GII         Using OGRE with the GII input library

Using OGRE with GII

As mentioned in a lot of places, OGRE is a rendering library. The input system that comes with it is only suited for the demos, thus if you are making a game you want a higher quality input library.
GII is a good choice for this because it handles all the kinds of joystick, keyboard and mouse input you want. In addition to scancodes, it also passes in keyboard input in unicode, thus no problems arise with different keyboard mappings.

It also has some advantages above SDL:

  • Less overhead if you just need an input system
  • Easier to bind to an existing window than SDL (no environment variable hacks needed for one thing)

Currently, this document only describes the mapping under Linux using the GLX platform. I hope to later extend this somehow to windows and MAC.

Also, the steps described here attempt in no way to lock up the mouse inside your window or translate absolute to relative mouse movement. This can be added if you need it, but I didn't.

Using GII

Get the CVS branch 0.9 as described here (be sure to get branch 0.9 as it fixes some nasty GLX issue).

Documentation can be found here

Include the following header

#include <ggi/gii.h>

For the GLX binding, also use

#include <ggi/input/xwin.h>

Binding to GII

This section describes the steps needed to bind the Ogre renderwindow to the GII input system. This is probably why you are here.
No matter what the platform, the steps need to be executed after the Ogre render window was created. We let Ogre create the window instead of GII because Ogre knows specifics like the type of pixel/framebuffer format it wants.


For GLX, the process of making libGII capture events from the Ogre window is described here. Make sure you have at least Ogre 1.0.1 for this to work.

After calling Root::initialise or creating your render window, do this:

// Initialize ggi input
            gii_inputxwin_arg giiarg;
            mWindow->getCustomAttribute("GLXWINDOW", &;
            mWindow->getCustomAttribute("GLXDISPLAY", &giiarg.disp);
            GLXWindowInterface *iface;
            mWindow->getCustomAttribute("GLXWINDOWINTERFACE", &iface);
            giiarg.ptralwaysrel = false;
            giiarg.wait = false;
            giiarg.exposefunc = &exposefunc;
            giiarg.exposearg = iface;
            giiarg.gglock = 0;
            giiarg.resizefunc = &resizefunc;
            giiarg.resizearg = iface;
            mGIIHandle = giiOpen("input-xwin", &giiarg);
            /// This seems to be needed as the Expose of gii is never called

GLXWindowInterface, exposefunc and resizefunc are defined like this

class GLXWindowInterface
    virtual ~GLXWindowInterface() = 0;
    virtual void exposed(bool active) = 0;
    virtual void resized(size_t width, size_t height) = 0;
int exposefunc(void *arg, int x, int y, int w, int h)
    return 0;
int resizefunc(void *arg, int w, int h, gii_event *ev)
    static_cast<GLXWindowInterface*>(arg)->resized((size_t)w, (size_t)h);
    return 0;


To keep it simple, I have based this on the OGRE example framework. In the frameStarted of my Input FrameListener I included the following event loop. This code fragment should be platform independent:

bool frameStarted(const FrameEvent& evt)
            return false;
        /// GII input handling
        struct timeval tv;
        tv.tv_sec = 0;
        tv.tv_usec = 0; 
        gii_event_mask mask = giiEventPoll(mGIIHandle, emAll, &tv);
        int nevents = giiEventsQueued(mGIIHandle, emAll);
            gii_event ev;
            giiEventRead(mGIIHandle, &ev, emAll);
            switch(ev.any.type) {
                case evKeyPress:
                case evKeyRepeat:
                    ///std::cerr << "Key pressed: " << std::hex << ev.key.sym << " " << ev.key.label << " " << convertGGIKeyToCegui(ev.key.label) << std::dec << std::endl;
                    if(GII_UNICODE(ev.key.sym) && ev.key.sym!=127)
                case evKeyRelease:
                case evPtrRelative:
                    CEGUI::System::getSingleton().injectMouseMove(ev.pmove.x, ev.pmove.y);
                    /// XXX wheel
                case evPtrAbsolute:
                    CEGUI::System::getSingleton().injectMousePosition(ev.pmove.x, ev.pmove.y);
                    /// XXX wheel
                case evPtrButtonPress:
                case evPtrButtonRelease:
                // evValAbsolute
                // evValRelative
        return true;

GUI system

To actually do something with the incoming input, the incoming events are translated and passsed to the GUI library CEGUI. If you don't use this in your game, translate the events to your ingame event system in your own way, this article just demonstrates how to do the binding.

