Possible out-by-one bug in GraphicsDevice.Viewport

Graphics
1

Before I raise this as a bug in github I wanted to check opinions here. Maybe it has always been like this, or is a “feature” inherited from XNA, but it certainly seems wrong to me. I’m using the 3.3 release.

GraphicsDevice.Viewport is reporting a width and height that are 1 pixel too small.

For example: on my Surface Pro 3, the default resolution is 2160x1440 but GraphicsDevice.Viewport.Width = 2159 and .Height=1439

TitleSafeArea is reporting the same figures.

Now, I’d expect bounds.Right to be 2159 and .Bottom to be 1439 as these are the “last pixels” - but the width and height should be the “whole numbers”. Just because we are zero-indexed doesn’t mean the width and height should be 1 pixel shorter than they actually are.

This problem is ruining my graphics scaling… I could compensate for it easily enough, but frankly I think this is wrong and would rather it was right at source (and so I’m not going to get any surprises when MonoGame fixes this in the future).

2

hi,

I’ve noticed this problem in WP8 too for a long time (not a 3.3 exclusive problem) but never paid much attention because it didn’t give me problems. Honestly, I don’t know if it’s a bug or a windows feature :slight_smile:

3

I think I found the real problem. It’s in MetroGameWindow.cs / SetClientBounds , pwidth and pheight gives a 1919.99999 value instead of 1920, which casted to int it’s still a 1919. Replacing the cast with a Math.Round or something like this should give the correct resolutions.

4

I just updated to the latest monogame repository and found that the problem was already fixed :slight_smile:

1 Like
5

Cheers, that’s good news. I’ll grab the latest and go from there.