Unsolved Check if a QImage is empty
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Hey guys
I am programming kind of a tileset creator for my 2D game. So I want to add a new picture from my hard disk which is bigger than the actual tilesize, then split it up into tiles.
I got that thing working, but when I use an image, it can happen that I have some tiles which are fully empty (because I didn't draw something on this part of the picture but can't leave this part away).So I asked my self, how is it possible to check if a QImage is completly empty? So every pixel of it is transparent?
I hope you can help me.
Thank you anyway :) -
This can help for little-endian CPUs and "QImage::Format_ARGB32":
quint32 *pixels = (quint32 *)img.bits(); int imgSize = img.width() * img.height(); bool isTransparent = true; for (int i = 0; i < imgSize; ++i) { if (((pixels[i] >> 24) & 0xFF) != 0) { isTransparent = false; break; } }
It checks that pixel is 100% transparent or not.