iPad is three years old now, and many tech blogs are writing stories to reflect what has changed. More than 100 million of them have been sold, alongside other popular tablets like the Kindle Fire and Nexus 7. But originally the reception was quite sceptical.
I’ve been working full time on my Android workstation for over a month now, and it is time to write an update about it. How has it worked out?
Few months ago I wrote a normal mapping series with part I and part II. That was a good experience, so series it is again! This time about implementing dynamic QML components, with an example case being busy&progress indicators. We'll call these specific ones QUItIndicators.
Let's start with obligatory video which demonstrates these components, BusyIndicator and ProgressIndicator, with few examples:
Traditionally indicators like these would be implemented as an animated GIF or a sprite. Cons of that approach are zero customization and memory consumption: 2s animation of 256x256px 32-bit color indicator at 60fps would mean 2*60*256*256*4 = 31.5Mb memory consumption. That's quite a bit for just one indicator, so usually frames are animated slower than 60fps which makes animation less smooth.
Alternative way to implement animated indicator would be using imperative drawing API (QPainter, Cairo, Skia etc.). Drawing freely to a canvas gives a lot of possibilities, but can easily lead to non-optimal performance. Many of these APIs have OpenGL backends which sounds good in theory, but the reality is that they can't take full gains out of modern GPUs. Like wise Tro^H^H^HDigians have said, combining QPainter with OpenGL backend doesn't make a perfect harmony.
So as you probably guessed, our indicators use Qt5+QML+GLSL instead. The pros of this approach compared to sprites or imperative drawing are rendering performance, low memory consumption and customization possibilities. There is also at least one con: Indicator needs to be designed so that required animations can be achieved with vertex & fragment shaders.
Next blog post goes through design thoughts behind these indicators. In the meantime, you can get the sources from here and try yourself!
Let's start with obligatory video which demonstrates these components, BusyIndicator and ProgressIndicator, with few examples:
Traditionally indicators like these would be implemented as an animated GIF or a sprite. Cons of that approach are zero customization and memory consumption: 2s animation of 256x256px 32-bit color indicator at 60fps would mean 2*60*256*256*4 = 31.5Mb memory consumption. That's quite a bit for just one indicator, so usually frames are animated slower than 60fps which makes animation less smooth.
Alternative way to implement animated indicator would be using imperative drawing API (QPainter, Cairo, Skia etc.). Drawing freely to a canvas gives a lot of possibilities, but can easily lead to non-optimal performance. Many of these APIs have OpenGL backends which sounds good in theory, but the reality is that they can't take full gains out of modern GPUs. Like wise Tro^H^H^HDigians have said, combining QPainter with OpenGL backend doesn't make a perfect harmony.
So as you probably guessed, our indicators use Qt5+QML+GLSL instead. The pros of this approach compared to sprites or imperative drawing are rendering performance, low memory consumption and customization possibilities. There is also at least one con: Indicator needs to be designed so that required animations can be achieved with vertex & fragment shaders.
Next blog post goes through design thoughts behind these indicators. In the meantime, you can get the sources from here and try yourself!
Overview
Erudite makes it possible to use Amazonâ€
s Cloud Reader on various mobile platforms which aren’t officially supported by Amazon. You can either read books online, or download them for reading offline. Your progress in a book is then also kept synchronised between your phone and other Kindle devices.
Symbian Belle support
Until recently Erudite only supported MeeGo Harmattan and Mer based phones (such as the Nokia N9), but now it’s also available for Symbian Belle phones as well. I’ll try and put together a build for Symbian Anna phones in the near future.
There’s a fairly comprehensive review of Erudite for Symbian over on All About Symbian: Erudite review.
Upcoming features
In the next release for both Symbian and MeeGo I’ll be focusing on orientation switching support, so users can optionally view their books in landscape mode, as well as investigating some apparent issues with very large books.
Download
- Symbian Belle version — Nokia 701, Nokia C6-01, Nokia C7-00, Nokia N8-00, Nokia X7-00, Nokia E6-00, Nokia 808 Pureview, Nokia 603, Nokia Oro, Nokia E7-00, and Nokia 700
- MeeGo Harmattan version — Nokia N9, Nokia N950