[Interest] Quick2 OpenGL inefficiency?

[Jani Tykka]

Images are passed from another thread in rate 15-30 fps. Is there an
example available how to achieve Image to OpenGL texture and use it in
scene graph?

On Mon, Mar 7, 2016 at 5:11 PM, Filip Piechocki <fpiechocki at gmail.com>
wrote:

> And where it comes from? How frequent it happens? Probably the best thing
> here would be to generate this image as an OpenGL texture and then use in
> the Qt's scene graph.
>
> On Mon, Mar 7, 2016 at 4:04 PM, Jani Tykka <jtykka at broadsoft.com> wrote:
>
>> Yes, the image is always changed when the update is invoked.
>>
>> On Mon, Mar 7, 2016 at 4:43 PM, Filip Piechocki <fpiechocki at gmail.com>
>> wrote:
>>
>>> Hi,
>>>
>>> Why are you re-creating the texture on every node update? Does the
>>> m_Renderer->getImage() really changes? My first guess would be that the
>>> texture creation from image is the most costly part here (uploading the
>>> texture to GPU?) and I would do this only if necessary (the image really
>>> changes).
>>>
>>> BR,
>>> Filip
>>>
>>> On Mon, Mar 7, 2016 at 3:04 PM, Jani Tykka <jtykka at broadsoft.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> We are rendering QImages on QQuickItem as following:
>>>>
>>>> QSGNode * DisplayItem::updatePaintNode( QSGNode * node, UpdatePaintNodeData * /*data*/ )
>>>>
>>>> {
>>>>
>>>> 	QSGSimpleTextureNode * n = static_cast< QSGSimpleTextureNode* >( node );
>>>>
>>>> 	if ( !n )
>>>>
>>>> 		n = new QSGSimpleTextureNode;
>>>>
>>>>
>>>> 	n->setRect( 0, 0, width(), height() );
>>>>
>>>>
>>>> 	delete m_Texture;
>>>>
>>>>
>>>> 	m_Texture = window()->createTextureFromImage( m_Renderer->getImage() );
>>>>
>>>> 	n->setTexture( m_Texture );
>>>>
>>>>
>>>> 	return n;
>>>>
>>>> }
>>>>
>>>>
>>>>
>>>> It seems that computers with separate GPU there is a decent amount of CPU utilised. We are running into problems if the machine lacks GPU, then with large images the CPU usage grows drastically. Any suggestions how to improve large image painting on QQuickItem? With Quick1 and painting directly on HWND/CocoaWindow we didn't experience this high CPU usage.
>>>>
>>>>
>>>>
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>>>
>>
>>
>> --
>> *Jani Tykkä*
>> Development Manager | BroadSoft, Inc. | +358 44 596 0587 |
>> jtykka at broadsoft.com
>>
>>
>> This email is intended solely for the person or entity to which it is
>> addressed and may contain confidential and/or privileged information. If
>> you are not the intended recipient and have received this email in error,
>> please notify BroadSoft, Inc. immediately by replying to this message, and
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>
>


-- 
*Jani Tykkä*
Development Manager | BroadSoft, Inc. | +358 44 596 0587 |
jtykka at broadsoft.com

-- 


This email is intended solely for the person or entity to which it is 
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