tree 5d53105b3a30a4be058b891a3143c77018a75adc
parent ccd3679621f889eca93584acf6854a5562f217ba
author Nigel Tao <nigeltao@golang.org> 1474365039 +1000
committer Nigel Tao <nigeltao@golang.org> 1474429693 +0000

shiny/iconvg: add 3 byte color encodings.

There are two new encodings, direct and indirect.

The indirect encoding, or at least some way to water down a custom palette
color, is necessary for icons like
https://raw.githubusercontent.com/google/material-design-icons/master/device/svg/production/ic_signal_wifi_2_bar_48px.svg
which say `<path fill-opacity=".3" d="etc">`. Rendering such icons need a
partially transparent version of a custom palette color, e.g. the theme
foreground color, which could be black for a traditional theme or white for a
dark theme.

The direct encoding doesn't offer anything beyond the existing 4 byte encoding,
other than being a shorter encoding. It could come up relatively often, though,
if e.g. the suggested palette's elements are all fully opaque. Reserved styling
opcodes aren't particularly scarce, so I think it's a win overall. I think we
might as well add it now, if we're adding the 3 byte indirect encoding, and
avoid re-basing the other opcodes again if we added it separately.

Also fix some opcode typos in encode.go, with TODOs for more tests.

Change-Id: I0dd004b8ccbeab77dbb6a954f650e7b470ef9af7
Reviewed-on: https://go-review.googlesource.com/29451
Reviewed-by: David Crawshaw <crawshaw@golang.org>