Merge pull request #1741 from qwerasd205/non-integer-point-size

feat(font): Non-integer point sizes

include/ghostty.h

@@ -379,7 +379,7 @@ typedef struct {
   ghostty_platform_u platform;
   void* userdata;
   double scale_factor;
-  uint8_t font_size;
+  float font_size;
   const char* working_directory;
   const char* command;
 } ghostty_surface_config_s;

macos/Sources/Ghostty/SurfaceView.swift

@@ -252,7 +252,7 @@ extension Ghostty {
     /// libghostty, usually from the Ghostty configuration.
     struct SurfaceConfiguration {
         /// Explicit font size to use in points
-        var fontSize: UInt8? = nil
+        var fontSize: Float32? = nil
         
         /// Explicit working directory to set
         var workingDirectory: String? = nil

pkg/harfbuzz/build.zig

@@ -41,7 +41,11 @@ pub fn build(b: *std.Build) !void {
         try apple_sdk.addPaths(b, module);
     }
 
-    const freetype_dep = b.dependency("freetype", .{ .target = target, .optimize = optimize });
+    const freetype_dep = b.dependency("freetype", .{
+        .target = target,
+        .optimize = optimize,
+        .@"enable-libpng" = true,
+    });
     lib.linkLibrary(freetype_dep.artifact("freetype"));
     module.addIncludePath(freetype_dep.builder.dependency("freetype", .{}).path("include"));
 

src/Surface.zig

@@ -194,7 +194,7 @@ const DerivedConfig = struct {
     arena: ArenaAllocator,
 
     /// For docs for these, see the associated config they are derived from.
-    original_font_size: u8,
+    original_font_size: f32,
     keybind: configpkg.Keybinds,
     clipboard_read: configpkg.ClipboardAccess,
     clipboard_write: configpkg.ClipboardAccess,
@@ -3008,18 +3008,25 @@ pub fn performBindingAction(self: *Surface, action: input.Binding.Action) !bool
         ),
 
         .increase_font_size => |delta| {
-            log.debug("increase font size={}", .{delta});
+            // Max delta is somewhat arbitrary.
+            const clamped_delta = @max(0, @min(255, delta));
+
+            log.debug("increase font size={}", .{clamped_delta});
 
             var size = self.font_size;
-            size.points +|= delta;
+            // Max point size is somewhat arbitrary.
+            size.points = @min(size.points + clamped_delta, 255);
             try self.setFontSize(size);
         },
 
         .decrease_font_size => |delta| {
-            log.debug("decrease font size={}", .{delta});
+            // Max delta is somewhat arbitrary.
+            const clamped_delta = @max(0, @min(255, delta));
+
+            log.debug("decrease font size={}", .{clamped_delta});
 
             var size = self.font_size;
-            size.points = @max(1, size.points -| delta);
+            size.points = @max(1, size.points - clamped_delta);
             try self.setFontSize(size);
         },
 

src/apprt/embedded.zig

@@ -314,7 +314,7 @@ pub const Surface = struct {
         scale_factor: f64 = 1,
 
         /// The font size to inherit. If 0, default font size will be used.
-        font_size: u8 = 0,
+        font_size: f32 = 0,
 
         /// The working directory to load into.
         working_directory: [*:0]const u8 = "",
@@ -1049,7 +1049,7 @@ pub const Surface = struct {
     }
 
     fn newSurfaceOptions(self: *const Surface) apprt.Surface.Options {
-        const font_size: u8 = font_size: {
+        const font_size: f32 = font_size: {
             if (!self.app.config.@"window-inherit-font-size") break :font_size 0;
             break :font_size self.core_surface.font_size.points;
         };

src/cli/args.zig

@@ -250,8 +250,10 @@ fn parseIntoField(
                     0,
                 ) catch return error.InvalidValue,
 
-                f64 => std.fmt.parseFloat(
+                f32,
                 f64,
+                => |Float| std.fmt.parseFloat(
+                    Float,
                     value orelse return error.ValueRequired,
                 ) catch return error.InvalidValue,
 

src/config/Config.zig

@@ -99,8 +99,12 @@ const c = @cImport({
 /// separate repetitive entries in your config).
 @"font-feature": RepeatableString = .{},
 
-/// Font size in points
-@"font-size": u8 = switch (builtin.os.tag) {
+/// Font size in points. This value can be a non-integer and the nearest integer
+/// pixel size will be selected. If you have a high dpi display where 1pt = 2px
+/// then you can get an odd numbered pixel size by specifying a half point.
+///
+/// For example, 13.5pt @ 2px/pt = 27px
+@"font-size": f32 = switch (builtin.os.tag) {
     // On macOS we default a little bigger since this tends to look better. This
     // is purely subjective but this is easy to modify.
     .macos => 13,

src/config/c_get.zig

@@ -42,8 +42,8 @@ fn getValue(ptr_raw: *anyopaque, value: anytype) bool {
             ptr.* = @intCast(value);
         },
 
-        f32, f64 => {
-            const ptr: *f64 = @ptrCast(@alignCast(ptr_raw));
+        f32, f64 => |Float| {
+            const ptr: *Float = @ptrCast(@alignCast(ptr_raw));
             ptr.* = @floatCast(value);
         },
 
