Posts tagged silverlight
For some reason Microsoft have made it difficult to work out how to support multiple languages in Silverlight. The solution isn’t hard, once you manage to work it out. It is complicated by the fact that accessing string tables in C# is completely different to accessing them in XAML. Plus there is a nasty bug in Visual Studio which apparently still isn’t fixed.
However, never fear. After trying several approaches, all of which failed in some way, the solution can be found on timheuer.com. Tim presents a clear and straightforward method without needing to do anything weird (except for the Visual Studio bug workaround).
About six months ago I posted a video showing a GPS track with 7,000 points in a slippy map control called DeepEarth. If you watch the video you can see that the track lags behind the map a little and I think I was at the limit of what was usable.
Yesterday I wrote about my new C# based slippy map control for Silverlight and Moonlight that can display 50,000 map markers and I wanted to see what it’s performance was like for a GPS track. I created a random track with 50,000 points in it to simulate a track from a GPS unit. Here is the result. More >
There are a range of pan and zoom map controls (sometimes called slippy maps) available for C#/.NET and Silverlight/Moonlight. All the ones I’ve seen have something in common – they are bloated. The authors attempt to address the needs of as many users as possible and the result is large downloads and far too many features. The forums and mailing lists are full of people asking how to achieve basic functionality because they are lost in the vast realm of classes.
Of course, it is possible to remove what you don’t need but that requires understanding the code and after all that effort you are left with code that might not have the right license for your needs. The solution? Time to cringe – reinventing the wheel.
Fortunately it’s not much of a wheel, assuming your requirements are simple as mine are. C# and good development tools (Visual Studio and MonoDevelop) makes it easy to quickly develop a lightweight and flexible slippy map that can be used in Windows, Mac OS X and Linux (using Moonlight). More >
Large GPS Track Logs
I had the need to display GPS tracks in DeepEarth. GPS tracks can contain thousands of points. DeepEarth has three update modes called ElementUpdate, PanOnlyUpdate and TransformUpdate for showing features such as tracks:
- ElementUpdate recalculates the point positions on every map movement. This produces an accurate track display but gets slower as the number of points increases.
- PanOnlyUpdate recalculates point positions during panning and hides features while zooming. Not too useful for me and didn’t seem to show anything anyway.
- TransformUpdate draws the tracks to the map once then scales and pans the vector graphic in synchronization with the map. This makes it very fast. Sadly the scaling code is flawed. Lines disappear as you zoom in and sections of the tracks become distorted, almost looking like calligraphy.
I wasted many evenings trying to get the scaling in TransformUpdate mode working before giving up. I then turned my attention back to the ElementUpdate mode to see where the bottleneck is. More >