I first learned how to make a mode 7 effect using software rendering in C, and it used subpixel coordinates. The equivalent to mode 7 on the Game Boy Advance also allows subpixel coordinates. So I thought it was SMK's engine until I read that the mode 7 scroll position (horizontal position in $210D, vertical position in $210E) has no subpixel bits.
I guess some of this has something to do with
a rant by Blake Reynolds of Dinofarm Games. There are plenty of cases where pixel art is used out of laziness, and pixels aren't even a consistent size, and sprites are rotated to put blocks of pixels at an angle.
blakereynolds wrote:Many developers who try to achieve the retro aesthetic overlook how much magnification is going on, resulting in not one, but several different resolutions at once.
To me, sprite magnification is an effect associated with the second generation (Atari 2600, Coleco/MSX, C64). The only examples of sprite magnification I'm aware of using third- or fourth-generation hardware are 1. status bars on Game Gear and PAL or PAL/M SMS games (which
had the magnification bug fixed), 2. 3D-style texture mapping performed on the CPU or GSU, and 3. back images of Red and his monsters in first-generation
Pokémon games on Game Boy Color, which are also scaled on the CPU but not moved much anyway.