mirror of
https://github.com/ghostty-org/ghostty.git
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font/opentype: add table parsing for head, hhea, post, and OS/2
(and a utility for parsing SFNT font files and fetching table data from them)
This commit is contained in:
Qwerasd
@ -1,6 +1,16 @@
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pub const sfnt = @import("opentype/sfnt.zig");
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const svg = @import("opentype/svg.zig");
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const os2 = @import("opentype/os2.zig");
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const post = @import("opentype/post.zig");
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const hhea = @import("opentype/hhea.zig");
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const head = @import("opentype/head.zig");
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pub const SVG = svg.SVG;
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pub const OS2 = os2.OS2;
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pub const Post = post.Post;
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pub const Hhea = hhea.Hhea;
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pub const Head = head.Head;
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test {
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@import("std").testing.refAllDecls(@This());
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179
src/font/opentype/head.zig
Normal file
179
src/font/opentype/head.zig
Normal file
@ -0,0 +1,179 @@
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const std = @import("std");
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const assert = std.debug.assert;
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const sfnt = @import("sfnt.zig");
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/// Font Header Table
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///
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/// References:
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/// - https://learn.microsoft.com/en-us/typography/opentype/spec/head
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pub const Head = extern struct {
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/// Major version number of the font header table — set to 1.
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majorVersion: sfnt.uint16 align(1),
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/// Minor version number of the font header table — set to 0.
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minorVersion: sfnt.uint16 align(1),
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/// Set by font manufacturer.
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fontRevision: sfnt.Fixed align(1),
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/// To compute: set it to 0, sum the entire font as uint32, then store
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/// 0xB1B0AFBA - sum. If the font is used as a component in a font
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/// collection file, the value of this field will be invalidated by
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/// changes to the file structure and font table directory, and must
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/// be ignored.
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checksumAdjustment: sfnt.uint32 align(1),
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/// Set to 0x5F0F3CF5.
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magicNumber: sfnt.uint32 align(1),
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/// Bit 0: Baseline for font at y=0.
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///
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/// Bit 1: Left sidebearing point at x=0
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/// (relevant only for TrueType rasterizers)
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///
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/// Bit 2: Instructions may depend on point size.
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///
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/// Bit 3: Force ppem to integer values for all internal scaler math; may
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/// use fractional ppem sizes if this bit is clear. It is strongly
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/// recommended that this be set in hinted fonts.
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///
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/// Bit 4: Instructions may alter advance width
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/// (the advance widths might not scale linearly).
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///
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/// Bit 5: This bit is not used in OpenType, and should not be set in order
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/// to ensure compatible behavior on all platforms. If set, it may
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/// result in different behavior for vertical layout in some
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/// platforms.
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///
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/// (See Apple’s specification for details
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/// regarding behavior in Apple platforms.)
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///
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/// Bits 6 – 10: These bits are not used in OpenType and should always be
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/// cleared.
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///
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/// (See Apple’s specification for details
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/// regarding legacy use in Apple platforms.)
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///
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/// Bit 11: Font data is “lossless” as a result of having been
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/// subjected to optimizing transformation and/or compression
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/// (such as compression mechanisms defined by ISO/IEC 14496-18,
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/// MicroType® Express, WOFF 2.0, or similar) where the original
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/// font functionality and features are retained but the binary
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/// compatibility between input and output font files is not
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/// guaranteed. As a result of the applied transform, the DSIG
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/// table may also be invalidated.
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///
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/// Bit 12: Font converted (produce compatible metrics).
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///
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/// Bit 13: Font optimized for ClearType®. Note, fonts that rely on embedded
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/// bitmaps (EBDT) for rendering should not be considered optimized
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/// for ClearType, and therefore should keep this bit cleared.
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///
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/// Bit 14: Last Resort font. If set, indicates that the glyphs encoded in
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/// the 'cmap' subtables are simply generic symbolic representations
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/// of code point ranges and do not truly represent support for
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/// those code points. If unset, indicates that the glyphs encoded
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/// in the 'cmap' subtables represent proper support for those code
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/// points.
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///
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/// Bit 15: Reserved, set to 0.
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flags: sfnt.uint16 align(1),
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/// Set to a value from 16 to 16384. Any value in this range is valid.
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///
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/// In fonts that have TrueType outlines, a power of 2 is recommended
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/// as this allows performance optimization in some rasterizers.
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unitsPerEm: sfnt.uint16 align(1),
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/// Number of seconds since 12:00 midnight that started
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/// January 1st, 1904, in GMT/UTC time zone.
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created: sfnt.LONGDATETIME align(1),
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/// Number of seconds since 12:00 midnight that started
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/// January 1st, 1904, in GMT/UTC time zone.
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modified: sfnt.LONGDATETIME align(1),
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/// Minimum x coordinate across all glyph bounding boxes.
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xMin: sfnt.int16 align(1),
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/// Minimum y coordinate across all glyph bounding boxes.
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yMin: sfnt.int16 align(1),
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/// Maximum x coordinate across all glyph bounding boxes.
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xMax: sfnt.int16 align(1),
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/// Maximum y coordinate across all glyph bounding boxes.
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yMax: sfnt.int16 align(1),
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/// Bit 0: Bold (if set to 1);
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/// Bit 1: Italic (if set to 1)
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/// Bit 2: Underline (if set to 1)
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/// Bit 3: Outline (if set to 1)
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/// Bit 4: Shadow (if set to 1)
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/// Bit 5: Condensed (if set to 1)
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/// Bit 6: Extended (if set to 1)
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/// Bits 7 – 15: Reserved (set to 0).
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macStyle: sfnt.uint16 align(1),
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/// Smallest readable size in pixels.
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lowestRecPPEM: sfnt.uint16 align(1),
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/// Deprecated (Set to 2).
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/// 0: Fully mixed directional glyphs;
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/// 1: Only strongly left to right;
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/// 2: Like 1 but also contains neutrals;
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/// -1: Only strongly right to left;
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/// -2: Like -1 but also contains neutrals.
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fontDirectionHint: sfnt.int16 align(1),
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/// 0 for short offsets (Offset16), 1 for long (Offset32).
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indexToLocFormat: sfnt.int16 align(1),
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/// 0 for current format.
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glyphDataFormat: sfnt.int16 align(1),
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/// Parse the table from raw data.
