WaveDrom allows for the programmatic creation of beautiful Diagram Timing Diagrams in Rust. This is the crate that powers all the wavedrom tools including the editor, the command-line interface, and the mdbook preprocessor.

This crate is be used in two ways. It can be given [WaveJson][wavejson] which is a JSON format to describe Diagram Timing Diagrams. Alternatively, you can programmatically define a figure by building it using the Figure struct.

Getting Started

Getting started with this crate is quite easy. Here, we have two examples. First, how to use [WaveJson][wavejson] as an input to your figures and second how to programmically define figures.

WaveJson

Result:

Programmically defining a Figure

use std::fs::File;
use wavedrom::{Figure, Signal};

let figure = Figure::new()
                 .header_text("Timing Schema")
                 .add_signals([
                     Signal::with_cycle_str("p........").name("clk"),
                     Signal::with_cycle_str("010......").name("req"),
                     Signal::with_cycle_str("0......10").name("done"),
                     Signal::with_cycle_str("0......10").name("done"),
                     Signal::with_cycle_str("==.=.=.=.").name("state")
                        .add_data_fields([
                            "Idle", "Fetch", "Calculate", "Return", "Idle",
                        ]),
                 ]);
let assembled_figure = figure.assemble();

let path = "path/to/file.svg";
let mut file = File::create(path)?;

assembled_figure.write_svg(&mut file)?;

Result:

Cargo Features

There are a set of cargo features, most of which are enabled by default.

• serde. Enabled by default. Adds the wavejson module, which defines the serialize and deserialize formats for a wave format for a wave.
• embed_font. Enabled by default. Adds an embedded Helvetica into the library which is used to find the dimensions of certain texts. When this is disabled, it is replaced by a width look-up table that is only accurate for ASCII and over-estimates the width for other UTF-8 characters.
• json5. Enabled by default. The human friendly variant of JSON that can be used with the serde feature to deserialize a WaveJson file.
• serde_json. Disabled by default. Formal version of JSON that can be used with the serde feature to deserialize a WaveJson file.
• skins. Enabled by default. Adds the skin module, which defines the serialize and deserialize formats for WaveDrom skins. Also adds logic to merge a skin into an existing set of options.

Rendering Process

The rendering process of this crate is done in 3 steps.

1. Create Figure

A Figure can be created in two ways. First, a Figure can be built programmatically with the Figure::new method and the builder pattern methods. Second, a Figure can be built by loading a [WaveJson][wavejson] file. This can be done with the Figure::from_json5 or Figure::from_json methods.

2. Assemble Figure to AssembledFigure

A Figure needs to be assembled. This shapes the signal waves removes any invalid groups and edges. Assembling is done with the Figure::assemble and Figure::assemble_with_options methods.

3. Render AssembledFigure to SVG

An AssembledFigure can be rendered by calling the AssembledFigure::write_svg or AssembledFigure::write_svg_with_options methods. This will write an SVG into an io::Write buffer. If a write to the io::Write is expensive, it is recommended to wrap the io::Write in a std::io::BufWriter.