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Notes on a Language of Game Design #2

October 15, 2011 0 Comments

One of the things that got me thinking about the possibility of a language of game design is the feeling I often get while playing that content doesn’t matter. After I’ve been playing games for far too long, the lush scenery and the carefully rendered characters devolve into blurry signifiers, shapes that appear in configuration with other shapes, triggering wordless actions that have been scoured into my mind by hours of play. Thoughtlessly, I finish every sentence the computer starts, never letting it complete itself before I have acted and moved on.

Game content can be interpreted in any number of ways, but the game rules only allow the objects and characters to behave in a limited number of ways. Eventually, the feeling of possibility evoked by the content diminishes as the player learns the few terms by which he is allowed to use it. The characters, landscapes and even storylines become icons in a much simpler network of concepts.

The relative simplicity of this network of concepts is one of the things that convinces designers that there is such a thing as a language of game design.

I am beginning to wonder how much of this perception that there is a language of game design is down to the controller, rather than anything to do with the logical form of game entities. Imagine actually performing the action in a game rather than using a joypad.  Is there still a sense of musicality and rhythm? When imagining driving, then shooting, then playing tennis, is there the same sense of rhythmic sameness that arises during long playing sessions on different games?  The controller masks the complexity of relations between game objects and makes them feel the same.

A language of game design would be the same as the language that describes relations between entities in the real world.  Certain types of relations would be more playable than others, and this would narrow things down, but the essential form of game entities is the same as it is in reality.

 

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Toxin – Coming Soon

June 10, 2011 0 Comments

Toxin Title Screen

This is the titlescreen of Toxin, my first iPhone game. It was only supposed to be a warm-up; a short project to help me get back into the game after a few years developing web applications, but it has taken much longer than I anticipated.

I’m doing the whole thing myself, code, graphics and sound, largely because I don’t know anyone who could help me out, but also because I was a child in the 80’s, and despite all the developments in gaming that have happened since then, I still have the image of the lone game developer somewhere in the foundations of my mind. I grew up idolizing 8-bit legends like Tony Crowther and Andrew Braybrook, and learned to code in a world where games had authors associated with them. Things have changed, but I still carry all that with me; I just wouldn’t feel like a proper game developer if I didn’t do at least one game on my own.

Oh, and the title screen is animated. It uses a pretty cool effect that I will probably write about soon.

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Getting the size of a PNG without loading it

October 9, 2010 1 Comment

My current iPhone game (more info coming soon, I promise!) has a resource system that allows me to load texture maps when I need them and unload them when I don’t. This helps makes the game very memory efficient, but it had one annoying flaw. At program startup I had to load and unload several textures to get size information I needed to set up other game structures. To avoid this wasteful operation I started looking at ways to extract information from a png without loading the whole thing.

This StackOverflow discussion was useful, along with this guide to the png format from the W3C, but unfortunately, Apple threw a spanner in the works.

If you’ve been programming the iPhone for a while you’ll know that by default, Xcode premultiplies the alpha channel of PNG files before adding them to the application bundle. It also adds its own undocumented data chunk to the beginning of the file, breaking PNG guidelines which state that the IHDR chunk should always be at the beginning.

This Objective C function will return the size of an image for both standard and Apple PNGs. It scans through the file looking for the IHDR chunk, making no assumptions about its position. It should be easy enough to convert to other members of the C family.

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#include <stdio.h>
 
//----------------------------------------------------------------------------
// GetPNGSize() - gets PNG Dimensions without loading any data
//----------------------------------------------------------------------------
BOOL GetPNGSize(const char *fileName,CGSize *pngSize)
{
    // PNG Signature
    unsigned char png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
    // IHDR chunk identifier
    unsigned char ihdr_signature[4]={'I','H','D','R'};
 
    FILE *fp;
    if( (fp = fopen(fileName,"rb")) == NULL )
    {
        return NO;
    }
 
    // load png signature and check it
    unsigned char sigBuf[8];
    fread(sigBuf, 1, 8, fp);
 
    if(memcmp(&sigBuf[0], &png_signature[0], 8))
    {
        fclose(fp);
        return NO;
    }
 
    // examine chunks until we find IHDR
    BOOL done = NO;
    while(!done && !feof(fp))
    {
        // get chunk length and type
        unsigned char chunkInfo[8];
        fread(&chunkInfo, 1, 8, fp);
 
        long length = (chunkInfo[0] << 24) | (chunkInfo[1] << 16) | (chunkInfo[2] << 8) | chunkInfo[3];
 
        // is this the IHDR?
        if(!memcmp(&chunkInfo[4], &ihdr_signature[0], 4))
        {
            unsigned char sizeInfo[8];
            fread(sizeInfo,1,8,fp);
 
            pngSize->width = (sizeInfo[0] << 24) | (sizeInfo[1] << 16) | (sizeInfo[2] << 8) | sizeInfo[3]; 
            pngSize->height= (sizeInfo[4] << 24) | (sizeInfo[5] << 16) | (sizeInfo[6] << 8) | sizeInfo[7];
            done = YES;
        }
        else 
        {
            // skip over the data and checksum and go to next chunk
            fseek(fp, length+4 , SEEK_CUR);
        }
    }
    fclose(fp);
    return done;
}
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AtlasMaker News

May 4, 2010 3 Comments

This is just a quick update for everyone wanting to know what’s happening with AtlasMaker. I have a new version planned, but I’m not quite sure when it’s going to get done. I wrote AtlasMaker over a couple of evenings to save me time with an iPhone game project I’m currently working on and that is taking priority at the moment.

The next version will hopefully contain the following features.

  • More/better error handling and a more robust and informative interface.
  • Several rectangle packing algorithms – choose the best one for your data.
  • Improved export file: more data, bigger text box for xml fragments etc.
  • You can choose the filename and location of the export file.
  • Optional flattening of layers on the finished document.

I was recently able to test AtlasMaker on CS4 (I developed it on CS2) and was dismayed by how slow it is in comparison. I managed to speed it up a bit by turning off “open documents in tabs”, but it still ran at a glacial pace.

I’m not sure what this means for the future of the project. It’s still quicker than making atlases it by hand, but I’m wondering if I should make the next-version-but-one a stand-alone program written in Python or C# or something. (I haven’t settled on a cross platform language for tool dev yet, but I am looking.)

Let me know what you think. Would you prefer a slow Photoshop script, or a faster external tool?

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