ioccc/2004/vik1

To build:

    make

NOTE: this entry requires the X11/Xlib.h header file and the X11 library to compile. For more information see the FAQ on "X11".

To use:

    ./vik1 [arg]

Try:

    ./vik1

    ./vik1 a

    ./vik1 d2

    ./vik1 ad3

Can you figure out how to cheat?

Also see the author's remarks below for more details on the different modes/options.

Judges' remarks:

Daniel Vik has presented a tour de force feature rich X11-based racing game that fit within the contest size limits. Take a glance at the feature list he provided below. Amazing!

The author posted a video of this on YouTube: https://www.youtube.com/watch?v=xTseqWCtAUA.

Happy touring on the road and in the code!

Author's remarks:

Features

This program is a complete car race game with a lot of nice features:

• Drive on a road in a 3D landscape with hills and curves.

• Mountains in the horizon.

• A sun in the sky when driving during the day.

• Dark sky and reduced visibility when driving at night.

• Snow when driving in the winter.

• Slippery road when driving in the winter.

• When driving off the road, the car slows down to a halt.

• Three different race tracks that takes about one minute to complete.

• Speedometer.

• Computer driven opponent cars.

• Collision detection when driving into other cars.

• Lap time measurement.

• The best lap time is stored as reference.

Build and Run

Compile the source code and link X libraries if necessary. The program takes three options which have to be typed in a specific order as described below.

Usage:

    ./vik1 ['a']['d'][#]

• a
  • Advanced racing in a winter landscape.
• d
  • Racing in at night in the dark.
• #
  • Race track selection 1-3 are valid numbers.

Examples:

• ./vik1

  • Run track 1 at daytime in the summer.

• ./vik1 a

  • Run track 1 at daytime in the winter.

• ./vik1 d

  • Run track 1 at night in the summer.

• ./vik1 3

  • Run track 3 at daytime in the summer.

• ./vik1 d3

  • Run track 3 at night in the summer.

• ./vik1 ad2

  • Run track 2 at night in the winter.

Note that the order in which the argument characters are entered is important. It is for example not possible to type ./vik1 da. (Well it is possible, but the result will not be as expected.)

The space key accelerates the car. Releasing the space key slowly reduces the speed. The left and right arrow keys are used to steer the car.

Obfuscation

The main obfuscation is the fact that the program is extremely compact. There are a few things I didn't want to do, e.g. define #define to a single letter to save some space, or to remove casts to save some space.

The program uses a lot of variables. In fact, all letters a-z are used and most letters A-Z.

The constants are chosen very carefully and they have multiple purposes, e.g. a constant can be both the length of the track and a color.

Most of the code is kept inside five for loops each without a body. Each for loop does many things. One for loop draws all cars by restarting a couple of times. Another draws the road, mountains, and the sun.

main() is called recursively. The return value and output depends on the arguments. main() can return the current time, draw lines and of course be the entry point of the application.

The program frequently uses the ?: operator mainly to save space but it makes the program more obscure.

Compiler warnings

There are no compiler warnings when compiling with -ansi but there are many warnings from lclint, mainly because the program is very optimized for code size.

Limitations

The program only compiles and runs on X based systems.

The program requires a display with 24 bit color depth. It also assumes that the byte order of the colors are as on my Linux PC. That is, The colors are represented by a 32 bit value where the bytes (from high to low) are { 0, RED, GREEN, BLUE }.