Q: Qt - [c++] Unknown OpenGL error

kevin_d

Hello Qt Forum!

I am frequently creating and deleting, as well as attaching, removing entities and components on a Qt3D Window (scene).

After creating the game scene a fourth or fifth time (having destroyed a lot of Qt3DCore::QEntities and then rebuilding the 3D scene), but rather randomly, suddenly, I get massive errors like this (from this point the program is vulnerable and may crash):

ARB::createContext: wglCreateContextAttribsARB() failed (GL error code: 0x0) for format: QSurfaceFormat(version 4.3, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize 24, redBufferSize -1, greenBufferSize -1, blueBufferSize -1, alphaBufferSize -1, stencilBufferSize 8, samples 4, swapBehavior QSurfaceFormat::DefaultSwapBehavior, swapInterval 1, colorSpace QSurfaceFormat::DefaultColorSpace, profile  QSurfaceFormat::CoreProfile), shared context: 0x0 (Der Vorgang wurde erfolgreich beendet.)
GDI::createContext: wglCreateContext failed. (Unknown error 0xc00705aa.)
Unable to create a GL Context.

Do you maybe know, where this is coming from?

best regards, kevin

kevin_d

Basically, this is the code, at which the error occurrs:
(But it is strange, because this happens indeterministic, or at least quite random after some time... the scene got recreated several times, without an error)
I am confident, that i destroyed oll my entities and components, before the scene gets recreated again.

...
    auto* transparentTileMesh = new Qt3DExtras::QCuboidMesh;
    transparentTileMesh->setXExtent(1);
    transparentTileMesh->setYExtent(1);
    transparentTileMesh->setZExtent(0.001f);

    auto *transparentEntity = new Qt3DCore::QEntity(_root);
    transparentEntity->addComponent(transparentTileMesh);

    Qt3DCore::QTransform *transparentScaleTransform = new Qt3DCore::QTransform;
    transparentScaleTransform->setScale3D(QVector3D(1,1,1));
    transparentScaleTransform->setTranslation(QVector3D(xPos, yPos, zPos + 0.125));

    transparentEntity->addComponent(transparentScaleTransform);

    Qt3DRender::QMaterial* material = new Qt3DExtras::QPhongAlphaMaterial;
    material->setAmbient(color);
    material->setDiffuse(color);
    material->setShininess(shininess);
    material->setSpecular(specular);
    material->setAlpha(alpha);
    material->setSourceAlphaArg(Qt3DRender::QBlendEquationArguments::DestinationColor);
...

// this is the function that may cast an error
void GeometryObject::setTransparentTexture(Qt3DRender::QMaterial* texture)
{
     if (material!= nullptr)
        transparentEntity->removeComponent(material);

    material = texture;
    transparentEntity->addComponent(material);
}

cheers, kevin

robert2001b

This post is deleted!