Input: Remove global variables from SDL Input

Changes the interface as well to remove any unique methods that
frontends needed to call such as StartJoystickEventHandler by
conditionally starting the polling thread only if the frontend hasn't
started it already. Additionally, moves all global state into a single
SDLState class in order to guarantee that the destructors are called in
the proper order

1 files changed, 12 insertions, 624 deletions

diff --git a/src/input_common/sdl/sdl.cpp b/src/input_common/sdl/sdl.cpp
index faf3c1fa3..644db3448 100644
--- a/src/input_common/sdl/sdl.cpp
+++ b/src/input_common/sdl/sdl.cpp
@@ -1,631 +1,19 @@
-// Copyright 2017 Citra Emulator Project
+// Copyright 2018 Citra Emulator Project
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
-#include <algorithm>
-#include <atomic>
-#include <cmath>
-#include <functional>
-#include <iterator>
-#include <mutex>
-#include <string>
-#include <thread>
-#include <tuple>
-#include <unordered_map>
-#include <utility>
-#include <vector>
-#include <SDL.h>
-#include "common/assert.h"
-#include "common/logging/log.h"
-#include "common/math_util.h"
-#include "common/param_package.h"
-#include "common/threadsafe_queue.h"
-#include "input_common/main.h"
 #include "input_common/sdl/sdl.h"
+#ifdef HAVE_SDL2
+#include "input_common/sdl/sdl_impl.h"
+#endif
 
-namespace InputCommon {
+namespace InputCommon::SDL {
 
-namespace SDL {
-
-class SDLJoystick;
-class SDLButtonFactory;
-class SDLAnalogFactory;
-
-/// Map of GUID of a list of corresponding virtual Joysticks
-static std::unordered_map<std::string, std::vector<std::shared_ptr<SDLJoystick>>> joystick_map;
-static std::mutex joystick_map_mutex;
-
-static std::shared_ptr<SDLButtonFactory> button_factory;
-static std::shared_ptr<SDLAnalogFactory> analog_factory;
-
-/// Used by the Pollers during config
-static std::atomic<bool> polling;
-static Common::SPSCQueue<SDL_Event> event_queue;
-
-static std::atomic<bool> initialized = false;
-
-static std::string GetGUID(SDL_Joystick* joystick) {
-    SDL_JoystickGUID guid = SDL_JoystickGetGUID(joystick);
-    char guid_str[33];
-    SDL_JoystickGetGUIDString(guid, guid_str, sizeof(guid_str));
-    return guid_str;
-}
-
-class SDLJoystick {
-public:
-    SDLJoystick(std::string guid_, int port_, SDL_Joystick* joystick,
-                decltype(&SDL_JoystickClose) deleter = &SDL_JoystickClose)
-        : guid{std::move(guid_)}, port{port_}, sdl_joystick{joystick, deleter} {}
-
-    void SetButton(int button, bool value) {
-        std::lock_guard<std::mutex> lock(mutex);
-        state.buttons[button] = value;
-    }
-
-    bool GetButton(int button) const {
-        std::lock_guard<std::mutex> lock(mutex);
-        return state.buttons.at(button);
-    }
-
-    void SetAxis(int axis, Sint16 value) {
-        std::lock_guard<std::mutex> lock(mutex);
-        state.axes[axis] = value;
-    }
-
-    float GetAxis(int axis) const {
-        std::lock_guard<std::mutex> lock(mutex);
-        return state.axes.at(axis) / 32767.0f;
-    }
-
-    std::tuple<float, float> GetAnalog(int axis_x, int axis_y) const {
-        float x = GetAxis(axis_x);
-        float y = GetAxis(axis_y);
-        y = -y; // 3DS uses an y-axis inverse from SDL
-
-        // Make sure the coordinates are in the unit circle,
-        // otherwise normalize it.