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pub fn init(data: []const u8) !Head {
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var fbs = std.io.fixedBufferStream(data);
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const reader = fbs.reader();
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return try reader.readStructEndian(Head, .big);
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}
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};
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test "head" {
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const testing = std.testing;
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const alloc = testing.allocator;
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const test_font = @import("../embedded.zig").julia_mono;
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const font = try sfnt.SFNT.init(test_font, alloc);
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defer font.deinit(alloc);
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const table = font.getTable("head").?;
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const head = try Head.init(table);
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try testing.expectEqualDeep(
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Head{
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.majorVersion = 1,
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.minorVersion = 0,
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.fontRevision = sfnt.Fixed.from(0.05499267578125),
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.checksumAdjustment = 1007668681,
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.magicNumber = 1594834165,
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.flags = 7,
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.unitsPerEm = 2000,
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.created = 3797757830,
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.modified = 3797760444,
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.xMin = -1000,
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.yMin = -1058,
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.xMax = 3089,
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.yMax = 2400,
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.macStyle = 0,
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.lowestRecPPEM = 7,
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.fontDirectionHint = 2,
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.indexToLocFormat = 1,
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.glyphDataFormat = 0,
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},
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head,
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);
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}
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115
src/font/opentype/hhea.zig
Normal file
115
src/font/opentype/hhea.zig
Normal file
@ -0,0 +1,115 @@
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const std = @import("std");
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const assert = std.debug.assert;
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const sfnt = @import("sfnt.zig");
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/// Horizontal Header Table
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///
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/// References:
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/// - https://learn.microsoft.com/en-us/typography/opentype/spec/hhea
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pub const Hhea = extern struct {
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/// Major version number of the horizontal header table — set to 1.
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majorVersion: sfnt.uint16 align(1),
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/// Minor version number of the horizontal header table — set to 0.
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minorVersion: sfnt.uint16 align(1),
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/// Typographic ascent—see remarks below.
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ascender: sfnt.FWORD align(1),
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/// Typographic descent—see remarks below.
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descender: sfnt.FWORD align(1),
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/// Typographic line gap.
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///
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/// Negative lineGap values are treated as zero
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/// in some legacy platform implementations.
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lineGap: sfnt.FWORD align(1),
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/// Maximum advance width value in 'hmtx' table.
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advanceWidthMax: sfnt.UFWORD align(1),
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/// Minimum left sidebearing value in 'hmtx' table for
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/// glyphs with contours (empty glyphs should be ignored).
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minLeftSideBearing: sfnt.FWORD align(1),
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/// Minimum right sidebearing value; calculated as
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/// min(aw - (lsb + xMax - xMin)) for glyphs with
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/// contours (empty glyphs should be ignored).
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minRightSideBearing: sfnt.FWORD align(1),
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/// Max(lsb + (xMax - xMin)).
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xMaxExtent: sfnt.FWORD align(1),
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/// Used to calculate the slope of the cursor (rise/run); 1 for vertical.
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caretSlopeRise: sfnt.int16 align(1),
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/// 0 for vertical.
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caretSlopeRun: sfnt.int16 align(1),
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/// The amount by which a slanted highlight on a glyph needs to be shifted
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/// to produce the best appearance. Set to 0 for non-slanted fonts
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caretOffset: sfnt.int16 align(1),
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/// set to 0
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_reserved0: sfnt.int16 align(1),
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/// set to 0
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_reserved1: sfnt.int16 align(1),
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/// set to 0
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_reserved2: sfnt.int16 align(1),
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/// set to 0
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_reserved3: sfnt.int16 align(1),
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/// 0 for current format.
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metricDataFormat: sfnt.int16 align(1),
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/// Number of hMetric entries in 'hmtx' table
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numberOfHMetrics: sfnt.uint16 align(1),
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/// Parse the table from raw data.
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pub fn init(data: []const u8) !Hhea {
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var fbs = std.io.fixedBufferStream(data);
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const reader = fbs.reader();
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return try reader.readStructEndian(Hhea, .big);
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}
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};
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test "hhea" {
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const testing = std.testing;
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const alloc = testing.allocator;
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const test_font = @import("../embedded.zig").julia_mono;
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const font = try sfnt.SFNT.init(test_font, alloc);
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defer font.deinit(alloc);
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const table = font.getTable("hhea").?;
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const hhea = try Hhea.init(table);
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try testing.expectEqualDeep(
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Hhea{
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.majorVersion = 1,
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.minorVersion = 0,
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.ascender = 1900,
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.descender = -450,
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.lineGap = 0,
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.advanceWidthMax = 1200,
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.minLeftSideBearing = -1000,
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.minRightSideBearing = -1889,
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.xMaxExtent = 3089,
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.caretSlopeRise = 1,
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.caretSlopeRun = 0,
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.caretOffset = 0,
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._reserved0 = 0,
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._reserved1 = 0,
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._reserved2 = 0,
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._reserved3 = 0,
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.metricDataFormat = 0,
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.numberOfHMetrics = 2,
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},
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hhea,
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);
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}
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577
src/font/opentype/os2.zig
Normal file
577
src/font/opentype/os2.zig
Normal file
@ -0,0 +1,577 @@
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const std = @import("std");
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const assert = std.debug.assert;
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const sfnt = @import("sfnt.zig");
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pub const FSSelection = packed struct(sfnt.uint16) {
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/// Font contains italic or oblique glyphs, otherwise they are upright.
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italic: bool = false,
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/// Glyphs are underscored.
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underscore: bool = false,
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/// Glyphs have their foreground and background reversed.
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negative: bool = false,
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/// Outline (hollow) glyphs, otherwise they are solid.
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outlined: bool = false,
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/// Glyphs are overstruck.
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strikeout: bool = false,
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/// Glyphs are emboldened.
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bold: bool = false,
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/// Glyphs are in the standard weight/style for the font.
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regular: bool = false,
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/// If set, it is strongly recommended that applications use
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/// OS/2.sTypoAscender - OS/2.sTypoDescender + OS/2.sTypoLineGap
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/// as the default line spacing for this font.
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use_typo_metrics: bool = false,
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/// The font has 'name' table strings consistent with a weight/width/slope
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/// family without requiring use of name IDs 21 and 22.
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wws: bool = false,
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/// Font contains oblique glyphs.
