From c9843ff8da2d26cd816931336b2642ad0522d3dd Mon Sep 17 00:00:00 2001
From: be5invis <belleve@typeof.net>
Date: Sat, 24 Feb 2024 20:47:23 -0800
Subject: [PATCH] Added a `MOSC` feature that turns certain geometric shapes
 into mosaics (#2212).

---
 changes/29.0.0.md                                    |  1 +
 packages/font-glyphs/src/symbol/mosaic/powerline.ptl |  7 +++++++
 packages/font-otl/src/index.ptl                      |  3 +++
 packages/glyph/src/relation.mjs                      | 10 ++++++++++
 4 files changed, 21 insertions(+)

diff --git a/changes/29.0.0.md b/changes/29.0.0.md
index 9f230127f..625486498 100644
--- a/changes/29.0.0.md
+++ b/changes/29.0.0.md
@@ -40,3 +40,4 @@
 * Fix a disjoint stroke of Outlined Curly `Z` under some weights (#2195).
 * Unify diagonal box drawings' angles (#2197).
 * Fix Large Type Piece `U+1CE3B` (#2206).
+* Added a `MOSC` feature that turns certain geometric shapes into mosaics (#2212).
diff --git a/packages/font-glyphs/src/symbol/mosaic/powerline.ptl b/packages/font-glyphs/src/symbol/mosaic/powerline.ptl
index 6a4e8d0ab..5b2563a08 100644
--- a/packages/font-glyphs/src/symbol/mosaic/powerline.ptl
+++ b/packages/font-glyphs/src/symbol/mosaic/powerline.ptl
@@ -1,6 +1,7 @@
 $$include '../../meta/macros.ptl'
 
 import [mix linreg clamp fallback] from "@iosevka/util"
+import as Gr from "@iosevka/glyph/relation"
 
 glyph-module
 
@@ -137,3 +138,9 @@ glyph-block Symbol-Mosaic-Powerline : begin
 		RotatedPowerline 'powerline/slashBottomRight' 0xE0BB 'powerline/slashTopLeft'
 		RotatedPowerline 'powerline/cornerTopRight' 0xE0BE 'powerline/cornerBottomLeft'
 		RotatedPowerline 'powerline/slashTopRight' 0xE0BF 'powerline/slashBottomLeft'
+
+
+		Gr.linkSingleGlyphPairGr glyphStore [MangleName 'blackTriangleRB'] [MangleName 'powerline/cornerBottomRight'] Gr.MosaicForm
+		Gr.linkSingleGlyphPairGr glyphStore [MangleName 'blackTriangleLB'] [MangleName 'powerline/cornerBottomLeft'] Gr.MosaicForm
+		Gr.linkSingleGlyphPairGr glyphStore [MangleName 'blackTriangleLT'] [MangleName 'powerline/cornerTopLeft'] Gr.MosaicForm
+		Gr.linkSingleGlyphPairGr glyphStore [MangleName 'blackTriangleRT'] [MangleName 'powerline/cornerTopRight'] Gr.MosaicForm
diff --git a/packages/font-otl/src/index.ptl b/packages/font-otl/src/index.ptl
index 130440669..ce8f6c833 100644
--- a/packages/font-otl/src/index.ptl
+++ b/packages/font-otl/src/index.ptl
@@ -32,6 +32,9 @@ define [buildGSUB para glyphStore markGlyphs] : begin
 	buildGrFeature gsub glyphStore Gr.Lnum
 	buildGrFeature gsub glyphStore Gr.Onum
 
+	# Mosaic form
+	buildGrFeature gsub glyphStore Gr.MosaicForm
+
 	# zero is handled inside the CV/SS feature builder
 	# As it is a cv/ss "cherry picking".
 
diff --git a/packages/glyph/src/relation.mjs b/packages/glyph/src/relation.mjs
index 64070ebee..47315e048 100644
--- a/packages/glyph/src/relation.mjs
+++ b/packages/glyph/src/relation.mjs
@@ -67,6 +67,7 @@ export const Wwid = OtlTaggedProp("Wwid", "WWID", "Narrow cell");
 export const Lnum = OtlTaggedProp("Lnum", "lnum", "Lining number");
 export const Onum = OtlTaggedProp("Onum", "onum", "Old-style number");
 export const Zero = OtlTaggedProp("Zero", "zero", "Slashed zero");
+export const MosaicForm = OtlTaggedProp("MosaicForm", "MOSC", "Mosaic form");
 export const AplForm = OtlTaggedProp("AplForm", "APLF", "APL form");
 export const NumeratorForm = OtlTaggedProp("Numerator", "numr");
 export const DenominatorForm = OtlTaggedProp("Denominator", "dnom");
@@ -330,6 +331,7 @@ export function createGrDisplaySheet(glyphStore, gn) {
 	displayQueryPairFeatures(glyph, "Width", Nwid, Wwid, typographicFeatures);
 	displayQueryPairFeatures(glyph, "Number Form", Lnum, Onum, typographicFeatures);
 	displayQuerySingleFeature(glyph, AplForm, typographicFeatures);
+	displayQuerySingleFeature(glyph, MosaicForm, typographicFeatures);
 	for (const gr of CvCherryPickingGrs) displayQuerySingleFeature(glyph, gr, typographicFeatures);
 
 	// Query selected character variants
@@ -447,6 +449,14 @@ export function linkSuffixPairGr(gs, tagCis, tagTrans, grCis, grTrans) {
 	}
 }
 
+export function linkSingleGlyphPairGr(gs, fromName, toName, gr) {
+	const gFrom = gs.queryByName(fromName);
+	if (!gFrom) return;
+	const gTo = gs.queryByName(toName);
+	if (!gTo) return;
+	gr.set(gFrom, toName);
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 export function hashCv(g) {