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Showing posts from May, 2013

Qt5 Battery Component

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After the QUItIndicator trilogy which introduced idea, design and performance of a specific Qt5 QML component there's room for more, right?! Something like this:


This time we have a dynamic QML component for showing the remaining power of your mobile device battery. As a recap, with "Dynamic QML component" I mean someting which utilizes not only basic QML animation properties (position, opacity, scale etc.) but also new Qt5 features (shaders, particles, scenegraph powa!) to appear "more dynamic". Maybe it's just me, but I would love to see UIs really utilizing modern GPUs... and accelerating this progress is one of the reasons why I code these examples and blog about them. Another reason being to rule-the-world, obviously ;-P

Instead of explaining design & features of QUItBattery component I'll let this video to do that:





If you want to use this liquid battery component in your UI: Download the sources from here, copy QUItBatteryComponent directory, …

QUItIndicators: Performance considerations

(This is part III, please check also parts I and II)

Even with a small component like this, there are plenty of possibilities to improve (or sink) the performance. To make sure that our indicators perform as expected, we'll test them on Nokia N9 and and on Raspberry Pi.

These both devices are relatively low-end by current standards. N9 contains 1GHz Cortex-A8 CPU which is still quite beefy, but GPU (SGX530) on the other hand is getting old and unable to handle more complicated fragment shaders. For RPi these are just the opposite: CPU is slowish 700MHz ARM11 while the GPU (VideoCore IV) is more performant than N9 SGX530. Because of these qualities (and because both support Qt5, naturally) this duo is excellent for our performance ensurement.

So here's a short video showing how our indicators perform on Nokia N9 and on RaspberryPi:




Performs pretty OK on both, right? ProgressIndicator stress test isn't smooth on RPi, which indicates that its CPU can't handle 100 indicato…