#Bitlang

Bitlang is a tiny stack-based DSL, designed for the sole purpose of producing procedurally generated 1-bit art.

It is implemented in ANSI-C, and written in a literate programming style.

#Sample

In bitlang, this expression:

x y + abs x y - abs 1 + ^ 2 << 3 % !

can be used to generate the following image:

by writing a 256 by 256 loop in C that sets x and y to each coordinate, asking bitlang the value of the expression, and treating true values as black pixels and false values as white pixels.

example.c shows how it works and is a good template to start from.

#Building

Bitlang and the example program can be built running the build.sh script.

./build.sh

In addition to building the program, this script will tangle the bitlang program using a local version of Worgle.

The program, once compiled can be run with:

./example

Running this program will generate a PBM file called example.pbm, which can be converted to a PNG file using imagemagick.

convert example.pbm example.png

#Tangling

Bitlang is written in a literate style, meaning that the code needs to be generated before it can be compiled. This process is called tangling. The tangler program has been included in this repo.

The files for bitlang (bitlang.c, bitlang.h) can be tangled by compiling the tangler and the running it on bitlang.org:

gcc worgle.c -o worglite
./worglite -g -Werror bitlang.org

#Language Overview

Bitlang is a stack-based language, similar to RPN calculators and programs like dc.

2 3 +

Adds 2 and 3 together and pushes 5 onto the stack.

Special variables x, y, w, h, and t correspond to XY position, width, height, and time (as a frame number).

The following operations are currently supported:

Basic arithmetic: +, -, *, /

Modulo: %

Left/right shift: <<, >>

Equals operation: =

Logical and Bitwise OR: ||, |

Bitwise AND: &

XOR: ^

Logical and Bitwise NOT: !, ~

Absolute Value: abs

#Using Bitlang

Bitlang tangles out into 2 files bitlang.c and bitlang.h. These can be dropped.

For API usage, see example.c.

#Woven HTML Output

Bitlang is written in a literate style. The woven HTML component can be found and read here.