Quake was one of the earliest DOS games to show most gamers the importance of having a fast FPU to play with. Were there any other games (probably 3D) before Quake that started using the FPU?
For example, I know Duke3D (also 1996) uses mostly fixed-point arithmetic during rendering, but slopes (which is something new compared to DOOM) involve the FPU. AFAIK this is what makes Duke3D so much slower on a 486SX (which has no FPU).
MobyGames lists a number of games with support for a FPU¹. The earliest shown there are Falcon 3.0 and Scorched Earth (1991), and like most of the other games in the list, the FPU is optional:
Note that Scorch will, by default, use a numeric coprocessor if present. This makes everything in the game go faster. In particular, you will want a much larger firing delay. To slow everything down, you can set the environment variable 87 to 'N'.
(quoting Scorched Earth’s documentation; see the Falcon 3.0 hardware requirements too).
The major difference with Quake was that it required a FPU, and wouldn’t start without one. As far as I’m aware it was the first major game to do so on the PC². Other games with FPU support would obviously use it if present, usually in a way that would count as “heavy use” (in my mind, a significant portion of per-frame calculations); but games were developed to be playable on FPU-less systems too — that was the reality of the market.
The change in Quake was possible because many new x86 CPUs were equipped with a FPU by default (486DX, Pentium, and later mainstream x86 CPUs). Its non-FPU-related requirements were demanding enough that a fast CPU was required anyway, so requiring a FPU wasn’t an onerous requirement in practice. In fact, rather than describing Quake as a game making heavy use of the FPU, it would be more accurate to describe it as a game designed for the Intel Pentium, in particular its U/V pipeline. Since the Pentium was guaranteed to have a FPU, and a substantially faster one than 486-era FPUs, it made sense to use it.
¹ This references games which list at least support for a FPU in their hardware requirements; games requiring a Pentium or later could assume a FPU was present, but the list doesn’t include those since their use of a FPU (or otherwise) is implicit.
² Some sources suggest that Magic Carpet 2 (1995) also required a FPU, but I haven’t been able to confirm that.
