• What version is it? Proton is unversioned and the only way to know what has changed or has been fixed is to look at the github history. Interfaces are not expected to change and no “breaking” changes should happen.
• Samples and docs are, how shall we say, lacking.
• Proton internally shares all Surfaces/SurfaceAnims that use the same filename, including grid settings if it is broken up into an anim. This could be a problem if you want to use a surface with multiple grid settings or want to dynamically modify a surface for only one instance - a work around is explained here. (If you aren't using SurfaceOverlay components or the ResourceManager() to get your surfaces, you won't be affected)
• A note about audio managers: AudioManagerFMODStudio works with the latest versions of FMOD, so use that instead of AudioManagerFMOD unless you're supporting old code.

• Audio systems supported on Windows: Audiere (recommended), FMOD, FMODStudio, SDL (SDL_Mixer)
• True fullscreen modes not supported, but window resizing and alt-enter to toggle a pseudo fullscreen is (stretches to full current resolution)
• If _CONSOLE is defined, can be used to create console only apps. (They also work in linux, good for writing a server..) It's possible to use SoftSurface in a console build. (RTPack does it)
• DirectX gamepads supported through GamepadManager
• Define RT_WIN_MULTITOUCH_SUPPORT to support multi-touch input. May need the Win 7 SDK
• Define RT_WIN_USE_APPDATA_SAVE_PATH if you want Proton's GetSavePath() to return a unique user data path based on CSIDL_LOCAL_APPDATA instead of the current dir, which is the “correct way” for Win these days. Note, you should also add a CreateDirectoryRecursively(“”, GetSavePath()); if you use this, as it returns a custom folder that might not exist, based on GetAppName()

• Basic support should be pretty close to what is supported on Windows. Some things missing, like gamapad support, copy & pasting
• Uses SDL for graphics and input, SDL_mixer for sound.
• The build system uses CMake. It's easy to start a new project, since there's a Proton.cmake module available that can be used. Just select the parts that are needed. See Compiling the examples for Linux, the examples' CMakeLists.txt files and the comments in the Proton.cmake file.
• Console apps are possible with _CONSOLE defined. (see RTPack for an example of this)
• GL ES acceleration works fine with latest Raspian on the Raspberry Pi as of July 28th 2018. (I only tested with no window manager, just from full screen apps from the command line)

• The only audio system currently supported is FMOD.
• CocosDenshion should also work for audio in theory but I've only set it up for iOS so far.
• Window rescaling/fullscreen toggle supported
• No gamepad supported

• iPod Touch/iPhone/iPhone 3GS/iPhone4/iPad/iPad4/iPhone5 native resolutions fully supported.
• Supports three audio targets, AudioManagerDenshion (Recommended), AudioManagerOS (simpler) and AudioManagerFMOD (more powerful, can play midi/mod etc.. but FMOD isn't free for commercial use)
• Only plays .wav and .mp3 formats when using AudioManagerOS and AudioManagerDenshion.
• Supports 60beat gamepad through GamepadManager. iCade/etc coming…
• AudioManagerDenshion gotcha - music MUST be .mp3 or it breaks sfx. Will change this to assert if
• Supports IAP - you must have RT_IAP_SUPPORT defined and InAppPurchaseManager.mm added to the project (see RTAdTest for an example of use)
• If RT_DISABLE_RETINA_ON_IPAD is defined project wide, iPad3 will run at iPad1 res instead of retina (useful if you don't want to update your GUI to the big screen or just want an FPS boost)

If you get a “dyld: Symbol not found: __NSConcreteGlobalBlock” error when running on iOS 3.X, you can fix this by adding -weak_library /usr/lib/libSystem.B.dylib to the extra linker command line in the project settings. (Not a Proton issue, but here just in case you need it)

• Only plays .wav and .ogg audio formats. Uses SoundPool for sfx internally, I think it needs sfx to be 1 mb or smaller, decompressed. 99 max loaded at once. (Things played as music don't apply to those limitations)
• If you tell it to play an .mp3, it will convert the file extension to .ogg automatically in AudioManagerAndroid. Same with .wav, if an .ogg version exists.
• 2D Particle system is slow, the iOS version uses point sprites but they didn't work on Android so it's using a fallback method at the moment. Will change to use the global texture batcher at some point.
• Doesn't support automatic orientation changes by tilting the device.
• If a header changes, you should run Clean.bat in case the ant ndk build system doesn't detect it. If you get weird crashes for no reason, this may be why.
• glClipPlane is ignored on a G1 and horribly slow on an Nexus One, avoid.
• Android In-App-Billing supported through IAPManager, see RTAdTest for example. Updated to use Android's V3 billing system in June '13.
• Tapjoy (ads and currency) and Hooked also supported

• Precompiled headers not setup, so compiling is slow
• Vibration not supported yet, not exposed in the 1.4.5 PDK
• Uses AudioManagerSDL for audio, the PDK requires us to. Supports both mp3 and ogg for music.
• Doesn't support automatic orientation changes by tilting the device.
• Touchpad supported. Define FORCE_IPHONE_SIZE if you want the Touchpad to use emulation mode and zoom up a 480×320 app itself
• IAP supported (will be functional on OS 3.0+ devices only, but you can target lower) (see RTAdTest for an example of use)
• No longer being developed as webOS seems to be dead

• Playbook supported. Only RTBareBones and RTSimpleApp have example projects setup currently, they all require the QNX IDE the Playbook SDK comes with. I plan to support makefile only builds later.
• Doesn't support automatic orientation changes by tilting the device.
• Note: Playbook supports only 4 touches at once
• OnEnterBackground gets incorrectly called at startup, this is because the OS is saying “We got thumbnailed” at startup and suspending (thumbnailing) and I don't see how to tell the difference
• Warning: I've had reports that builds I did for the Playbook do not work on the Alpha BB10 devices. Probably need to compile with the new SDK, dunno. Need device for testing

• Based on 1.7.1 beta (GLES branch)
• The Irrlicht 3D example RT3DApp might not be setup for all platforms.
• Irrlicht has been modified so it uses the WindowsDevice for ALL platforms for GL, and the iPhone device for ALL GLES platforms. Platform specific code has been removed, as it overlapped with Proton. It has no message pump, etc.
• Irrlicht has GLES 2.X support (?) but until Proton SDK adds GLES 2.X support it can't be used
• It's been modified to support release/reload textures at any time. (Needed for Android)
• It's been modified to be able to directly load the .rttex texture format, and transparently uses the Proton filesystem, so mounted zip files in Proton work in Irrlicht too. (Was important for Android, Irrlicht's zip loader couldn't handle Android .jars for some reason)
• You CAN use Irrlicht's internal GUI if you want, but the examples don't. To do it, add all the their .cpp files to your project, and define _IRR_COMPILE_WITH_GUI_ - mouse input is not handled though, you'd probably have it a bit so you could send Proton mouse/touch events.
• RTPhysics uses Irrlicht, IrrBullet and Bullet to show 3d physics.. the sample projects are only setup on Win and iPhone I believe.

• All non-Irrlicht examples are now compiling and running in Flash - although actually the latest Flash player seems to break input slightly so clicks go to the wrong place, need to investigate and update to the latest SDK. But isn't Flash dying now? Not sure if it's worth the time.

• Works well on all popular browsers, including on iOS and Android.