| Re: [AD] update bitmap drawing after addition of transformations |
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On 2010-08-13, Elias Pschernig <elias.pschernig@xxxxxxxxxx> wrote:
> On Fri, 2010-08-13 at 10:57 +1000, Peter Wang wrote:
> >
> > I have not benchmarked it yet, but I imagine the performance loss will be
> > significant. If it is, can we not make the memory draw_bitmap_region
> > implementation infer the rotate/scale special cases from the transformation
> > matrix and call the specialised functions?
> >
>
> We can check for identity transform and for only scaled transform quite
> easily I think.
>
> Not sure about rotation.
Should be okay, just check for:
[cosθ -sinθ]
[sinθ cosθ]
cos²θ + sin²θ = 1
It's a bit silly. But, on the bright side, we can infer rotations even
if you use a transformation rather than calling al_draw_rotated_bitmap.
Peter