Input.h

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// Copyright © 2008-2021 Pioneer Developers. See AUTHORS.txt for details
// Licensed under the terms of the GPL v3. See licenses/GPL-3.txt
 
#ifndef INPUT_H
#define INPUT_H
 
#include "InputBindings.h"
#include "utils.h"
 
#include <algorithm>
#include <array>
 
class IniConfig;
 
// Macro to simplify registering input bindings in the codebase
// TODO: evaluate if registering key bindings via lua / json file works better
#define REGISTER_INPUT_BINDING(name)                                   \
    namespace name##Input                                              \
    {                                                                  \
        void Register(Input::Manager *input);                          \
        bool name##Registered = Input::AddBindingRegistrar(&Register); \
    }                                                                  \
    void name##Input::Register(Input::Manager *input)
 
namespace Input {
    class Manager;
 
    // The Page->Group->Binding system serves as a thin veneer for the UI to make
    // sane reasonings about how to structure the Options dialog.
    struct BindingGroup {
        enum EntryType : uint8_t {
            ENTRY_ACTION,
            ENTRY_AXIS
        };
 
        std::map<std::string, EntryType> bindings;
    };
 
    struct BindingPage {
        BindingGroup *GetBindingGroup(std::string id) { return &groups[id]; }
 
        std::map<std::string, BindingGroup> groups;
    };
 
    struct InputFrame {
        using Axis = InputBindings::Axis;
        using Action = InputBindings::Action;
 
        InputFrame(Input::Manager *man, bool modal = false) :
            manager(man),
            modal(modal)
        {}
 
        std::vector<Action *> actions;
        std::vector<Axis *> axes;
 
        // Must set this to a valid Input::Manager instance before using AddAction / AddAxis
        Manager *manager = nullptr;
        bool active = false;
        bool modal = false;
 
        // Call this at startup to register all the bindings associated with the frame.
        virtual void RegisterBindings(){};
 
        // Called when the frame is added to the stack.
        sigc::signal<void, InputFrame *> onFrameAdded;
 
        // Called when the frame is removed from the stack.
        sigc::signal<void, InputFrame *> onFrameRemoved;
 
        Action *AddAction(std::string id);
        Axis *AddAxis(std::string id);
    };
 
    struct JoystickInfo {
        struct Axis {
            float value = 0.0;
            float deadzone = 0.0;
            float curve = 1.0;
            bool zeroToOne = false;
        };
 
        SDL_Joystick *joystick;
        SDL_JoystickGUID guid;
        std::string name;
 
        std::vector<bool> buttons;
        std::vector<int> hats;
 
        std::vector<Axis> axes;
    };
 
    void InitJoysticks(IniConfig *config);
    std::map<SDL_JoystickID, JoystickInfo> &GetJoysticks();
 
    // User display name for the joystick from the API/OS.
    std::string JoystickName(int joystick);
    // fetch the GUID for the named joystick
    SDL_JoystickGUID JoystickGUID(int joystick);
    std::string JoystickGUIDString(int joystick);
 
    // reverse map a JoystickGUID to the actual internal ID.
    int JoystickFromGUIDString(const std::string &guid);
    int JoystickFromGUIDString(const char *guid);
    int JoystickFromGUID(SDL_JoystickGUID guid);
 
    // We use SDL's joystick IDs because they're stable enough for the job.
    inline int JoystickFromID(SDL_JoystickID id) { return id; }
 
    // An adapter to decouple input frame creation from input binding registration.
    // The functions registered via AddBindingRegistrar should be thread-safe and
    // should not depend on anything but the manager object being passed in.
    // The registrars are guaranteed to be called after static initialization has finished.
    std::vector<sigc::slot<void, Input::Manager *>> &GetBindingRegistration();
    bool AddBindingRegistrar(sigc::slot<void, Input::Manager *> &&fn);
} // namespace Input
 
class Input::Manager {
public:
    Manager(IniConfig *config, SDL_Window *window);
    void InitGame();
 
    // Call this at the start of a frame, before passing SDL events in
    void NewFrame();
 
    // Call once per SDL event, handles updating all internal state
    void HandleSDLEvent(SDL_Event &ev);
 
    // Call immediately after processing events, dispatches events to Action / Axis bindings.
    void DispatchEvents();
 
    // When enable is false, this prevents the input system from writing to the config file.
    void EnableConfigSaving(bool enable) { m_enableConfigSaving = enable; }
 
    BindingPage *GetBindingPage(std::string id) { return &bindingPages[id]; }
    std::map<std::string, BindingPage> GetBindingPages() { return bindingPages; }
 
    // Pushes an InputFrame onto the input stack.
    bool AddInputFrame(InputFrame *frame);
 
