Re: QT map widget
Hi, Am Freitag 11 Juni 2010 schrieb Marijn Kruisselbrink: You might also want to look at the marblewidget (http://edu.kde.org/marble/). As far as I know it can be built without any kde dependency, and is pretty powerful. I did. On the n900 as well as on the linux desktop. While i really think this is great for desktops i also think that it isn't the right thing for mobile devices. There are several issues: - It is big and installs ~10MB data - It is pretty complex and doesn't really fit on the small screen - It takes several seconds to load - It runs pretty slow I do understand why people like it, really. But i think the latter two issues are show stoppers. People just won't accept that adding simple map to their programs will cause it to run slow. I have read that poeple are working on the speed issue. But speed alone isn't the problem. More important is battery consumption as those apps tend to be used for a longer period of time. And you wouldn't just have to make it run fast, you'd have to make it run fast without imposing a significant CPU load. Thus i think this whole 3D approach, as cool as it is, doesn't suit the mobile world. All the trigonometrics involved in 3D and the additional CPU load required for proper image stretching/scaling imho doesn't justify the battery drain this will cause. Or am i mistaken and the Marble widget can be switched into some fast and low-CPU 2D mode? Till ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: QT map widget
Till Harbaum / Lists wrote: Hi, Am Freitag 11 Juni 2010 schrieb Marijn Kruisselbrink: You might also want to look at the marblewidget (http://edu.kde.org/marble/). I did. On the n900 as well as on the linux desktop. While i really think this is great for desktops i also think that it isn't the right thing for mobile devices. There are several issues: - It is big and installs ~10MB data - It is pretty complex and doesn't really fit on the small screen - It takes several seconds to load - It runs pretty slow snip I have read that poeple are working on the speed issue. But speed alone isn't And speedups may be very possible - if for example you can offload portions of the workload onto a GPU. But, for the forseeable future, 3D will not always be available on the mobile platform. Especially as I wouldn't expect the future of featurephones to be a simple race to 2GHz/GPU/... Yes, that'll be happening - but in parallel will be soon coming out (I predict - regrettably I have no inside info) n900-lite devices based on whatever can be gotten that week in china. It's also not impossible that as capacities of cheap phones rise - take a look at http://noknok.tv/2010/01/04/nokia-5230-officially-shipping/ - for example - and even phones at the very bottom of the market are starting to include 'web browsers' - capabilities of the processors and GPU will not be up to n900 levels for some years. The ability for such a widget to be 'cross platform' - and run on small devices would be a valuable one. ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: QT map widget
Hi, Am Samstag 12 Juni 2010 schrieb Ian Stirling: And speedups may be very possible - if for example you can offload portions of the workload onto a GPU. That addresses the performance problem, but this likely also if you do this for performance reasons, it also increases battery consumption as you put additional load onto another component of the SOC. But it may still be good to offload certain tasks from the main CPU to the GPU as the GPU may do the same thing more power efficient. I really think low battery consumption is the most important issue with a map widget as this type of widget is meant to be used over a longer period of time and while being away from stationary power. Till ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: QT map widget
[Till Harbaum / Lists Sa 12. Juni 2010]: Hi, Am Samstag 12 Juni 2010 schrieb Ian Stirling: And speedups may be very possible - if for example you can offload portions of the workload onto a GPU. That addresses the performance problem, but this likely also if you do this for performance reasons, it also increases battery consumption as you put additional load onto another component of the SOC. It's rather moot, as this isn't a movie at 25fps, so an occasional image refresh, no matter how it's done, will take magnitudes less energy per time in average, than the backlight eats to display the image. When screen is dimmed (or the widget invisible/hidden/background) then of course all gfx workload should suspend, for obvious reasons /j signature.asc Description: This is a digitally signed message part. ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
