Better joystick hotplug support.

Combine SDL events with polling the axes and buttons of controllers
every 10 milliseconds, this is necessary because of this bug in SDL:

https://bugzilla.libsdl.org/show_bug.cgi?id=4886

which causes SDL to not generation button and axes events after a
joystick is disconnected and then reconnected to the system.

Change the axes state from a unordered_map to an std::array because the
number of axes is fixed, add analogous buttons array.

Keep controller state synchronized between the event receiving code and
the polling code.

Signed-off-by: Rafael Kitover <rkitover@gmail.com>

src/wx/widgets/sdljoy.cpp

@@ -2,7 +2,6 @@
 #include "wx/sdljoy.h"
 #include "SDL.h"
 #include <SDL_events.h>
-#include <SDL_gamecontroller.h>
 #include <wx/window.h>
 #include "../common/range.hpp"
 #include "../common/contains.h"
@@ -26,7 +25,7 @@ wxSDLJoy::~wxSDLJoy()
     // SDL_QuitSubSystem(SDL_INIT_JOYSTICK);
 }
 
-static int axisval(int x)
+static int16_t axisval(int16_t x)
 {
     if (x > 0x1fff)
         return 1;
@@ -41,6 +40,8 @@ void wxSDLJoy::Poll()
     wxEvtHandler* handler = evthandler ? evthandler : wxWindow::FindFocus();
     SDL_Event e;
 
+    bool got_event = false;
+
     while (SDL_PollEvent(&e)) {
         switch (e.type) {
             case SDL_CONTROLLERBUTTONDOWN:
@@ -51,9 +52,9 @@ void wxSDLJoy::Poll()
                 if (contains(joystate, joy)) {
                     auto but      = e.cbutton.button;
                     auto val      = e.cbutton.state;
-                    auto prev_val = !val;
+                    auto prev_val = joystate[joy].button[but];
 
-                    if (handler) {
+                    if (handler && val != prev_val) {
                         wxSDLJoyEvent ev(wxEVT_SDLJOY);
                         ev.joy           = joy;
                         ev.ctrl_type     = WXSDLJOY_BUTTON;
@@ -64,8 +65,13 @@ void wxSDLJoy::Poll()
                         handler->ProcessEvent(ev);
                     }
 
+                    joystate[joy].button[but] = val;
+
                     wxLogDebug("GOT SDL_CONTROLLERBUTTON: joy:%d but:%d val:%d prev_val:%d", joy, but, val, prev_val);
                 }
+
+                got_event = true;
+
                 break;
             }
             case SDL_CONTROLLERAXISMOTION:
@@ -92,6 +98,9 @@ void wxSDLJoy::Poll()
                         wxLogDebug("GOT SDL_CONTROLLERAXISMOTION: joy:%d axis:%d val:%d prev_val:%d", joy, axis, val, prev_val);
                     }
                 }
+
+                got_event = true;
+
                 break;
             }
             case SDL_CONTROLLERDEVICEADDED:
@@ -105,6 +114,9 @@ void wxSDLJoy::Poll()
 
                     systemScreenMessage(wxString::Format(_("Connected game controller %d"), joy + 1));
                 }
+
+                got_event = true;
+
                 break;
             }
             case SDL_CONTROLLERDEVICEREMOVED:
@@ -116,10 +128,71 @@ void wxSDLJoy::Poll()
 
                     systemScreenMessage(wxString::Format(_("Disconnected game controller %d"), joy + 1));
                 }
+
+                got_event = true;
+
                 break;
             }
         }
     }
+
+    // I am only doing this shit because hotplug support is fucking broken in SDL right now.
+
+    bool do_poll  = false;
+    wxLongLong tm = wxGetUTCTimeMillis();
+
+    if (got_event)
+        last_poll = tm;
+    else if (tm - last_poll > POLL_TIME_MS) {
+        do_poll   = true;
+        last_poll = tm;
+    }
+
+    if (do_poll) {
+        for (auto&& joy : joystate) {
+            for (uint8_t but = 0; but < SDL_CONTROLLER_BUTTON_MAX; but++) {
+                auto last_state = joy.second.button[but];
+                auto state      = SDL_GameControllerGetButton(joy.second.dev, static_cast<SDL_GameControllerButton>(but));
+
+                if (last_state != state) {
+                    if (handler) {
+                        wxSDLJoyEvent ev(wxEVT_SDLJOY);
+                        ev.joy           = joy.first;
+                        ev.ctrl_type     = WXSDLJOY_BUTTON;
+                        ev.ctrl_idx      = but;
+                        ev.ctrl_val      = state;
+                        ev.prev_val      = last_state;
+
+                        handler->ProcessEvent(ev);
+                    }
+
+                    joy.second.button[but] = state;
+
+                    wxLogDebug("POLLED SDL_CONTROLLERBUTTON: joy:%d but:%d val:%d prev_val:%d", joy.first, but, state, last_state);
+                }
+            }
+
+            for (uint8_t axis = 0; axis < SDL_CONTROLLER_AXIS_MAX; axis++) {
+                auto val      = axisval(SDL_GameControllerGetAxis(joy.second.dev, static_cast<SDL_GameControllerAxis>(axis)));
+                auto prev_val = joy.second.axis[axis];
+
+                if (handler && val != prev_val) {
+                    wxSDLJoyEvent ev(wxEVT_SDLJOY);
+                    ev.joy           = joy.first;
+                    ev.ctrl_type     = WXSDLJOY_AXIS;
+                    ev.ctrl_idx      = axis;
+                    ev.ctrl_val      = val;
+                    ev.prev_val      = prev_val;
+
+                    handler->ProcessEvent(ev);
+
+                    joy.second.axis[axis] = val;
+
+                    wxLogDebug("POLLED SDL_CONTROLLERAXISMOTION: joy:%d axis:%d val:%d prev_val:%d", joy.first, axis, val, prev_val);
+                }
+            }
+        }
+    }
 }
 
 void wxSDLJoy::ConnectController(uint8_t joy)

src/wx/widgets/wx/sdljoy.h

@@ -9,8 +9,10 @@
 //
 //   The target window will receive EVT_SDLJOY events of type wxSDLJoyEvent.
 
+#include <array>
 #include <vector>
 #include <unordered_map>
+#include <wx/time.h>
 #include <wx/event.h>
 #include <wx/timer.h>
 #include <SDL_gamecontroller.h>
@@ -18,7 +20,8 @@
 
 struct wxSDLJoyState {
     SDL_GameController* dev = nullptr;
-    std::unordered_map<uint8_t, int8_t> axis;
+    std::array<int16_t, SDL_CONTROLLER_AXIS_MAX>   axis{};
+    std::array<uint8_t, SDL_CONTROLLER_BUTTON_MAX> button{};
 };
 
 class wxSDLJoy : public wxTimer {
@@ -52,10 +55,15 @@ protected:
     void Notify();
     void ConnectController(uint8_t joy);
     void DisconnectController(uint8_t joy);
+
+    const uint8_t POLL_TIME_MS = 10;
+
 private:
     std::unordered_map<uint8_t, wxSDLJoyState> joystate;
     wxEvtHandler* evthandler;
     bool add_all = false, rumbling = false;
+
+    wxLongLong last_poll = wxGetUTCTimeMillis();
 };
 
 enum {