From 8afd3ccb106196c230741417d8364722df7f6e32 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Wed, 18 Jan 2023 20:43:10 -0700
Subject: [PATCH] [paint] Add HB_PAINT_PALETTE_INDEX_CUSTOM

---
 src/hb-font.cc |  3 ++-
 src/hb-paint.h | 12 ++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/hb-font.cc b/src/hb-font.cc
index f8eb60a19..3f169ee54 100644
--- a/src/hb-font.cc
+++ b/src/hb-font.cc
@@ -1440,7 +1440,8 @@ hb_font_draw_glyph (hb_font_t *font,
  *
  * If the font has color palettes (see hb_ot_color_has_palettes()),
  * then @palette_index selects the palette to use. If the font doesn't
- * have palettes, passing 0 is fine.
+ * have palettes, passing 0 is fine.  Use %HB_PAINT_PALETTE_INDEX_CUSTOM
+ * for custom palette.
  *
  * Since: REPLACEME
  */
diff --git a/src/hb-paint.h b/src/hb-paint.h
index 5779d3c77..3f21c89e1 100644
--- a/src/hb-paint.h
+++ b/src/hb-paint.h
@@ -33,6 +33,18 @@
 
 HB_BEGIN_DECLS
 
+
+/**
+ * HB_PAINT_PALETTE_INDEX_CUSTOM
+ *
+ * A palette index signifying that custom colors are in use.
+ * Such colors are fetched from the client using the
+ * custom-palette-color callback of the paint functions.
+ *
+ * Since: REPLACEME
+ **/
+#define HB_PAINT_PALETTE_INDEX_CUSTOM 0xFFFFFFFF
+
 /**
  * hb_paint_funcs_t:
  *