We need a view written in Objective C for an existing iPhone application. This view will operate like a radar screen. It first needs to load a png image (which acts as the radar screen) and then perform drawing steps for the sweep line.
The attached image provides a (still) representation of how the drawing should work. The green line cycles around with a gradient fading behind to transparent. The animation needs to run at between 10 and 15 frames per second (or it begins to look choppy).
As with real radar the sweep line will illuminate dots which should be a path gradient that is bright in the middle and fades to transparent. Oval size needs to be a variable so we can experiment with good sizes. The dots will be represented by an X Y coordinate (provided in a simple array) within the rectangle holding the radar screen. Dots illuminate as the sweep line reaches them and stay lit until the sweep line comes around again (just as you would expect in a real radar screen).
The Array that provides the dot locations should be evaluated once per complete sweep. The data can be retrieved through a class we have created. It would be best if this were accomplished in another thread but I'm not familiar with how hard that might be in the iPhone.
I have already written most of this code in Visual C++ using gdiplus and you are free to use that code to work from if you like. It is not complete, however it does have all of the necessary geometry which is the most complicated aspect of the project.
It is very important that there is a smooth feel to the operation of this screen. Choppy animation will not be acceptable.