    // Get a read-only list of input frames.
    const std::vector<InputFrame *> &GetInputFrames() { return m_inputFrames; }
 
    // Check if a specific input frame is currently on the stack.
    bool HasInputFrame(InputFrame *frame)
    {
        return std::count(m_inputFrames.begin(), m_inputFrames.end(), frame) > 0;
    }
 
    // Remove an arbitrary input frame from the input stack.
    void RemoveInputFrame(InputFrame *frame);
 
    // Inform the input system that a binding or frame was changed this frame.
    void MarkBindingsDirty() { m_frameListChanged = true; }
 
    // Creates a new action binding, copying the provided binding.
    // The returned binding pointer points to the actual binding.
    InputBindings::Action *AddActionBinding(std::string id, BindingGroup *group, InputBindings::Action &&binding);
    InputBindings::Action *GetActionBinding(std::string id);
 
    // Creates a new axis binding, copying the provided binding.
    // The returned binding pointer points to the actual binding.
    InputBindings::Axis *AddAxisBinding(std::string id, BindingGroup *group, InputBindings::Axis &&binding);
    InputBindings::Axis *GetAxisBinding(std::string id);
 
    // Call EnableBindings() to temporarily disable handling input bindings while
    // you're recording a new input binding or are in a modal window.
    void EnableBindings(bool enabled) { m_enableBindings = enabled; }
 
    bool KeyState(SDL_Keycode k) { return IsKeyDown(k); }
 
    // returns true if key K is currently pressed
    bool IsKeyDown(SDL_Keycode k) { return keyState[k] & 0x3; }
 
    // returns true if key K was pressed this frame
    bool IsKeyPressed(SDL_Keycode k) { return keyState[k] == 1; }
 
    // returns true if key K was released this frame
    bool IsKeyReleased(SDL_Keycode k) { return keyState[k] == 4; }
 
    int KeyModState() { return keyModState; }
 
    int JoystickButtonState(int joystick, int button);
    int JoystickHatState(int joystick, int hat);
    float JoystickAxisState(int joystick, int axis);
 
    bool IsJoystickEnabled() { return joystickEnabled; }
    void SetJoystickEnabled(bool state);
 
    bool IsMouseYInvert() { return mouseYInvert; }
    void SetMouseYInvert(bool state);
 
    int MouseButtonState(int button) { return mouseButton[button]; }
    void SetMouseButtonState(int button, bool state) { mouseButton[button] = state; }
 
    void GetMouseMotion(int motion[2])
    {
        std::copy_n(mouseMotion.data(), mouseMotion.size(), motion);
    }
 
    int GetMouseWheel() { return mouseWheel; }
 
    // Capturing the mouse hides the cursor, puts the mouse into relative mode,
    // and passes all mouse inputs to the input system, regardless of whether
    // ImGui is using them or not.
    bool IsCapturingMouse() const { return m_capturingMouse; }
 
    // Set whether the application would like to capture the mouse.
    // To avoid contention between different classes, please only call this when the state
    // has actually changed.
    void SetCapturingMouse(bool enabled);
 
    sigc::signal<void, SDL_Keysym *> onKeyPress;
    sigc::signal<void, SDL_Keysym *> onKeyRelease;
    sigc::signal<void, int, int, int> onMouseButtonUp;
    sigc::signal<void, int, int, int> onMouseButtonDown;
    sigc::signal<void, bool> onMouseWheel;
 
private:
    void RebuildInputFrames();
    bool GetModifierState(InputBindings::KeyChord *key);
    bool GetBindingState(InputBindings::KeyBinding &key);
    float GetAxisState(InputBindings::JoyAxis &axis);
 
    SDL_Window *m_window;
    IniConfig *m_config;
    bool m_enableConfigSaving;
 
    std::map<SDL_Keycode, uint8_t> keyState;
    int keyModState;
    std::array<char, 6> mouseButton;
    std::array<int, 2> mouseMotion;
    int mouseWheel;
    bool m_capturingMouse;
 
    bool joystickEnabled;
    bool mouseYInvert;
 
    std::map<std::string, BindingPage> bindingPages;
    std::map<std::string, InputBindings::Action> actionBindings;
    std::map<std::string, InputBindings::Axis> axisBindings;
    bool m_enableBindings;
 
    std::vector<InputFrame *> m_inputFrames;
    bool m_frameListChanged;
 
    std::vector<InputBindings::Action *> m_activeActions;
    std::vector<InputBindings::Axis *> m_activeAxes;
 
    std::map<InputBindings::KeyBinding, bool> m_modifiers;
    std::vector<InputBindings::KeyChord *> m_chords;
};
 
#endif