font: move shaper into comptime interface

src/font/main.zig

@@ -10,7 +10,8 @@ pub const Face = face.Face;
 pub const Group = @import("Group.zig");
 pub const GroupCache = @import("GroupCache.zig");
 pub const Glyph = @import("Glyph.zig");
-pub const Shaper = @import("Shaper.zig");
+pub const shape = @import("shape.zig");
+pub const Shaper = shape.Shaper;
 pub const sprite = @import("sprite.zig");
 pub const Sprite = sprite.Sprite;
 pub const Descriptor = discovery.Descriptor;

src/font/shape.zig

@@ -0,0 +1,14 @@
+const builtin = @import("builtin");
+const options = @import("main.zig").options;
+const harfbuzz = @import("shaper/harfbuzz.zig");
+
+/// Shaper implementation for our compile options.
+pub const Shaper = switch (options.backend) {
+    .freetype,
+    .fontconfig_freetype,
+    .coretext_freetype,
+    .coretext,
+    => harfbuzz.Shaper,
+
+    .web_canvas => harfbuzz.Shaper,
+};

src/font/shaper/harfbuzz.zig

@@ -1,23 +1,22 @@
-//! This struct handles text shaping.
-const Shaper = @This();
-
 const std = @import("std");
 const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 const harfbuzz = @import("harfbuzz");
 const trace = @import("tracy").trace;
-const font = @import("main.zig");
-const Face = @import("main.zig").Face;
-const DeferredFace = @import("main.zig").DeferredFace;
-const Group = @import("main.zig").Group;
-const GroupCache = @import("main.zig").GroupCache;
-const Library = @import("main.zig").Library;
-const Style = @import("main.zig").Style;
-const Presentation = @import("main.zig").Presentation;
-const terminal = @import("../terminal/main.zig");
+const font = @import("../main.zig");
+const Face = font.Face;
+const DeferredFace = font.DeferredFace;
+const Group = font.Group;
+const GroupCache = font.GroupCache;
+const Library = font.Library;
+const Style = font.Style;
+const Presentation = font.Presentation;
+const terminal = @import("../../terminal/main.zig");
 
 const log = std.log.scoped(.font_shaper);
 
+/// Shaper that uses Harfbuzz.
+pub const Shaper = struct {
     /// The buffer used for text shaping. We reuse it across multiple shaping
     /// calls to prevent allocations.
     hb_buf: harfbuzz.Buffer,
@@ -226,6 +225,7 @@ pub const RunIterator = struct {
             };
         }
     };
+};
 
 test "run iterator" {
     const testing = std.testing;
@@ -619,7 +619,7 @@ const TestShaper = struct {
     shaper: Shaper,
     cache: *GroupCache,
     lib: Library,
-    cell_buf: []Cell,
+    cell_buf: []Shaper.Cell,
 
     pub fn deinit(self: *TestShaper) void {
         self.shaper.deinit();
@@ -632,9 +632,9 @@ const TestShaper = struct {
 
 /// Helper to return a fully initialized shaper.
 fn testShaper(alloc: Allocator) !TestShaper {
-    const testFont = @import("test.zig").fontRegular;
-    const testEmoji = @import("test.zig").fontEmoji;
-    const testEmojiText = @import("test.zig").fontEmojiText;
+    const testFont = @import("../test.zig").fontRegular;
+    const testEmoji = @import("../test.zig").fontEmoji;
+    const testEmojiText = @import("../test.zig").fontEmojiText;
 
     var lib = try Library.init();
     errdefer lib.deinit();
@@ -653,10 +653,10 @@ fn testShaper(alloc: Allocator) !TestShaper {
     try cache_ptr.group.addFace(alloc, .regular, DeferredFace.initLoaded(try Face.init(lib, testEmoji, .{ .points = 12 })));
     try cache_ptr.group.addFace(alloc, .regular, DeferredFace.initLoaded(try Face.init(lib, testEmojiText, .{ .points = 12 })));
 
-    var cell_buf = try alloc.alloc(Cell, 80);
+    var cell_buf = try alloc.alloc(Shaper.Cell, 80);
     errdefer alloc.free(cell_buf);
 
-    var shaper = try init(cell_buf);
+    var shaper = try Shaper.init(cell_buf);
     errdefer shaper.deinit();
 
     return TestShaper{