summaryrefslogtreecommitdiffstats
path: root/src/input_common/sdl/sdl_impl.cpp
blob: b132d77f5d7b6756b269a573824623af4a8ad1a4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
// 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 "core/frontend/input.h"
#include "input_common/sdl/sdl_impl.h"

namespace InputCommon {

namespace SDL {

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;
}

/// Creates a ParamPackage from an SDL_Event that can directly be used to create a ButtonDevice
static Common::ParamPackage SDLEventToButtonParamPackage(SDLState& state, const SDL_Event& event);

static int SDLEventWatcher(void* userdata, SDL_Event* event) {
    SDLState* sdl_state = reinterpret_cast<SDLState*>(userdata);
    // Don't handle the event if we are configuring
    if (sdl_state->polling) {
        sdl_state->event_queue.Push(*event);
    } else {
        sdl_state->HandleGameControllerEvent(*event);
    }
    return 0;
}

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
 */
std::shared_ptr<SDLJoystick> SDLState::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
 */
std::shared_ptr<SDLJoystick> SDLState::GetSDLJoystickBySDLID(SDL_JoystickID sdl_id) {
    auto sdl_joystick = SDL_JoystickFromInstanceID(sdl_id);
    const std::string guid = GetGUID(sdl_joystick);
    std::lock_guard<std::mutex> lock(joystick_map_mutex);
    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 SDLState::InitJoystick(int joystick_index) {
    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);
    std::lock_guard<std::mutex> lock(joystick_map_mutex);
    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 SDLState::CloseJoystick(SDL_Joystick* sdl_joystick) {
    std::string guid = GetGUID(sdl_joystick);
    std::shared_ptr<SDLJoystick> joystick;
    {
        std::lock_guard<std::mutex> lock(joystick_map_mutex);
        // This call to guid is safe since the joystick is guaranteed to be in the 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 = *joystick_it;
    }
    // Destruct SDL_Joystick outside the lock guard because SDL can internally call event calback
    // which locks the mutex again
    joystick->SetSDLJoystick(nullptr, [](SDL_Joystick*) {});
}

void SDLState::HandleGameControllerEvent(const SDL_Event& event) {
    switch (event.type) {
    case SDL_JOYBUTTONUP: {
        if (auto joystick = GetSDLJoystickBySDLID(event.jbutton.which)) {
            joystick->SetButton(event.jbutton.button, false);
        }
        break;
    }
    case SDL_JOYBUTTONDOWN: {
        if (auto joystick = GetSDLJoystickBySDLID(event.jbutton.which)) {
            joystick->SetButton(event.jbutton.button, true);
        }
        break;
    }
    case SDL_JOYHATMOTION: {
        if (auto joystick = GetSDLJoystickBySDLID(event.jhat.which)) {
            joystick->SetHat(event.jhat.hat, event.jhat.value);
        }
        break;
    }
    case SDL_JOYAXISMOTION: {
        if (auto joystick = GetSDLJoystickBySDLID(event.jaxis.which)) {
            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 SDLState::CloseJoysticks() {
    std::lock_guard<std::mutex> lock(joystick_map_mutex);
    joystick_map.clear();
}

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_, float deadzone_)
        : joystick(std::move(joystick_)), axis_x(axis_x_), axis_y(axis_y_), deadzone(deadzone_) {}

    std::tuple<float, float> GetStatus() const override {
        const auto [x, y] = joystick->GetAnalog(axis_x, axis_y);
        const float r = std::sqrt((x * x) + (y * y));
        if (r > deadzone) {
            return std::make_tuple(x / r * (r - deadzone) / (1 - deadzone),
                                   y / r * (r - deadzone) / (1 - deadzone));
        }
        return std::make_tuple<float, float>(0.0f, 0.0f);
    }

private:
    std::shared_ptr<SDLJoystick> joystick;
    const int axis_x;
    const int axis_y;
    const float deadzone;
};

/// A button device factory that creates button devices from SDL joystick
class SDLButtonFactory final : public Input::Factory<Input::ButtonDevice> {
public:
    explicit SDLButtonFactory(SDLState& state_) : state(state_) {}

