What is so special about SNES mode 7?

[Optimouse]

I came here because I was searching for that rumor that Amiga can do better mode 7 than SNES. I don't think that's the case, most examples of rotozoomers in games or demos are not highres enough, or with less colors (because of bitplanes format in Amiga) or not full framerate. I was looking at the game Brian the Lion, I really need to test it on emulator in normal A500 speed, because  in some videos some of the mode 7 tricks are slowing down the frame rate a lot, in some others it's better (but maybe it's the Amiga CD 32 version, the 68020 with some good programming could finally make good highres rotozoomer). But the comment of the programmer was about the accuracy in angle rotation and not speed or quality, which would make sense since the CPU is 32bit and it's coded (partially or not, I don't know, maybe they also use the blitter somehow) on the CPU, they can have more accuracy than custom chip which makes you stick with what the hardware gives. But that's just better accuracy, definitely not more highres, full color, fullscreen, 60fps rotozoomers. What I was seeing on the SNES at the time of it's release is nothing of speed and quality I have ever seen before.

So, I don't think it's correct to say that it was overrated and a marketing fad. It really was a unique chip producing mapping effects not seen before on other consoles (maybe with the exception of the lynx which I am not familiar with, but the resolution is very small), so well detailed background zooming and rotating so smoothly. Maybe after years, Mega Drive and others mimicked the effect, there are many nice examples, where they use different tricks depending on the game, for example racing roads where it curves but not rotates 360, you can blit very fast with DMA I believe horizontal bitmap lines of different scales. It's easier to do the single zoom, or a horizontally rotated cube, and such, since they can all be translated to blitting of different bitmap lines. But full highres rotate and zoom of big background, is another story.

Actually, I was wondering how the Mode 7 chip works and I've read somewhere that normally you have to send two vectors (and maybe some more) for transformation of bitmap per frame. This way you have simple 2d zoom rotate bitmap. But the tricks are resending new values every rasterline. And that's how floor/ceiling mapping, cylinder mapping and distortions and all other stuff are possible. I can understand this since I've coded rotozoomer and floor mapper on PC. It's only that the CPU has to calculate (unless it's precalculated in memory) which vectors to send per line to achieve different effects. Maybe that DSP-1 was helping into this, I don't know. But yes, I heard it too that more chips would be added to the SNES, but removed to reduce cost. I think Yoshi's island has additional chip in cartidge to also allow mode 7 on sprites. But yes, the original snes only had the plain background rotozoom chip. Which could also sometimes appear in the foreground as a fake big sprite, changing layers rendering priority I guess. And you could also add hardware blending, so you had highres bitmap rotating, mapping on floor ceiling, blending, and all just without extra chip on the hardware. People say most effects are because of extra chip on cartidge, but really the majority of the impressive stuff were done with a stock SNES.

Sorry for the rant, I just was a bit wondering why everyone says the Amiga500 can compete with snes mode7, and kinda furious most people thinking it's overrated.

p.s. I do admire though the whole tricks people invented on the Mega Drive could cheat some of these tricks. That Mode 7 flying video of that game, is the most impressive mode 7 floor on the machine I have seen.

[zapiy]

Welcome please take the time to introduce yourself HERE

I would not say that was a rant more your opinion and we are all allowed them.. I agree that Mode 7 was a wonderful idea and still is, certainly many of my fav SNES titles used it.

[MadCommodore]

I came here because I was searching for that rumor that Amiga can do better mode 7 than SNES. 

As a person who loves racing games the SNES was the biggest pile of rubbish going. There is not one single game on the SNES that is either as realistic looking with a sense of speed as Lotus Turbo Challenge II (including Colin McRae Rally style fog/rain/night racing effects).

So my question is why would you want to play a racing game that looks like a POV video of a baby pushing his matchbox cars on one of those playmats with roads drawn on it. The Megadrive can do it,  Lotus RECS II and Outrun clearly show that, but F-zero and Mario Kart look suitable only for players who still have a dummy in their mouths haha If you like motorcycles instead try Prime Mover by Psygnosis. Real roads have objects on the side of them and hills and valleys in the road

There is no way that any SNES racing game comes close to playing Lotus II on an NTSC Amiga, your reflexes and retinas will be given a full workout. The Amiga is better because it doesn't have to use Mode 7 sorry.

SNES = baby pushing his matchbox car on playmat POV racing games.