Crate `plot_icon`

Overview

This is a lib crate for generating standard 19-circle icons in png and in svg format.

Output could be in form of .png or .svg files, or the Vec with png data, or svg::Document with svg data.

The code is following the published javascript code for icon generation from https://github.com/paritytech/oo7/blob/master/packages/polkadot-identicon/src/index.jsx.

Input needed to generate data (to be used in Signer)

Input requires:

actual input data:
- Vec<u8> to be used with png_data_from_vec and svg_from_vec functions
- or hex format string to be used with png_data_from_hex and svg_from_hex functions
- or base58 format string to be used with png_data_from_base58 and svg_from_base58 functions
size parameter halfsize of final file (created image is square, with halfsize`*2+1 pixels side for png and halfsize`*2 for svg)

Input needed to make files (at the moment, mainly for test pics)

Input requires:

actual input data:
- Vec<u8> to be used with plot_png_from_vec and plot_svg_from_vec functions
- or hex format string to be used with plot_png_from_hex and plot_svg_from_hex functions
- or base58 format string to be used with plot_png_from_base58 and plot_svg_from_base58 functions
size parameter halfsize of final file (created image is square, with halfsize`*2+1 pixels side for png and halfsize`*2 for svg)
output file name

Tests and Examples

Currently there are tests to check if the color sets calculated for Alice and Bob are identical to the colors in the corresponding well-known icons.

Examples are plotting both .png and .svg icons for base58 westend Alice address, and hex westend genesis hash.

Notes

There are several uncertainties about how the original published code was designed to work, those should be clarified.

For example, calculated HSL color saturation could range 30..109, and is processed as percents. Crate palette (currently used here) processes saturation values over 100 as percents over 100, and gives some results (slightly different from results for 100% saturation), but it is necessary to check if the calculations in js and here are matching.