Landon Curt Noll
0bc6c3e413
We quasi-canonicalized markdown links to FAQ entries. **IMPORTANT NOTE**: This is a useful step in completing issue #2417. This commit is consistent with the top level TODO comment requirements. Nevertheless, this changes made by this commit needs to be examined and in some cases improved. A link to an FAQ entry is of the form: ``` FAQ on "[the link text](....faq.html#string)" FAQ on "[the link text](....faq.html#string)" ``` The "FAQ" is at the start of the line, or in rare cases is preceded only by whitespace. The reference to the FAQ starts outside of the markdown link with the string **FAQ ON "**. After the markdown link is a **"** followed by either the end of line or a single punctuation character such as a period or comma. We reduced the size of "the link text" that refer to an FAQ to at most 3 words. In some cases the sentence and/or text surrounding the markdown link to a FAQ may need to be further adjusted to better accommodate this new style. **IMPORTANT NOTE**: References to a FAQ entry are on a separate line. p.s. When linking to the `faq.html` file itself, we use markdown of the form "`the [IOCCC FAQ](..../faq.html)`" and place the word "the" outside of the "IOCCC FAQ" link text. Given the above system (and because references to an FAQ entry is on a separate line), the following command shows links to FAQ entries, sorted by FAQ entry "link #name" so that one may evaluate the way a given FAQ entry is referenced: ```sh find * -name '*.md' -print0 | xargs0 grep -E '^[[:space:]]*FAQ on "' | sed -e 's/^\([^:]*\):\( *FAQ on "[^#]*\)#\([^)]*\)\()".*\)$/#\3\t\1\t\2#\3\4/' | sort ``` The above command shows the value of consistency when it comes to FAQ references. **NOTE**: There are a few differences on how a given FAQ is references. That is probably OK as there is NOT an "total mandate" that all references to a given FAQ must have the same "link text" for example. On the other hand if references to a given FAQ can be identical, that might be helpful. We are certain that in some contexts the "link text" might need to change. Should we decide to change the way FAQ are referenced, we will be able to modify identify and modify them with greater ease.' Examine the changes made by this commit and adjust and/or improve as needed. Performed `make www` to accomplish the above and to test under macOS.
To build:
This entry requires SDL2 to be installed. See FAQ on "SDL1 and SDL2" if you don't have it installed and don't know how to do so.
make
To use:
./prog
Try:
./prog ioccc.txt
./prog prog.c
./prog sand.txt
./prog sand.alt.txt
NOTE: these invocations will take quite some time to finish.
Judges' remarks:
Can you explain the behavior of the program when ioccc.txt is given to it as input?
How would the description of the state machine look like when translated from Polynomish to English?
Author's remarks:
Remarks
This entry graphically displays a simulation of sand falling. It uses SDL to draw the interface.
The code makes the following assumptions about the underlying system:
- SDL2 is installed from https://libsdl.org or your package manager.
doubleis an IEEE 754 floating-point type andsizeof(double)==8.- The compiler supports the C99 standard.
In order to simulate the motion of the sand, a cellular automaton is used. The
state transition table is not stored directly. Instead, the program stores the
coefficients of a polynomial that map each state to the correct one. These
coefficients are stored as raw hexadecimal in the V[] array, and they are
reinterpreted as doubles when used. This allows more numeric precision in fewer
characters (base 16 > base 10), and makes the purpose of the array less clear.
The code is laid out graphically as a bucket pouring sand, and it is far easier to observe this high-level layout than the code's actual function.
The preprocessor is used to both obfuscate the code as a whole and abbreviate the calls to SDL. Additionally, throughout the code, the variables were named so that they are short and easily confused with each other.