EmscriptenGamepad.h

#pragma once
 
#include "ViewContext.h"
 
#include <emscripten/html5.h>
 
#include "Input/InputManager.h"
#include "Input/GamepadMapping.h"
 
using namespace Cogs::Core;
 
namespace Cogs
{
  namespace Platform
  {
    static EM_BOOL gamepadCallback(int eventType, const EmscriptenGamepadEvent *gamepadEvent, void *userData);
 
    class GamepadHandler
    {
    public:
      void initialize(Core::ViewContext* viewContext)
      {
        this->view = viewContext;
 
        emscripten_set_gamepadconnected_callback(this, 1, gamepadCallback);
        emscripten_set_gamepaddisconnected_callback(this, 1, gamepadCallback);
      }
 
      const int axisMapping[6] = {
        Gamepad::AxisNo::StickLeftX,
        Gamepad::AxisNo::StickLeftY,
        Gamepad::AxisNo::StickRightX,
        Gamepad::AxisNo::StickRightY,
        Gamepad::AxisNo::TriggerLeft,
        Gamepad::AxisNo::TriggerRight,
      };
 
      const float axisMultiplier[6] = {
        1.0f,
        -1.0f,
        1.0f,
        -1.0f,
        1.0f,
        1.0f
      };
 
      const int buttonMapping[16] = {
        Gamepad::ButtonNo::A,
        Gamepad::ButtonNo::B,
        Gamepad::ButtonNo::Y,
        Gamepad::ButtonNo::X,
        Gamepad::ButtonNo::LeftShoulder,
        Gamepad::ButtonNo::RightShoulder,
        Gamepad::ButtonNo::PlaceHolder0,
        Gamepad::ButtonNo::PlaceHolder1,
        Gamepad::ButtonNo::Back,
        Gamepad::ButtonNo::Start,
        Gamepad::ButtonNo::LeftThumb,
        Gamepad::ButtonNo::RightThumb,
        Gamepad::ButtonNo::DPadUp,
        Gamepad::ButtonNo::DPadDown,
        Gamepad::ButtonNo::DPadLeft,
        Gamepad::ButtonNo::DPadRight,
      };
 
      void update()
      {
        auto inputManager = view->inputManager.get();
 
        int numGamepads = 0;
        if (EMSCRIPTEN_RESULT_SUCCESS == emscripten_sample_gamepad_data()) {
          numGamepads = emscripten_get_num_gamepads();
        }
 
        for (int i = 0; i < numGamepads; ++i) {
          EmscriptenGamepadEvent g{};
          emscripten_get_gamepad_status(i, &g);
 
          auto & state = inputManager->getDevice((InputDevices::EValues)(InputDevices::Gamepad0 + i));
          state.isConnected = true;
 
          state.axisMask = 0x000000000000003F;
          state.buttonMask = 0x000000000000FFFF;
 
          for (int i = 0; i < g.numButtons; ++i) {
            state.setButton(buttonMapping[i], g.digitalButton[i]);
          }
 
          for (int i = 0; i < g.numAxes; ++i) {
            state.setAxis(axisMapping[i], axisMultiplier[i] * static_cast<float>(g.axis[i]));
          }
        }
      }
 
    private:
      Core::ViewContext* view;
    };
 
    EM_BOOL gamepadCallback(int /*eventType*/, const EmscriptenGamepadEvent */*gamepadEvent*/, void * /*userData*/)
    {
      return 1;
    }
  }
}