[PyQt] Implementation of the QQuickFramebufferObject

[Rostyslav Lyulinetskyy]

On 18.09.2015 19:03, Phil Thompson wrote:
> On 15 Sep 2015, at 12:14 pm, Rostyslav Lyulinetskyy <info at rostik.de> wrote:
>> Hi,
>>
>> I am trying to port my c++ code to python and I am integrating a custom OpenGL rendering with Qt Quick via QQuickFramebufferObject (as described here: https://blog.qt.io/blog/2015/05/11/integrating-custom-opengl-rendering-with-qt-quick-via-qquickframebufferobject/)
>> Everything works well in c++, but for various reasons I need to port this to python and it doesn't seem to work. The virtual function createRenderer() in the QQuickFramebufferObject must be overridden so one can return a new renderer, but for some reason this function is not even called when using PyQt.
>>
>> Is it even possible to override this virtual function from python? Am I missing something?
>>
>> Here is a small example to replicate that the createRenderer() function is not called:
>> https://gist.github.com/rostikL/7876e4c47fc8dd8ce02f
> Tonight's snapshot will make sure createRenderer() is called. However there may well be issues with the ownership of the returned renderer. Please test and let me know.
>
> Phil
Hi,

Thanks for the implementation. I have tested it and createRenderer() 
function is being called now. I have now extended the example 
(https://gist.github.com/rostikL/7876e4c47fc8dd8ce02f) to get a new 
Renderer object which inherits from the QQuickFramebufferObject.Renderer 
class and the application crashes with "Segmentation fault" as error 
message.

The same thing happens in c++ when the following 3 functions are not 
implemented in the new Renderer:
- createFrameBufferObject(self, size)
- render () (is called when something changes)
- synchronize(self, item) (called as a result of 
QQuickFramebufferObject::update())

So I assume these methods are not properly implemented in PyQt and can 
not be overridden at the moment?

Regards,
Rostik