-        float r = x * x + y * y;
-        if (r > 1.0f) {
-            r = std::sqrt(r);
-            x /= r;
-            y /= r;
-        }
-
-        return std::make_tuple(x, y);
-    }
-
-    void SetHat(int hat, Uint8 direction) {
-        std::lock_guard<std::mutex> lock(mutex);
-        state.hats[hat] = direction;
-    }
-
-    bool GetHatDirection(int hat, Uint8 direction) const {
-        std::lock_guard<std::mutex> lock(mutex);
-        return (state.hats.at(hat) & direction) != 0;
-    }
-    /**
-     * The guid of the joystick
-     */
-    const std::string& GetGUID() const {
-        return guid;
-    }
-
-    /**
-     * The number of joystick from the same type that were connected before this joystick
-     */
-    int GetPort() const {
-        return port;
-    }
-
-    SDL_Joystick* GetSDLJoystick() const {
-        return sdl_joystick.get();
-    }
-
-    void SetSDLJoystick(SDL_Joystick* joystick,
-                        decltype(&SDL_JoystickClose) deleter = &SDL_JoystickClose) {
-        sdl_joystick =
-            std::unique_ptr<SDL_Joystick, decltype(&SDL_JoystickClose)>(joystick, deleter);
-    }
-
-private:
-    struct State {
-        std::unordered_map<int, bool> buttons;
-        std::unordered_map<int, Sint16> axes;
-        std::unordered_map<int, Uint8> hats;
-    } state;
-    std::string guid;
-    int port;
-    std::unique_ptr<SDL_Joystick, decltype(&SDL_JoystickClose)> sdl_joystick;
-    mutable std::mutex mutex;
-};
-
-/**
- * Get the nth joystick with the corresponding GUID
- */
-static std::shared_ptr<SDLJoystick> GetSDLJoystickByGUID(const std::string& guid, int port) {
-    std::lock_guard<std::mutex> lock(joystick_map_mutex);
-    const auto it = joystick_map.find(guid);
-    if (it != joystick_map.end()) {
-        while (it->second.size() <= port) {
-            auto joystick = std::make_shared<SDLJoystick>(guid, it->second.size(), nullptr,
-                                                          [](SDL_Joystick*) {});
-            it->second.emplace_back(std::move(joystick));
-        }
-        return it->second[port];
-    }
-    auto joystick = std::make_shared<SDLJoystick>(guid, 0, nullptr, [](SDL_Joystick*) {});
-    return joystick_map[guid].emplace_back(std::move(joystick));
-}
-
-/**
- * Check how many identical joysticks (by guid) were connected before the one with sdl_id and so tie
- * it to a SDLJoystick with the same guid and that port
- */
-static std::shared_ptr<SDLJoystick> GetSDLJoystickBySDLID(SDL_JoystickID sdl_id) {
-    std::lock_guard<std::mutex> lock(joystick_map_mutex);
-    auto sdl_joystick = SDL_JoystickFromInstanceID(sdl_id);
-    const std::string guid = GetGUID(sdl_joystick);
-    auto map_it = joystick_map.find(guid);
-    if (map_it != joystick_map.end()) {
-        auto vec_it = std::find_if(map_it->second.begin(), map_it->second.end(),
-                                   [&sdl_joystick](const std::shared_ptr<SDLJoystick>& joystick) {
-                                       return sdl_joystick == joystick->GetSDLJoystick();
-                                   });
-        if (vec_it != map_it->second.end()) {
-            // This is the common case: There is already an existing SDL_Joystick maped to a
-            // SDLJoystick. return the SDLJoystick
-            return *vec_it;
-        }
-        // Search for a SDLJoystick without a mapped SDL_Joystick...
