Since version 1.9.x, IceBreaker supports themes. Yes, I know this makes the lovely story about penguins totally break down, but hey, it's cool feature. Feel free to use any imaginative device you want to overcome the resulting cognitive dissonance.
I don't have any separate "theme packs" for download, because they're such tiny things that there's no issue at all with including all I've got in the main package. What do these look like? Check out the screenshots. Or really, just download the game and play.
If you like variety and surprise (small surprise, at least), you can set your theme to random, and every level will be different. Well, as different as the themes can make it. Gameplay is pretty much going to stay at "obsessively trap the bouncing things".
IceBreaker themes are simple to create. They're are definined in text files with the extension .ibt (that's IceBreaker Theme) in the IceBreaker data directory. The filename is the name of the theme itself, which must be seven characters or less -- not because of the DOS 8.3 limit but because more than seven requires the options menubox to be really big and ugly and we don't want that.
The file consists mostly of color definitions, and also gives the location of the two sound files and the one sprite bitmap. Color definitions begin with a keyword ("Background", "NormalText", etc.) and then give decimal values from 0-255 for red, green, and blue, respectively.
The sound and image defintions are just the keyword followed by a filename. More info on file formats in a bit.
The keywords aren't case sensitive, and you can use any amount of whitespace you want. If you leave out a particular keyword, IceBreaker will use the default but spit out a complaint on stderr -- so don't do that. (There's currently one exception -- SpriteMirrorBitmap, which I'll get to in a bit.)
The default theme is "linux", and the file linux.ibt looks approximately like this:
Background 0 64 128 NormalText 255 255 255 BoardFillMin 224 224 224 BoardFillMax 255 255 255 Gridline 192 192 192 GridHighlight 192 192 192 Line1 0 0 0 Line2 192 0 64 MenuHighlight 255 255 255 GameoverText 192 0 64 ScorescrollText 0 0 0 BonusscrollText 192 0 64 TextentryBox 0 0 0 TextentryText 255 255 255 CopyrightText 192 192 192 SpriteTransparent 255 0 0 SpriteBitmap penguin.bmp SoundOuch ouch.wav SoundCrash crash.wav
The names should mostly be self-explanatory. If something is unclear, let me know, and I'll either change the name in a future version or write better documentation here. A few things bear mentioning:
BoardFillMin and BoardFillMax define the colors of the game play area. The values will be randomly selected from the range given, but there's a twist -- if two (or three) of the red, green, or blue values have identical Min and identical Max values, those two will be "locked" together. This way, you can produce grey or monotone backgrounds instead of having every theme look like the mutant love child of Rainbow Brite and the Swamp Thing.
SpriteTransparent is the color value which will be treated as clear when drawing the bitmap. In the above example, the penguin.bmp has a bright red background, and since SpriteTransparent is set to the matching value, the background isn't shown.
The bitmap file should be a 24-bit MS-Windows-style .bmp format. I know that this is Lame but the SDL library which IceBreaker uses understands this format natively, and so using it allows us to avoid having a whole extra library just to load some really tiny bitmaps. They should be 14x14, by the way. If you want, you can make them as small as 12x12, but that's basically treated as the top-left of 14x14, and support for that may vanish in a future version. (If you want smaller, just mask out most of the image.)
Don't underestimate how hard it is to make a sprite image look good at such a tiny size. Making a theme which represents something in real life rather than being abstract or iconic is a challenge. A future version of IceBreaker may allow you to include background and playing board graphics instead of just colors -- but don't hold your breath for that.
In addition to SpriteBitmap, you may also set SpriteMirrorBitmap. If this tag exists, the given image will be used when the sprite is moving to the right, and the main SpriteBitmap when it's moving to the left. If you leave out this tag, there will be no warning -- the main bitmap will be used for both. In fact, leaving it out is the best thing to do if you don't want your image to flip, because it saves, like, 500 bytes of RAM over defining the same image twice. And we all know how important those few bytes of RAM are these days, right?
The sound files in the development versions are 8 bit mono PCM at 22050. (In earlier releases, this was 11025, but I've decided that this wasn't quite sufficient at conveying high-pitched sounds. If you're working on a theme and need to test this properly, check out the latest devel version.) They should also be really short -- under a second. This'll mean the total size will be easily less than 30k -- if it's not, something's not right.
If you do produce a good theme, let me know -- send it to me, and I'll consider including it with the main distribution. All themes must be licensed under the GPL.