| Re: [AD] OpenGL and upside down |
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On 2008-03-15, Peter Hull <peterhull90@xxxxxxxxxx> wrote:
> If you lock the OpenGL back-buffer, it currently reads the pixels and
> then reverses the order of the rows (because OpenGL bitmaps start from
> the bottom up and Allegro start from the top down). When you unlock,
> the opposite process occurs. This reversing is done by a load of
> memcpy-ing.
>
> Would it be possible to avoid this by returning a locked region with
> data pointing to the last row of the region but with a negative pitch?
Sounds like it would work.
Peter