From 718a0218173a1e70896d13d739f87b11afcdb38a Mon Sep 17 00:00:00 2001
From: Wez Furlong <wez@wezfurlong.org>
Date: Thu, 28 Jul 2022 17:09:15 -0700
Subject: [PATCH] termwiz: use `6` for the rgba colorspace

`4` is actually defined as CMYK according to ITU-T Rec. T.416:

> A parameter substring for values 38 or 48 may be divided by one or more separators (03/10) into parameter elements,
> denoted as Pe. The format of such a parameter sub-string is indicated as:
>
>     Pe : P ...
>
> Each parameter element consists of zero, one or more bit combinations from 03/00 to 03/09, representing the digits
> 0 to 9. An empty parameter element represents a default value for this parameter element. Empty parameter elements at
> the end of the parameter substring need not be included.
>
> The first parameter element indicates a choice between:
>
> 0    implementation defined (only applicable for the character foreground colour)
> 1    transparent;
> 2    direct colour in RGB space;
> 3    direct colour in CMY space;
> 4    direct colour in CMYK space;
> 5    indexed colour.

refs: https://github.com/wez/wezterm/commit/6e9a22e199cc40ed75a26708343ea34a899542d5#commitcomment-79669016
---
 termwiz/src/escape/csi.rs        | 12 ++++++------
 termwiz/src/escape/parser/mod.rs |  2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/termwiz/src/escape/csi.rs b/termwiz/src/escape/csi.rs
index b90b1970a..af7f530bd 100644
--- a/termwiz/src/escape/csi.rs
+++ b/termwiz/src/escape/csi.rs
@@ -1448,7 +1448,7 @@ impl Display for Sgr {
                 } else {
                     write!(
                         f,
-                        "{}:4::{}:{}:{}:{}m",
+                        "{}:6::{}:{}:{}:{}m",
                         SgrCode::ForegroundColor as i64,
                         red,
                         green,
@@ -1494,7 +1494,7 @@ impl Display for Sgr {
                 } else {
                     write!(
                         f,
-                        "{}:4::{}:{}:{}:{}m",
+                        "{}:6::{}:{}:{}:{}m",
                         SgrCode::BackgroundColor as i64,
                         red,
                         green,
@@ -1518,7 +1518,7 @@ impl Display for Sgr {
                 } else {
                     write!(
                         f,
-                        "{}:4::{}:{}:{}:{}m",
+                        "{}:6::{}:{}:{}:{}m",
                         SgrCode::UnderlineColor as i64,
                         red,
                         green,
@@ -2240,19 +2240,19 @@ impl<'a> CSIParser<'a> {
     fn parse_sgr_color(&mut self, params: &'a [CsiParam]) -> Result<ColorSpec, ()> {
         match params {
             // wezterm extension to support an optional alpha channel in the `:` form only
-            [_, CsiParam::P(b':'), CsiParam::Integer(4), CsiParam::P(b':'),
+            [_, CsiParam::P(b':'), CsiParam::Integer(6), CsiParam::P(b':'),
                     CsiParam::Integer(_colorspace), CsiParam::P(b':'),
                     red, CsiParam::P(b':'), green, CsiParam::P(b':'), blue, CsiParam::P(b':'), alpha, ..] => {
                 let res: SrgbaTuple = (to_u8(red)?, to_u8(green)?, to_u8(blue)?, to_u8(alpha)?).into();
                 Ok(self.advance_by(13, params, res.into()))
             }
-            [_, CsiParam::P(b':'), CsiParam::Integer(4), CsiParam::P(b':'),
+            [_, CsiParam::P(b':'), CsiParam::Integer(6), CsiParam::P(b':'),
                     /* empty colorspace */ CsiParam::P(b':'),
                     red, CsiParam::P(b':'), green, CsiParam::P(b':'), blue, CsiParam::P(b':'), alpha, ..] => {
                 let res: SrgbaTuple = (to_u8(red)?, to_u8(green)?, to_u8(blue)?, to_u8(alpha)?).into();
                 Ok(self.advance_by(12, params, res.into()))
             }
-            [_, CsiParam::P(b':'), CsiParam::Integer(4), CsiParam::P(b':'), red, CsiParam::P(b':'), green,
+            [_, CsiParam::P(b':'), CsiParam::Integer(6), CsiParam::P(b':'), red, CsiParam::P(b':'), green,
                     CsiParam::P(b':'), blue, CsiParam::P(b':'), alpha, ..] =>
             {
                 let res: SrgbaTuple = (to_u8(red)?, to_u8(green)?, to_u8(blue)?, to_u8(alpha)?).into();
diff --git a/termwiz/src/escape/parser/mod.rs b/termwiz/src/escape/parser/mod.rs
index 83e47f827..dd1949a26 100644
--- a/termwiz/src/escape/parser/mod.rs
+++ b/termwiz/src/escape/parser/mod.rs
@@ -453,7 +453,7 @@ mod test {
             actions
         );
 
-        let actions = p.parse_as_vec(b"\x1b[38:4:0:255:0:127mw");
+        let actions = p.parse_as_vec(b"\x1b[38:6:0:255:0:127mw");
         assert_eq!(
             vec![
                 Action::CSI(CSI::Sgr(Sgr::Foreground(ColorSpec::TrueColor(