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oblique: bool = false,
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_reserved: u6 = 0,
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};
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/// OS/2 and Windows Metrics Table
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///
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/// References:
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/// - https://learn.microsoft.com/en-us/typography/opentype/spec/os2
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pub const OS2v5 = extern struct {
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version: sfnt.uint16 align(1),
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xAvgCharWidth: sfnt.FWORD align(1),
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usWeightClass: sfnt.uint16 align(1),
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usWidthClass: sfnt.uint16 align(1),
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fsType: sfnt.uint16 align(1),
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ySubscriptXSize: sfnt.FWORD align(1),
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ySubscriptYSize: sfnt.FWORD align(1),
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ySubscriptXOffset: sfnt.FWORD align(1),
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ySubscriptYOffset: sfnt.FWORD align(1),
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ySuperscriptXSize: sfnt.FWORD align(1),
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ySuperscriptYSize: sfnt.FWORD align(1),
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ySuperscriptXOffset: sfnt.FWORD align(1),
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ySuperscriptYOffset: sfnt.FWORD align(1),
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yStrikeoutSize: sfnt.FWORD align(1),
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yStrikeoutPosition: sfnt.FWORD align(1),
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sFamilyClass: sfnt.int16 align(1),
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panose: [10]sfnt.uint8 align(1),
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ulUnicodeRange1: sfnt.uint32 align(1),
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ulUnicodeRange2: sfnt.uint32 align(1),
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ulUnicodeRange3: sfnt.uint32 align(1),
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ulUnicodeRange4: sfnt.uint32 align(1),
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achVendID: sfnt.Tag align(1),
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fsSelection: FSSelection align(1),
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usFirstCharIndex: sfnt.uint16 align(1),
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usLastCharIndex: sfnt.uint16 align(1),
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sTypoAscender: sfnt.FWORD align(1),
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sTypoDescender: sfnt.FWORD align(1),
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sTypoLineGap: sfnt.FWORD align(1),
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usWinAscent: sfnt.UFWORD align(1),
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usWinDescent: sfnt.UFWORD align(1),
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ulCodePageRange1: sfnt.uint32 align(1),
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ulCodePageRange2: sfnt.uint32 align(1),
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sxHeight: sfnt.FWORD align(1),
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sCapHeight: sfnt.FWORD align(1),
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usDefaultChar: sfnt.uint16 align(1),
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usBreakChar: sfnt.uint16 align(1),
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usMaxContext: sfnt.uint16 align(1),
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usLowerOpticalPointSize: sfnt.uint16 align(1),
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usUpperOpticalPointSize: sfnt.uint16 align(1),
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};
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pub const OS2v4_3_2 = extern struct {
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version: sfnt.uint16 align(1),
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xAvgCharWidth: sfnt.FWORD align(1),
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usWeightClass: sfnt.uint16 align(1),
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usWidthClass: sfnt.uint16 align(1),
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fsType: sfnt.uint16 align(1),
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ySubscriptXSize: sfnt.FWORD align(1),
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ySubscriptYSize: sfnt.FWORD align(1),
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ySubscriptXOffset: sfnt.FWORD align(1),
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ySubscriptYOffset: sfnt.FWORD align(1),
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ySuperscriptXSize: sfnt.FWORD align(1),
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ySuperscriptYSize: sfnt.FWORD align(1),
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ySuperscriptXOffset: sfnt.FWORD align(1),
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ySuperscriptYOffset: sfnt.FWORD align(1),
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yStrikeoutSize: sfnt.FWORD align(1),
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yStrikeoutPosition: sfnt.FWORD align(1),
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sFamilyClass: sfnt.int16 align(1),
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panose: [10]sfnt.uint8 align(1),
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ulUnicodeRange1: sfnt.uint32 align(1),
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ulUnicodeRange2: sfnt.uint32 align(1),
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ulUnicodeRange3: sfnt.uint32 align(1),
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ulUnicodeRange4: sfnt.uint32 align(1),
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achVendID: sfnt.Tag align(1),
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fsSelection: FSSelection align(1),
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usFirstCharIndex: sfnt.uint16 align(1),
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usLastCharIndex: sfnt.uint16 align(1),
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sTypoAscender: sfnt.FWORD align(1),
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sTypoDescender: sfnt.FWORD align(1),
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sTypoLineGap: sfnt.FWORD align(1),
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usWinAscent: sfnt.UFWORD align(1),
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usWinDescent: sfnt.UFWORD align(1),
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ulCodePageRange1: sfnt.uint32 align(1),
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ulCodePageRange2: sfnt.uint32 align(1),
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sxHeight: sfnt.FWORD align(1),
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sCapHeight: sfnt.FWORD align(1),
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usDefaultChar: sfnt.uint16 align(1),
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usBreakChar: sfnt.uint16 align(1),
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usMaxContext: sfnt.uint16 align(1),
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};
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pub const OS2v1 = extern struct {
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version: sfnt.uint16 align(1),
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xAvgCharWidth: sfnt.FWORD align(1),
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usWeightClass: sfnt.uint16 align(1),
|
||||
usWidthClass: sfnt.uint16 align(1),
|
||||
fsType: sfnt.uint16 align(1),
|
||||
ySubscriptXSize: sfnt.FWORD align(1),
|
||||
ySubscriptYSize: sfnt.FWORD align(1),
|
||||
ySubscriptXOffset: sfnt.FWORD align(1),
|
||||
ySubscriptYOffset: sfnt.FWORD align(1),
|
||||
ySuperscriptXSize: sfnt.FWORD align(1),
|
||||
ySuperscriptYSize: sfnt.FWORD align(1),
|
||||
ySuperscriptXOffset: sfnt.FWORD align(1),
|
||||
ySuperscriptYOffset: sfnt.FWORD align(1),
|
||||
yStrikeoutSize: sfnt.FWORD align(1),
|
||||
yStrikeoutPosition: sfnt.FWORD align(1),
|
||||
sFamilyClass: sfnt.int16 align(1),
|
||||
panose: [10]sfnt.uint8 align(1),
|
||||
ulUnicodeRange1: sfnt.uint32 align(1),
|
||||
ulUnicodeRange2: sfnt.uint32 align(1),
|
||||
ulUnicodeRange3: sfnt.uint32 align(1),
|
||||
ulUnicodeRange4: sfnt.uint32 align(1),
|
||||
achVendID: sfnt.Tag align(1),
|
||||
fsSelection: FSSelection align(1),
|
||||
usFirstCharIndex: sfnt.uint16 align(1),
|
||||
usLastCharIndex: sfnt.uint16 align(1),
|
||||
sTypoAscender: sfnt.FWORD align(1),
|
||||
sTypoDescender: sfnt.FWORD align(1),
|
||||
sTypoLineGap: sfnt.FWORD align(1),
|
||||
usWinAscent: sfnt.UFWORD align(1),
|
||||
usWinDescent: sfnt.UFWORD align(1),
|
||||
ulCodePageRange1: sfnt.uint32 align(1),
|
||||
ulCodePageRange2: sfnt.uint32 align(1),
|
||||
};
|
||||
|
||||
pub const OS2v0 = extern struct {
|
||||
version: sfnt.uint16 align(1),
|
||||
xAvgCharWidth: sfnt.FWORD align(1),
|
||||
usWeightClass: sfnt.uint16 align(1),
|
||||
usWidthClass: sfnt.uint16 align(1),
|
||||
fsType: sfnt.uint16 align(1),
|
||||
ySubscriptXSize: sfnt.FWORD align(1),
|
||||
ySubscriptYSize: sfnt.FWORD align(1),
|
||||
ySubscriptXOffset: sfnt.FWORD align(1),
|
||||
ySubscriptYOffset: sfnt.FWORD align(1),
|
||||
ySuperscriptXSize: sfnt.FWORD align(1),
|
||||
ySuperscriptYSize: sfnt.FWORD align(1),
|
||||
ySuperscriptXOffset: sfnt.FWORD align(1),
|
||||
ySuperscriptYOffset: sfnt.FWORD align(1),
|
||||
yStrikeoutSize: sfnt.FWORD align(1),
|
||||
yStrikeoutPosition: sfnt.FWORD align(1),
|
||||
sFamilyClass: sfnt.int16 align(1),
|
||||
panose: [10]sfnt.uint8 align(1),
|
||||
ulUnicodeRange1: sfnt.uint32 align(1),
|
||||
ulUnicodeRange2: sfnt.uint32 align(1),
|
||||
ulUnicodeRange3: sfnt.uint32 align(1),
|
||||
ulUnicodeRange4: sfnt.uint32 align(1),
|
||||
achVendID: sfnt.Tag align(1),
|
||||
fsSelection: FSSelection align(1),
|
||||
usFirstCharIndex: sfnt.uint16 align(1),
|
||||
usLastCharIndex: sfnt.uint16 align(1),
|
||||
sTypoAscender: sfnt.FWORD align(1),
|
||||
sTypoDescender: sfnt.FWORD align(1),
|
||||
sTypoLineGap: sfnt.FWORD align(1),
|
||||
usWinAscent: sfnt.UFWORD align(1),
|
||||
usWinDescent: sfnt.UFWORD align(1),
|
||||
};
|
||||
|
||||
/// Generic OS/2 table with optional fields
|
||||
/// for those that don't exist in all versions.