/// Map GII mouse button to CEGUI
CEGUI::MouseButton convertGGIButtonToCegui(unsigned int buttonID)
    switch (buttonID)
        return CEGUI::LeftButton;
        return CEGUI::RightButton;
        return CEGUI::MiddleButton;
        return CEGUI::LeftButton;
// Map GII keyboard key to CEGUI
unsigned int convertGGIKeyToCegui(unsigned int buttonID)
    using namespace CEGUI;
    switch (buttonID)
    case GIIUC_Escape: return Key::Escape;
    case GIIUC_1: return Key::One;
    case GIIUC_2: return Key::Two;
    case GIIUC_3: return Key::Three;
    case GIIUC_4: return Key::Four;
    case GIIUC_5: return Key::Five;
    case GIIUC_6: return Key::Six;
    case GIIUC_7: return Key::Seven;
    case GIIUC_8: return Key::Eight;
    case GIIUC_9: return Key::Nine;
    case GIIUC_0: return Key::Zero;
    case GIIUC_Minus: return Key::Minus;
    case GIIUC_Equal: return Key::Equals;
    case GIIUC_BackSpace: return Key::Backspace;
    case GIIUC_Tab: return Key::Tab;
    case GIIUC_Q: return Key::Q;
    case GIIUC_W: return Key::W;
    case GIIUC_E: return Key::E;
    case GIIUC_R: return Key::R;
    case GIIUC_T: return Key::T;
    case GIIUC_Y: return Key::Y;
    case GIIUC_U: return Key::U;
    case GIIUC_I: return Key::I;
    case GIIUC_O: return Key::O;
    case GIIUC_P: return Key::P;
    case GIIUC_BracketLeft: return Key::LeftBracket;
    case GIIUC_BracketRight: return Key::RightBracket;
    case GIIUC_Return: return Key::Return;
    case GIIK_CtrlL: return Key::LeftControl;
    case GIIUC_A: return Key::A;
    case GIIUC_S: return Key::S;
    case GIIUC_D: return Key::D;
    case GIIUC_F: return Key::F;
    case GIIUC_G: return Key::G;
    case GIIUC_H: return Key::H;
    case GIIUC_J: return Key::J;
    case GIIUC_K: return Key::K;
    case GIIUC_L: return Key::L;
    case GIIUC_Semicolon: return Key::Semicolon;
    case GIIUC_Apostrophe: return Key::Apostrophe;
    case GIIUC_Grave: return Key::Grave;
    case GIIK_ShiftL: return Key::LeftShift;
    case GIIUC_BackSlash: return Key::Backslash;
    case GIIUC_Z: return Key::Z;
    case GIIUC_X: return Key::X;
    case GIIUC_C: return Key::C;
    case GIIUC_V: return Key::V;
    case GIIUC_B: return Key::B;
    case GIIUC_N: return Key::N;
    case GIIUC_M: return Key::M;
    case GIIUC_Comma: return Key::Comma;
    case GIIUC_Period: return Key::Period;
    case GIIUC_Slash: return Key::Slash;
    case GIIK_ShiftR: return Key::RightShift;
    case GIIUC_Multiply: return Key::Multiply;
    case GIIK_AltL: return Key::LeftAlt;
    case GIIUC_Space: return Key::Space;
    case GIIK_CapsLock: return Key::Capital;
    case GIIK_F1: return Key::F1;
    case GIIK_F2: return Key::F2;
    case GIIK_F3: return Key::F3;
    case GIIK_F4: return Key::F4;
    case GIIK_F5: return Key::F5;
    case GIIK_F6: return Key::F6;
    case GIIK_F7: return Key::F7;
    case GIIK_F8: return Key::F8;
    case GIIK_F9: return Key::F9;
    case GIIK_F10: return Key::F10;
    case GIIK_NumLock: return Key::NumLock;
    case GIIK_ScrollLock: return Key::ScrollLock;
    case GIIK_P7: return Key::Numpad7;
    case GIIK_P8: return Key::Numpad8;
