DrawLine and DrawLineAa don't draw correctly on larger WriteableBitmaps

[lsilvand]

Drawing a line over large distances with DrawLine, the end will be off. In the example below there is a difference of 39 pixels in height.
Drawing a line with DrawLineAa, the end will be of by 1 in width and height.

 WriteableBitmap image = new WriteableBitmap(30000, 10000, 96, 96, PixelFormats.Pbgra32, null);
 image.Clear(Colors.White);
 image.DrawLine(0, 0, 29999, 9999, Colors.Black);
 image.DrawLineAa(0, 0, 29999, 9999, Colors.Red);

[reneschulte]

Hi @lsilvand see the PR that was created. Looks OK to me but please try the PR and see if it works for you all.

[lsilvand]

It looks much better. There is still a pixel difference in height for the DrawLine but it is acceptable for me.
I also noticed that there is a pixel in width and height difference still but noticed that it is also at the start, maybe it is because of the antialiasing?