    /**
     * 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 = state.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);
    }

private:
    SDLState& state;
};

/// An analog device factory that creates analog devices from SDL joystick
class SDLAnalogFactory final : public Input::Factory<Input::AnalogDevice> {
public:
    explicit SDLAnalogFactory(SDLState& state_) : state(state_) {}
    /**
     * 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);
        float deadzone = std::clamp(params.Get("deadzone", 0.0f), 0.0f, .99f);

        auto joystick = state.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, deadzone);
    }

private:
    SDLState& state;
};

SDLState::SDLState() {
    using namespace Input;
    RegisterFactory<ButtonDevice>("sdl", std::make_shared<SDLButtonFactory>(*this));
    RegisterFactory<AnalogDevice>("sdl", std::make_shared<SDLAnalogFactory>(*this));

    // If the frontend is going to manage the event loop, then we dont start one here
    start_thread = !SDL_WasInit(SDL_INIT_JOYSTICK);
    if (start_thread && SDL_Init(SDL_INIT_JOYSTICK) < 0) {
        LOG_CRITICAL(Input, "SDL_Init(SDL_INIT_JOYSTICK) failed with: {}", SDL_GetError());
        return;
    }
    if (SDL_SetHint(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1") == SDL_FALSE) {
        LOG_ERROR(Input, "Failed to set Hint for background events", SDL_GetError());
    }

    SDL_AddEventWatch(&SDLEventWatcher, this);

    initialized = true;
    if (start_thread) {
        poll_thread = std::thread([this] {
            using namespace std::chrono_literals;
            while (initialized) {
                SDL_PumpEvents();
                std::this_thread::sleep_for(10ms);
            }
        });
    }
    // Because the events for joystick connection happens before we have our event watcher added, we
    // can just open all the joysticks right here
    for (int i = 0; i < SDL_NumJoysticks(); ++i) {
        InitJoystick(i);
    }
}

SDLState::~SDLState() {
    using namespace Input;
    UnregisterFactory<ButtonDevice>("sdl");
    UnregisterFactory<AnalogDevice>("sdl");

    CloseJoysticks();
    SDL_DelEventWatch(&SDLEventWatcher, this);

    initialized = false;
    if (start_thread) {
        poll_thread.join();
        SDL_QuitSubSystem(SDL_INIT_JOYSTICK);
    }
}

Common::ParamPackage SDLEventToButtonParamPackage(SDLState& state, const SDL_Event& event) {
    Common::ParamPackage params({{"engine", "sdl"}});

    switch (event.type) {
    case SDL_JOYAXISMOTION: {
        auto joystick = state.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 = state.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 = state.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:
    explicit SDLPoller(SDLState& state_) : state(state_) {}

    void Start() override {
        state.event_queue.Clear();
        state.polling = true;
    }

    void Stop() override {
        state.polling = false;
    }

protected:
    SDLState& state;
};

class SDLButtonPoller final : public SDLPoller {
public:
    explicit SDLButtonPoller(SDLState& state_) : SDLPoller(state_) {}

    Common::ParamPackage GetNextInput() override {
        SDL_Event event;
        while (state.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(state, event);
            }
        }
        return {};
    }
};

class SDLAnalogPoller final : public SDLPoller {
public:
    explicit SDLAnalogPoller(SDLState& state_) : SDLPoller(state_) {}

    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 (state.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 = state.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;
};
} // namespace Polling

SDLState::Pollers SDLState::GetPollers(InputCommon::Polling::DeviceType type) {
    Pollers pollers;

    switch (type) {
    case InputCommon::Polling::DeviceType::Analog:
        pollers.emplace_back(std::make_unique<Polling::SDLAnalogPoller>(*this));
        break;
    case InputCommon::Polling::DeviceType::Button:
        pollers.emplace_back(std::make_unique<Polling::SDLButtonPoller>(*this));
        break;
    }

    return pollers;
}

} // namespace SDL
} // namespace InputCommon