[Development] QImage::transformed returns shallow copy for QTransform::TxNone matrix type.

Giuseppe D'Angelo dangelog at gmail.com
Mon Jul 11 13:52:30 CEST 2016

On Mon, Jul 11, 2016 at 1:40 PM, Tomasz Olszak <olszak.tomasz at gmail.com> wrote:
> The problem here is that you can't say if transformed returns shallow or
> deep copy. Result depends on argument value. Of course the transform
> returning shallow copy on identity matrix is nice but should be documented
> somewhere. After reading docs I expected deep copy like from copy function.
> But maybe it's only me :)

Then always deep copy and then move on with the processing? Because
relying on shallow copies is a bit of a gamble -- by the same
reasoning, can you be sure that setPixel(x, y, color) always detaches?
What if it gets implemented in a way that first checks if the pixel
already has that color, and if so, it doesn't do anything?

Giuseppe D'Angelo

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