|
||||
///
|
||||
/// References:
|
||||
/// - https://learn.microsoft.com/en-us/typography/opentype/spec/os2
|
||||
pub const OS2 = struct {
|
||||
/// The version number for the OS/2 table: 0x0000 to 0x0005.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2#version
|
||||
version: u16,
|
||||
/// The Average Character Width field specifies the arithmetic average of the escapement (width) of all non-zero width glyphs in the font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#xavgcharwidth
|
||||
xAvgCharWidth: i16,
|
||||
/// Indicates the visual weight (degree of blackness or thickness of strokes) of the characters in the font. Values from 1 to 1000 are valid.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#usweightclass
|
||||
usWeightClass: u16,
|
||||
/// Indicates a relative change from the normal aspect ratio (width to height ratio) as specified by a font designer for the glyphs in a font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#uswidthclass
|
||||
usWidthClass: u16,
|
||||
/// Indicates font embedding licensing rights for the font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#fstype
|
||||
fsType: u16,
|
||||
/// The recommended horizontal size in font design units for subscripts for this font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ysubscriptxsize
|
||||
ySubscriptXSize: i16,
|
||||
/// The recommended vertical size in font design units for subscripts for this font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ysubscriptysize
|
||||
ySubscriptYSize: i16,
|
||||
/// The recommended horizontal offset in font design units for subscripts for this font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ysubscriptxoffset
|
||||
ySubscriptXOffset: i16,
|
||||
/// The recommended vertical offset in font design units from the baseline for subscripts for this font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ysubscriptyoffset
|
||||
ySubscriptYOffset: i16,
|
||||
/// The recommended horizontal size in font design units for superscripts for this font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ysuperscriptxsize
|
||||
ySuperscriptXSize: i16,
|
||||
/// The recommended vertical size in font design units for superscripts for this font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ysuperscriptysize
|
||||
ySuperscriptYSize: i16,
|
||||
/// The recommended horizontal offset in font design units for superscripts for this font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ysuperscriptxoffset
|
||||
ySuperscriptXOffset: i16,
|
||||
/// The recommended vertical offset in font design units from the baseline for superscripts for this font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ysuperscriptyoffset
|
||||
ySuperscriptYOffset: i16,
|
||||
/// Thickness of the strikeout stroke in font design units. Should be > 0.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ystrikeoutsize
|
||||
yStrikeoutSize: i16,
|
||||
/// The position of the top of the strikeout stroke relative to the baseline in font design units.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ystrikeoutposition
|
||||
yStrikeoutPosition: i16,
|
||||
/// This field provides a classification of font-family design.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#sfamilyclass
|
||||
sFamilyClass: i16,
|
||||
/// This 10-byte array of numbers is used to describe the visual characteristics of a given typeface.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#panose
|
||||
panose: [10]u8,
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ulunicoderange
|
||||
ulUnicodeRange1: u32,
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ulunicoderange
|
||||
ulUnicodeRange2: u32,
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ulunicoderange
|
||||
ulUnicodeRange3: u32,
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ulunicoderange
|
||||
ulUnicodeRange4: u32,
|
||||
/// The four character identifier for the vendor of the given type face.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#achvendid
|
||||
achVendID: [4]u8,
|
||||
/// Contains information concerning the nature of the font patterns.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#fsselection
|
||||
fsSelection: FSSelection,
|
||||
/// The minimum Unicode index (character code) in this font, according to the 'cmap' subtable for platform ID 3 and platform-specific encoding ID 0 or 1.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#usfirstcharindex
|
||||
usFirstCharIndex: u16,
|
||||
/// The maximum Unicode index (character code) in this font, according to the 'cmap' subtable for platform ID 3 and encoding ID 0 or 1.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#uslastcharindex
|
||||
usLastCharIndex: u16,
|
||||
/// The typographic ascender for this font. This field should be combined with the sTypoDescender and sTypoLineGap values to determine default line spacing.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#stypoascender
|
||||
sTypoAscender: i16,
|
||||
/// The typographic descender for this font. This field should be combined with the sTypoAscender and sTypoLineGap values to determine default line spacing.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#stypodescender
|
||||
sTypoDescender: i16,
|
||||
/// The typographic line gap for this font. This field should be combined with the sTypoAscender and sTypoDescender values to determine default line spacing.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#stypolinegap
|
||||
sTypoLineGap: i16,
|
||||
/// The “Windows ascender” metric. This should be used to specify the height above the baseline for a clipping region.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#uswinascent
|
||||
usWinAscent: u16,
|
||||
/// The “Windows descender” metric. This should be used to specify the vertical extent below the baseline for a clipping region.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#uswindescent
|
||||
usWinDescent: u16,
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ulcodepagerange
|
||||
ulCodePageRange1: ?u32 = null,
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#ulcodepagerange
|
||||
ulCodePageRange2: ?u32 = null,
|
||||
/// This metric specifies the distance between the baseline and the approximate height of non-ascending lowercase letters measured in font design units.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#sxheight
|
||||
sxHeight: ?i16 = null,
|
||||
/// This metric specifies the distance between the baseline and the approximate height of uppercase letters measured in font design units.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#scapheight
|
||||
sCapHeight: ?i16 = null,
|
||||
/// This is the Unicode code point, in UTF-16 encoding, of a character that can be used for a default glyph if a requested character is not supported in the font.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#usdefaultchar
|
||||
usDefaultChar: ?u16 = null,
|
||||
/// This is the Unicode code point, in UTF-16 encoding, of a character that can be used as a default break character.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#usbreakchar
|
||||
usBreakChar: ?u16 = null,
|
||||
/// The maximum length of a target glyph context for any feature in this font. For example, a font which has only a pair kerning feature should set this field to 2.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#usmaxcontext
|
||||
usMaxContext: ?u16 = null,
|
||||
/// This field is used for fonts with multiple optical styles.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#usloweropticalpointsize
|
||||
usLowerOpticalPointSize: ?u16 = null,
|
||||
/// This field is used for fonts with multiple optical styles.
