IC Forum Archive

ecchi · Posts: 148

Sorry about the subject line, it just wouldn't fit.

Anyway, I decided to install SDL yesterday and I started a game with it. Maybe a little ambitious, especially considering the only other things I've made are PHP MySQL helpers and C++ sudoku solvers, but things have been going pretty well so far.

The game is called Slingshot, and my main inspiration was Orbital from the GBA Bit Generations series. The attract/repel mechanic is near-identical, but much faster and stronger. Instead of slowly picking up other planets, though, the game is about using gravity to propel oneself to a goal. Or into orbit around a goal. Or something. I haven't really gotten that far yet. How far have I gotten?

The red rectangle is the player, and the greens are non-moving planets. Attraction/repulsion works and the player can fly out into infinity -- the levels can be as large as I want.

I'm not sure of the best way to handle this game, though, from a design standpoint. Should I remove the repulsion ability and focus solely on the attraction? I think that could end up making the game much easier to balance. Should the field be done in the wraparound style of Orbital/Asteroids or should there be designated boundaries? I am leaning towards the latter. Would it be an appropriate goal to crash into an ending planet, or should I require that the player stay in a certain zone for a long enough time? Should there be any obstacles other than the planets? Heat-seeking missiles/comets like in N could be fun, especially if they were effected by your gravitational field.

Speaking of N, the Flash ninja game, I'd like to incorporate internet time rankings and a built-in level editing/sharing system.

TECHNICAL QUESTIONS:
Right now everything that makes up a level is hard-coded. Would it be worth it to use some sort of XML-parsing library to simplify the save/load process, or should I just roll my own crappy thing? Also, when loading an arbitrary number of planets, I would probably want to use a linked list, right?

Is using pure SDL going to hold me back in terms of visual appearance? Every game I can recall that used SDL for graphics looked pretty lame. Is that an issue of bad artists/programmers or are decent-looking sprite animations out of the question?

I think that's it for now. Thanks for any advice!!

Screwtape · Posts: 81

ecchi wrote:

I'm not sure of the best way to handle this game, though, from a design standpoint. Should I remove the repulsion ability and focus solely on the attraction? I think that could end up making the game much easier to balance.

Well, that depends on what feeling you're trying to evoke. Try both, see which you like better!

Off-the-top-of-the-head guesses: with both attraction and repulsion, the player has an 'oh no!' button they can use to get themselves out of bad situations, and the game could well be faster and more dynamic. With only attraction, once you've committed to a course there's no going back, so your game will have to cater to slow, methodical play, and perhaps give players an advantage by using static levels (that they can memorise, rhythm-game-style).

ecchi · Posts: 148

That was pretty helpful!

ecchi · Posts: 148

Using this as a dev-journal of sorts, just to track my own progress. Hope that's okay.

I was burned-out on gameplay coding so I added graphics even though I'm not sure if the game will be fun. It's been decided that the player controls a moon that doesn't fit in with his solar system, so he sets off to find a new one. These graphics don't really mesh with that (and are ugly) so they probably will not stay, but it's all just .pngs specified by the level designer so no biggie. The moon slowly rotates based on its velocity.

I turned down repulsion's force to .05 times attraction's and it seems to work better. I may also limit its usage with a replenishing bar or something.

My friend made a couple music tracks that may or may not work!

Screwtape · Posts: 81

ecchi wrote:

Using this as a dev-journal of sorts, just to track my own progress. Hope that's okay.

Your words intrigue me, and I wish to subscribe to your dev-journal.

I mean, heck, it's not like anybody else is posting in the dev-forum. :(

Actually, I made this post to ask a simple question: if/when your game reaches a point where you're happy for other people to play it, are you likely to release the source-code so us hippie Linux/OS X types can join the fun?

dessgeega · Posts: 3317

ecchi wrote:

Using this as a dev-journal of sorts, just to track my own progress. Hope that's okay.

use you water to drink and food to eat?

(by which i mean of course it's okay, silly.)

ecchi · Posts: 148

Screwtape wrote:

if/when your game reaches a point where you're happy for other people to play it, are you likely to release the source-code so us hippie Linux/OS X types can join the fun?

Actually, yes, I was planning on doing exactly that, for exactly that purpose! Though, my code is really really really ugly so I don't really want anyone to see it...

I don't think I'm doing anything VC++/Windows-specific, so it'd just require getting SDL to work and compiling.

Hopefully the game ends up being fun enough to make it that far!

