Setting size of GameViewportClient gives different results on Android than in Editor

Setting size of GameViewportClient gives different results on Android than in Editor

OpenGL ES renders with the viewport origin in the bottom left, so that's potentially related to the problem.

A number of changes were made for 4.16 to support r.ScreenPercentage which fixes some viewport sizing problems in the mobile tonemapper. That code is related.

Originally reported in this thread: モバイルでの描画サイズに関して (Japanese)

1. Download [Link Removed]
2. Generate solution file for 4.14
3. Build and run
4. Preview and editor, should look like this:
   • [Link Removed]
5. Launch on android device, gameviewport is shifted slightly down:
   • [Link Removed]
6. In the code, in UMyGameViewportClient::LayoutPlayers() there is code that multiplies SizeX and SizeY of FSplitScreenData by 0.8, change it to 0.5 and rebuild and relaunch the editor
7. Preview in editor should look like this:
   • [Link Removed]
8. Deploy to android device, notice GameViewport is not rendered at all:
   • [Link Removed]