[Interest] Quick2 OpenGL inefficiency?

[Filip Piechocki]

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.
>
>
>
> 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
> destroy all copies of this message, along with any attachment, prior to
> reading, distributing or copying it.
>
> _______________________________________________
> Interest mailing list
> Interest at qt-project.org
> http://lists.qt-project.org/mailman/listinfo/interest
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20160307/13ddcd72/attachment.html>