David Ludwig
I have created a new driver for SDL's Joystick and Game-Controller subsystem: a Virtual driver. This driver allows one to create a software-based joystick, which to SDL applications will look and react like a real joystick, but whose state can be set programmatically. A primary use case for this is to help enable developers to add touch-screen joysticks to their apps.
The driver comes with a set of new, public APIs, with functions to attach and detach joysticks, set virtual-joystick state, and to determine if a joystick is a virtual-one.
Use of virtual joysticks goes as such:
1. Attach one or more virtual joysticks by calling SDL_JoystickAttachVirtual. If successful, this returns the virtual-device's joystick-index.
2. Open the virtual joysticks (using indicies returned by SDL_JoystickAttachVirtual).
3. Call any of the SDL_JoystickSetVirtual* functions when joystick-state changes. Please note that virtual-joystick state will only get applied on the next call to SDL_JoystickUpdate, or when pumping or polling for SDL events (via SDL_PumpEvents or SDL_PollEvent).
Here is a listing of the new, public APIs, at present and subject to change:
------------------------------------------------------------
/**
* Attaches a new virtual joystick.
* Returns the joystick's device index, or -1 if an error occurred.
*/
extern DECLSPEC int SDLCALL SDL_JoystickAttachVirtual(SDL_JoystickType type, int naxes, int nballs, int nbuttons, int nhats);
/**
* Detaches a virtual joystick
* Returns 0 on success, or -1 if an error occurred.
*/
extern DECLSPEC int SDLCALL SDL_JoystickDetachVirtual(int device_index);
/**
* Indicates whether or not a virtual-joystick is at a given device index.
*/
extern DECLSPEC SDL_bool SDLCALL SDL_JoystickIsVirtual(int device_index);
/**
* Set values on an opened, virtual-joystick's controls.
* Returns 0 on success, -1 on error.
*/
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualAxis(SDL_Joystick * joystick, int axis, Sint16 value);
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualBall(SDL_Joystick * joystick, int ball, Sint16 xrel, Sint16 yrel);
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualButton(SDL_Joystick * joystick, int button, Uint8 value);
extern DECLSPEC int SDLCALL SDL_JoystickSetVirtualHat(SDL_Joystick * joystick, int hat, Uint8 value);
------------------------------------------------------------
Miscellaneous notes on the initial patch, which are also subject to change:
1. no test code is present in SDL, yet. This should, perhaps, change. Initial development was done with an ImGui-based app, which potentially is too thick for use in SDL-official. If tests are to be added, what kind of tests? Automated? Graphical?
2. virtual game controllers can be created by calling SDL_JoystickAttachVirtual with a joystick-type of SDL_JOYSTICK_TYPE_GAME_CONTROLLER, with naxes (num axes) set to SDL_CONTROLLER_AXIS_MAX, and with nbuttons (num buttons) set to SDL_CONTROLLER_BUTTON_MAX. When updating their state, values of type SDL_GameControllerAxis or SDL_GameControllerButton can be casted to an int and used for the control-index (in calls to SDL_JoystickSetVirtual* functions).
3. virtual joysticks' guids are mostly all-zeros with the exception of the last two bytes, the first of which is a 'v', to indicate that the guid is a virtual one, and the second of which is a SDL_JoystickType that has been converted into a Uint8.
4. virtual joysticks are ONLY turned into virtual game-controllers if and when their joystick-type is set to SDL_JOYSTICK_TYPE_GAMECONTROLLER. This is controlled by having SDL's default list of game-controllers have a single entry for a virtual game controller (of guid, "00000000000000000000000000007601", which is subject to the guid-encoding described above).
5. regarding having to call SDL_JoystickUpdate, either directly or indirectly via SDL_PumpEvents or SDL_PollEvents, before new virtual-joystick state becomes active (as specified via SDL_JoystickSetVirtual* function-calls), this was done to match behavior found in SDL's other joystick drivers, almost all of which will only update SDL-state during SDL_JoystickUpdate.
6. the initial patch is based off of SDL 2.0.12
7. the virtual joystick subsystem is disabled by default. It should be possible to enable it by building with SDL_JOYSTICK_VIRTUAL=1
Questions, comments, suggestions, or bug reports very welcome!
Mohamed
It would be useful to be able to do either `#include "SDL2/SDL.h"` or `#include "SDL.h"`. This patch allows that and adds compatibility with other build systems. It also allows differentiating between SDL1 and SDL2.
The Offscreen video driver is intended to be used for headless rendering
as well as allows for multiple GPUs to be used for headless rendering
Currently only supports EGL (OpenGL / ES) or Framebuffers
Adds a hint to specifiy which EGL device to use: SDL_HINT_EGL_DEVICE
Adds testoffscreen.c which can be used to test the backend out
Disabled by default for now
To use, set the following CMake variables when running CMake's configuration stage:
- CMAKE_SYSTEM_NAME=tvOS
- CMAKE_OSX_SYSROOT=<SDK> (examples: appletvos, appletvsimulator, appletvos12.4, /full/path/to/AppleTVOS.sdk, etc.)
- CMAKE_OSX_ARCHITECTURES=<semicolon-separated list of CPU architectures> (example: "arm64;x86_64")
When using a recent version of CMake (3.14+), this should make it possible to:
- build SDL for iOS, both static and dynamic
- build SDL test apps (as iOS .app bundles)
- generate a working SDL_config.h for iOS (using SDL_config.h.cmake as a basis)
To use, set the following CMake variables when running CMake's configuration stage:
- CMAKE_SYSTEM_NAME=iOS
- CMAKE_OSX_SYSROOT=<SDK> (examples: iphoneos, iphonesimulator, iphoneos12.4, /full/path/to/iPhoneOS.sdk, etc.)
