Hi,
I have rendered a FBO camera to image by using a callback (as seen in the code
below), however some OpenGL warnings/erros are raised when I resize at runtime
by setupViewer() method. I debugged the code by using
Code:
export OSG_GL_ERROR_CHECKING=ON
and got the following error:
Code:
Warning: detected OpenGL error 'invalid operation' after applying attribute
Viewport 0x7fb35406e500
How can I properly do the resizing of my FBO camera?
Code:
// create a RTT (render to texture) camera
osg::Camera *ImageViewerCaptureTool::createRTTCamera(osg::Camera* cam,
osg::Camera::BufferComponent buffer, osg::Texture2D *tex, osg::GraphicsContext
*gfxc)
{
osg::ref_ptr<osg::Camera> camera = cam;
camera->setClearColor(osg::Vec4(0, 0, 0, 1));
camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
camera->setRenderTargetImplementation(osg::Camera::FRAME_BUFFER_OBJECT);
camera->setRenderOrder(osg::Camera::PRE_RENDER, 0);
camera->setViewport(0, 0, tex->getTextureWidth(), tex->getTextureHeight());
camera->setGraphicsContext(gfxc);
camera->setDrawBuffer(GL_FRONT);
camera->setComputeNearFarMode(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR);
camera->attach(buffer, tex);
return camera.release();
}
// create float textures to be rendered in FBO
osg::Texture2D* ImageViewerCaptureTool::createFloatTexture(uint width, uint
height)
{
osg::ref_ptr<osg::Texture2D> tex2D = new osg::Texture2D;
tex2D->setTextureSize( width, height );
tex2D->setInternalFormat( GL_RGB32F_ARB );
tex2D->setSourceFormat( GL_RGBA );
tex2D->setSourceType( GL_FLOAT );
tex2D->setResizeNonPowerOfTwoHint( false );
tex2D->setFilter( osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR );
tex2D->setFilter( osg::Texture2D::MAG_FILTER, osg::Texture2D::LINEAR );
return tex2D.release();
}
void ImageViewerCaptureTool::setupViewer(uint width, uint height, double fovY)
{
// set graphics contexts
osg::ref_ptr<osg::GraphicsContext::Traits> traits = new
osg::GraphicsContext::Traits;
traits->x = 0;
traits->y = 0;
traits->width = width;
traits->height = height;
traits->pbuffer = true;
traits->readDISPLAY();
osg::ref_ptr<osg::GraphicsContext> gfxc =
osg::GraphicsContext::createGraphicsContext(traits.get());
// set the main camera
_viewer = new osgViewer::Viewer;
osg::ref_ptr<osg::Texture2D> tex = createFloatTexture(width, height);
osg::ref_ptr<osg::Camera> cam = createRTTCamera(_viewer->getCamera(),
osg::Camera::COLOR_BUFFER0, tex, gfxc);
cam->setProjectionMatrixAsPerspective(osg::RadiansToDegrees(fovY), (width *
1.0 / height), 0.1, 1000);
// render texture to image
_capture = new WindowCaptureScreen(gfxc, tex);
cam->setFinalDrawCallback(_capture);
}
osg::ref_ptr<osg::Image>
ImageViewerCaptureTool::grabImage(osg::ref_ptr<osg::Node> node)
{
// set the current node
_viewer->setSceneData(node);
// if the view matrix is invalid (NaN), use the identity
if (_viewer->getCamera()->getViewMatrix().isNaN())
_viewer->getCamera()->setViewMatrix(osg::Matrixd::identity());
// grab the current frame
_viewer->frame();
return _capture->captureImage();
}
////////////////////////////////
////WindowCaptureScreen METHODS
////////////////////////////////
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);
_image->readImageFromCurrentTexture(renderInfo.getContextID(), true,
GL_FLOAT);
// grants the access to image
_condition->signal();
_mutex->unlock();
}
}
...
Thanks in advance,
Cheers,
Rômulo
------------------
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http://forum.openscenegraph.org/viewtopic.php?p=75005#75005
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