Because linedashphase was very important in my app, i spend time to figure out why linedashphase doesn't stay consistent with linedashpattern on some device. Linedashphase doesn't seem to be translated from user space to screen space like the linedashpattern is. Indeed, the solution is to take care of UIScreen scale to correctly set linedashphase in order to work right on all device. I use Quartz 2D within Mapkit renderer.
So I have to multiply my phase value with the screen scale, like this..
myrenderer.lineDashPhase = myphasevalue * [UIScreen mainScreen].scale;
So, I post this to help someone who might have the same problem and because I did not find any Quartz documentation that specify the right linedahphase behavior. Any comments are welcome if someone have a better solution or I might be wrong with that.