-        auto nullptr_it = std::find_if(map_it->second.begin(), map_it->second.end(),
-                                       [](const std::shared_ptr<SDLJoystick>& joystick) {
-                                           return !joystick->GetSDLJoystick();
-                                       });
-        if (nullptr_it != map_it->second.end()) {
-            // ... and map it
-            (*nullptr_it)->SetSDLJoystick(sdl_joystick);
-            return *nullptr_it;
-        }
-        // There is no SDLJoystick without a mapped SDL_Joystick
-        // Create a new SDLJoystick
-        auto joystick = std::make_shared<SDLJoystick>(guid, map_it->second.size(), sdl_joystick);
-        return map_it->second.emplace_back(std::move(joystick));
-    }
-    auto joystick = std::make_shared<SDLJoystick>(guid, 0, sdl_joystick);
-    return joystick_map[guid].emplace_back(std::move(joystick));
-}
-
-void InitJoystick(int joystick_index) {
-    std::lock_guard<std::mutex> lock(joystick_map_mutex);
-    SDL_Joystick* sdl_joystick = SDL_JoystickOpen(joystick_index);
-    if (!sdl_joystick) {
-        LOG_ERROR(Input, "failed to open joystick {}", joystick_index);
-        return;
-    }
-    std::string guid = GetGUID(sdl_joystick);
-    if (joystick_map.find(guid) == joystick_map.end()) {
-        auto joystick = std::make_shared<SDLJoystick>(guid, 0, sdl_joystick);
-        joystick_map[guid].emplace_back(std::move(joystick));
-        return;
-    }
-    auto& joystick_guid_list = joystick_map[guid];
-    const auto it = std::find_if(
-        joystick_guid_list.begin(), joystick_guid_list.end(),
-        [](const std::shared_ptr<SDLJoystick>& joystick) { return !joystick->GetSDLJoystick(); });
-    if (it != joystick_guid_list.end()) {
-        (*it)->SetSDLJoystick(sdl_joystick);
-        return;
-    }
-    auto joystick = std::make_shared<SDLJoystick>(guid, joystick_guid_list.size(), sdl_joystick);
-    joystick_guid_list.emplace_back(std::move(joystick));
-}
-
-void CloseJoystick(SDL_Joystick* sdl_joystick) {
-    std::lock_guard<std::mutex> lock(joystick_map_mutex);
-    std::string guid = GetGUID(sdl_joystick);
-    // This call to guid is save since the joystick is guranteed to be in that map
-    auto& joystick_guid_list = joystick_map[guid];
-    const auto joystick_it =
-        std::find_if(joystick_guid_list.begin(), joystick_guid_list.end(),
-                     [&sdl_joystick](const std::shared_ptr<SDLJoystick>& joystick) {
-                         return joystick->GetSDLJoystick() == sdl_joystick;
-                     });
-    (*joystick_it)->SetSDLJoystick(nullptr, [](SDL_Joystick*) {});
-}
-
-void HandleGameControllerEvent(const SDL_Event& event) {
-    switch (event.type) {
-    case SDL_JOYBUTTONUP: {
-        auto joystick = GetSDLJoystickBySDLID(event.jbutton.which);
-        if (joystick) {
-            joystick->SetButton(event.jbutton.button, false);
-        }
-        break;
-    }
-    case SDL_JOYBUTTONDOWN: {
-        auto joystick = GetSDLJoystickBySDLID(event.jbutton.which);
-        if (joystick) {
-            joystick->SetButton(event.jbutton.button, true);
-        }
-        break;
-    }
-    case SDL_JOYHATMOTION: {
-        auto joystick = GetSDLJoystickBySDLID(event.jhat.which);
-        if (joystick) {
-            joystick->SetHat(event.jhat.hat, event.jhat.value);
-        }
-        break;
-    }
-    case SDL_JOYAXISMOTION: {
-        auto joystick = GetSDLJoystickBySDLID(event.jaxis.which);
-        if (joystick) {
-            joystick->SetAxis(event.jaxis.axis, event.jaxis.value);
-        }
-        break;
-    }
-    case SDL_JOYDEVICEREMOVED:
-        LOG_DEBUG(Input, "Controller removed with Instance_ID {}", event.jdevice.which);
-        CloseJoystick(SDL_JoystickFromInstanceID(event.jdevice.which));
-        break;
-    case SDL_JOYDEVICEADDED:
-        LOG_DEBUG(Input, "Controller connected with device index {}", event.jdevice.which);
-        InitJoystick(event.jdevice.which);
-        break;
-    }
-}
-
-void CloseSDLJoysticks() {
-    std::lock_guard<std::mutex> lock(joystick_map_mutex);
-    joystick_map.clear();
-}
-
-void PollLoop() {
-    if (SDL_Init(SDL_INIT_JOYSTICK) < 0) {
