Skip to main content
How to show the mouse cursor without CEGUI         Show / display mouse cursor without a GUI library
Page actions
Print

Show / display mouse cursor without a GUI library


A GUI library is great for many things, but it can be a little bit overwhelming for your application. I have seen the question about how to display a mouse cursor without a GUI library asked in the forums a number of times. The answer was either "Use CEGUI/QuickGUI/MyGUI", or "It shouldn't be hard to do this with a Panel" without more help for the poor newbie (like me).

Here is how I make a mouse cursor without resorting to a GUI library, using the example framework (somewhat).

First way: Software cursor (your application own cursor)


If you want the mouse cursor to always stay in the render window and to use your own image you can use following.

Initial Construction:

Copy to clipboard
mMouseCursor = new MouseCursor();
        mMouseCursor->setImage("entis.png");
        mMouseCursor->setVisible(true);
        mMouseCursor->setWindowDimensions(win->getWidth(), win->getHeight());

Update mouse position when needed:

Copy to clipboard
mMouseCursor->updatePosition(mMouse->getMouseState().X.abs, mMouse->getMouseState().Y.abs);

Update window dimensions when needed:

Copy to clipboard
mMouseCursor->setWindowDimensions(rw->getWidth(), rw->getHeight());


MouseCursor.h

Copy to clipboard
#ifndef __MOUSECURSOR_H__
#define __MOUSECURSOR_H__

#include <OgrePanelOverlayElement.h>

using namespace Ogre;

class MouseCursor
{
private:
    Overlay* mGuiOverlay;
    OverlayContainer* mCursorContainer;
    TexturePtr mTexture;
    MaterialPtr mMaterial;

    Real mWindowWidth;
    Real mWindowHeight;

public:
    MouseCursor(): mGuiOverlay(0), mCursorContainer(0)
    {
        mMaterial = MaterialManager::getSingleton().create("MouseCursor/default", "General");
        mCursorContainer = (OverlayContainer*) OverlayManager::getSingletonPtr()->createOverlayElement("Panel", "MouseCursor");
        mCursorContainer->setMaterialName(mMaterial->getName());
        mCursorContainer->setPosition(0, 0);

        mGuiOverlay = OverlayManager::getSingletonPtr()->create("MouseCursor");
        mGuiOverlay->setZOrder(649);
        mGuiOverlay->add2D(mCursorContainer);
        mGuiOverlay->show();
    }

    ~MouseCursor(void) {}

    void setImage(const String& filename)
    {
        mTexture = TextureManager::getSingleton().load(filename, "General");

        TextureUnitState *pTexState;
        if(mMaterial->getTechnique(0)->getPass(0)->getNumTextureUnitStates())
        {
            pTexState = mMaterial->getTechnique(0)->getPass(0)->getTextureUnitState(0);
        }
        else
        {
            pTexState = mMaterial->getTechnique(0)->getPass(0)->createTextureUnitState( mTexture->getName() );
        }
        pTexState->setTextureAddressingMode(TextureUnitState::TAM_CLAMP);
        mMaterial->getTechnique(0)->getPass(0)->setSceneBlending(SBT_TRANSPARENT_ALPHA);
    }

    void setWindowDimensions(unsigned int width, unsigned int height) {
        mWindowWidth = (width > 0) ? width : 1;
        mWindowHeight = (height > 0) ? height : 1;

        mCursorContainer->setWidth(mTexture->getWidth() / mWindowWidth);
        mCursorContainer->setHeight(mTexture->getHeight() / mWindowHeight);
    }

    void setVisible(bool visible)
    {
        if(visible) {
            mCursorContainer->show();
        } else {
            mCursorContainer->hide();
        }
    }

    void updatePosition(int x, int y)
    {
        Real rx = x / mWindowWidth;
        Real ry = y / mWindowHeight;
        mCursorContainer->setPosition(clamp(rx, 0.0f, 1.0f), clamp(ry, 0.0f, 1.0f));
    }

    Real clamp(Real a, Real min, Real max) {
        if (a < min) {
            return min;
        }
        if (a > max) {
            return max;
        } 
        return a;
    }
};

