The get and set methods seem to work normally on windows, but on linux, the get method always returns a blank color.

As far as my understanding of the code goes, you seem to be initializing the BaseBitmap with a pointer to the Data array, so it can be a direct access to the pixels on the Bitmap, and that seems to be causing an issue with the Graphics.DrawImage method, which seems to not be drawing at all on the BaseBitmap when the code is ran on linux.

I'm using Ubuntu 20.04, and verified that If you just call DrawImage on a regular bitmap, it works as expected with no issues, but when creating a FastBitmap object, passing a Bitmap object as argument, the Data array is entirely comprised of zeros. If you use any of the set methods, it works just fine, which leads to DrawImage being the culprit.

I'm not sure if it's possible, but instead of getting the pointer of the Data array, and embedding in the BaseBitmap, do the opposite, get the Data array to point to the BaseBitmap internal data, that could be a solution, and also would remove the need to draw the image parameter on the BaseBitmap. But i'm not knowledgeable enough to know if that's a possibility. But I will try some other possible solutions in the mean time, while I wait for your answer.

Overview

Read/Write methods should be added to this library to allow faster operations when working with raw data. This was first proposed on pull request #5, but I believe this will take quite a bit of time and code to implement properly. I've created a new branch called readwrite to expedite pull requests into that branch.

Implementation

I've done some experiments and concluded that the Read and Write methods should act as they do in Stream's, but also include a position argument to dictate where in the bitmap the pixel data should be read or written.

Both Read and Write methods should return an int to communicate how much of the buffer was used, because both read and write can't change the size of the bitmap or buffer.

Any contributions and discussion are welcome, and I hope this will improve the usability of this library greatly.

The code below results in no change to FastBitmap.Data when it is ran on Linux (Ubuntu 20.04).

using (Graphics g = Graphics.FromImage(FastBmp.BaseBitmap))
using (SolidBrush brush = new SolidBrush(Color.Red))
{
    g.FillRectangle(brush, 0, 0, FastBmp.Width, FastBmp.Height);
    g.Flush();
}