-        LOG_CRITICAL(Input, "SDL_Init(SDL_INIT_JOYSTICK) failed with: {}", SDL_GetError());
-        return;
-    }
-
-    SDL_Event event;
-    while (initialized) {
-        // Wait for 10 ms or until an event happens
-        if (SDL_WaitEventTimeout(&event, 10)) {
-            // Don't handle the event if we are configuring
-            if (polling) {
-                event_queue.Push(event);
-            } else {
-                HandleGameControllerEvent(event);
-            }
-        }
-    }
-    CloseSDLJoysticks();
-    SDL_QuitSubSystem(SDL_INIT_JOYSTICK);
-}
-
-class SDLButton final : public Input::ButtonDevice {
-public:
-    explicit SDLButton(std::shared_ptr<SDLJoystick> joystick_, int button_)
-        : joystick(std::move(joystick_)), button(button_) {}
-
-    bool GetStatus() const override {
-        return joystick->GetButton(button);
-    }
-
-private:
-    std::shared_ptr<SDLJoystick> joystick;
-    int button;
-};
-
-class SDLDirectionButton final : public Input::ButtonDevice {
-public:
-    explicit SDLDirectionButton(std::shared_ptr<SDLJoystick> joystick_, int hat_, Uint8 direction_)
-        : joystick(std::move(joystick_)), hat(hat_), direction(direction_) {}
-
-    bool GetStatus() const override {
-        return joystick->GetHatDirection(hat, direction);
-    }
-
-private:
-    std::shared_ptr<SDLJoystick> joystick;
-    int hat;
-    Uint8 direction;
-};
-
-class SDLAxisButton final : public Input::ButtonDevice {
-public:
-    explicit SDLAxisButton(std::shared_ptr<SDLJoystick> joystick_, int axis_, float threshold_,
-                           bool trigger_if_greater_)
-        : joystick(std::move(joystick_)), axis(axis_), threshold(threshold_),
-          trigger_if_greater(trigger_if_greater_) {}
-
-    bool GetStatus() const override {
-        float axis_value = joystick->GetAxis(axis);
-        if (trigger_if_greater)
-            return axis_value > threshold;
-        return axis_value < threshold;
-    }
-
-private:
-    std::shared_ptr<SDLJoystick> joystick;
-    int axis;
-    float threshold;
-    bool trigger_if_greater;
-};
-
-class SDLAnalog final : public Input::AnalogDevice {
-public:
-    SDLAnalog(std::shared_ptr<SDLJoystick> joystick_, int axis_x_, int axis_y_)
-        : joystick(std::move(joystick_)), axis_x(axis_x_), axis_y(axis_y_) {}
-
-    std::tuple<float, float> GetStatus() const override {
-        return joystick->GetAnalog(axis_x, axis_y);
-    }
-
-private:
-    std::shared_ptr<SDLJoystick> joystick;
-    int axis_x;
-    int axis_y;
-};
-
-/// A button device factory that creates button devices from SDL joystick
-class SDLButtonFactory final : public Input::Factory<Input::ButtonDevice> {
-public:
-    /**
-     * Creates a button device from a joystick button
-     * @param params contains parameters for creating the device:
-     *     - "guid": the guid of the joystick to bind
-     *     - "port": the nth joystick of the same type to bind
-     *     - "button"(optional): the index of the button to bind
-     *     - "hat"(optional): the index of the hat to bind as direction buttons
-     *     - "axis"(optional): the index of the axis to bind
-     *     - "direction"(only used for hat): the direction name of the hat to bind. Can be "up",
-     *         "down", "left" or "right"
-     *     - "threshold"(only used for axis): a float value in (-1.0, 1.0) which the button is
-     *         triggered if the axis value crosses
-     *     - "direction"(only used for axis): "+" means the button is triggered when the axis
-     * value is greater than the threshold; "-" means the button is triggered when the axis
-     * value is smaller than the threshold
-     */
-    std::unique_ptr<Input::ButtonDevice> Create(const Common::ParamPackage& params) override {
-        const std::string guid = params.Get("guid", "0");
-        const int port = params.Get("port", 0);
-
-        auto joystick = GetSDLJoystickByGUID(guid, port);
-
-        if (params.Has("hat")) {
-            const int hat = params.Get("hat", 0);
-            const std::string direction_name = params.Get("direction", "");
-            Uint8 direction;
-            if (direction_name == "up") {