@@ -102,9 +102,9 @@ test "u8" {
     defer c.deinit();
     c.@"font-size" = 24;
 
-    var cval: c_uint = undefined;
+    var cval: f32 = undefined;
     try testing.expect(get(&c, .@"font-size", &cval));
-    try testing.expectEqual(@as(c_uint, 24), cval);
+    try testing.expectEqual(@as(f32, 24), cval);
 }
 
 test "enum" {

src/font/DeferredFace.zig

@@ -371,7 +371,7 @@ pub const Wasm = struct {
         }
     }
 
-    export fn deferred_face_load(self: *DeferredFace, pts: u16) void {
+    export fn deferred_face_load(self: *DeferredFace, pts: f32) void {
         self.load(.{}, .{ .points = pts }) catch |err| {
             log.warn("error loading deferred face err={}", .{err});
             return;

src/font/SharedGridSet.zig

@@ -575,7 +575,9 @@ pub const Key = struct {
     /// Hash the key with the given hasher.
     pub fn hash(self: Key, hasher: anytype) void {
         const autoHash = std.hash.autoHash;
-        autoHash(hasher, self.font_size);
+        autoHash(hasher, @as(u32, @bitCast(self.font_size.points)));
+        autoHash(hasher, self.font_size.xdpi);
+        autoHash(hasher, self.font_size.ydpi);
         autoHash(hasher, self.descriptors.len);
         for (self.descriptors) |d| d.hash(hasher);
         self.codepoint_map.hash(hasher);

src/font/discovery.zig

@@ -49,7 +49,7 @@ pub const Descriptor = struct {
     /// Font size in points that the font should support. For conversion
     /// to pixels, we will use 72 DPI for Mac and 96 DPI for everything else.
     /// (If pixel conversion is necessary, i.e. emoji fonts)
-    size: u16 = 0,
+    size: f32 = 0,
 
     /// True if we want to search specifically for a font that supports
     /// specific styles.
@@ -69,7 +69,7 @@ pub const Descriptor = struct {
         autoHashStrat(hasher, self.family, .Deep);
         autoHashStrat(hasher, self.style, .Deep);
         autoHash(hasher, self.codepoint);
-        autoHash(hasher, self.size);
+        autoHash(hasher, @as(u32, @bitCast(self.size)));
         autoHash(hasher, self.bold);
         autoHash(hasher, self.italic);
         autoHash(hasher, self.monospace);
@@ -125,7 +125,7 @@ pub const Descriptor = struct {
         }
         if (self.size > 0) assert(pat.add(
             .size,
-            .{ .integer = self.size },
+            .{ .integer = @intFromFloat(@round(self.size)) },
             false,
         ));
         if (self.bold) assert(pat.add(
@@ -183,7 +183,7 @@ pub const Descriptor = struct {
 
         // Set our size attribute if set
         if (self.size > 0) {
-            const size32 = @as(i32, @intCast(self.size));
+            const size32: i32 = @intFromFloat(@round(self.size));
             const size = try macos.foundation.Number.create(
                 .sint32,
                 &size32,

src/font/face.zig

@@ -35,7 +35,7 @@ pub const Options = struct {
 /// The desired size for loading a font.
 pub const DesiredSize = struct {
     // Desired size in points
-    points: u8,
+    points: f32,
 
     // The DPI of the screen so we can convert points to pixels.
     xdpi: u16 = default_dpi,
@@ -44,8 +44,7 @@ pub const DesiredSize = struct {
     // Converts points to pixels
     pub fn pixels(self: DesiredSize) u16 {
         // 1 point = 1/72 inch
-        const points_u16: u16 = @intCast(self.points);
-        return (points_u16 * self.ydpi) / 72;
+        return @intFromFloat(@round((self.points * @as(f32, @floatFromInt(self.ydpi))) / 72));
     }
 };
 

src/font/face/freetype.zig

@@ -137,7 +137,7 @@ pub const Face = struct {
         // to what the user requested. Otherwise, we can choose an arbitrary
         // pixel size.
         if (face.isScalable()) {
-            const size_26dot6 = @as(i32, @intCast(size.points)) << 6; // mult by 64
+            const size_26dot6: i32 = @intFromFloat(@round(size.points * 64));
             try face.setCharSize(0, size_26dot6, size.xdpi, size.ydpi);
         } else try selectSizeNearest(face, size.pixels());
     }

src/font/face/web_canvas.zig

@@ -497,7 +497,7 @@ pub const Wasm = struct {
         return face_new_(ptr, len, pts, p) catch null;
     }
 
-    fn face_new_(ptr: [*]const u8, len: usize, pts: u16, presentation: u16) !*Face {
+    fn face_new_(ptr: [*]const u8, len: usize, pts: f32, presentation: u16) !*Face {
         var face = try Face.initNamed(
             alloc,
             ptr[0..len],

src/input/Binding.zig

@@ -158,8 +158,8 @@ pub const Action = union(enum) {
     paste_from_selection: void,
 
     /// Increase/decrease the font size by a certain amount.
-    increase_font_size: u8,
-    decrease_font_size: u8,
+    increase_font_size: f32,
+    decrease_font_size: f32,
 
     /// Reset the font size to the original configured size.
     reset_font_size: void,