8 way scrolling for JRPG game

[Marle]

Originally Posted by kgc210

Marle what are your thoughts on the story so far?
Or are you just focusing on the technical / functionality side of things for now?

Ok so this is the part of the game that needs serious work. At the moment I am just figuring out the basics like the 8 way scrolling and some advanced graphic techniques because if I can't crack the code (and this is meant to run on a 7MHz PAL Amiga....) then all the story in the world won't help. But the idea is that in this day and age we're not limited to distributing by floppy disk and I think that was a big limiting factor for the Amiga in the early 90s. I know Mega Drive and SNES carts weren't huge either, but I think in the case of the SNES it had some funky ways of compressing sound and graphics in ways that perhaps the bitmap based displays of the Amiga wasn't as optimised for (maybe I'm talking rot here but that's my basic and possibly totally incorrect knowledge!)

So the story though, I am trying to avoid a whole 'save the world' thing as it's been done quite a bit. I'm replaying a lot of my favourite games at the moment like Secret of Mana, Grandia, Final Fantasy VI so just getting ideas.

I always loved the story and aspect of Grandia and Lunar Silver Star Story.

I expect compared to modern games my take on it will be fairly innocent, but that's intentionally my point!

I inherited a whole bunch of PS2 games from clearing out a friend's house about 10 years ago and never looked at them as they were almost entirely things I dislike and I noticed one of them on Cex's website said they'd buy it for £10... I though unusual, the rest of these they're barely giving me 40p for them as I wanted to clear stuff out. Turns out this game having read the wikipedia page is my idea of my worst nightmare, Manhunt II. I stopped at the bit about the pliers.... Still it looks like it will sell on eBay

[dodke]

I've been meaning to try coding a 2d tile engine and came across this package with sources (in C) and documentation for the 'most efficient' way of having 8 way infinite scrolling on Amiga:
http://aminet.net/package/dev/src/ScrollingTrick

Marle, Not sure if you've seen it but if you haven't the documentation might be useful.

From what I gather you should only need a screen that's a few blocks wider and taller than the visible area.
Also to make it work past one or two blocks you'll need to code a raster split. Basically when you scroll down for example you'll hit the bottom of your buffer and at that position on the screen you need to have the copperlist switch the bitplane pointers back to the top of the buffer.

[E-Penguin]

Just about getting my head around this - if using double buffering, does it mean each new column has to be drawn 4 times? Eg ahead of the movement, at the back of the screen, and all again when the back buffer comes to the front?

[Daedalus]

Essentially, yes. With double buffering, you're basically running two independent copies of the play area. But if you're using a dual playfield display, you likely don't need to draw anything to the background so you only need to double buffer the foreground where the drawing and erasing is happening. The background can simply be scrolled around smoothly since all the drawing happens off-screen.

[MickGyver]

Marle, did you manage to get 8-way scrolling to work?