-                direction = SDL_HAT_UP;
-            } else if (direction_name == "down") {
-                direction = SDL_HAT_DOWN;
-            } else if (direction_name == "left") {
-                direction = SDL_HAT_LEFT;
-            } else if (direction_name == "right") {
-                direction = SDL_HAT_RIGHT;
-            } else {
-                direction = 0;
-            }
-            // This is necessary so accessing GetHat with hat won't crash
-            joystick->SetHat(hat, SDL_HAT_CENTERED);
-            return std::make_unique<SDLDirectionButton>(joystick, hat, direction);
-        }
-
-        if (params.Has("axis")) {
-            const int axis = params.Get("axis", 0);
-            const float threshold = params.Get("threshold", 0.5f);
-            const std::string direction_name = params.Get("direction", "");
-            bool trigger_if_greater;
-            if (direction_name == "+") {
-                trigger_if_greater = true;
-            } else if (direction_name == "-") {
-                trigger_if_greater = false;
-            } else {
-                trigger_if_greater = true;
-                LOG_ERROR(Input, "Unknown direction '{}'", direction_name);
-            }
-            // This is necessary so accessing GetAxis with axis won't crash
-            joystick->SetAxis(axis, 0);
-            return std::make_unique<SDLAxisButton>(joystick, axis, threshold, trigger_if_greater);
-        }
-
-        const int button = params.Get("button", 0);
-        // This is necessary so accessing GetButton with button won't crash
-        joystick->SetButton(button, false);
-        return std::make_unique<SDLButton>(joystick, button);
-    }
-};
-
-/// An analog device factory that creates analog devices from SDL joystick
-class SDLAnalogFactory final : public Input::Factory<Input::AnalogDevice> {
-public:
-    /**
-     * Creates analog device from joystick axes
-     * @param params contains parameters for creating the device:
-     *     - "guid": the guid of the joystick to bind
-     *     - "port": the nth joystick of the same type
-     *     - "axis_x": the index of the axis to be bind as x-axis
-     *     - "axis_y": the index of the axis to be bind as y-axis
-     */
-    std::unique_ptr<Input::AnalogDevice> Create(const Common::ParamPackage& params) override {
-        const std::string guid = params.Get("guid", "0");
-        const int port = params.Get("port", 0);
-        const int axis_x = params.Get("axis_x", 0);
-        const int axis_y = params.Get("axis_y", 1);
-
-        auto joystick = GetSDLJoystickByGUID(guid, port);
-
-        // This is necessary so accessing GetAxis with axis_x and axis_y won't crash
-        joystick->SetAxis(axis_x, 0);
-        joystick->SetAxis(axis_y, 0);
-        return std::make_unique<SDLAnalog>(joystick, axis_x, axis_y);
-    }
-};
-
-void Init() {
-    using namespace Input;
-    RegisterFactory<ButtonDevice>("sdl", std::make_shared<SDLButtonFactory>());
-    RegisterFactory<AnalogDevice>("sdl", std::make_shared<SDLAnalogFactory>());
-    polling = false;
-    initialized = true;
-}
-
-void Shutdown() {
-    if (initialized) {
-        using namespace Input;
-        UnregisterFactory<ButtonDevice>("sdl");
-        UnregisterFactory<AnalogDevice>("sdl");
-        initialized = false;
-    }
-}
-
-Common::ParamPackage SDLEventToButtonParamPackage(const SDL_Event& event) {
-    Common::ParamPackage params({{"engine", "sdl"}});
-    switch (event.type) {
-    case SDL_JOYAXISMOTION: {
-        auto joystick = GetSDLJoystickBySDLID(event.jaxis.which);
-        params.Set("port", joystick->GetPort());
-        params.Set("guid", joystick->GetGUID());
-        params.Set("axis", event.jaxis.axis);
-        if (event.jaxis.value > 0) {
-            params.Set("direction", "+");
-            params.Set("threshold", "0.5");
-        } else {
-            params.Set("direction", "-");
-            params.Set("threshold", "-0.5");
-        }
-        break;
-    }
-    case SDL_JOYBUTTONUP: {
-        auto joystick = GetSDLJoystickBySDLID(event.jbutton.which);
-        params.Set("port", joystick->GetPort());
-        params.Set("guid", joystick->GetGUID());
