Qt Quick 3D DynamicMeters demo

Lately we have been working to perfect the Qt Quick 3D for the 5.15 release. There are still some tweaking to do, but things are looking pretty nice already!

In order to prove (to ourselves and to others) that Quick 3D is ready for the prime time, we have also been implementing some demos with it. Tomi already made a blog post about Quick 3D Benchmarking demo here, go check it out if you haven't already. This benchmarking application can be used to test many features of Quick 3D and to evaluate how different hardware can handle the load when the model count, complexity, texture sizes etc. are increased.

Another demo we have prepared is called DynamicMeters. The main targets of this demo were:
Demonstrate how Quick 3D and Qt Quick (2D) can easily be combined into single UX. While 3D is great, most applications want to combine also traditional 2D elements in different ways.Test how Quick 3D works together with 3rd party OpenGL libraries. Make sure that the performance is good and the…

Qt painting performance with 4 different embedded GPUs (Mali, Adreno, PowerVR)

Summer is approaching, Qt 5.12.2 is out and we wanted to again get concrete painting performance numbers on some lower end embedded SOC GPUs. The kind of chipsets which people are using for embedded devices in multiple places. If user interface contains dynamically painted elements and target is 60fps (or maybe 30fps), how much could you actually paint and which Qt technologies to reach out?

To do this testing in easily approachable way, we grabbed 3 cheaper Android™ tablets with different GPUs for testing. Other option would have been different development boards, but those need a bit more setup time and time-to-market (or time-to-blog.. ;-) ) is important to all of us. We also wanted to give Qt 5.12.2 a go while it's hot.

So let's first introduce the tablets & chipsets used for this testing:

1) Lenovo Tab 7 Essential, MediaTek MT8167D, GPU: IMG PowerVR GE8300. This GPU is exactly the same which e.g. Renesas D3 uses, so if you are into automotives this GPU may be interes…

Using QNanoPainter without QtQuick (pure C++)

Originally, QNanoPainter library was implemented to fulfill the needs of easy to use but performant custom OpenGL QQuickItems. For the needs, Qt Quick Scene graph QSG* classes felt a bit too low-level to be productive, while QQuickPaintedItem was slightly lacking in performance and rendering quality on mobile hardware. For more details, please read this QNanoPainter introduction blog post.

I like (OK, love) Qt Quick & QML and have used them successfully in many different projects. On desktop, mobile and embedded software. A lot. But Qt Quick doesn't suit all situations or it is not always required. As explained in this Qt blog post, Qt 5.12 improves Qt Quick performance and memory usage. But naturally there still is some memory and startup time additions coming from Qt Quick engine.

Fear not, QNanoPainter can be used also without Qt Quick. Available entry points are:
QNanoQuickItem & QNanoQuickItemPainter - This is where it all started, use these to implement your QQuickIte…

Qt 5.10 Windows Rendering Benchmarks

At the end of the previous blog post I promised to do a follow-up about Windows side rendering performance. So here we go.

But before that, let's revisit one earlier case. Previously decided to provide results with and without "Bezier lines" test because it seemed to perform particularly poorly when rendered using QML Shape backend. Instead of just letting this one go, I decided to dig a bit deeper to try to improve QML Shape performance. After all, just disabling slow tests doesn't sound like a preferred long-term plan... ;-)

Improving QML Shape paths performance After some trial and error, found out that QQuickPath::createPath() uses considerable amount of time every time path changes and reason is in QPainterPath::length() which e.g. for all curved paths calls QBezier::length(). This isn't usually problem for PathView as its normal use-case is creating path once and then just moving elements along the path. But new ShapePath on the other hand might be animated…

Qt 5.10 Rendering Benchmarks

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 Shapeelement, 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 16 items:


Qt 5.10 QML Shape testing

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 QNanoPainter and QQuic…

FitGraph NG UI prototype

About a month ago I started exercising more, mostly jogging, weights and soccer (with kids). Target is to be in superb shape when 2018 starts, and I'm already feeling stronger & more energetic during the day so looking good!

Anyway, this blog post is somewhat related to that. There's plenty of health-related apps and gadgets available these days and in the past I used some time pondering what would be a perfect activity tracking app for my needs. Now I decided to revive this earlier concept as 'FitGraph NG' while porting it to use QNanoPainter and polishing some parts.

As usual, let's start with a video demonstrating the actual application:

There would of course be more views available, this being just the 'activity timeline' part, but it would already cover many of my initial wishes:
Showing the whole day as a graph, data or textually depending on needs.Automatic annotation of activities, type, duration and related activity data. And importantly, being …