Axel Dörfler wrote:
Adi Oanca <e2joseph@xxxxxxxxxx> wrote:
So from the SIMD coders perspective, it would be very good if Haiku would offer some control over data alignment for bitmap allocations.
This includes not only the base address of the bitmap, but should ideally extend to each bitmap row, in cases where each row has to be processed separately (e.g. by blur routines:).
Of course there'd be some 'waste', but I don't think this would matter too much on modern systems. Binary compatibility shouldn't be a problem either, as the BeBook already says that BytesPerRow() are decisive on determing a bitmaps actual size.
This might be implemented by an additional constructor without too much fuss, I'd guess. It would be great if you could implement this, as this would make SIMD coding much easier and less bug-prone.
OK, you'll have that. Now, I have to see how. :-) Axel, can you help?
What he means is: we would need a change of the public API, that is add another BBitmap constructor that allows an alignment. What we could also do is to add another bitmap flag to force an ideal alignment for the current CPU.
Adi.
