tree 18e663504f7fea8cd6a11f224a653323de41fa80
parent 0d8d4a79d87ebd9e2b8da7c1f9eb89786e75e33e
author Nigel Tao <nigeltao@golang.org> 1625578971 +1000
committer Nigel Tao <nigeltao@golang.org> 1630632909 +0000

shiny/iconvg: add UpgradeToFileFormatVersion1

The iconvg Go implementation started at golang.org/x/exp/shiny/iconvg in
2016, speaking a file format retroactively named FFV0 (File Format
Version 0). The github.com/google/iconvg/src/go/* packages were created
more recently in 2021 and will speak a revised format, FFV1.

The long term plan is for the github.com/... packages to *only* speak
FFV1. The golang.org/... package (this package) will continue to speak
FFV0 directly and will additionally delegate decoding FFV1 to the
github.com/... packages. FFV0 will be considered a deprecated experiment
(it was marked EXPERIMENTAL ever since its inception). See
https://github.com/google/iconvg/issues/4

This commit, which decodes FFV0 and encodes FFV1, lives in the
golang.org/... packages, since it involves FFV0. Testing it (beyond the
basic consistency checks in upgrade_test.go) lives in the github.com/...
packages, since that involves decoding FFV1. For example, some outputs
of the UpgradeToFileFormatVersion1 function (added by this commit) were
checked in as https://github.com/google/iconvg/commit/c98b08c

Change-Id: Ib5861ae97928cf31faf207b915568532e2624f09
Reviewed-on: https://go-review.googlesource.com/c/exp/+/332989
Trust: Nigel Tao <nigeltao@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>