Is there a way to do a 2x nearest neighbour upscale before bilinearly scaling down to fit the 3DS screen? I found there is a libretro shader called sharp-bilinear which does just this, but I assume shaders only work on other platforms.
I'm using Gambatte and finding that with integer scaling enabled the image is a bit too small, and with integer off + bilinear on it's a bit too blurry. Enabling a Scale2x filter + bilinear is almost ideal, giving a much sharper scaled image, but it also alters the image too much. Unless I've overlooked another method, am I right in thinking there would need to be a nearestneighbour2x filter to do what I want?