diff options
| -rw-r--r-- | src/font/Collection.zig | 23 | ||||
| -rw-r--r-- | src/font/face/coretext.zig | 184 | ||||
| -rw-r--r-- | src/font/face/freetype.zig | 188 |
3 files changed, 218 insertions, 177 deletions
diff --git a/src/font/Collection.zig b/src/font/Collection.zig index 2b5f591a5..ad9590d70 100644 --- a/src/font/Collection.zig +++ b/src/font/Collection.zig @@ -92,7 +92,6 @@ pub const AddOptions = struct { pub const AddError = Allocator.Error || - Face.GetMetricsError || error{ /// There's no more room in the collection. CollectionFull, @@ -127,7 +126,7 @@ pub fn add( // Scale factor to adjust the size of the added face. const scale_factor = self.scaleFactor( - try owned_face.getMetrics(), + owned_face.getMetrics(), opts.size_adjustment, ); @@ -225,7 +224,7 @@ fn getFaceFromEntry( // entry now that we have a loaded face. entry.scale_factor = .{ .scale = self.scaleFactor( - try face.getMetrics(), + face.getMetrics(), entry.scale_factor.adjustment, ), }; @@ -592,7 +591,7 @@ fn scaleFactor( @branchHint(.unlikely); // If we can't load the primary face, just use 1.0 as the scale factor. const primary_face = self.getFace(.{ .idx = 0 }) catch return 1.0; - self.primary_face_metrics = primary_face.getMetrics() catch return 1.0; + self.primary_face_metrics = primary_face.getMetrics(); } const primary_metrics = self.primary_face_metrics.?; @@ -652,7 +651,7 @@ fn scaleFactor( return primary_metric / face_metric; } -const UpdateMetricsError = font.Face.GetMetricsError || error{ +const UpdateMetricsError = error{ CannotLoadPrimaryFont, }; @@ -663,7 +662,7 @@ const UpdateMetricsError = font.Face.GetMetricsError || error{ pub fn updateMetrics(self: *Collection) UpdateMetricsError!void { const primary_face = self.getFace(.{ .idx = 0 }) catch return error.CannotLoadPrimaryFont; - self.primary_face_metrics = try primary_face.getMetrics(); + self.primary_face_metrics = primary_face.getMetrics(); var metrics = Metrics.calc(self.primary_face_metrics.?); @@ -1288,8 +1287,8 @@ test "adjusted sizes" { // The chosen metric should match. { - const primary_metrics = try (try c.getFace(.{ .idx = 0 })).getMetrics(); - const fallback_metrics = try (try c.getFace(fallback_idx)).getMetrics(); + const primary_metrics = (try c.getFace(.{ .idx = 0 })).getMetrics(); + const fallback_metrics = (try c.getFace(fallback_idx)).getMetrics(); try std.testing.expectApproxEqAbs( @field(primary_metrics, metric).?, @@ -1302,8 +1301,8 @@ test "adjusted sizes" { // Resize should keep that relationship. try c.setSize(.{ .points = 37, .xdpi = 96, .ydpi = 96 }); { - const primary_metrics = try (try c.getFace(.{ .idx = 0 })).getMetrics(); - const fallback_metrics = try (try c.getFace(fallback_idx)).getMetrics(); + const primary_metrics = (try c.getFace(.{ .idx = 0 })).getMetrics(); + const fallback_metrics = (try c.getFace(fallback_idx)).getMetrics(); try std.testing.expectApproxEqAbs( @field(primary_metrics, metric).?, @@ -1359,8 +1358,8 @@ test "adjusted sizes" { // Test fallback to lineHeight() (ex_height and cap_height not defined in symbols font). { - const primary_metrics = try (try c.getFace(.{ .idx = 0 })).getMetrics(); - const symbol_metrics = try (try c.getFace(symbol_idx)).getMetrics(); + const primary_metrics = (try c.getFace(.{ .idx = 0 })).getMetrics(); + const symbol_metrics = (try c.getFace(symbol_idx)).getMetrics(); try std.testing.expectApproxEqAbs( primary_metrics.lineHeight(), diff --git a/src/font/face/coretext.zig b/src/font/face/coretext.zig index a85c94430..2804ce2cb 100644 --- a/src/font/face/coretext.zig +++ b/src/font/face/coretext.zig @@ -574,19 +574,12 @@ pub const Face = struct { }; } - pub const GetMetricsError = error{ - CopyTableError, - InvalidHeadTable, - InvalidPostTable, - InvalidHheaTable, - }; - /// Get the `FaceMetrics` for this face. - pub fn getMetrics(self: *Face) GetMetricsError!font.Metrics.FaceMetrics { + pub fn getMetrics(self: *Face) font.Metrics.FaceMetrics { const ct_font = self.font; // Read the 'head' table out of the font data. - const head: opentype.Head = head: { + const head_: ?opentype.Head = head: { // macOS bitmap-only fonts use a 'bhed' tag rather than 'head', but // the table format is byte-identical to the 'head' table, so if we // can't find 'head' we try 'bhed' instead before failing. @@ -597,29 +590,26 @@ pub const Face = struct { const data = ct_font.copyTable(head_tag) orelse ct_font.copyTable(bhed_tag) orelse - return error.CopyTableError; + break :head null; defer data.release(); const ptr = data.getPointer(); const len = data.getLength(); break :head opentype.Head.init(ptr[0..len]) catch |err| { - return switch (err) { - error.EndOfStream, - => error.InvalidHeadTable, - }; + log.warn("error parsing head table: {}", .