diff --git a/pkg/macos/text/font.zig b/pkg/macos/text/font.zig index 67a303018..6423d82ea 100644 --- a/pkg/macos/text/font.zig +++ b/pkg/macos/text/font.zig @@ -217,6 +217,10 @@ pub const FontOrientation = enum(c_uint) { pub const FontTableTag = enum(u32) { svg = c.kCTFontTableSVG, + os2 = c.kCTFontTableOS2, + head = c.kCTFontTableHead, + hhea = c.kCTFontTableHhea, + post = c.kCTFontTablePost, _, pub fn init(v: *const [4]u8) FontTableTag { diff --git a/src/font/face/coretext.zig b/src/font/face/coretext.zig index 09fdd7ad0..6389ba67e 100644 --- a/src/font/face/coretext.zig +++ b/src/font/face/coretext.zig @@ -534,8 +534,6 @@ pub const Face = struct { CopyTableError, InvalidHeadTable, InvalidPostTable, - InvalidOS2Table, - OS2VersionNotSupported, InvalidHheaTable, }; @@ -569,18 +567,16 @@ pub const Face = struct { }; }; - // Read the 'OS/2' table out of the font data. - const os2: opentype.OS2 = os2: { + // Read the 'OS/2' table out of the font data if it's available. + const maybe_os2: ?opentype.OS2 = os2: { const tag = macos.text.FontTableTag.init("OS/2"); - const data = ct_font.copyTable(tag) orelse return error.CopyTableError; + const data = ct_font.copyTable(tag) orelse break :os2 null; defer data.release(); const ptr = data.getPointer(); const len = data.getLength(); break :os2 opentype.OS2.init(ptr[0..len]) catch |err| { - return switch (err) { - error.EndOfStream => error.InvalidOS2Table, - error.OS2VersionNotSupported => error.OS2VersionNotSupported, - }; + log.warn("Error parsing OS/2 table: {any}", .{err}); + break :os2 null; }; }; @@ -603,54 +599,65 @@ pub const Face = struct { const px_per_unit: f64 = px_per_em / units_per_em; const ascent: f64, const descent: f64, const line_gap: f64 = vertical_metrics: { - const os2_ascent: f64 = @floatFromInt(os2.sTypoAscender); - const os2_descent: f64 = @floatFromInt(os2.sTypoDescender); - const os2_line_gap: f64 = @floatFromInt(os2.sTypoLineGap); + const hhea_ascent: f64 = @floatFromInt(hhea.ascender); + const hhea_descent: f64 = @floatFromInt(hhea.descender); + const hhea_line_gap: f64 = @floatFromInt(hhea.lineGap); - // If the font says to use typo metrics, trust it. - if (os2.fsSelection.use_typo_metrics) { + if (maybe_os2) |os2| { + const os2_ascent: f64 = @floatFromInt(os2.sTypoAscender); + const os2_descent: f64 = @floatFromInt(os2.sTypoDescender); + const os2_line_gap: f64 = @floatFromInt(os2.sTypoLineGap); + + // If the font says to use typo metrics, trust it. + if (os2.fsSelection.use_typo_metrics) { + break :vertical_metrics .{ + os2_ascent * px_per_unit, + os2_descent * px_per_unit, + os2_line_gap * px_per_unit, + }; + } + + // Otherwise we prefer the height metrics from 'hhea' if they + // are available, or else OS/2 sTypo* metrics, and if all else + // fails then we use OS/2 usWin* metrics. + // + // This is not "standard" behavior, but it's our best bet to + // account for fonts being... just weird. It's pretty much what + // FreeType does to get its generic ascent and descent metrics. + + if (hhea.ascender != 0 or hhea.descender != 0) { + break :vertical_metrics .{ + hhea_ascent * px_per_unit, + hhea_descent * px_per_unit, + hhea_line_gap * px_per_unit, + }; + } + + if (os2_ascent != 0 or os2_descent != 0) { + break :vertical_metrics .{ + os2_ascent * px_per_unit, + os2_descent * px_per_unit, + os2_line_gap * px_per_unit, + }; + } + + const win_ascent: f64 = @floatFromInt(os2.usWinAscent); + const win_descent: f64 = @floatFromInt(os2.usWinDescent); break :vertical_metrics .