From 4397a1814fd1ecc998c0dcd542ae2fcc8da6827f Mon Sep 17 00:00:00 2001
From: ant <ant@domain.xyz>
Date: Sat, 4 Jan 2025 21:59:53 +0100
Subject: [PATCH] fontfeature patch

---
 hb.c          | 13 +++++--------
 hb.h          |  4 ++++
 patches.def.h |  6 +++++-
 x.c           | 20 ++++++++++++++++++++
 4 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/hb.c b/hb.c
index ae3dcc3..d2edd98 100644
--- a/hb.c
+++ b/hb.c
@@ -35,13 +35,6 @@ typedef struct {
 static RuneBuffer hbrunebuffer = { 0, NULL };
 static hb_buffer_t *hbbuffer;
 
-/*
- * Poplulate the array with a list of font features, wrapped in FEATURE macro,
- * e. g.
- * FEATURE('c', 'a', 'l', 't'), FEATURE('d', 'l', 'i', 'g')
- */
-hb_feature_t features[] = { };
-
 void
 hbcreatebuffer(void)
 {
@@ -125,7 +118,11 @@ hbtransform(HbTransformData *data, XftFont *xfont, const Glyph *glyphs, int star
 	hb_buffer_add_codepoints(buffer, hbrunebuffer.runes, length, 0, length);
 
 	/* Shape the segment. */
-	hb_shape(font, buffer, features, sizeof(features)/sizeof(hb_feature_t));
+  #if FONTFEATURES_PATCH
+	hb_shape(font, buffer, data->features, data->features_count);
+  #else
+	hb_shape(font, buffer, NULL, 0);
+  #endif
 
 	/* Get new glyph info. */
 	hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, &glyph_count);
diff --git a/hb.h b/hb.h
index cb7ea48..3517855 100644
--- a/hb.h
+++ b/hb.h
@@ -7,6 +7,10 @@ typedef struct {
 	hb_glyph_info_t *glyphs;
 	hb_glyph_position_t *positions;
 	unsigned int count;
+#if FONTFEATURES_PATCH
+  hb_feature_t *features;
+  int features_count;
+#endif // FONTFEATURES_PATCH
 } HbTransformData;
 
 void hbcreatebuffer(void);
diff --git a/patches.def.h b/patches.def.h
index ae5d37b..dbfb2a0 100644
--- a/patches.def.h
+++ b/patches.def.h
@@ -233,7 +233,11 @@
  * https://github.com/cog1to/st-ligatures
  * https://st.suckless.org/patches/ligatures/
  */
-#define LIGATURES_PATCH 0
+#define LIGATURES_PATCH 1
+
+/* This patch add support for custom font features. It depends on the LIGATURES_PATCH patch
+ */
+#define FONTFEATURES_PATCH 1
 
 /* This patch makes st ignore terminal color attributes by forcing display of the default
  * foreground and background colors only - making for a monochrome look. Idea ref.
diff --git a/x.c b/x.c
index be1a6ba..a54304f 100644
--- a/x.c
+++ b/x.c
@@ -1724,6 +1724,26 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
 	xp = winx, yp = winy + font->ascent;
 	#endif // VERTCENTER_PATCH
 	cluster_xp = xp; cluster_yp = yp;
+  #if FONTFEATURES_PATCH
+  { // Get font features
+    shaped.features = (hb_feature_t *) malloc(sizeof(hb_feature_t) * 128);
+    FcChar8 *s;
+    int feature_idx = 0;
+    while (FcPatternGetString(font->pattern, FC_FONT_FEATURES, feature_idx, &s) == FcResultMatch) {
+      if (strlen(s) != 4)
+        die("Invalid font feature tag");
+      if (feature_idx >= 128)
+        die("Too many font features");
+      shaped.features[feature_idx].tag = HB_TAG(s[0], s[1], s[2], s[3]);
+      shaped.features[feature_idx].value = 1;
+      shaped.features[feature_idx].start = HB_FEATURE_GLOBAL_START;
+      shaped.features[feature_idx].end = HB_FEATURE_GLOBAL_END;
+      feature_idx++;
+    }
+    shaped.features_count = feature_idx;
+  }
+  #endif // FONTFEATURES_PATCH
+
 	/* Shape the segment. */
 	hbtransform(&shaped, font->match, glyphs, 0, len);
 	#endif // LIGATURES_PATCH