Killer Game Programming in Java

Loading Images

The ImagesLoader class can load four different formats of images, which I call o, n, s, and g images. The images are assumed to be in a local JAR file in a subdirectory Images/ below ImagesLoader. They are loaded as BufferedImages using ImageIO's read(), so they can become managed images.

The typical way of using an ImagesLoader object is to supply it with a configuration file containing the filenames of the images that should be loaded before game play

Figure 6-2. Class diagrams for ImagesTests

begins. However, it is possible to call ImagesLoader's load methods at any time during execution.

Here is the imsInfo.txt configuration file used in ImagesTests:

    // imsInfo.txt images

    o atomic.gif
    o balls.jpg
    o bee.gif
    o cheese.gif
    o eyeChart.gif
    o house.gif
    o pumpkin.png
    o scooter.gif
    o ufo.gif
    o owl.png

    n numbers*.gif  6
    n figure*.gif 9

    g fighter  left.gif right.gif still.gif up.gif
   

    s cars.gif 8
    s cats.gif 6
    s kaboom.gif 6

    o basn6a08.png
    o basn6a16.png

Blank lines, and lines beginning with //, are ignored by the loader. The syntax for the four image formats is:

    o <fnm>
    n <fnm*.ext> <number>
    s <fnm> <number>
    g <name> <fnm> [ <fnm> ]*

An o line causes a single filename, called <fnm>, to be loaded from Images/.

A n line loads a series of numbered image files, whose filenames use the numbers 0-<number>-1 in place of the * character in the filename. For example:

    n numbers*.gif  6

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