- CMAKE_OSX_ARCHITECTURES=<semicolon-separated list of CPU architectures> (example: "arm64;armv7s")
Examples:
- for Simulator, using the latest, installed SDK:
cmake path/to/SDL -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphonesimulator -DCMAKE_OSX_ARCHITECTURES=x86_64
- for Device, using the latest, installed SDK, 64-bit only
cmake path/to/SDL -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos -DCMAKE_OSX_ARCHITECTURES=arm64
- for Device, using the latest, installed SDK, mixed 32/64 bit
cmake path/to/SDL -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos -DCMAKE_OSX_ARCHITECTURES="arm64;armv7s"
- for Device, using a specific SDK revision (iOS 12.4, in this example):
cmake path/to/SDL -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphoneos12.4 -DCMAKE_OSX_ARCHITECTURES=arm64
- for Simulator, using the latest, installed SDK, and building SDL test apps (as .app bundles):
cmake path/to/SDL -DSDL_TEST=1 -DCMAKE_SYSTEM_NAME=iOS -DCMAKE_OSX_SYSROOT=iphonesimulator -DCMAKE_OSX_ARCHITECTURES=x86_64
Callum McGing
While the CMake build checks for ibus and does enable the ibus backend with set(HAVE_IBUS_IBUS_H TRUE), this does not define SDL_USE_IME, thus CMake built SDL2 (as in Arch Linux) cannot use IME at all.
The attached patch fixes this behaviour when building against ibus. IME support will still fail when only fcitx is available on the build system.
This is currently supported on Linux and macOS. iOS and Android are not
supported at all, Windows support could be added with some changes to the libusb
backend. The Visual Studio and Xcode projects do not use this feature.
Based on Valve Software's hid.cpp, written in collaboration with Andrew Eikum.
Braden Obrzut
https://hg.libsdl.org/SDL/file/7dc39b047055/CMakeLists.txt#l911
I believe the following should also be specified there:
set(SDL_VIDEO_OPENGL_ES 1)
set(SDL_VIDEO_RENDER_OGL_ES 1)
As it is now GLES1 support is missing when building for Android despite it linking to the library.
Ozkan Sezer
A horde of strict aliasing violation warnings are emitted from joystick
layer, and also from a few other places. This happens with gcc-4.4.7 on
Linux CentOS 6.10. Some other sysjoystick would possibly have the same
warnings.
Attached my full log here. Example entry:
src/joystick/SDL_joystick.c: In function 'SDL_GetJoystickGUIDInfo':
src/joystick/SDL_joystick.c:1094: warning: dereferencing pointer '({anonymous})' does break strict-aliasing rules
tschwinger
Respect the BUILD_SHARED_LIBS variable when defined, and build either shared or static libs, which is CMake's default behavior (See https://cmake.org/cmake/help/latest/variable/BUILD_SHARED_LIBS.html).
If the variable is not defined, the current behavior remains unchanged and both variants are built where the platform supports it. This way, it remains possible to build both in one shot, which seems convenient for distro builds and useful to promote some consistency between them.
tschwinger
Followup to #3651
As already noted by Ryan, no framework is being built, so we better install to lib/cmake.
That code was originally part of a patch submitted by David Demelier, whose credit BTW got lost (I combined his patch for #3572 with fixes for #2576 and #3613 resulting in #3651 because things started to depend on another).
I tested that the configuration files are found correctly in the new location on MacOS X based on a hint to the root (see https://cmake.org/cmake/help/latest/command/find_package.html#search-procedure).
Manuel Sabogal
I noticed that the current Android.mk builds a libhidapi.so library for Android but the CMake build hasn't been updated to do so. I'll attach a patch that fixes this issue.
This lets you build a custom embedded device that roughly offers the "this
process is going to the background NOW" semantics of SDL on a mobile device.
From Tom Black:
I'm having problems initializing the sensor module. I'm compiling with a standard ./configure && make && sudo make install, and the module says it's enabled, but SDL_Init(SDL_INIT_EVERYTHING) is failing with SDL_GetError() returning "SDL not built with sensor support".
Author: Micha? Janiszewski <janisozaur+signed@gmail.com>
Date: Fri Sep 28 20:38:04 2018 +0200
CMake: fix building tests on Linux
In case where libunwind.h has been found, it will be used by compiler,
but linker wasn't updated to reflect use of this new library.
add HAVE_ENDPOINTVOLUME_H, HAVE_MMDEVICEAPI_H and HAVE_AUDIOCLIENT_H
in SDL_config.h.in, SDL_config.h.cmake, SDL_config_windows.h, and in
SDL_config_winrt.h.
Wayde Reitsma
After attempting to use SDL2 in the way described in this bug, I found the main issue was the includes not being added to the compiler command.
I found the issue was that the target_include_directories commands for the SDL2, SDL2-static and SDL2main targets only sets the public includes for installations using the INSTALL_INTERFACE generator expression.
I have written a patch to CMakeLists.txt that fixes this issue by adding another item to the target_include_directories commands, utilizing the BUILD_INTERFACE generator expression to correctly add the include directory during builds.
Sam Lantinga
Cameron Cawley
Ryan C. Gordon
Ozkan Sezer
Brandon Schaefer
David Ludwig
Sylvain Becker
Alex Szpakowski
Ethan Lee
Andrew Eikum
Serhii Charykov
Hugh McMaster
Drew Pirrone-Brusse