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/os2/#usupperopticalpointsize
|
||||
usUpperOpticalPointSize: ?u16 = null,
|
||||
|
||||
/// Parse the table from raw data.
|
||||
pub fn init(data: []const u8) !OS2 {
|
||||
var fbs = std.io.fixedBufferStream(data);
|
||||
const reader = fbs.reader();
|
||||
|
||||
const version = try reader.readInt(sfnt.uint16, .big);
|
||||
|
||||
// Return to the start, cause the version is part of the struct.
|
||||
try fbs.seekTo(0);
|
||||
|
||||
switch (version) {
|
||||
5 => {
|
||||
const table = try reader.readStructEndian(OS2v5, .big);
|
||||
return .{
|
||||
.version = table.version,
|
||||
.xAvgCharWidth = table.xAvgCharWidth,
|
||||
.usWeightClass = table.usWeightClass,
|
||||
.usWidthClass = table.usWidthClass,
|
||||
.fsType = table.fsType,
|
||||
.ySubscriptXSize = table.ySubscriptXSize,
|
||||
.ySubscriptYSize = table.ySubscriptYSize,
|
||||
.ySubscriptXOffset = table.ySubscriptXOffset,
|
||||
.ySubscriptYOffset = table.ySubscriptYOffset,
|
||||
.ySuperscriptXSize = table.ySuperscriptXSize,
|
||||
.ySuperscriptYSize = table.ySuperscriptYSize,
|
||||
.ySuperscriptXOffset = table.ySuperscriptXOffset,
|
||||
.ySuperscriptYOffset = table.ySuperscriptYOffset,
|
||||
.yStrikeoutSize = table.yStrikeoutSize,
|
||||
.yStrikeoutPosition = table.yStrikeoutPosition,
|
||||
.sFamilyClass = table.sFamilyClass,
|
||||
.panose = table.panose,
|
||||
.ulUnicodeRange1 = table.ulUnicodeRange1,
|
||||
.ulUnicodeRange2 = table.ulUnicodeRange2,
|
||||
.ulUnicodeRange3 = table.ulUnicodeRange3,
|
||||
.ulUnicodeRange4 = table.ulUnicodeRange4,
|
||||
.achVendID = table.achVendID,
|
||||
.fsSelection = table.fsSelection,
|
||||
.usFirstCharIndex = table.usFirstCharIndex,
|
||||
.usLastCharIndex = table.usLastCharIndex,
|
||||
.sTypoAscender = table.sTypoAscender,
|
||||
.sTypoDescender = table.sTypoDescender,
|
||||
.sTypoLineGap = table.sTypoLineGap,
|
||||
.usWinAscent = table.usWinAscent,
|
||||
.usWinDescent = table.usWinDescent,
|
||||
.ulCodePageRange1 = table.ulCodePageRange1,
|
||||
.ulCodePageRange2 = table.ulCodePageRange2,
|
||||
.sxHeight = table.sxHeight,
|
||||
.sCapHeight = table.sCapHeight,
|
||||
.usDefaultChar = table.usDefaultChar,
|
||||
.usBreakChar = table.usBreakChar,
|
||||
.usMaxContext = table.usMaxContext,
|
||||
.usLowerOpticalPointSize = table.usLowerOpticalPointSize,
|
||||
.usUpperOpticalPointSize = table.usUpperOpticalPointSize,
|
||||
};
|
||||
},
|
||||
4, 3, 2 => {
|
||||
const table = try reader.readStructEndian(OS2v4_3_2, .big);
|
||||
return .{
|
||||
.version = table.version,
|
||||
.xAvgCharWidth = table.xAvgCharWidth,
|
||||
.usWeightClass = table.usWeightClass,
|
||||
.usWidthClass = table.usWidthClass,
|
||||
.fsType = table.fsType,
|
||||
.ySubscriptXSize = table.ySubscriptXSize,
|
||||
.ySubscriptYSize = table.ySubscriptYSize,
|
||||
.ySubscriptXOffset = table.ySubscriptXOffset,
|
||||
.ySubscriptYOffset = table.ySubscriptYOffset,
|
||||
.ySuperscriptXSize = table.ySuperscriptXSize,
|
||||
.ySuperscriptYSize = table.ySuperscriptYSize,
|
||||
.ySuperscriptXOffset = table.ySuperscriptXOffset,
|
||||
.ySuperscriptYOffset = table.ySuperscriptYOffset,
|
||||
.yStrikeoutSize = table.yStrikeoutSize,
|
||||
.yStrikeoutPosition = table.yStrikeoutPosition,
|
||||
.sFamilyClass = table.sFamilyClass,
|
||||
.panose = table.panose,
|
||||
.ulUnicodeRange1 = table.ulUnicodeRange1,
|
||||
.ulUnicodeRange2 = table.ulUnicodeRange2,
|
||||
.ulUnicodeRange3 = table.ulUnicodeRange3,
|
||||
.ulUnicodeRange4 = table.ulUnicodeRange4,
|
||||
.achVendID = table.achVendID,
|
||||
.fsSelection = table.fsSelection,
|
||||
.usFirstCharIndex = table.usFirstCharIndex,
|
||||
.usLastCharIndex = table.usLastCharIndex,
|
||||
.sTypoAscender = table.sTypoAscender,
|
||||
.sTypoDescender = table.sTypoDescender,
|
||||
.sTypoLineGap = table.sTypoLineGap,
|
||||
.usWinAscent = table.usWinAscent,
|
||||
.usWinDescent = table.usWinDescent,
|
||||
.ulCodePageRange1 = table.ulCodePageRange1,
|
||||
.ulCodePageRange2 = table.ulCodePageRange2,
|
||||
.sxHeight = table.sxHeight,
|
||||
.sCapHeight = table.sCapHeight,
|
||||
.usDefaultChar = table.usDefaultChar,
|
||||
.usBreakChar = table.usBreakChar,
|
||||
.usMaxContext = table.usMaxContext,
|
||||
};
|
||||
},
|
||||
1 => {
|
||||
const table = try reader.readStructEndian(OS2v1, .big);
|
||||
return .{
|
||||
.version = table.version,
|
||||
.xAvgCharWidth = table.xAvgCharWidth,
|
||||
.usWeightClass = table.usWeightClass,
|
||||
.usWidthClass = table.usWidthClass,
|
||||
.fsType = table.fsType,
|
||||
.ySubscriptXSize = table.ySubscriptXSize,
|
||||
.ySubscriptYSize = table.ySubscriptYSize,
|
||||
.ySubscriptXOffset = table.ySubscriptXOffset,
|
||||
.ySubscriptYOffset = table.ySubscriptYOffset,
|
||||