{err}); + break :head null; }; }; // Read the 'post' table out of the font data. - const post: opentype.Post = post: { + const post_: ?opentype.Post = post: { const tag = macos.text.FontTableTag.init("post"); - const data = ct_font.copyTable(tag) orelse return error.CopyTableError; + const data = ct_font.copyTable(tag) orelse break :post null; defer data.release(); const ptr = data.getPointer(); const len = data.getLength(); break :post opentype.Post.init(ptr[0..len]) catch |err| { - return switch (err) { - error.EndOfStream => error.InvalidPostTable, - }; + log.warn("error parsing post table: {}", .{err}); + break :post null; }; }; @@ -637,96 +627,114 @@ pub const Face = struct { }; // Read the 'hhea' table out of the font data. - const hhea: opentype.Hhea = hhea: { + const hhea_: ?opentype.Hhea = hhea: { const tag = macos.text.FontTableTag.init("hhea"); - const data = ct_font.copyTable(tag) orelse return error.CopyTableError; + const data = ct_font.copyTable(tag) orelse break :hhea null; defer data.release(); const ptr = data.getPointer(); const len = data.getLength(); break :hhea opentype.Hhea.init(ptr[0..len]) catch |err| { - return switch (err) { - error.EndOfStream => error.InvalidHheaTable, - }; + log.warn("error parsing hhea table: {}", .{err}); + break :hhea null; }; }; - const units_per_em: f64 = @floatFromInt(head.unitsPerEm); + const units_per_em: f64 = + if (head_) |head| + @floatFromInt(head.unitsPerEm) + else + @floatFromInt(self.font.getUnitsPerEm()); const px_per_em: f64 = ct_font.getSize(); const px_per_unit: f64 = px_per_em / units_per_em; const ascent: f64, const descent: f64, const line_gap: f64 = vertical_metrics: { - const hhea_ascent: f64 = @floatFromInt(hhea.ascender); - const hhea_descent: f64 = @floatFromInt(hhea.descender); - const hhea_line_gap: f64 = @floatFromInt(hhea.lineGap); - - if (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_) |hhea| { + const hhea_ascent: f64 = @floatFromInt(hhea.ascender); + const hhea_descent: f64 = @floatFromInt(hhea.descender); + const hhea_line_gap: f64 = @floatFromInt(hhea.lineGap); + + if (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 .{ + 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, + }; + } - if (hhea.ascender != 0 or hhea.descender != 0) break :vertical_metrics .{ + // If our font has no OS/2 table, then we just + // blindly use the metrics from the hhea table. + 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 .{ - 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, - }; } - // If our font has no OS/2 table, then we just - // blindly use the metrics from the hhea table. + // If we couldn't get the hhea table, rely on metrics from CoreText. break :vertical_metrics .{ - hhea_ascent * px_per_unit, - hhea_descent * px_per_unit, - hhea_line_gap * px_per_unit, + self.font.getAscent(), + -self.font.getDescent(), + self.font.getLeading(), }; }; - // Some fonts have degenerate 'post' tables where the underline - // thickness (and often position) are 0. We consider them null - // if this is the case and use our own fallbacks when we calculate. - const has_broken_underline = post.underlineThickness == 0; + const underline_position, const underline_thickness = ul: { + const post = post_ orelse break :ul .{ null, null }; - // If the underline position isn't 0 then we do use it, - // even if the thickness is't properly specified. - const underline_position: ?f64 = if (has_broken_underline and post.underlinePosition == 0) - null - else - @as(f64, @floatFromInt(post.underlinePosition)) * px_per_unit; + // Some fonts have degenerate 'post' tables where the underline + // thickness (and often position) are 0. We consider them null + // if this is the case and use our own fallbacks when we calculate. + const has_broken_underline = post.underlineThickness == 0; - const underline_thickness = if (has_broken_underline) - null - else - @as(f64, @floatFromInt(post.underlineThickness)) * px_per_unit; + // If the underline position isn't 0 then we do use it, + // even if the thickness is't properly specified. + const pos: ?f64 = if (has_broken_underline and post.underlinePosition == 0) + null + else + @as(f64, @floatFromInt(post.underlinePosition)) * px_per_unit; + + const thick: ?f64 = if (has_broken_underline) + null + else + @as(f64, @floatFromInt(post.underlineThickness)) * px_per_unit; + + break :ul .