The constants ::wxIMAGE_ALPHA_TRANSPARENT and ::wxIMAGE_ALPHA_OPAQUE can be
used to indicate those values in a more readable form.
- Unlike RGB data, not all images have an alpha channel and before using
- wxImage::GetAlpha you should check if this image contains an alpha channel
- with wxImage::HasAlpha. Note that currently only the PNG format has full
- alpha channel support so only the images loaded from PNG files can have
+ While all images have RGB data, not all images have an alpha channel. Before
+ using wxImage::GetAlpha you should check if this image contains an alpha
+ channel with wxImage::HasAlpha. Note that currently only the PNG format has
+ full alpha channel support so only the images loaded from PNG files can have
alpha and, if you initialize the image alpha channel yourself using
wxImage::SetAlpha, you should save it in PNG format to avoid losing it.