Stu's Rusty Bucket

GP2X dev : Fishguts I

GP2X GameDev Blog #1 : FishGuts I

Ive been itching to get a GP2X for a long time. Right now the hardware has stabalised at the MK2 design. So I’ve decided to write a game while i save up some spare cash for it.

I’m going to write a simple/basic CRPG along the lines of my fav Ultima III and Magic Candle. There will be elements of Questron II and other classic RPG’s as well.

Random Design Notes
Were dealing with a small screen, so any text needs to be readable. Based on this Ive dropped lowercase letters from my display font.

Must be navigable using the systems default buttons (two shoulders, 4 firing buttons and the directional pad).

We have a limited amount of memory to play with. No caching of huge lists and unrequired graphic data etc.

Other Stuff
Got lua 5.1.1 built to use int/long instead of double, which will help with speed since GP2X doesnt have an fpu, and lua’s default is double. Ditched the math library which I dont need.

Need to remove the other stuff, oslib etc. All I really need is the string library, table library and base.
Added special 5.1.1 arm patches for speedup

Cant decouple the built in compiler, its too integrated into lua to remove and just rely on precompiled bytecode.

Can now load compressed bytecode, decompress it into a buffer and attach it to a Lua State. Its a PITA, since Lua only has functions to read from disk or read an uncompiled string. grr.. Had to write a Lua memory Reader.

NPCs
There will be lots of NPC’s like Ultima III to talk to. This means I need to create an efficient conversation tree routine (done in lua). This will require NPC memory across the game but should only nesecitate several bitflags per npc which is fine.. Game state will so far be very minimal which is nice (as far as save / load go)..

Graphics
I’ve decided to use 24x24 tiles which gives me 312x240. I’ve decided that 312x240 as 24x24 tiles will be nicer on a 3.5” screen than tiny 16x16 tiles. 24x24 gives me 13x10.

Most base tiles are single 24x24 tiles, some like mountains and forest Ive done 48x48 (2x2) tile arrangements to break it out for bigger things.

Most tiles are backed by black, which might change, since I wanted to keep this game simple, I’m not doing fringe tiles in this engine (planed for the sequel)..

Need to work on the indoor tileset and monster tileset.

I’m debating right now if dungeon exploration will have a 3d feel or if it will remain topdown. I’m hopeing to go for basic 3d fixed 90 degree angles. Simple pre-cacled single texture would be fine, but would nescesitate new monster graphics different than the tilesets…

Overworld map has been created.

Story + Mechanics
No real story, just some vague ideas and quests right now. Some mechanics also thought out. Teleport stones that use a destination rune stone (key). Like a cross between Ultima III moongates and the Stargate. Touch the teleportal with the destinatin rune stone to go there.

There will be skills (not many) and gold will be scares in the game. I dont want gold to unbalace the skills later in the game. eg: hunting vs buying food obsoleting the hunting skill.

Advancement in the game will be different from standard crpg’s. Opportunity to increase hitpoints will be limited (but possible). Survival will depend on better gear and weaponry and magic.

Magic will revolve around Fire / Water / Iron / Earth. I might replace Iron with Spirit but will see how the spell lists balance out.

I’m undecided about religion in the game. It will be in the game, but ‘clerics’ and worship and things.. I need to think about it more and its impact on balance and gameplay. It would kinda obsolete spirit, which means I can leave in Iron....

Saving will be automatic when you enter/exit a town, change map segment, dungeon level etc.  There will be no explicit saving.

I’m going to need a popup keyboard to enter players names.. I was hoping to do without that kind of thing.

Combat / Party
I want a party of 3 or 4 characters. Combat will be tactical turn based like Magic Candle I, Ultima III, Gold Box games.

I like the idea of hiring another character to the party.

There are lots of other areas I need to work on before I lay much code down..