    case GIIK_P9: return Key::Numpad9;
    case GIIK_PMinus: return Key::Subtract;
    case GIIK_P4: return Key::Numpad4;
    case GIIK_P5: return Key::Numpad5;
    case GIIK_P6: return Key::Numpad6;
    case GIIK_PPlus: return Key::Add;
    case GIIK_P1: return Key::Numpad1;
    case GIIK_P2: return Key::Numpad2;
    case GIIK_P3: return Key::Numpad3;
    case GIIK_P0: return Key::Numpad0;
    case GIIK_PDecimal: return Key::Decimal;
    //case GIIUC_OEM_102: return Key::OEM_102;
    case GIIK_F11: return Key::F11;
    case GIIK_F12: return Key::F12;
    case GIIK_F13: return Key::F13;
    case GIIK_F14: return Key::F14;
    case GIIK_F15: return Key::F15;
    //case GIIUC_Kana: return Key::Kana;
    //case GIIUC_ABNT_C1: return Key::ABNT_C1;
    //case GIIUC_Convert: return Key::Convert;
    //case GIIUC_NoConvert: return Key::NoConvert;
    //case GIIUC_Yen: return Key::Yen;
    //case GIIUC_ABNT_C2: return Key::ABNT_C2;
    case GIIK_PEqual: return Key::NumpadEquals;
    case GIIK_PreviousSong: return Key::PrevTrack;
    case GIIUC_At: return Key::At;
    case GIIUC_Colon: return Key::Colon;
    case GIIUC_Underscore: return Key::Underline;
    //case GIIUC_Kanji: return Key::Kanji;
    //case GIIUC_AX: return Key::AX;
    //case GIIUC_Unlabeled: return Key::Unlabeled;
    case GIIK_NextSong: return Key::NextTrack;
    case GIIK_PEnter: return Key::NumpadEnter;
    case GIIK_CtrlR: return Key::RightControl;
    case GIIK_Mute: return Key::Mute;
    case GIIK_Calc: return Key::Calculator;
    case GIIK_PlayPause: return Key::PlayPause;
    case GIIK_StopCd: return Key::MediaStop;
    case GIIK_VolumeDown: return Key::VolumeDown;
    case GIIK_VolumeUp: return Key::VolumeUp;
    case GIIK_Homepage: return Key::WebHome;
    case GIIK_PSeparator: return Key::NumpadComma;
    case GIIK_PSlash: return Key::Divide;
    case GIIK_PrintScreen: return Key::SysRq;
    case GIIK_AltR: return Key::RightAlt;
    //case GIIK_PauseCd: return Key::Pause;
    case GIIK_Stop: return Key::Pause;
    case GIIK_Home: return Key::Home;
    case GIIK_Up: return Key::ArrowUp;
    case GIIK_Prior: return Key::PageUp;
    case GIIK_Left: return Key::ArrowLeft;
    case GIIK_Right: return Key::ArrowRight;
    case GIIK_End: return Key::End;
    case GIIK_Down: return Key::ArrowDown;
    case GIIK_Next: return Key::PageDown;
    case GIIK_Insert: return Key::Insert;
    case GIIK_Delete: return Key::Delete;
    case GIIK_SuperL: return Key::LeftWindows;
    case GIIK_SuperR: return Key::RightWindow;
    case GIIK_Menu: return Key::AppMenu;
    case GIIK_Power: return Key::Power;
    case GIIK_Sleep: return Key::Sleep;
    case GIIK_Wakeup: return Key::Wake;
    case GIIK_Search: return Key::WebSearch;
    case GIIK_Favorites: return Key::WebFavorites;
    case GIIK_Refresh: return Key::WebRefresh;
    //case GIIUC_WebStop: return Key::WebStop;
    case GIIK_Forward: return Key::WebForward;
    case GIIK_Back: return Key::WebBack;
    case GIIK_Computer: return Key::MyComputer;
    case GIIK_Mail: return Key::Mail;
    case GIIK_Media: return Key::MediaSelect;
        return 0;