.ySuperscriptXSize = table.ySuperscriptXSize,
|
||||
.ySuperscriptYSize = table.ySuperscriptYSize,
|
||||
.ySuperscriptXOffset = table.ySuperscriptXOffset,
|
||||
.ySuperscriptYOffset = table.ySuperscriptYOffset,
|
||||
.yStrikeoutSize = table.yStrikeoutSize,
|
||||
.yStrikeoutPosition = table.yStrikeoutPosition,
|
||||
.sFamilyClass = table.sFamilyClass,
|
||||
.panose = table.panose,
|
||||
.ulUnicodeRange1 = table.ulUnicodeRange1,
|
||||
.ulUnicodeRange2 = table.ulUnicodeRange2,
|
||||
.ulUnicodeRange3 = table.ulUnicodeRange3,
|
||||
.ulUnicodeRange4 = table.ulUnicodeRange4,
|
||||
.achVendID = table.achVendID,
|
||||
.fsSelection = table.fsSelection,
|
||||
.usFirstCharIndex = table.usFirstCharIndex,
|
||||
.usLastCharIndex = table.usLastCharIndex,
|
||||
.sTypoAscender = table.sTypoAscender,
|
||||
.sTypoDescender = table.sTypoDescender,
|
||||
.sTypoLineGap = table.sTypoLineGap,
|
||||
.usWinAscent = table.usWinAscent,
|
||||
.usWinDescent = table.usWinDescent,
|
||||
.ulCodePageRange1 = table.ulCodePageRange1,
|
||||
.ulCodePageRange2 = table.ulCodePageRange2,
|
||||
};
|
||||
},
|
||||
0 => {
|
||||
const table = try reader.readStructEndian(OS2v0, .big);
|
||||
return .{
|
||||
.version = table.version,
|
||||
.xAvgCharWidth = table.xAvgCharWidth,
|
||||
.usWeightClass = table.usWeightClass,
|
||||
.usWidthClass = table.usWidthClass,
|
||||
.fsType = table.fsType,
|
||||
.ySubscriptXSize = table.ySubscriptXSize,
|
||||
.ySubscriptYSize = table.ySubscriptYSize,
|
||||
.ySubscriptXOffset = table.ySubscriptXOffset,
|
||||
.ySubscriptYOffset = table.ySubscriptYOffset,
|
||||
.ySuperscriptXSize = table.ySuperscriptXSize,
|
||||
.ySuperscriptYSize = table.ySuperscriptYSize,
|
||||
.ySuperscriptXOffset = table.ySuperscriptXOffset,
|
||||
.ySuperscriptYOffset = table.ySuperscriptYOffset,
|
||||
.yStrikeoutSize = table.yStrikeoutSize,
|
||||
.yStrikeoutPosition = table.yStrikeoutPosition,
|
||||
.sFamilyClass = table.sFamilyClass,
|
||||
.panose = table.panose,
|
||||
.ulUnicodeRange1 = table.ulUnicodeRange1,
|
||||
.ulUnicodeRange2 = table.ulUnicodeRange2,
|
||||
.ulUnicodeRange3 = table.ulUnicodeRange3,
|
||||
.ulUnicodeRange4 = table.ulUnicodeRange4,
|
||||
.achVendID = table.achVendID,
|
||||
.fsSelection = table.fsSelection,
|
||||
.usFirstCharIndex = table.usFirstCharIndex,
|
||||
.usLastCharIndex = table.usLastCharIndex,
|
||||
.sTypoAscender = table.sTypoAscender,
|
||||
.sTypoDescender = table.sTypoDescender,
|
||||
.sTypoLineGap = table.sTypoLineGap,
|
||||
.usWinAscent = table.usWinAscent,
|
||||
.usWinDescent = table.usWinDescent,
|
||||
};
|
||||
},
|
||||
else => return error.OS2VersionNotSupported,
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
test "OS/2" {
|
||||
const testing = std.testing;
|
||||
const alloc = testing.allocator;
|
||||
const test_font = @import("../embedded.zig").julia_mono;
|
||||
|
||||
const font = try sfnt.SFNT.init(test_font, alloc);
|
||||
defer font.deinit(alloc);
|
||||
|
||||
const table = font.getTable("OS/2").?;
|
||||
|
||||
const os2 = try OS2.init(table);
|
||||
|
||||
try testing.expectEqualDeep(OS2{
|
||||
.version = 4,
|
||||
.xAvgCharWidth = 1200,
|
||||
.usWeightClass = 400,
|
||||
.usWidthClass = 5,
|
||||
.fsType = 0,
|
||||
.ySubscriptXSize = 1300,
|
||||
.ySubscriptYSize = 1200,
|
||||
.ySubscriptXOffset = 0,
|
||||
.ySubscriptYOffset = 150,
|
||||
.ySuperscriptXSize = 1300,
|
||||
.ySuperscriptYSize = 1200,
|
||||
.ySuperscriptXOffset = 0,
|
||||
.ySuperscriptYOffset = 700,
|
||||
.yStrikeoutSize = 100,
|
||||
.yStrikeoutPosition = 550,
|
||||
.sFamilyClass = 0,
|
||||
.panose = .{ 2, 11, 6, 9, 6, 3, 0, 2, 0, 4 },
|
||||
.ulUnicodeRange1 = 3843162111,
|
||||
.ulUnicodeRange2 = 3603300351,
|
||||
.ulUnicodeRange3 = 117760229,
|
||||
.ulUnicodeRange4 = 96510060,
|
||||
.achVendID = "corm".*,
|
||||
.fsSelection = .{
|
||||
.regular = true,
|
||||
.use_typo_metrics = true,
|
||||
},
|
||||
.usFirstCharIndex = 13,
|
||||
.usLastCharIndex = 65535,
|
||||
.sTypoAscender = 1900,
|
||||
.sTypoDescender = -450,
|
||||
.sTypoLineGap = 0,
|
||||
.usWinAscent = 2400,
|
||||
.usWinDescent = 450,
|
||||
.ulCodePageRange1 = 1613234687,
|
||||
.ulCodePageRange2 = 0,
|
||||
.sxHeight = 1100,
|
||||
.sCapHeight = 1450,
|
||||
.usDefaultChar = 0,
|
||||
.usBreakChar = 32,
|
||||
.usMaxContext = 126,
|
||||
.usLowerOpticalPointSize = null,
|
||||
.usUpperOpticalPointSize = null,
|
||||
}, os2);
|
||||
}
|
||||
82
src/font/opentype/post.zig
Normal file
82
src/font/opentype/post.zig
Normal file
@ -0,0 +1,82 @@
|
||||
const std = @import("std");
|
||||
const assert = std.debug.assert;
|
||||
const sfnt = @import("sfnt.zig");
|
||||
|
||||
/// PostScript Table
|
||||
///
|
||||
/// This implementation doesn't parse the
|
||||
/// extra fields in versions 2.0 and 2.5.
