2 QOpenGLWidget shared context

glararan

Hi,

I would like to solve problem that I still deal with.. thats render 2 QOpenGLWidgets at same time in different top level windows with shared shader programs etc.

My first attempt was to use one context, wasnt working.

The question: Is it even possible currently with QOpenGLWidget? Or I have to go to older QGLWidget? Or use something else?

testAttribute for Qt::AA_ShareOpenGLContexts returns true so there is not problem with sharing
even QOpenGLContext::areSharing returns true. So there is something I missing or I dont know. Not using threads.

If you need anything more to debug this problem tell me.

Debug output:
@MapExplorer true true
true
QOpenGLShaderProgram::bind: program is not valid in the current context.
MapExlorer paintGL ends
MapExplorer true true
true
QOpenGLShaderProgram::bind: program is not valid in the current context.
MapExlorer paintGL ends
QOpenGLFramebufferObject::bind() called from incompatible context
QOpenGLShaderProgram::bind: program is not valid in the current context.
QOpenGLShaderProgram::bind: program is not valid in the current context.
QOpenGLShaderProgram::bind: program is not valid in the current context.
QOpenGLFramebufferObject::bind() called from incompatible context
QOpenGLFramebufferObject::bind() called from incompatible context@

MapView initializeGL:
@void MapView::initializeGL()
{
this->makeCurrent();

initializeOpenGLFunctions();

// Initialize World
world->initialize(this->context(), size(), worldCoords);

// Initialize camera shader
camera->initialize();

// Enable depth testing
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);

glDepthFunc(GL_LEQUAL); // just testing new depth func

glClearColor(0.65f, 0.77f, 1.0f, 1.0f);

}@

MapView paintGL:
@void MapView::paintGL()
{
this->makeCurrent();

glDrawBuffer(GL_FRONT);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

world->draw(...);

}@

MapExplorer initializeGL:
@void MapExplorer::initializeGL()
{
this->makeCurrent();

QOpenGLContext* _context = _mapView->context();
_context->setShareContext(this->context());
_context->create();

this->context()->create();
this->makeCurrent();

initializeOpenGLFunctions();

// Enable depth testing
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);

glDepthFunc(GL_LEQUAL); // just testing new depth func

glClearColor(0.65f, 0.77f, 1.0f, 1.0f);

}@

MapExplorer paintGL:
@void MapExplorer::paintGL()
{
this->makeCurrent();

qDebug() << "MapExplorer" << QOpenGLContext::areSharing(this->context(), _mapView->context()) << (QOpenGLContext::currentContext() == this->context());

QOpenGLShaderProgram* shader = world->getTerrainShader();
qDebug() << shader->create();
shader->bind(); // debug error "QOpenGLShaderProgram::bind: program is not valid in the current context."

// We need the viewport size to calculate tessellation levels and the geometry shader also needs the viewport matrix
shader->setUniformValue("viewportSize",   viewportSize);
shader->setUniformValue("viewportMatrix", viewportMatrix);

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

qDebug() << "MapExlorer paintGL ends";

//world->drawExplorerView(...);

}@

Thanks.

Regards, glararan.