcut is F1) and scroll down to the ‘netplay’ submenu. From there, choose ‘Start netplay host’ and it will announce your game to the lobby server for other users to join. You can go ahead and start playing and new players can jump in at any time. That is, RetroArch no longer stalls out until clients join.

Joining an existing session is just as easy. From the main menu, navigate over to the netplay tab (the icon looks like a wifi symbol), scroll down to ‘Refresh Room List’ and hit the ‘accept’ key/button (the default keyboard shortcut is the ‘X’ key). RetroArch will fetch the current list of available hosts and display them right there in the netplay tab. From there, just pick the host you wish to join and RetroArch will cycle through your playlists searching for a content match. If it finds a match, you’ll jump right into the host’s game already in progress.

To use manual connection, the host does the exact same steps. The client must load the same core and game first, then choose the “connect to netplay host” option from the netplay menu. You will be prompted for the IP address of the host. Enter it to connect.

To keep your games private, the host may set a password, required to connect, in the network settings menu.

We want your feedback and input on netplay, and the aim is that we take your feedback into consideration for 1.5.0 (which we will launch early March) to put the final finishing touches on netplay in general. Things like chat, friend lists and so on will all need to be implemented still.

Multi-language support/Japanese language support

We have added UTF-8 support and we have added translations for several languages now. Of these, Japanese is probably second to English in terms of being the most complete translation.

In addition to this, the new onscreen keyboard also has multilingual support, and supports Japanese fully (Hiragana, Katakana).

Free homebrew Bomberman clone game – Mr.Boom

Mr.Boom is a Bomberman clone. It supports up to 8 players and features like pushing bombs, remote controls and kangaroo riding.

This was an old MS-DOS/Windows 9x homebrew game that https://github.com/frranck converted over to C with a self-made tool he calls asm2c.

Right now, this core works for Mac/Windows/Linux/ We are still working on Android support!

Mr. Boom currently requires at least a minimum of 2 players. There is no singleplayer mode (yet). It can not yet be used with netplay but that is our ultimate aim! Free 8-player easy Bomberman-like gameplay for everybody! We will make an announcement later when netplay support is fully working for this core!

New menu graphical effects

In addition to the ribbon effects, we have added some new menu effects : Bokeh, and Snow.

Check the accompanying video to see them in action. You can access these menu effects by going to

Settings -> User Interface -> Menu and setting “Menu Shader Pipeline” to any effect of your choosing.

NOTE: These two new menu effects are not yet available for Vulkan and Cg. Ports would have to be made first of these menu effects, since they are completely shader-based.

Quality-of-Life improvements to the menu

We have taken all the criticisms of the menu UI to heart and we really pushed ourselves to make the menu much more pleasant to deal with.

  • We have gone to the painstaking effort of making sure that nearly every menu entry now has a small description below it.
  • Loading content has been massively streamlined. There is no longer a separate ‘Load Content’ and ‘Load Content (Detect Core)’ option. You simply select a starting point directory, you then select your game and you decide which core to use.
  • There is a new onscreen keyboard made for the menu which is compatible with touch and the mouse. It not only supports traditional western characters but thanks to improved multilingual support it will also support Japanese (Kanji, Hiragana, Katakana and Romaji).
  • In fullscreen mode, the mouse cursor inside the menu will only show for about 5 seconds. If there is no mouse activity it will disappear from the screen until you move the mouse again.

Improved error handling

Cores should now report an error message back to RetroArch in most instances where a ROM/content fails to load.  We went over most cores and we are reasonably comfortable in that we took care of most of the trouble spots.

Vulkan N64 and PSX now works on Android!

To read more about these projects, read our past articles here –

Introducing Vulkan PSX renderer for Beetle/Mednafen PSX

Nintendo 64 Vulkan Low-Level emulator – paraLLel – pre-alpha release

ParaLLel (Nintendo 64 core with Vulkan renderer) and Mednafen PSX HW should now work on Android devices that support Vulkan!

Unfortunately, GPU is currently not the bottleneck here. In the case of both of these emulators, more work is required before they will start to run at fullspeed on Android devices. We need to get the LLVM dynarec working on ARM devices.

In the case of Mednafen PSX HW, the interpreter CPU core is the main bottleneck which prevents the emulator from reaching playable speeds right now. An experimental dynarec was written a year ago but it still needs a lot of work before it could be considered ‘usable’.

