include/vcl/bitmap/BitmapTypes.hxx | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
New commits: commit 45a80756a97a906a5700b13e60e2a60d6f492197 Author: Noel Grandin <[email protected]> AuthorDate: Sat Sep 6 09:05:46 2025 +0200 Commit: Noel Grandin <[email protected]> CommitDate: Sat Sep 6 12:06:24 2025 +0200 document the weirdness of PixelFormat::N32_BPP Change-Id: I6e648e0152474c027f63bbf4079148f45fa005be Reviewed-on: https://gerrit.libreoffice.org/c/core/+/190629 Reviewed-by: Noel Grandin <[email protected]> Tested-by: Jenkins diff --git a/include/vcl/bitmap/BitmapTypes.hxx b/include/vcl/bitmap/BitmapTypes.hxx index 6f1cc220a977..8e11203cb100 100644 --- a/include/vcl/bitmap/BitmapTypes.hxx +++ b/include/vcl/bitmap/BitmapTypes.hxx @@ -15,7 +15,14 @@ namespace vcl { -/** Pixel format of the bitmap in bits per pixel */ +/** Pixel format of the bitmap in bits per pixel. + + The N32_BPP value here is tricky, because some of the backends do not support 3-byte pixels, and will instead + use 4-byte pixels and ignore the 4th byte. + So, when creating a Bitmap, it means "give me something with 3 8-bit color channels and a 8-bit alpha channel" + But when getting the format of a bitmap, just means that the underlying bitmap has 32-bits per pixel, + it does not necessarily mean that the underlying bitmap has an active alpha channel. +*/ enum class PixelFormat { INVALID = 0,
