LibNX - Screen Ratio Problem

[SeongGino]

Issue:

Mednafen PCE-Fast (or PCE-SGX, the mainline alternative), upon sequential ROM loads, will stretch from the pre-determined screen ratio (1:1 PAR) to a different wider display output despite using the same display settings with no game overrides in place.

Steps to reproduce:

1. Load a game using PCE-Fast, while using a screen display ratio of "1:1 PAR" or "Config".
2. Load another game using PCE-Fast, using either of the same display ratios.

This will result in the screen being stretched by default, unless the user manipulates the screen rendering options (scanline overscan compensation, via "Initial Scanline" and "Last Scanline" parameters) from the core's options.

Tested on:

RetroArch: 1.7.5 (LibNX version)

Notes:

There is a workaround, by loading the same/similar compatible ROMs, but alternating between PCE-Fast and PCE-SGX, depending on the core used directly beforehand, to return to expected behavior. The steps to reproduce above, however, remain applicable.

This only applies to the LibNX version of RetroArch for Nintendo Switch, and is not a core issue acknowledged on other platforms (I.E. x86_64, ARM, etc.). This has been tested using Homebrew Launcher as a system application, meaning RetroArch has a total ~400MB available RAM to use. This issue has been noted since before the official RetroArch for Nintendo Switch release (formerly known as "RetroNX").