switch to UE 4.17, joystick code for Linux

Unreal/Plugins/AirSim/Source/SimJoyStick/SimJoyStick.cpp

@@ -1,5 +1,5 @@
-#include "SimJoyStick.h"
-
+#include "SimJoyStick.h"
+
 #if defined _WIN32 || defined _WIN64
 
 #include "common/common_utils/StrictMode.hpp"
@@ -12,7 +12,7 @@ STRICT_MODE_OFF
 //Below is old way of doing it?
 //#include "AllowWindowsPlatformTypes.h"
 //#define WIN32_LEAN_AND_MEAN
-//#define NOMINMAX
+//#define NOMINMAX
 //#include <windows.h>
 //#include <XInput.h>
 //#include "HideWindowsPlatformTypes.h"
@@ -63,28 +63,158 @@ struct SimJoyStick::impl {
 
 #else
 
+#include <fcntl.h>
+#include <iostream>
+#include <string>
+#include <sstream>
+#include <iostream>
+#include "unistd.h"
+
 //implementation for unsupported OS
 struct SimJoyStick::impl {
+private:
+
+
+
+    class JoystickEvent
+    {
+    public:
+      /** Minimum value of axes range */
+      static const short MIN_AXES_VALUE = -32768;
+
+      /** Maximum value of axes range */
+      static const short MAX_AXES_VALUE = 32767;
+
+      /**
+       * The timestamp of the event, in milliseconds.
+       */
+      unsigned int time;
+
+      /**
+       * The value associated with this joystick event.
+       * For buttons this will be either 1 (down) or 0 (up).
+       * For axes, this will range between MIN_AXES_VALUE and MAX_AXES_VALUE.
+       */
+      short value;
+
+      /**
+       * The event type.
+       */
+      unsigned char type;
+
+      /**
+       * The axis/button number.
+       */
+      unsigned char number;
+
+      /**
+       * Returns true if this event is the result of a button press.
+       */
+      bool isButton()
+      {
+        static constexpr unsigned char JS_EVENT_BUTTON = 0x01; // button pressed/released
+        return (type & JS_EVENT_BUTTON) != 0;
+      }
+
+      /**
+       * Returns true if this event is the result of an axis movement.
+       */
+      bool isAxis()
+      {
+        static constexpr unsigned char JS_EVENT_AXIS = 0x02; // joystick moved
+        return (type & JS_EVENT_AXIS) != 0;
+      }
+
+      /**
+       * Returns true if this event is part of the initial state obtained when
+       * the joystick is first connected to.
+       */
+      bool isInitialState()
+      {
+        static constexpr unsigned char JS_EVENT_INIT = 0x80; // initial state of device
+        return (type & JS_EVENT_INIT) != 0;
+      }
+
+      /**
+       * The ostream inserter needs to be a friend so it can access the
+       * internal data structures.
+       */
+      friend std::ostream& operator<<(std::ostream& os, const JoystickEvent& e);
+    };
+
+
 public:
+    ~impl()
+    {
+        if (fd_ >= 0)
+            close(fd_);
+    }
+
     void getJoyStickState(unsigned int index, SimJoyStick::State& state)
     {
-        //not implemented
-        state.is_connected = false;
+        static constexpr bool blocking = false;
+
+        if (index != last_index_) {
+            if (fd_ >= 0)
+                close(fd_);
+
+            std::stringstream devicePath;
+            devicePath << "/dev/input/js" << index;
+
+            fd_ = open(devicePath.str().c_str(), blocking ? O_RDONLY : O_RDONLY | O_NONBLOCK);
+
+            last_index_ = index;
+        }
+
+        if (fd_ >= 0) {
+            int bytes = read(fd_, &event_, sizeof(event_)); 
+
+            if (bytes == -1 || bytes != sizeof(event_)) {
+                // NOTE if this condition is not met, we're probably out of sync and this
+                // Joystick instance is likely unusable
+                state.is_connected = false;
+            }
+            else {
+                state.is_connected = true;
+
+                if (event_.isButton()) {
+                    if (event_.value == 0)
+                        state.buttons &= ~(1 << event_.number);
+                    else
+                        state.buttons |= (1 << event_.number);
+                }
+                else if (event_.isAxis()) {
+                    switch(event_.number) {
+                    case 0: state.left_y = event_.value; break;
+                    case 1: state.right_x = event_.value; break;
+                    case 2: state.right_y = event_.value; break;
+                    case 3: state.left_x = event_.value; break;
+                    default: break;
+                    }
+                }
+                //else ignore
+            }
+        }
     }
+
+private:
+    unsigned int last_index_ = -1;
+    int fd_ = -1;
+    JoystickEvent event_;
 };
 
 #endif
 
 bool SimJoyStick::initialized_success_ = false;
 
-void SimJoyStick::setInitializedSuccess(bool success)
-{
-    initialized_success_ = success;
+void SimJoyStick::setInitializedSuccess(bool success)
+{
+    initialized_success_ = success;
+}
+bool SimJoyStick::isInitializedSuccess()
+{
+    return initialized_success_;
 }
-bool SimJoyStick::isInitializedSuccess()
-{
-    return initialized_success_;
-}
 
 SimJoyStick::SimJoyStick()
 {

docs/linux_build.md

@@ -11,7 +11,7 @@ It's super simple 1-2-3!
 2. Clone Unreal in your favorite folder and run setup.sh (this may take a while!). Note: We only support Unreal 4.16 and newer.
 ```
      # go to folder where you clone GitHub projects
-     git clone -b 4.16 https://github.com/EpicGames/UnrealEngine.git
+     git clone -b 4.17 https://github.com/EpicGames/UnrealEngine.git
      cd UnrealEngine
      ./Setup.sh
      ./GenerateProjectFiles.sh

install_run_all.sh

@@ -23,7 +23,7 @@ fi
 
 #install unreal
 if [[ !(-d "$UnrealDir") ]]; then
-	git clone -b 4.16 https://github.com/EpicGames/UnrealEngine.git "$UnrealDir"
+	git clone -b 4.17 https://github.com/EpicGames/UnrealEngine.git "$UnrealDir"
 	pushd "$UnrealDir" >/dev/null
 
 	./Setup.sh