I was wondering if it would be possible to implement a feature that would upscale text in Citra (and potentially other elements) with the Nearest Neighbor upscaling method. As seen in a screenshot below, the font for the pokemon names and the dialogue is blurry since the game is upscaled but with a bicubic resizer creating a blurry product. I feel if the correct rescale method was used it would make it look more visually appealing and closer to the original.
Thanks :D

If this were to be implemented, would it be better for nearest neighbor up-scaling be applied to all images or just text/pixel art? I've looked into this a bit, and there are advantages and disadvantages to both methods. Maybe it would be best to introduce a setting that allow users to pick the up-scaling method they prefer.
Selecting specific textures for nearest neighbor/no filter scaling is something that would require a non-trivial amount of effort. Dolphin has a setting to force filtering for all textures (and on the other hand, Ishiruka has a setting to force nearest neighbor for all textures). If those settings could be incorporated in a way that makes sense, I feel that that would be enough (since pokemon games are already "pixelated", having everything use nearest-neighbor wouldn't look too bad IMO)
Having a drop-down with different texture filtering options would be really cool.
Even with "Enable linear filtering" option unchecked only part of textures and text looks sharp but others still looks blurry (like text in Pokemon on that screenshot)
The recently added "Enable linear filtering" option is for post-processing part of the renderer where the final screen content is blit to the window. It has nothing to do with the internal texture filtering.
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Having a drop-down with different texture filtering options would be really cool.