[osg-users] Read Image from RTT

[Rômulo Cerqueira]

Hi,

I have tried to read image from RTT (where the image is "not attached", but 
available on buffer) using a osg::Camera::DrawCallback, the compilation is 
working, however the executable brings me a segmentation fault during image 
rendering. How can I solve this?



Code:
WindowCaptureScreen::WindowCaptureScreen(osg::ref_ptr<osg::GraphicsContext> 
gfxc, osg::Texture2D* tex) {
    _mutex = new OpenThreads::Mutex();
    _condition = new OpenThreads::Condition();
    _image = new osg::Image();

    // checks the GraficContext from the camera viewer
    if (gfxc->getTraits()) {
        _tex = tex;
        int width = gfxc->getTraits()->width;
        int height = gfxc->getTraits()->height;
        _image->allocateImage(width, height, 1, GL_RGBA, GL_FLOAT);
    }
}

WindowCaptureScreen::~WindowCaptureScreen() {
    delete (_condition);
    delete (_mutex);
}

osg::ref_ptr<osg::Image> WindowCaptureScreen::captureImage() {
    //wait to finish the capture image in call back
    _condition->wait(_mutex);

    return _image;
}

void WindowCaptureScreen::operator ()(osg::RenderInfo& renderInfo) const {
    osg::ref_ptr<osg::GraphicsContext> gfxc = 
renderInfo.getState()->getGraphicsContext();

    if (gfxc->getTraits()) {
        _mutex->lock();

        // read the color buffer as 32-bit floating point
        renderInfo.getState()->applyTextureAttribute(0, _tex);

        // THE PROGRAM CRASHES HERE
        _image->readImageFromCurrentTexture(renderInfo.getContextID(), true, 
GL_FLOAT);

        // grants the access to image
        _condition->signal();
        _mutex->unlock();
    }
}




Output from GDB:


Code:
#0  0xffffffffffffff88 in ?? ()
#1  0x00007fffef1ee39d in normal_depth_map::WindowCaptureScreen::operator() 
(this=0x7fffb53ee7a0, renderInfo=...)
    at 
/home/romulo/dev/sonarsim/simulation/normal_depth_map/src/ImageViewerCaptureTool.cpp:158
#2  0x00007fffebb43b10 in osgUtil::RenderStage::draw(osg::RenderInfo&, 
osgUtil::RenderLeaf*&) ()
   from target:/usr/lib/x86_64-linux-gnu/libosgUtil.so.100
#3  0x00007fffebb4bdb7 in osgUtil::SceneView::draw() () from 
target:/usr/lib/x86_64-linux-gnu/libosgUtil.so.100
#4  0x00007fffec31c03f in osgViewer::Renderer::draw() () from 
target:/usr/lib/x86_64-linux-gnu/libosgViewer.so.100
#5  0x00007fffef557d49 in osg::GraphicsContext::runOperations() ()
   from target:/usr/lib/x86_64-linux-gnu/libosg.so.100
#6  0x00007fffef5a7bbf in osg::OperationThread::run() () from 
target:/usr/lib/x86_64-linux-gnu/libosg.so.100
#7  0x00007fffef5596f8 in osg::GraphicsThread::run() () from 
target:/usr/lib/x86_64-linux-gnu/libosg.so.100
#8  0x00007fffecbd06c8 in OpenThreads::ThreadPrivateActions::StartThread(void*) 
()
   from target:/usr/lib/x86_64-linux-gnu/libOpenThreads.so.20
#9  0x00007ffff60246ba in start_thread (arg=0x7fffa7efe700) at 
pthread_create.c:333
#10 0x00007ffff130f41d in clone () at 
../sysdeps/unix/sysv/linux/x86_64/clone.S:109




Thanks in advance,

Cheers,
Rômulo

------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=74982#74982





_______________________________________________
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org