The lookForFileHeader param was added in July 2020.
The hackAround64BitLongs param was added December 21, 2020. You should probably never use this unless you know for sure you have a file corrupted in this specific way. View the source to see a comment inside the file to describe it a bit more.
The hasAndMask param was added July 21, 2022. This is set to true if it is a bitmap from a .ico file or similar, where the top half of the file (by height) is the xor mask, then the bottom half is the and mask.
Reads using a delegate to read instead of assuming a direct file. View the source of readBmp's overloads for fairly simple examples of how you can use it