DirectInput Joystick class

dinput8_joystick.cpp

#include <windows.h>
#include <stdio.h>
#define DIRECTINPUT_VERSION 0x0800
#include <dinput.h>
#pragma comment(lib, "dinput8.lib")
#pragma comment(lib, "dxguid.lib")


class DiJoyStick {
public:
    struct Entry {
        DIDEVICEINSTANCE        diDeviceInstance;
        DIDEVCAPS               diDevCaps;
        LPDIRECTINPUTDEVICE8    diDevice;
        DIJOYSTATE2             joystate;
    };

    DiJoyStick() : entry(0), maxEntry(0), nEntry(0), di(0) {
    }

    ~DiJoyStick() {
        clear();
    }

    void clear() {
        if(entry) {
            delete [] entry;
            entry = 0;
        }
        maxEntry    = 0;
        nEntry      = 0;
        di          = 0;
    }

    void enumerate(LPDIRECTINPUT di, DWORD dwDevType = DI8DEVTYPE_JOYSTICK, LPCDIDATAFORMAT lpdf = &c_dfDIJoystick2, DWORD dwFlags = DIEDFL_ATTACHEDONLY, int maxEntry = 16) {
        clear();

        entry           = new Entry [maxEntry];
        this->di        = di;
        this->maxEntry  = maxEntry;
        nEntry          = 0;
        this->lpdf      = lpdf;

        di->EnumDevices(dwDevType, DIEnumDevicesCallback_static, this, dwFlags);

        this->di        = 0;
    }

    int getEntryCount() const {
        return nEntry;
    }

    const Entry* getEntry(int index) const {
        const Entry* e = 0;
        if(index >= 0 && index < nEntry) {
            e = &entry[index];
        }
        return e;
    }

    void update() {
        for(int iEntry = 0; iEntry < nEntry; ++iEntry) {
            Entry& e = entry[iEntry];
            LPDIRECTINPUTDEVICE8 d = e.diDevice;

            if(FAILED(d->Poll())) {
                HRESULT hr = d->Acquire();
                while(hr == DIERR_INPUTLOST) {
                    hr = d->Acquire();
                }
            } else {
                d->GetDeviceState(sizeof(DIJOYSTATE2), &e.joystate);
            }
        }
    }

protected:
    static BOOL CALLBACK DIEnumDevicesCallback_static(LPCDIDEVICEINSTANCE lpddi, LPVOID pvRef) {
        return reinterpret_cast<DiJoyStick*>(pvRef)->DIEnumDevicesCallback(lpddi, pvRef);
    }

    BOOL DIEnumDevicesCallback(LPCDIDEVICEINSTANCE lpddi, LPVOID pvRef) {
        if(nEntry < maxEntry) {
            Entry e = { 0 };

            memcpy(&e.diDeviceInstance, lpddi, sizeof(e.diDeviceInstance));
            e.diDevCaps.dwSize = sizeof(e.diDevCaps);

            LPDIRECTINPUTDEVICE8    did = 0;

            if(SUCCEEDED(di->CreateDevice(lpddi->guidInstance, (LPDIRECTINPUTDEVICE*) &did, 0))) {
                if(SUCCEEDED(did->SetDataFormat(lpdf))) {
                    if(SUCCEEDED(did->GetCapabilities(&e.diDevCaps))) {
                        e.diDevice = did;
                        entry[nEntry++] = e;
                    }
                }
            }
        }
        return DIENUM_CONTINUE;
    }

    //
    Entry*          entry;
    int             maxEntry;
    int             nEntry;
    LPDIRECTINPUT   di;
    LPCDIDATAFORMAT lpdf;
};


int main(int, const char*) {
    DiJoyStick djs;
    LPDIRECTINPUT lpDi = 0;

    if(SUCCEEDED(DirectInput8Create(GetModuleHandle(0), DIRECTINPUT_VERSION, IID_IDirectInput8, (void**) &lpDi, 0))) {
        djs.enumerate(lpDi);
        for(;;) {
            djs.update();

            const DiJoyStick::Entry* e = djs.getEntry(0);
            if(e) {
                const DIJOYSTATE2* js = &e->joystate;

                int pov = js->rgdwPOV[0];
                if(pov < 0) {
                    pov = -1;
                } else {
                    pov /= 100;
                }
                int btn = 0;
                for(int i = 0; i < 32; ++i) {
                    if(js->rgbButtons[i]) {
                        btn |= 1 << i;
                    }
                }

                printf("pov=%3d, button=%08x\r", pov, btn);
            }
        }
    }

    return 0;
}