{ - os2_ascent * px_per_unit, - os2_descent * px_per_unit, - os2_line_gap * px_per_unit, + win_ascent * px_per_unit, + // usWinDescent is *positive* -> down unlike sTypoDescender + // and hhea.Descender, so we flip its sign to fix this. + -win_descent * px_per_unit, + 0.0, }; } - // Otherwise we prefer the height metrics from 'hhea' if they - // are available, or else OS/2 sTypo* metrics, and if all else - // fails then we use OS/2 usWin* metrics. - // - // This is not "standard" behavior, but it's our best bet to - // account for fonts being... just weird. It's pretty much what - // FreeType does to get its generic ascent and descent metrics. - - if (hhea.ascender != 0 or hhea.descender != 0) { - const hhea_ascent: f64 = @floatFromInt(hhea.ascender); - const hhea_descent: f64 = @floatFromInt(hhea.descender); - const hhea_line_gap: f64 = @floatFromInt(hhea.lineGap); - break :vertical_metrics .{ - hhea_ascent * px_per_unit, - hhea_descent * px_per_unit, - hhea_line_gap * px_per_unit, - }; - } - - if (os2_ascent != 0 or os2_descent != 0) { - break :vertical_metrics .{ - os2_ascent * px_per_unit, - os2_descent * px_per_unit, - os2_line_gap * px_per_unit, - }; - } - - const win_ascent: f64 = @floatFromInt(os2.usWinAscent); - const win_descent: f64 = @floatFromInt(os2.usWinDescent); + // If our font has no OS/2 table, then we just + // blindly use the metrics from the hhea table. break :vertical_metrics .{ - win_ascent * px_per_unit, - // usWinDescent is *positive* -> down unlike sTypoDescender - // and hhea.Descender, so we flip its sign to fix this. - -win_descent * px_per_unit, - 0.0, + hhea_ascent * px_per_unit, + hhea_descent * px_per_unit, + hhea_line_gap * px_per_unit, }; }; @@ -672,30 +679,46 @@ pub const Face = struct { @as(f64, @floatFromInt(post.underlineThickness)) * px_per_unit; // Similar logic to the underline above. - const has_broken_strikethrough = os2.yStrikeoutSize == 0; + const strikethrough_position, const strikethrough_thickness = st: { + if (maybe_os2) |os2| { + const has_broken_strikethrough = os2.yStrikeoutSize == 0; - const strikethrough_position: ?f64 = if (has_broken_strikethrough and os2.yStrikeoutPosition == 0) - null - else - @as(f64, @floatFromInt(os2.yStrikeoutPosition)) * px_per_unit; + const pos: ?f64 = if (has_broken_strikethrough and os2.yStrikeoutPosition == 0) + null + else + @as(f64, @floatFromInt(os2.yStrikeoutPosition)) * px_per_unit; - const strikethrough_thickness: ?f64 = if (has_broken_strikethrough) - null - else - @as(f64, @floatFromInt(os2.yStrikeoutSize)) * px_per_unit; + const thick: ?f64 = if (has_broken_strikethrough) + null + else + @as(f64, @floatFromInt(os2.yStrikeoutSize)) * px_per_unit; - // We fall back to whatever CoreText does if - // the OS/2 table doesn't specify a cap height. - const cap_height: f64 = if (os2.sCapHeight) |sCapHeight| - @as(f64, @floatFromInt(sCapHeight)) * px_per_unit - else - ct_font.getCapHeight(); + break :st .{ pos, thick }; + } - // Ditto for ex height. - const ex_height: f64 = if (os2.sxHeight) |sxHeight| - @as(f64, @floatFromInt(sxHeight)) * px_per_unit - else - ct_font.getXHeight(); + break :st .{ null, null }; + }; + + // We fall back to whatever CoreText does if the + // OS/2 table doesn't specify a cap or ex height. + const cap_height: f64, const ex_height: f64 = heights: { + if (maybe_os2) |os2| { + break :heights .{ + if (os2.sCapHeight) |sCapHeight| + @as(f64, @floatFromInt(sCapHeight)) * px_per_unit + else + ct_font.getCapHeight(), + if (os2.sxHeight) |sxHeight| + @as(f64, @floatFromInt(sxHeight)) * px_per_unit + else + ct_font.getXHeight(), + }; + } + break :heights .{ + ct_font.getCapHeight(), + ct_font.getXHeight(), + }; + }; // Cell width is calculated by calculating the widest width of the // visible ASCII characters. Usually 'M' is widest but we just take