Lots of other miscellaneous stuff

  • Improved performance
  • (Linux) DRM/KMS context driver should be more compatible now
  • (Linux) The GLX context driver now uses GLX_OML_sync_control when available, leading to much improved swap control. Potential video tearing and frame time deviation will be way lower in general.
  • (Linux) Attaching a PS4 gamepad will allow you to use the audio headphone jack to route sound to your headphones if you use the ALSA audio driver. It will now query the available audio output sampling rates that an audio device supports, and if the recommended output sampling rate that we use in RetroArch doesn’t match, we will use a sampling rate that the audio device DOES support instead. The PS4 pad only works with 32Khz audio, hence why we need to switch to it on the fly in order to get sound working with it.
  • (Android) Should fix a longstanding touch input bug that might have prevented touch from working altogether on certain devices.
  • (Android) GLES3/3.1 support, the fancy ribbon effect and Snow/Bokeh should also be available on Android now.
  • (Linux/Wayland) Full input support, keyboard and mouse.
  • Too much stuff to mention

Also read our companion article for more information here –

RetroArch 1.4.1 Major Changes Detailed!

And even more!

RetroArch 1.4.1 Progress report – DOS/Windows 9x/Windows 2K

Improved documentation

From now on, all documentation for RetroArch (both development and user-facing info) will be posted here –

https://buildbot.libretro.com/docs/

Mednafen/Beetle PSX – PGXP arrives!

Mednafen/Beetle PSX has made another significant stride forward! iCatButler has contributed a working backport of PGXP for Mednafen/Beetle PSX.

PlayStation rasterization issues

Several issues can be noticed in most PlayStation games’ graphics.

Continue reading “Mednafen/Beetle PSX – PGXP arrives!”

Mednafen/Beetle PSX HW – Alpha test version

Parasite Eve with the experimental GL renderer. Note the screen residue glitches at the bottom.
Parasite Eve with the experimental GL renderer. Note the screen residue glitches at the bottom.

Here is the first release of Mednafen/Beetle PSX HW. You can download this core right now for Windows, Linux, and OSX.

NOTE: THIS IS AN ALPHA VERSION AND IT IS NOT REPRESENTATIVE OF THE UPCOMING BETA VERSION. PERFORMANCE RIGHT NOW IS A LOT LOWER THAN WHAT IT WILL BE FOR THE BETA VERSION. EXPECT BUGS TOO.

See a complete screenshot gallery here.

Where to get it?

Rage Racer using experimental GL renderer
Rage Racer using experimental GL renderer
Final Fantasy VII using experimental GL renderer
Final Fantasy VII using experimental GL renderer

Go to RetroArch, go to Online Updater, go to ‘Update Cores’, and download ‘PlayStation (Mednafen PSX HW)’. You might need to update your core info files first before this will show up properly. To do this, go to ‘Online Updater’, and select Update Core Info Files’.

Continue reading “Mednafen/Beetle PSX HW – Alpha test version”

RetroArch/libretro project status update

Craft

qTILoyDWe have decided to port over a promising Minecraft clone to the libretro API. The original source repository can be found here, and the libretro repository can be found here.

Windows/Linux/OSX users can already download this core by going to the Core Updater and downloading ‘Craft’. You can directly start the core since it requires no content to be loaded, it can be started as-is without needing any ROM or content file.

The original Craft upstream repository was a bit barebones, so we have decided to expand this port:

  • Biomes were added (these were located on a branch that was never merged into master), this adds hills / fortresses as can be seen in the screenshot
  • Water was added (this was located on a branch, never merged into master).
  • More sophisticated sunrise/sunset color blending (from Konstrukts).
  • A ‘Jumping Flash’ mode that allows you to jump infinitely into the air all while the camera faces downwards.
  • Configurable draw distance. The draw distance has a big effect on the framerate, a draw distance of 1 or 2 can make this core playable even on very lightweight computers.
  • Configurable field of view.
  • Gamepad support (including analog stick support) configurable analog sensitivity and deadzones, preliminary mouse and keyboard support.
  • Configurable resolutions, up to 4K.
  • A lot of changes under the hood, some of them which are detailed in the Making Of Article.

Continue reading “RetroArch/libretro project status update”