Did Treasure really programmed scaling rotation through software?

[darkangel]

I know for the helicoptor level in Gunstar Heroes, it was vertical tile scrolling + line scrolling, but what about the smaller multijoined sprites? Sometimes during the 7-force boss, when the robot shaped like a gun shoots at a funny angle, the sprites that are making the gunbarrel are not in a straight line. Could have Treasure just used tons of prerendered rotation frames like everybody else did, and they just pretended that they actually did it in software?

[ccovell]

The fact that it's a multijointed sprite gives it away.

Round sprites don't need to be rotated, and straight sprites are predrawn at several angles from 0-90 degrees. All other angles can be displayed through hardware sprite flipping.

[7Force]

It's pretty obvious they did that, since the Mega Drive/Genesis can't do hardware rotation. Talented programmers can work around a lot of hardware limitations, just look at the Saturn games that have "transparencies" :nod:

[Yakumo]

Wolf Team were doing rotation on the Mega Drive years before Treasure even came about.

Yakumo

[darkangel]

I've seen rotation being done in a lot of Genesis games. I don't know if that's what they did, but I think some people faked rotation by building the rotating sprites out of smaller sprites, and adjusted the placement of the smaller sprites a little to give the illusion of rotation, and before it gets too obvious, they use another frame, (lets say 22.5 degrees) and do the same with that.

[MottZilla]

Wasn't there a bug with the background rendering or something that gave partial rotation?

[selgus]

I have some rotation assembly code for the Genesis, if people would like me to post?
--Selgus

[darkangel]

I have some rotation assembly code for the Genesis, if people would like me to post?
--Selgus

interesting:thumbsup:

[TmEE]

you do not have to scale and rotate things on the fly... in Treasure games, the stuff is either pre scaled or rotated into RAM/VRAM or its already so in the ROM... I think its the first way, since there are usually no artistic measures taken...

[darkangel]

I don't believe it's technically possible to do all the sprite rotation/scaling in realtime. The only time it would be reasonable to do sprite rotation/scaling in realtime is if you ran out of v-ram AND you ran out of work ram AND you ran out of cartridge memory.