// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <cmath>
#include <string>
#include <tuple>
#include <unordered_map>
#include <utility>
#include <SDL.h>
#include "common/logging/log.h"
#include "common/math_util.h"
#include "common/param_package.h"
#include "input_common/main.h"
#include "input_common/sdl/sdl.h"
namespace InputCommon {
namespace SDL {
class SDLJoystick;
class SDLButtonFactory;
class SDLAnalogFactory;
static std::unordered_map<int, std::weak_ptr<SDLJoystick>> joystick_list;
static std::shared_ptr<SDLButtonFactory> button_factory;
static std::shared_ptr<SDLAnalogFactory> analog_factory;
static bool initialized = false;
class SDLJoystick {
public:
explicit SDLJoystick(int joystick_index)
: joystick{SDL_JoystickOpen(joystick_index), SDL_JoystickClose} {
if (!joystick) {
LOG_ERROR(Input, "failed to open joystick {}", joystick_index);
}
}
bool GetButton(int button) const {
if (!joystick)
return {};
SDL_JoystickUpdate();
return SDL_JoystickGetButton(joystick.get(), button) == 1;
}
float GetAxis(int axis) const {
if (!joystick)
return {};
SDL_JoystickUpdate();
return SDL_JoystickGetAxis(joystick.get(), 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);
}
bool GetHatDirection(int hat, Uint8 direction) const {
return (SDL_JoystickGetHat(joystick.get(), hat) & direction) != 0;
}
SDL_JoystickID GetJoystickID() const {
return SDL_JoystickInstanceID(joystick.get());
}
private:
std::unique_ptr<SDL_Joystick, decltype(&SDL_JoystickClose)> joystick;
};
class SDLButton final : public Input::ButtonDevice {
public:
explicit SDLButton(std::shared_ptr<SDLJoystick> joystick_, int button_)
: joystick(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(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(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(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;
};
static std::shared_ptr<SDLJoystick> GetJoystick(int joystick_index) {
std::shared_ptr<SDLJoystick> joystick = joystick_list[joystick_index].lock();
if (!joystick) {
joystick = std::make_shared<SDLJoystick>(joystick_index);
joystick_list[joystick_index] = joystick;
}
return joystick;
}
/// 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:
* - "joystick": the index of the joystick 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 int joystick_index = params.Get("joystick", 0);
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;
}
return std::make_unique<SDLDirectionButton>(GetJoystick(joystick_index), 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);
}
return std::make_unique<SDLAxisButton>(GetJoystick(joystick_index), axis, threshold,
trigger_if_greater);
}
const int button = params.Get("button", 0);
return std::make_unique<SDLButton>(GetJoystick(joystick_index), 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:
* - "joystick": the index of the joystick to bind
* - "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 int joystick_index = params.Get("joystick", 0);
const int axis_x = params.Get("axis_x", 0);
const int axis_y = params.Get("axis_y", 1);
return std::make_unique<SDLAnalog>(GetJoystick(joystick_index), axis_x, axis_y);
}
};
void Init() {
if (SDL_Init(SDL_INIT_JOYSTICK) < 0) {
LOG_CRITICAL(Input, "SDL_Init(SDL_INIT_JOYSTICK) failed with: {}", SDL_GetError());
} else {
using namespace Input;
RegisterFactory<ButtonDevice>("sdl", std::make_shared<SDLButtonFactory>());
RegisterFactory<AnalogDevice>("sdl", std::make_shared<SDLAnalogFactory>());
initialized = true;
}
}
void Shutdown() {
if (initialized) {
using namespace Input;
UnregisterFactory<ButtonDevice>("sdl");
UnregisterFactory<AnalogDevice>("sdl");
SDL_QuitSubSystem(SDL_INIT_JOYSTICK);
}
}
/**
* This function converts a joystick ID used in SDL events to the device index. This is necessary
* because Citra opens joysticks using their indices, not their IDs.
*/
static int JoystickIDToDeviceIndex(SDL_JoystickID id) {
int num_joysticks = SDL_NumJoysticks();
for (int i = 0; i < num_joysticks; i++) {
auto joystick = GetJoystick(i);
if (joystick->GetJoystickID() == id) {
return i;
}
}
return -1;
}
Common::ParamPackage SDLEventToButtonParamPackage(const SDL_Event& event) {
Common::ParamPackage params({{"engine", "sdl"}});
switch (event.type) {
case SDL_JOYAXISMOTION:
params.Set("joystick", JoystickIDToDeviceIndex(event.jaxis.which));
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:
params.Set("joystick", JoystickIDToDeviceIndex(event.jbutton.which));
params.Set("button", event.jbutton.button);
break;
case SDL_JOYHATMOTION:
params.Set("joystick", JoystickIDToDeviceIndex(event.jhat.which));
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 {
// SDL joysticks must be opened, otherwise they don't generate events
SDL_JoystickUpdate();
int num_joysticks = SDL_NumJoysticks();
for (int i = 0; i < num_joysticks; i++) {
joysticks_opened.emplace_back(GetJoystick(i));
}
// Empty event queue to get rid of old events. citra-qt doesn't use the queue
SDL_Event dummy;
while (SDL_PollEvent(&dummy)) {
}
}
void Stop() override {
joysticks_opened.clear();
}
private:
std::vector<std::shared_ptr<SDLJoystick>> joysticks_opened;
};
class SDLButtonPoller final : public SDLPoller {
public:
Common::ParamPackage GetNextInput() override {
SDL_Event event;
while (SDL_PollEvent(&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 (SDL_PollEvent(&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) {
params.Set("engine", "sdl");
params.Set("joystick", JoystickIDToDeviceIndex(analog_axes_joystick));
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;
}
} // namespace Polling
} // namespace SDL
} // namespace InputCommon
