Qt Contributors' Summit



I will be mostly interested in discussions about Qt5 graphics stack, qml-box2d, QtQuick 2.0 and of course QML Scene Graph. So whenever something related to these is going on, please grab me in!

Comments

Post a Comment

Popular posts from this blog

Qt 5.10 QML Shape testing

Image
When implementing component into QtQuick UI which needs something more than rectangles, images and texts, pure declarative QML hasn't been enough. Popular choices to use for items with some sort of vector drawing are QML Canvas , QQuickPaintedItem  or QNanoPainter . But with Qt 5.10 there will be supports for new Shape  element with paths that contain lines, quads, arcs etc. so I decided to install Qt 5.10 beta3 and implement all tests of "qnanopainter_vs_qpainter_demo" with also QML + Shape elements. ( This kinda makes it "qnanopainter_vs_qpainter_vs_qmlshape_demo" but not renaming now ). So here is in all glory the same UI implemented with QNanoPainter (left), QQuickPaintedItem (center), and QML+Shape (right): Hard to spot the differences right? If only there would be a way to prove this, some way to x-ray into these UIs... like QSG_VISUALIZE=overdraw  to visualize what Qt Quick Scene Graph Renderer sees? Here you can see that scene graph sees QNan...
Read more

Introducing QNanoPainter

Qt World Summit is just about to start! I’m not participating this time, but wanted to contribute one-more-thing to discuss in UI groups at the heart of Berlin ;) During the past about six months we at QUIt Coding have had a side-side-project called QNanoPainter. This library is designed for implementing custom QQuickItems into Qt5 scene graph. Currently if you want to implement custom Qt Quick item, options are at least: QQuickItem : Offers best performance due to Qt5 scene graph integration. But QSG* classes are relatively low-level with vertices, indices & materials. Painting more complicated things requires quite an expert and even then productivity is not very high. QQuickFramebufferObject : This is a good option if you want to draw with OpenGL into QQuickItem. But as we all know, OpenGL is also quite low-level API so no productivity wins here. QQuickPaintedItem : This means painting with good old QPainter C++ API. Weakness of QPainter with modern graphics accelerated ...
Read more

Qt 5.10 Rendering Benchmarks

Image
Qt 5.10.0 RC packages are available now and actual release is happening pretty soon. So this seems to be a good time to run some rendering benchmarks with 5.10, including new QML Shape element, QQuickPaintedItem and QNanoPainter . After my previous blog post , some initial comments mentioned how QML Shape didn't reach their performance expectations. But I think that might be more of a "use the right tool for the job" -kind of thing. This demo application is very much designed to test the limits of how much heavily animated graphics can be drawn while keeping performance high and while having its own strengths, QML Shape likely isn't the tool for that. To prove this point, there is a new ' flower ' test case in QNanoPainter demo app which renders a nice flower path, animating gradient color & rotation (but not path). Combining it with new setting to render multiple items (not just multiple renders per item) and the outcome looks like this with 1 and 1...
Read more