Showing posts from March, 2019

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

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