Hi Romain Looking further into the Android source code when you create a 32-bit color bitmap the system always assumes you have alpha and there is no way to turn it off. Only when you load a JPEG or something does the system set the flag to ignore it.
That is an unnecessary performance penalty that can easily be avoided. For Honeycomb could you please make the setHasAlpha public or provide an XRGB_8888 config. For the upcoming tablets we are going to draw even more and bigger bitmaps. On Jan 24, 10:01 pm, webmonkey <[email protected]> wrote: > But that seems to be the only way to tell the system that it can > ignore the alpha channel. Bitmap.hasAlpha() just returns the flag. > > I am updating the bitmap a lot with copyPixelsFromBuffer so how do I > tell the system that it can ignore the alpha channel? > > On Jan 24, 9:49 pm, Romain Guy <[email protected]> wrote: > > > > > No you cannot. Methods marked @hide are not part of the public API. They are > > not present in ADT's android.jar so you cannot compile against it. We also > > might rename or remove such APIs at any point in the future. > > > On Mon, Jan 24, 2011 at 12:42 PM, webmonkey <[email protected]> wrote: > > > Ah thanks, I just checked the Android source and there is the > > > following function > > > > public void setHasAlpha(boolean hasAlpha) { > > > nativeSetHasAlpha(mNativeBitmap, hasAlpha); > > > } > > > > But it is set to @hide so it is not in the docs, can we use this > > > function? > > > > On Jan 24, 6:14 pm, Romain Guy <[email protected]> wrote: > > > > The system can detect when a ARGB_8888 bitmap is opaque (see > > > > Bitmap.hasAlpha()). > > > > > On Mon, Jan 24, 2011 at 8:26 AM, webmonkey <[email protected]> > > > wrote: > > > > > Now that Gingerbread has moved to 32-bit windows is there a way to > > > > > create a 32-bit bitmap without alpha to improve drawing performance of > > > > > opaque bitmaps? > > > > > > Something like Bitmap.createBitmap( 512, 512, > > > > > Bitmap.Config.XRGB_8888 ) > > > > > > Or does the system somehow detect that the bitmap is opaque? > > > > > > -- > > > > > You received this message because you are subscribed to the Google > > > > > Groups "Android Developers" group. > > > > > To post to this group, send email to > > > [email protected] > > > > > To unsubscribe from this group, send email to > > > > > [email protected]<android-developers%2Bunsubs > > > > > [email protected]><android-developers%2Bunsubs > > > [email protected]> > > > > > For more options, visit this group at > > > > >http://groups.google.com/group/android-developers?hl=en > > > > > -- > > > > Romain Guy > > > > Android framework engineer > > > > [email protected] > > > > > 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 [email protected] > > > To unsubscribe from this group, send email to > > > [email protected]<android-developers%2Bunsubs > > > [email protected]> > > > For more options, visit this group at > > >http://groups.google.com/group/android-developers?hl=en > > > -- > > Romain Guy > > Android framework engineer > > [email protected] > > > 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 [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