-        params.Set("button", event.jbutton.button);
-        break;
-    }
-    case SDL_JOYHATMOTION: {
-        auto joystick = GetSDLJoystickBySDLID(event.jhat.which);
-        params.Set("port", joystick->GetPort());
-        params.Set("guid", joystick->GetGUID());
-        params.Set("hat", event.jhat.hat);
-        switch (event.jhat.value) {
-        case SDL_HAT_UP:
-            params.Set("direction", "up");
-            break;
-        case SDL_HAT_DOWN:
-            params.Set("direction", "down");
-            break;
-        case SDL_HAT_LEFT:
-            params.Set("direction", "left");
-            break;
-        case SDL_HAT_RIGHT:
-            params.Set("direction", "right");
-            break;
-        default:
-            return {};
-        }
-        break;
-    }
-    }
-    return params;
-}
-
-namespace Polling {
-
-class SDLPoller : public InputCommon::Polling::DevicePoller {
-public:
-    void Start() override {
-        event_queue.Clear();
-        polling = true;
-    }
-
-    void Stop() override {
-        polling = false;
-    }
-};
-
-class SDLButtonPoller final : public SDLPoller {
-public:
-    Common::ParamPackage GetNextInput() override {
-        SDL_Event event;
-        while (event_queue.Pop(event)) {
-            switch (event.type) {
-            case SDL_JOYAXISMOTION:
-                if (std::abs(event.jaxis.value / 32767.0) < 0.5) {
-                    break;
-                }
-            case SDL_JOYBUTTONUP:
-            case SDL_JOYHATMOTION:
-                return SDLEventToButtonParamPackage(event);
-            }
-        }
-        return {};
-    }
-};
-
-class SDLAnalogPoller final : public SDLPoller {
-public:
-    void Start() override {
-        SDLPoller::Start();
-
-        // Reset stored axes
-        analog_xaxis = -1;
-        analog_yaxis = -1;
-        analog_axes_joystick = -1;
-    }
-
-    Common::ParamPackage GetNextInput() override {
-        SDL_Event event;
-        while (event_queue.Pop(event)) {
-            if (event.type != SDL_JOYAXISMOTION || std::abs(event.jaxis.value / 32767.0) < 0.5) {
-                continue;
-            }
-            // An analog device needs two axes, so we need to store the axis for later and wait for
-            // a second SDL event. The axes also must be from the same joystick.
-            int axis = event.jaxis.axis;
-            if (analog_xaxis == -1) {
-                analog_xaxis = axis;
-                analog_axes_joystick = event.jaxis.which;
-            } else if (analog_yaxis == -1 && analog_xaxis != axis &&
-                       analog_axes_joystick == event.jaxis.which) {
-                analog_yaxis = axis;
-            }
-        }
-        Common::ParamPackage params;
-        if (analog_xaxis != -1 && analog_yaxis != -1) {
-            auto joystick = GetSDLJoystickBySDLID(event.jaxis.which);
-            params.Set("engine", "sdl");
-            params.Set("port", joystick->GetPort());
-            params.Set("guid", joystick->GetGUID());
-            params.Set("axis_x", analog_xaxis);
-            params.Set("axis_y", analog_yaxis);
-            analog_xaxis = -1;
-            analog_yaxis = -1;
-            analog_axes_joystick = -1;
-            return params;
-        }
-        return params;
-    }
-
-private:
-    int analog_xaxis = -1;
-    int analog_yaxis = -1;
-    SDL_JoystickID analog_axes_joystick = -1;
-};
-
-std::vector<std::unique_ptr<InputCommon::Polling::DevicePoller>> GetPollers(
-    InputCommon::Polling::DeviceType type) {
-    std::vector<std::unique_ptr<InputCommon::Polling::DevicePoller>> pollers;
-    switch (type) {
-    case InputCommon::Polling::DeviceType::Analog:
-        pollers.push_back(std::make_unique<SDLAnalogPoller>());
-        break;
-    case InputCommon::Polling::DeviceType::Button:
-        pollers.push_back(std::make_unique<SDLButtonPoller>());
-        break;
-    }
-    return pollers;
+std::unique_ptr<State> Init() {
+#ifdef HAVE_SDL2
+    return std::make_unique<SDLState>();
+#else
+    return std::make_unique<NullState>();
+#endif
 }
-} // namespace Polling
-} // namespace SDL
-} // namespace InputCommon
+} // namespace InputCommon::SDL