| Re: [AD] Poor Ming performance |
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> but *why* would hardware be sometimes faster and sometimes
> not ? the length of lines to draw ? it might be better to find out
> if there is not a hidden catch before trying to find a solution to this
Because of the overhead of locking/unlocking the screen and its dilution:
- per software-rendered hline: lock the screen (slow), draw 1 line (very
fast), unlock the screen (very fast)
- per hw-rendered hline: tell the gfx processor to draw 1 line (fast)
- per software-rendered triangle: lock the screen (slow), draw n lines (very
fast x n), unlock the screen (very fast)
- per hw-rendered triangle: tell the gfx processor to draw n lines (fast x
n)
As soon as n hits a threshold, the software hline renderer [slow + (very
fast)x(n+1)] is faster than the hardware one [fast x n].
--
Eric Botcazou
ebotcazou@xxxxxxxxxx