|
||||
///
|
||||
/// References:
|
||||
/// - https://learn.microsoft.com/en-us/typography/opentype/spec/post
|
||||
pub const Post = extern struct {
|
||||
version: sfnt.Version16Dot16 align(1),
|
||||
|
||||
/// Italic angle in counter-clockwise degrees from the vertical.
|
||||
/// Zero for upright text, negative for text that leans to the
|
||||
/// right (forward).
|
||||
italicAngle: sfnt.Fixed align(1),
|
||||
|
||||
/// Suggested y-coordinate of the top of the underline.
|
||||
underlinePosition: sfnt.FWORD align(1),
|
||||
|
||||
/// Suggested values for the underline thickness.
|
||||
/// In general, the underline thickness should match the thickness of
|
||||
/// the underscore character (U+005F LOW LINE), and should also match
|
||||
/// the strikeout thickness, which is specified in the OS/2 table.
|
||||
underlineThickness: sfnt.FWORD align(1),
|
||||
|
||||
/// Set to 0 if the font is proportionally spaced, non-zero if
|
||||
/// the font is not proportionally spaced (i.e. monospaced).
|
||||
isFixedPitch: sfnt.uint32 align(1),
|
||||
|
||||
/// Minimum memory usage when an OpenType font is downloaded.
|
||||
minMemType42: sfnt.uint32 align(1),
|
||||
|
||||
/// Maximum memory usage when an OpenType font is downloaded.
|
||||
maxMemType42: sfnt.uint32 align(1),
|
||||
|
||||
/// Minimum memory usage when an OpenType
|
||||
/// font is downloaded as a Type 1 font.
|
||||
minMemType1: sfnt.uint32 align(1),
|
||||
|
||||
/// Maximum memory usage when an OpenType
|
||||
/// font is downloaded as a Type 1 font.
|
||||
maxMemType1: sfnt.uint32 align(1),
|
||||
|
||||
/// Parse the table from raw data.
|
||||
pub fn init(data: []const u8) !Post {
|
||||
var fbs = std.io.fixedBufferStream(data);
|
||||
const reader = fbs.reader();
|
||||
|
||||
return try reader.readStructEndian(Post, .big);
|
||||
}
|
||||
};
|
||||
|
||||
test "post" {
|
||||
const testing = std.testing;
|
||||
const alloc = testing.allocator;
|
||||
const test_font = @import("../embedded.zig").julia_mono;
|
||||
|
||||
const font = try sfnt.SFNT.init(test_font, alloc);
|
||||
defer font.deinit(alloc);
|
||||
|
||||
const table = font.getTable("post").?;
|
||||
|
||||
const post = try Post.init(table);
|
||||
|
||||
try testing.expectEqualDeep(
|
||||
Post{
|
||||
.version = sfnt.Version16Dot16{ .minor = 0, .major = 2 },
|
||||
.italicAngle = sfnt.Fixed.from(0.0),
|
||||
.underlinePosition = -200,
|
||||
.underlineThickness = 100,
|
||||
.isFixedPitch = 1,
|
||||
.minMemType42 = 0,
|
||||
.maxMemType42 = 0,
|
||||
.minMemType1 = 0,
|
||||
.maxMemType1 = 0,
|
||||
},
|
||||
post,
|
||||
);
|
||||
}
|
||||
314
src/font/opentype/sfnt.zig
Normal file
314
src/font/opentype/sfnt.zig
Normal file
@ -0,0 +1,314 @@
|
||||
const std = @import("std");
|
||||
const assert = std.debug.assert;
|
||||
const Allocator = std.mem.Allocator;
|
||||
|
||||
/// 8-bit unsigned integer.
|
||||
pub const uint8 = u8;
|
||||
|
||||
/// 8-bit signed integer.
|
||||
pub const int8 = i8;
|
||||
|
||||
/// 16-bit unsigned integer.
|
||||
pub const uint16 = u16;
|
||||
|
||||
/// 16-bit signed integer.
|
||||
pub const int16 = i16;
|
||||
|
||||
/// 24-bit unsigned integer.
|
||||
pub const uint24 = u24;
|
||||
|
||||
/// 32-bit unsigned integer.
|
||||
pub const uint32 = u32;
|
||||
|
||||
/// 32-bit signed integer.
|
||||
pub const int32 = i32;
|
||||
|
||||
/// 32-bit signed fixed-point number (16.16)
|
||||
pub const Fixed = FixedPoint(i32, 16, 16);
|
||||
|
||||
/// int16 that describes a quantity in font design units.
|
||||
pub const FWORD = i16;
|
||||
|
||||
/// uint16 that describes a quantity in font design units.
|
||||
pub const UFWORD = u16;
|
||||
|
||||
/// 16-bit signed fixed number with the low 14 bits of fraction (2.14).
|
||||
pub const F2DOT14 = FixedPoint(i16, 2, 14);
|
||||
|
||||
/// Date and time represented in number of seconds since 12:00 midnight, January 1, 1904, UTC. The value is represented as a signed 64-bit integer.
|
||||
pub const LONGDATETIME = i64;
|
||||
|
||||
/// Array of four uint8s (length = 32 bits) used to identify a table,
|
||||
/// design-variation axis, script, language system, feature, or baseline.
|
||||
pub const Tag = [4]u8;
|
||||
|
||||
/// 8-bit offset to a table, same as uint8, NULL offset = 0x00
|
||||
pub const Offset8 = u8;
|
||||
|
||||
/// Short offset to a table, same as uint16, NULL offset = 0x0000
|
||||
pub const Offset16 = u16;
|
||||
|
||||
/// 24-bit offset to a table, same as uint24, NULL offset = 0x000000
|
||||
pub const Offset24 = u24;
|
||||
|
||||
/// Long offset to a table, same as uint32, NULL offset = 0x00000000
|
||||
pub const Offset32 = u32;
|
||||
|
||||
/// Packed 32-bit value with major and minor version numbers
|
||||
pub const Version16Dot16 = packed struct(u32) {
|
||||
minor: u16,
|
||||
major: u16,
|
||||
};
|
||||
|
||||
/// 32-bit signed 26.6 fixed point numbers.