{ pos, thick }; + }; // Similar logic to the underline above. const strikethrough_position, const strikethrough_thickness = st: { @@ -989,7 +997,7 @@ test { alloc, &atlas, face.glyphIndex(i).?, - .{ .grid_metrics = font.Metrics.calc(try face.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(face.getMetrics()) }, ); } } @@ -1054,7 +1062,7 @@ test "in-memory" { alloc, &atlas, face.glyphIndex(i).?, - .{ .grid_metrics = font.Metrics.calc(try face.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(face.getMetrics()) }, ); } } @@ -1081,7 +1089,7 @@ test "variable" { alloc, &atlas, face.glyphIndex(i).?, - .{ .grid_metrics = font.Metrics.calc(try face.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(face.getMetrics()) }, ); } } @@ -1112,7 +1120,7 @@ test "variable set variation" { alloc, &atlas, face.glyphIndex(i).?, - .{ .grid_metrics = font.Metrics.calc(try face.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(face.getMetrics()) }, ); } } diff --git a/src/font/face/freetype.zig b/src/font/face/freetype.zig index 1d8d2efff..ef4275131 100644 --- a/src/font/face/freetype.zig +++ b/src/font/face/freetype.zig @@ -784,12 +784,8 @@ pub const Face = struct { return @as(F26Dot6, @bitCast(@as(i32, @intCast(v)))).to(f64); } - pub const GetMetricsError = error{ - CopyTableError, - }; - /// Get the `FaceMetrics` for this face. - pub fn getMetrics(self: *Face) GetMetricsError!font.Metrics.FaceMetrics { + pub fn getMetrics(self: *Face) font.Metrics.FaceMetrics { const face = self.face; const size_metrics = face.handle.*.size.*.metrics; @@ -799,10 +795,10 @@ pub const Face = struct { assert(size_metrics.x_ppem == size_metrics.y_ppem); // Read the 'head' table out of the font data. - const head = face.getSfntTable(.head) orelse return error.CopyTableError; + const head_ = face.getSfntTable(.head); // Read the 'post' table out of the font data. - const post = face.getSfntTable(.post) orelse return error.CopyTableError; + const post_ = face.getSfntTable(.post); // Read the 'OS/2' table out of the font data. const os2_: ?*freetype.c.TT_OS2 = os2: { @@ -812,92 +808,130 @@ pub const Face = struct { }; // Read the 'hhea' table out of the font data. - const hhea = face.getSfntTable(.hhea) orelse return error.CopyTableError; + const hhea_ = face.getSfntTable(.hhea); + + // Whether the font is in a scalable format. We need to know this + // because many of the metrics provided by FreeType are invalid for + // non-scalable fonts. + const is_scalable = face.handle.*.face_flags & freetype.c.FT_FACE_FLAG_SCALABLE != 0; - const units_per_em = head.Units_Per_EM; + // We get the UPM from the head table. + // + // If we have no head, but it is a scalable face, take the UPM from + // FreeType's units_per_EM, otherwise we'll assume that UPM == PPEM. + const units_per_em: freetype.c.FT_UShort = + if (head_) |head| + head.Units_Per_EM + else if (is_scalable) + face.handle.*.units_per_EM + else + size_metrics.y_ppem; const px_per_em: f64 = @floatFromInt(size_metrics.y_ppem); const px_per_unit = px_per_em / @as(f64, @floatFromInt(units_per_em)); const ascent: f64, const descent: f64, const line_gap: f64 = vertical_metrics: { - const hhea_ascent: f64 = @floatFromInt(hhea.Ascender); - const hhea_descent: f64 = @floatFromInt(hhea.Descender); - const hhea_line_gap: f64 = @floatFromInt(hhea.Line_Gap); - - if (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. - // (The USE_TYPO_METRICS bit is bit 7) - if (os2.fsSelection & (1 << 7) != 0) { - break :vertical_metrics .