Mr. Business · Posts: 1530

It should, perhaps, be noted that ABA Games uses SDL on all of its games, which look pretty good from my experience (though that's probably not related to the use of SDL).

ecchi · Posts: 148

He uses OpenGL for rendering, though -- that's why I asked. Whatever happens with this, my next project will probably be to teach myself OpenGL.

ecchi · Posts: 148

Took a break for a few days, then hunkered down and gave myself a gigantic headache with the level-loading code. Teaching myself the proper syntax for creating pointers to arrays of pointers to objects and then loading those objects from a file was pretty awful, but now loading works! The file format is terrible (plaintext) but it works and that's really all I care about right now. That lex/yacc stuff is a little too complex for me right now.

Next: level editor, field boundaries and goal code!

ecchi · Posts: 148

I took a week off, then got sick, then finally got back to this and worked really hard only to realize that my program design really sucked. So I rewrote a lot of stuff to use linked lists, making the level editor much easier to implement. So... it's now implemented -- you can interrupt gameplay at any time by hitting an arrow key, place/remove planets, then resume the game/save the level. I also fixed a bunch of stuff that made the game feel sluggish.

I've run into a problem, though!

It's really hard to tell where, exactly, you're supposed to go. My idea was to create some sort of visual indicator of planet locations. The first draft of this idea looked like this:

In case you can't tell, each planet has a transparent circle radiating out of it. But this destroys the framerate, as SDL sucks at lots of alpha transparency. So my current idea is to have stars in the background, with different densities based on how close they are to a planet. I just don't really have any good idea on how to implement that. Any ideas?

Mr. Business · Posts: 1530

Welp, here's a very vague idea.

You build some sort of particle engine for the stars. This particle engine will take the generic star graphic and increase the size (and maybe brightness) based on proximity to a planet. You could just calculate the distance from a planet by means of pythagorean theorem, or something like that, maybe. I'm not really sure.

I'm sure that someone else can think of a better way to do it.

I'm sorry to hear that SDL sucks for alpha.

ecchi · Posts: 148

That's basically what I was thinking -- something like any given coordinate has a point value equal to the sum of 1/(distance from each planet), and then I'd randomly sprinkle stars in some intuitive way that makes higher-scoring areas more noticable. But that 'intuitive way' is what's giving me problems, as making a star "brighter" would require alpha (can't do) or a bunch of different images... which, come to think of it, might be doable if they're small.

I'm weary of doing the scaling thing, though, unless it's really subtle. I'll see what happens.

edit: Or, maybe, I'll do some sort of "weighted random" thing -- randomly sprinkle, say, 100 particle-stars in the area of radius 100 - 200 pixels, then 100 more in 200-300, etc. Note to self: use polar coordinates! Perhaps your size/brightness thing can be incorporated also.

vision · Posts: 472

I think a dashed line between planets would work. You'd see perhaps Earth with four dashed lines jutting off into space indicating the four closest planets are in those directions. The lines could be of different width or alpha based on the distance to the linked planet.

I think that if done subtly, that might work very well towards what you are trying to accomplish.

exodus · Posts: 385

I haven't read all of this, but you should check out WireRobo, a doujin game mentioned on ic back in uhhhhhhh 2003.

It's certainly not precisely what you're doing, but is an interesting take on the attraction thing.

http://nepiaworld.com/menu/works/wr/

Mr. Business · Posts: 1530

ecchi wrote:

edit: Or, maybe, I'll do some sort of "weighted random" thing -- randomly sprinkle, say, 100 particle-stars in the area of radius 100 - 200 pixels, then 100 more in 200-300, etc. Note to self: use polar coordinates! Perhaps your size/brightness thing can be incorporated also.

This would probably reduce the amount of calculations to be made in general, so this might very well be the best way to go.

Are the planets going to be moving?

ecchi · Posts: 148

vision wrote:

I think a dashed line between planets would work. You'd see perhaps Earth with four dashed lines jutting off into space indicating the four closest planets are in those directions. The lines could be of different width or alpha based on the distance to the linked planet.

I think that if done subtly, that might work very well towards what you are trying to accomplish.

I liked this idea a lot, but I had a hard time making it look anything but awful. Perhaps if I revisit this project with more experience, I'll be able to pull it off.

Mr. Business · Posts: 1530

Actually, that does look pretty random. Truly random numbers tend to result in clusters like that.

You might consider using the Mersenne Twister that Kenta Cho uses. It's quite a miraculous piece of work.

Zmann · Posts: 21

Mr. Business wrote:

Actually, that does look pretty random. Truly random numbers tend to result in clusters like that.

Not the exact same clusters multiple times, though.

Sawtooth · Posts: 2350

yeah, that starfield looks itunes-random, not random-random

Takashi · Posts: 820

i just remembered that a gravity grid, provably in a dark gray or something, would provably look nifty.

Mr. Business · Posts: 1530

Zmann wrote:

Mr. Business wrote:

Actually, that does look pretty random. Truly random numbers tend to result in clusters like that.

Not the exact same clusters multiple times, though.

Ah, hm, I hadn't noticed that!