Qt 3D, being a retained mode high level graphic API abstraction, tries to hide most of the details involved in rendering the data provided by applications. It makes a lot of decisions and operations in the background in order to get pixels on the screen. But, because Qt 3D also has very rich API, developers […]

Did you miss the past Qt World Summit? Were you there, but you couldn't attend that talk or two that you really wanted to see because the conference was so, so packed with awesome content? Fear no more! We are glad to announce that the talks at the past Qt World Summit 2019 in Berlin […]

Have you ever noticed code highlighting disappearing in Qt Creator for some projects, without any apparent reason? Can't get Ctrl+Click to work on any class name or function name anymore? Maybe you have ignored it at first, got used to it, and decided it's just one of those things that just "happen sometimes"; or maybe […]

As mentioned in the previous article in this series, Qt 3D 5.14 is bringing a number of changes aimed at improving performance. Most people familiar with Qt 3D will know that the API is designed around the construction of a scene graph, creating a hierarchy of Entities, each of them having having any number of […]

In the previous two blogs in this series I showed how solving an apparently simple problem about loading a lot of data into RAM using mmap() also turned out to require a solution that improved CPU use across cores. In this blog, I’ll show how we dealt with the bottleneck problems that ensued, and finally, […]

We have released version 2.11.0 of our Qt application monitoring tool GammaRay. GammaRay allows you to observe behavior and data structures of Qt code inside your program live at runtime. GammaRay 2.11 comes with a new inspection tool for Qt's event handling, providing even more insights into the inner working of your application. Besides looking […]

In the first blog in this series, I showed how we solved the original problem of how to use mmap() to load a large set of data into RAM all at once, in response to a request for help from a bioinformatics group dealing with massive data sets on a regular basis. The catch in […]

A few months ago, we received a phone call from a bioinformatics group at a European university. The problem they were having appeared very simple. They wanted to know how to usemmap() to be able to load a large data set into RAM at once. OK I thought, no problem, I can handle that one. […]

Sometimes it seems that we have nearly infinite memory resources, especially compared to the tiny 48K RAM of yesteryear’s 8-bit computers. But today’s complex applications can soak up megabytes before you know it. While it would be great if developers planned their memory management for all applications, thinking through a memory management strategy is crucial […]

We have released version 2.10.0 of our Qt application introspection tool GammaRay. GammaRay allows you to observe behavior and data structures of Qt code inside your program live at runtime. GammaRay 2.10 comes with an entirely new inspection tool for QtLocation geo positioning data. Besides visualizing the currently provided positioning data on a map, it […]

KDAB is proud to announce that for the first time ever we will be present at Embedded Technology outside of Tokyo in Japan. Every year more than 25000 visitors attend over 3 days! The event takes place in the Pacifico Yokohama exhibition center and focuses on Embedded AI, IoT Wireless Technology, Smart Sensing and Safety […]

After more than a year of work, I'm pleased to release another version of heaptrack, the Linux memory profiler! The new version 1.1.0 comes with some new features, significant performance improvements and - most importantly - much improved stability and correctness. If you have tried version v1.0 in the past and encountered problems, update to […]

While I was working on a yet-to-be-announced super secret and cool Qt on Android project, I had to do a lot of debugging. This way I found that debugging Qt apps on Android using QtCreator was ok, but it had some issues, which was kinda frustrating. First issue was that I could not debug on […]

With the introduction of the Qt Quick software renderer it became possible to use Qt Quick on devices without a GPU. We investigated how viable this option is on a lower end device, particularly the NXP i.MX6 ULL. It turns out that with some (partially not yet integrated) patches developed by KDAB and The Qt […]

"I have also done some last minute performance improvements with the help of KDAB Hotspot/perf, and I must say that the days of profiling with weird/huge perf command line options are gone, awesome tool!" Hotspot is a KDAB R&D project to create a standalone GUI for performance data. It is a replacement for perf report. […]

The City Lights demo is an example of Qt 3D being put to novel use to implement a deferred rendering pipeline. With OpenGL, the number of lights you can show on a screen, also affecting objects in a scene, is limited by the need to use a forward renderer. Using Qt 3D, the geometry considerations […]

We have released version 2.9.0 of our Qt application introspection tool GammaRay. GammaRay allows you to observe behavior and data structures of Qt code inside your program live at runtime. GammaRay 2.9 introduces a number of new features interesting to Qt Quick, QWidgets, Qt 3D and non-graphical Qt users alike. Qt Quick One focus area […]

Today I want to share 13 mistakes regarding signals, slots and connect statements and how to find them at compile time with clazy, our open-source static-analyzer for Qt. Clazy is a compiler plugin which generates warnings related to Qt. You can read more about it in our previous blog posts: How to use static analysis […]

Linux perf is an immensely useful and powerful tool suite for profiling of C/C++ applications. I have used it extensively and successfully on various customer projects, both for desktop applications as well as automotive or industrial projects targeting low-end embedded Linux targets running on ARM hardware. The biggest problem with perf really is its usability, […]

Close to three months after the initial hotspot release, I'm happy to announce the release of version 1.1.0. Quick recap: Hotspot is a graphical frontend to the Linux perf profiler suite. It allows you to visually analyze perf.data files with the built-in Flame Graph and the Bottom-Up, Top-Down, or Caller-Callee data tables. It is a […]