I don't know the actual G1 hardware. On some HW devices however even hardware rotation has its price like - power consumption - memory bandwidth issues
If the architecture has shared memory between application processor and display controller, then even HW rotation might have one read and write the entire framebuffer in order to perform the rotation. Or if one wants to avoid the read and write of the frame buffer one had to perform scattered RAM accesses accross multiple RAM banks. Both can increase the memory bandwidth consumption and might thus stall the main processor more often. In order to test this you had to try running an application which modifies the screen rather frequently and which tries to perform some memory intensive (out of cache) native operations. If one case is slower, then you know, which rotation is 'native' or, that the hardware is built such, that there is no performance hit. Without knowing the HW in detail difficult to say. On May 14, 4:52 pm, Romain Guy <romain...@google.com> wrote: > It doesn't really matter, especially on a G1. The screen orientation > is handled at the low level by SurfaceFlinger so the orientation > doesn't impact the actual Skia (SGL) drawing commands. The rotation > itself is handled by a special hardware chip on G1. > > On Thu, May 14, 2009 at 6:29 AM, admin.androidsl...@googlemail.com > > <admin.androidsl...@googlemail.com> wrote: > > > Presumably one layout or other must be native to the O/S and the other > > layout needs an expensive internal rotation + transformation in order > > to display in correct position. > > -- > Romain Guy > Android framework engineer > romain...@android.com > > Note: please don't send private questions to me, as I don't have time > to provide private support. All such questions should be posted on > public forums, where I and others can see and answer them --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~----------~----~----~----~------~----~------~--~---
