Hello,
Apology in advance if I am duplicating an existing thread on this topic (found none),
Is there any way to set BufferedBitmap background to transparent ?
If not - does anyone have a suggestion how to work around the issue below ?
Given:
Code uses a BufferedBitmap for better battery-usage/performance (i.e. all HH/MM marks/ticks, background outlines, etc) are (computed and) drawn toBufferedBitmap andBufferedBitmap is then reused during onUpdate (in which code wipes dc, then draws the BufferedBitmap, then draws time).
Further, to save on memory, the BufferedBitmap uses a restricted palette (which only contains the colors used by the the background 'decorations' mentioned above);
Lastly, as a side note, this BufferedBitmap is mostly empty/free-space (as most of its content is around the perimeter)
And now I would like to add an image, which means it needs to be drawn either on the BufferedBitmap, or on the 'main'-dc (passed to onUpdate)
Problem:
- if I add the image to the BufferedBitmap, I must remove the limited-palette restriction, and this costs ~32k bytes (!)
- if I add the image to the 'main'-dc (i.e. 'main'-dc clears then draws image then draws BufferedBitmap then draws time) the image cannot be seen since the BuffredBitmap on top of it is opaque.
I will add that an attempt to make the BufferedBitmap transparent by BufferedBitmap.getDc().setColor(<one of its palette colors>, transparent) followed by BufferedBitmap.getDc().clear() crashes the sim, even though as per DC API DOC "Starting form version 3.1.0, COLOR_TRANSPARENT will also be honored as background color, which will cause the value of pixels in the clip region to be replaced by COLOR_TRANSPARENT". And just to eliminate the possibility this crash not a bug in the sim I have tested the code on an actual device and same result (watchface crashes).
Any advise would be appreciated.