XNA games for WP 7 have problems on some WP8 resolutions?

[Ahmed Emad]

Hi all
as Microsoft announced support for developing games with XNA in WP8 is not available anymore , but WP8 devices can run games developed to WP7 .

So WP7 games work well on WP8 devices on resolution ( WVGA) as a full screen game .

but on resolutions :

- WXGA
- 720P

the game doesn't work on all the screen size there is always a black area distorted ( Vertical or horizontal according to chosen resolution) which look like the gamed doesn’t run on a full screen mode for the user.

as there any work around to avoid this distortion ?

[mostafa.elabady]

I have the same issue !

I think you should start building it again using Direct3D 11, because I think that XNA will not be supported again.

[joaocardoso]

I dont think you will have a way to fix this unless you more your game to DirectX but then you will no longer be able to target WP7. Its not a easy decision to make. You can always consider Monogame, as its an easier path to migrate from XNA I think.

[Ahmed Emad]

Thx Joao , Monogame still not fully implemented and there are some methods which through Notimplemented exception and moving to DirectX and C++ at the same time need high learning curve though I search for a solution to write XNA and run apps properly on Windows Phone 8 or another intermediate solution to deal with DirectX without need of thousands of hours to learn C++ & DirectX.

Most third parties i found is not fully implemented and can't be dependable until now.

Another challenge is that in some times I need only 3D models or some work like Panorama inside my application not Full 3D Game and in this case certainly I can't use XNA if my application is developed to WP8.

So, as there any full implemented free third party i can use for 3D models and Panorama?

[to_pe]

You can fix this easily. XNA is limited at 800x480 resolution and when you use it on 1280x768 resolutions, hardware scaler will scale up your image and you won't find any distortions. However, when you run your app on 720p displays, due to the fact that the aspect ration is different i.e. the screen is wider, your image is scaled up and padded with black rectangles.

To avoid this issue, you need to detect if you are running on 720p devices using reflection and change back buffer dimensions to 800x450. Now you will not feature any black bands on either side. You have also gained some free performance since you are rendering less pixels.

[mostafa.elabady]

You can fix this easily. XNA is limited at 800x480 resolution and when you use it on 1280x768 resolutions, hardware scaler will scale up your image and you won't find any distortions. However, when you run your app on 720p displays, due to the fact that the aspect ration is different i.e. the screen is wider, your image is scaled up and padded with black rectangles.

To avoid this issue, you need to detect if you are running on 720p devices using reflection and change back buffer dimensions to 800x450. Now you will not feature any black bands on either side. You have also gained some free performance since you are rendering less pixels.

Do you have any samples of how to detect that the Wp7 app is running on 720p device using reflection ?!

[Ahmed Emad]

Thx Mostafa for your help