{ - os2_ascent * px_per_unit, - os2_descent * px_per_unit, - os2_line_gap * px_per_unit, - }; - } + if (hhea_) |hhea| { + const hhea_ascent: f64 = @floatFromInt(hhea.Ascender); + const hhea_descent: f64 = @floatFromInt(hhea.Descender); + const hhea_line_gap: f64 = @floatFromInt(hhea.Line_Gap); + + if (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. + // (The USE_TYPO_METRICS bit is bit 7) + if (os2.fsSelection & (1 << 7) != 0) { + 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. + // 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 (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, + }; + } - if (os2_ascent != 0 or os2_descent != 0) { + 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, }; } - 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, }; } - // If our font has no OS/2 table, then we just - // blindly use the metrics from the hhea table. + // If we couldn't get the hhea table, rely on metrics from FreeType. + const ascender = f26dot6ToF64(size_metrics.ascender); + const descender = f26dot6ToF64(size_metrics.descender); + const height = f26dot6ToF64(size_metrics.height); break :vertical_metrics .{ - hhea_ascent * px_per_unit, - hhea_descent * px_per_unit, - hhea_line_gap * px_per_unit, + ascender, + descender, + // We compute the line gap by adding the (negative) descender + // and subtracting the (positive) ascender from the line height + // to get the remaining gap size. + // + // NOTE: This might always be 0... but it doesn't hurt to do. + height + descender - ascender, }; }; - // Some fonts have degenerate 'post' tables where the underline - // thickness (and often position) are 0. We consider them null - // if this is the case and use our own fallbacks when we calculate. - const has_broken_underline = post.underlineThickness == 0; + const underline_position: ?f64, const underline_thickness: ?f64 = ul: { + const post = post_ orelse break :ul .{ null, null }; + + // Some fonts have degenerate 'post' tables where the underline + // thickness (and often position) are 0. We consider them null + // if this is the case and use our own fallbacks when we calculate. + const has_broken_underline = post.underlineThickness == 0; - // If the underline position isn't 0 then we do use it, - // even if the thickness is't properly specified. - const underline_position = if (has_broken_underline and post.underlinePosition == 0) - null - else - @as(f64, @floatFromInt(post.underlinePosition)) * px_per_unit; + // If the underline position isn't 0 then we do use it, + // even if the thickness is't properly specified. + const pos: ?f64 = if (has_broken_underline and post.underlinePosition == 0) + null + else + @as(f64, @floatFromInt(post.underlinePosition)) * px_per_unit; + + const thick: ?f64 = if (has_broken_underline) + null + else + @as(f64, @floatFromInt(post.underlineThickness)) * px_per_unit; - const underline_thickness = if (has_broken_underline) - null - else - @as(f64, @floatFromInt(post.underlineThickness)) * px_per_unit; + break :ul .{ pos, thick }; + }; // Similar logic to the underline above. const strikethrough_position, const strikethrough_thickness = st: { @@ -1085,7 +1119,7 @@ test { alloc, &atlas, ft_font.glyphIndex(i).?, - .{ .grid_metrics = font.Metrics.calc(try ft_font.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(ft_font.getMetrics()) }, ); } @@ -1095,7 +1129,7 @@ test { alloc, &atlas, ft_font.glyphIndex('A').?, - .{ .grid_metrics = font.Metrics.calc(try ft_font.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(ft_font.getMetrics()) }, ); try testing.expectEqual(@as(u32, 11), g1.height); @@ -1104,7 +1138,7 @@ test { alloc, &atlas, ft_font.glyphIndex('A').?, - .{ .grid_metrics = font.Metrics.calc(try ft_font.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(ft_font.getMetrics()) }, ); try testing.expectEqual(@as(u32, 20), g2.height); } @@ -1131,7 +1165,7 @@ test "color emoji" { alloc, &atlas, ft_font.glyphIndex('🥸').?, - .{ .grid_metrics = font.Metrics.calc(try ft_font.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(ft_font.getMetrics()) }, ); // Make sure this glyph has color @@ -1191,7 +1225,7 @@ test "mono to bgra" { alloc, &atlas, 3, - .{ .grid_metrics = font.Metrics.calc(try ft_font.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(ft_font.getMetrics()) }, ); } @@ -1255,7 +1289,7 @@ test "bitmap glyph" { alloc, &atlas, 77, - .{ .grid_metrics = font.Metrics.calc(try ft_font.getMetrics()) }, + .{ .grid_metrics = font.Metrics.calc(ft_font.getMetrics()) }, ); // should render crisp |