From 4daa49fe27c5aea0ebfec6fde757fa0e529760ec Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 28 May 2024 20:25:49 -0700
Subject: [PATCH] font/freetype: update to new presentation APIs

---
 pkg/freetype/face.zig      |  6 ++++++
 src/font/face/freetype.zig | 37 ++++++++++++++++++++-----------------
 2 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/pkg/freetype/face.zig b/pkg/freetype/face.zig
index 7b72d1b94..f4eaf24f0 100644
--- a/pkg/freetype/face.zig
+++ b/pkg/freetype/face.zig
@@ -26,6 +26,12 @@ pub const Face = struct {
         return c.FT_HAS_COLOR(self.handle);
     }
 
+    /// A macro that returns true whenever a face object contains an ‘sbix’
+    /// OpenType table and outline glyphs.
+    pub fn hasSBIX(self: Face) bool {
+        return c.FT_HAS_SBIX(self.handle);
+    }
+
     /// A macro that returns true whenever a face object contains some
     /// multiple masters.
     pub fn hasMultipleMasters(self: Face) bool {
diff --git a/src/font/face/freetype.zig b/src/font/face/freetype.zig
index 33eca002c..6037f6c0c 100644
--- a/src/font/face/freetype.zig
+++ b/src/font/face/freetype.zig
@@ -15,7 +15,6 @@ const Allocator = std.mem.Allocator;
 const font = @import("../main.zig");
 const Glyph = font.Glyph;
 const Library = font.Library;
-const Presentation = font.Presentation;
 const convert = @import("freetype_convert.zig");
 const fastmem = @import("../../fastmem.zig");
 const quirks = @import("../../quirks.zig");
@@ -32,10 +31,6 @@ pub const Face = struct {
     /// Harfbuzz font corresponding to this face.
     hb_font: harfbuzz.Font,
 
-    /// The presentation for this font. This is a heuristic since fonts don't have
-    /// a way to declare this. We just assume a font with color is an emoji font.
-    presentation: Presentation,
-
     /// Metrics for this font face. These are useful for renderers.
     metrics: font.face.Metrics,
 
@@ -67,17 +62,10 @@ pub const Face = struct {
             .lib = lib.lib,
             .face = face,
             .hb_font = hb_font,
-            .presentation = if (face.hasColor()) .emoji else .text,
             .metrics = calcMetrics(face, opts.metric_modifiers),
         };
         result.quirks_disable_default_font_features = quirks.disableDefaultFontFeatures(&result);
 
-        // See coretext.zig which has a similar check for this.
-        if (result.presentation == .emoji and result.glyphIndex('🥸') == null) {
-            log.warn("font has colorized glyphs but isn't emoji, treating as text", .{});
-            result.presentation = .text;
-        }
-
         // In debug mode, we output information about available variation axes,
         // if they exist.
         if (comptime builtin.mode == .Debug) mm: {
@@ -219,10 +207,29 @@ pub const Face = struct {
 
     /// Returns true if this font is colored. This can be used by callers to
     /// determine what kind of atlas to pass in.
-    fn hasColor(self: Face) bool {
+    pub fn hasColor(self: Face) bool {
         return self.face.hasColor();
     }
 
+    /// Returns true if the given glyph ID is colorized.
+    pub fn isColorGlyph(self: *const Face, glyph_id: u32) bool {
+        // sbix table is always true for now
+        if (self.face.hasSBIX()) return true;
+
+        // Otherwise, load the glyph and see what format it is in.
+        self.face.loadGlyph(glyph_id, .{
+            .render = true,
+            .color = self.face.hasColor(),
+            .no_bitmap = !self.face.hasColor(),
+        }) catch return false;
+
+        // If the glyph is SVG we assume colorized
+        const glyph = self.face.handle.*.glyph;
+        if (glyph.*.format == freetype.c.FT_GLYPH_FORMAT_SVG) return true;
+
+        return false;
+    }
+
     /// Render a glyph using the glyph index. The rendered glyph is stored in the
     /// given texture atlas.
     pub fn renderGlyph(
@@ -655,8 +662,6 @@ test {
     );
     defer ft_font.deinit();
 
-    try testing.expectEqual(Presentation.text, ft_font.presentation);
-
     // Generate all visible ASCII
     var i: u8 = 32;
     while (i < 127) : (i += 1) {
@@ -691,8 +696,6 @@ test "color emoji" {
     );
     defer ft_font.deinit();
 
-    try testing.expectEqual(Presentation.emoji, ft_font.presentation);
-
     _ = try ft_font.renderGlyph(alloc, &atlas, ft_font.glyphIndex('🥸').?, .{});
 
     // resize