#endif


Main.cpp

Copy to clipboard
#include "ExampleApplication.h"
#include "MouseCursor.h"

class MCFrameListener : public ExampleFrameListener
{
private :
    MouseCursor* mMouseCursor;
public:
    MCFrameListener(RenderWindow* win, Camera* cam)
        : ExampleFrameListener(win, cam), mMouseCursor(0)
    {
        mMouseCursor = new MouseCursor();
        mMouseCursor->setImage("entis.png");
        mMouseCursor->setVisible(true);
        mMouseCursor->setWindowDimensions(win->getWidth(), win->getHeight());
    }

    bool frameStarted(const FrameEvent& evt)
    {
        if(ExampleFrameListener::frameStarted(evt) == false)
            return false;
        mMouseCursor->updatePosition(mMouse->getMouseState().X.abs, mMouse->getMouseState().Y.abs);
        return true;
    }

    virtual void windowResized(RenderWindow* rw)
    {
        ExampleFrameListener::windowResized(rw);
        mMouseCursor->setWindowDimensions(rw->getWidth(), rw->getHeight());
    }
};

class MCApplication : public ExampleApplication
{
public:
    MCApplication() {}

    ~MCApplication() {}

protected:

    virtual void chooseSceneManager(void)
    {
        mSceneMgr = mRoot->createSceneManager(ST_GENERIC);
    }

    virtual void createCamera(void)
    {
        mCamera = mSceneMgr->createCamera("Camera0");
        mCamera->setPosition(Vector3(0, 0, 100));
        mCamera->lookAt(Vector3(0, 0, 0));
        mCamera->setNearClipDistance(5);
    }

    virtual void createScene(void) {
        // put an ogrehead
        mSceneMgr->getRootSceneNode()->createChildSceneNode()->attachObject(mSceneMgr->createEntity("ogre", "ogrehead.mesh"));
    }
   
    // Create new frame listener
    void createFrameListener(void)
    {
        mFrameListener= new MCFrameListener(mWindow, mCamera);
        mRoot->addFrameListener(mFrameListener);
    }
};

#if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
#define WIN32_LEAN_AND_MEAN
#include "windows.h"
#endif

#ifdef __cplusplus
extern "C" {
#endif

#if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
INT WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR strCmdLine, INT )
#else
int main(int argc, char *argv[])
#endif
{
    // Create application object
    MCApplication app;

    try {
        app.go();
    } catch( Ogre::Exception& e ) {
#if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
        MessageBox( NULL, e.getFullDescription().c_str(), "An exception has occured!", MB_OK | MB_ICONERROR | MB_TASKMODAL);
#else
        std::cerr << "An exception has occured: " <<
            e.getFullDescription().c_str() << std::endl;
#endif
    }

    return 0;
}

#ifdef __cplusplus
}
#endif

Second way: System cursor (OIS cursor)


If you want to use the native mouse cursor and to let the cursor go outside the window, then create your input manager with a paramlist and right before calling

Copy to clipboard
mInputSystem = OIS::InputManager::createInputSystem( paramList );

insert the following lines

Copy to clipboard
#if defined OIS_WIN32_PLATFORM
    paramList.insert(std::make_pair(std::string("w32_mouse"), std::string("DISCL_FOREGROUND" )));
    paramList.insert(std::make_pair(std::string("w32_mouse"), std::string("DISCL_NONEXCLUSIVE")));
    paramList.insert(std::make_pair(std::string("w32_keyboard"), std::string("DISCL_FOREGROUND")));
    paramList.insert(std::make_pair(std::string("w32_keyboard"), std::string("DISCL_NONEXCLUSIVE")));
    #elif defined OIS_LINUX_PLATFORM
    paramList.insert(std::make_pair(std::string("x11_mouse_grab"), std::string("false")));
    paramList.insert(std::make_pair(std::string("x11_mouse_hide"), std::string("false")));
    paramList.insert(std::make_pair(std::string("x11_keyboard_grab"), std::string("false")));
    paramList.insert(std::make_pair(std::string("XAutoRepeatOn"), std::string("true")));
    #endif

For more information on this and OIS: Using OIS

Notes

  • This will show the Ogre head with no lighting.
  • Any alpha blended texture will work for cursor image.
  • Please send feedback to this forum entry or privately to madmark.

Alias: How to show the Mouse Cursor W/O CEGUI

History Source