iconscript

iconscript is a language for describing pixel-wise pictograms in the style of the Röntgen project.

The grammar of the language is described in the ANTLR4 grammar/IconScript.g4 file.

SVG generation

There are two implementations of iconscript for parsing and generating SVG files.

• Rust: cargo install iconscript. Rust implementation is faster and more reliable. It uses linesweeper library for Boolean path operations and SVG optimizations.
• JavaScript (TypeScript): npm install iconscript. JavaScript implementation uses Paper.js library, that may produce wrong outputs.

Generating from SVG sketches

The Rust implementation supports generating icons directly from an SVG sketch file using the --from-svg flag (Rust only):

iconscript --from-svg sketch.svg $OUTPUT_DIR

The SVG file should contain groups whose id attribute follows the pattern <name>_v<version> (e.g. my_icon_v0). Each group is treated as one icon and produces one output file named <id>.svg.

Inside each group, standard SVG elements are supported: path, rect, circle, ellipse. Their fill and stroke colors control how shapes are combined:

Color	Effect
Black (#000000)	Union (add shape to icon)
White (#ffffff)	Subtract (cut shape from icon)
Red (#ff0000)	Size indicator — defines the icon's bounding box

Stroked paths are expanded to filled outlines with round caps and joins. Transforms (matrix, translate, scale, rotate) on groups and elements are applied.

Syntax

Syntax slightly resembles the syntax of path commands in SVG. Positions on the plane are coded as two floating point number separated by comma: <x>,<y> or +<x>,<y>. + means that the position is relative to the position.

If current position is (5, 5), +1,2 will give (6, 7) and update current position to (6, 7) as well.

Global context

• position — vector of two floats, current position of the cursor.
• width — float, stroke width.
• fill — Boolean, whether objects should be filled.

Commands

Command	Description
subtract	Set subtraction mode
fill	Set fill mode
w <float>	Set width to a value
m <position>	Set position to a value
l [<position>]	Draw lines between positions
e <position> <float>	Draw circle specified by center point and radius
r <position> <position>	Draw rectangle specified by top left and bottom right points
a <position> <float> <float> <float>	Draw arc specified by center point, radius, and two angles in radians

Variables

Variables can be defined with <variable> = [<command>] and accessed with @<variable>.

Scopes

Scopes group commands together using { and }. They can be nested and are used to incapsulate context changes.

Example

square = fill r +0,0 +2,2
icon glider = {
    m 6,2   @square m +4,4 @square
    m +-8,4 @square m +4,0 @square m +4,0 @square
}

This code defines a square (lf, filled line — polygon with 5 points). It then reuses square variable 5 times to draw a glider.