|
||||
pub const F26Dot6 = FixedPoint(i32, 26, 6);
|
||||
|
||||
fn FixedPoint(comptime T: type, int_bits: u64, frac_bits: u64) type {
|
||||
const type_info: std.builtin.Type.Int = @typeInfo(T).Int;
|
||||
comptime assert(int_bits + frac_bits == type_info.bits);
|
||||
|
||||
return packed struct(T) {
|
||||
const Self = FixedPoint(T, int_bits, frac_bits);
|
||||
const frac_factor: comptime_float = @floatFromInt(std.math.pow(
|
||||
u64,
|
||||
2,
|
||||
frac_bits,
|
||||
));
|
||||
const half = @as(T, 1) << @intCast(frac_bits - 1);
|
||||
|
||||
frac: std.meta.Int(.unsigned, frac_bits),
|
||||
int: std.meta.Int(type_info.signedness, int_bits),
|
||||
|
||||
pub fn to(self: Self, comptime FloatType: type) FloatType {
|
||||
const i: FloatType = @floatFromInt(self.int);
|
||||
const f: FloatType = @floatFromInt(self.frac);
|
||||
|
||||
return i + f / frac_factor;
|
||||
}
|
||||
|
||||
pub fn from(float: anytype) Self {
|
||||
const int = @floor(float);
|
||||
const frac = @abs(float - int);
|
||||
|
||||
return .{
|
||||
.int = @intFromFloat(int),
|
||||
.frac = @intFromFloat(@round(frac * frac_factor)),
|
||||
};
|
||||
}
|
||||
|
||||
/// Round to the nearest integer, .5 rounds away from 0.
|
||||
pub fn round(self: Self) T {
|
||||
if (self.frac & half != 0)
|
||||
return self.int + 1
|
||||
else
|
||||
return self.int;
|
||||
}
|
||||
|
||||
pub fn format(
|
||||
self: Self,
|
||||
comptime fmt: []const u8,
|
||||
options: std.fmt.FormatOptions,
|
||||
writer: anytype,
|
||||
) !void {
|
||||
_ = fmt;
|
||||
_ = options;
|
||||
|
||||
try writer.print("{d}", .{self.to(f64)});
|
||||
}
|
||||
};
|
||||
}
|
||||
|
||||
test FixedPoint {
|
||||
const testing = std.testing;
|
||||
|
||||
const p26d6 = F26Dot6.from(26.6);
|
||||
try testing.expectEqual(F26Dot6{
|
||||
.int = 26,
|
||||
.frac = 38,
|
||||
}, p26d6);
|
||||
try testing.expectEqual(26.59375, p26d6.to(f64));
|
||||
try testing.expectEqual(27, p26d6.round());
|
||||
|
||||
const n26d6 = F26Dot6.from(-26.6);
|
||||
try testing.expectEqual(F26Dot6{
|
||||
.int = -27,
|
||||
.frac = 26,
|
||||
}, n26d6);
|
||||
try testing.expectEqual(-26.59375, n26d6.to(f64));
|
||||
try testing.expectEqual(-27, n26d6.round());
|
||||
}
|
||||
|
||||
/// Wrapper for parsing a SFNT font and accessing its tables.
|
||||
///
|
||||
/// References:
|
||||
/// - https://learn.microsoft.com/en-us/typography/opentype/spec/otff
|
||||
/// - https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6.html
|
||||
pub const SFNT = struct {
|
||||
const Directory = struct {
|
||||
offset: OffsetSubtable,
|
||||
records: []TableRecord,
|
||||
|
||||
/// The static (fixed-sized) portion of the table directory
|
||||
///
|
||||
/// This struct matches the memory layout of the TrueType/OpenType
|
||||
/// TableDirectory, but does not include the TableRecord array, since
|
||||
/// that is dynamically sized, so we parse it separately.
|
||||
///
|
||||
/// In the TrueType reference manual this
|
||||
/// is referred to as the "offset subtable".
|
||||
///
|
||||
/// https://learn.microsoft.com/en-us/typography/opentype/spec/otff#table-directory
|
||||
const OffsetSubtable = extern struct {
|
||||
/// Indicates the type of font file we're reading.
|
||||
/// - 0x00_01_00_00 ---- TrueType
|
||||
/// - 0x74_72_75_65 'true' TrueType
|
||||
/// - 0x4F_54_54_4F 'OTTO' OpenType
|
||||
/// - 0x74_79_70_31 'typ1' PostScript
|
||||
sfnt_version: uint32 align(1),
|
||||
/// Number of tables.
|
||||
num_tables: uint16 align(1),
|
||||
/// Maximum power of 2 less than or equal to numTables, times 16 ((2**floor(log2(numTables))) * 16, where “**” is an exponentiation operator).
|
||||
search_range: uint16 align(1),
|
||||
/// Log2 of the maximum power of 2 less than or equal to numTables (log2(searchRange/16), which is equal to floor(log2(numTables))).
|
||||
entry_selector: uint16 align(1),
|
||||
/// numTables times 16, minus searchRange ((numTables * 16) - searchRange).
|
||||
range_shift: uint16 align(1),
|
||||
|
||||
pub fn format(
|
||||
self: OffsetSubtable,
|
||||
comptime fmt: []const u8,
|
||||
options: std.fmt.FormatOptions,
|
||||
writer: anytype,
|
||||
) !void {
|
||||
_ = fmt;
|
||||
_ = options;
|
||||
|
||||
try writer.print(
|
||||
"OffsetSubtable('{s}'){{ .num_tables = {} }}",
|
||||
.{
|
||||
if (self.sfnt_version == 0x00_01_00_00)
|
||||
&@as([10]u8, "0x00010000".*)
|
||||
else
|
||||
&@as([4]u8, @bitCast(
|
||||
std.mem.nativeToBig(u32, self.sfnt_version),
|
||||
)),
|
||||
self.num_tables,
|
||||
},
|
||||
);
|
||||
}
|
||||
};
|
||||
|
||||
const TableRecord = extern struct {
|
||||
/// Table identifier.
|
||||
tag: Tag align(1),
|
||||
/// Checksum for this table.
|
||||
checksum: uint32 align(1),
|
||||
/// Offset from beginning of font file.
|
||||
offset: Offset32 align(1),
|
||||
/// Length of this table.
|
||||
length: uint32 align(1),
|
||||
|
||||
pub fn format(
|
||||
self: TableRecord,
|
||||
comptime fmt: []const u8,
|
||||
options: std.fmt.FormatOptions,
|
||||
writer: anytype,
|
||||
) !void {
|
||||
_ = fmt;
|
||||
_ = options;
|
||||
|
||||
try writer.print(
|
||||
"TableRecord(\"{s}\"){{ .checksum = {}, .offset = {}, .length = {} }}",
|
||||
.{
|
||||
self.tag,
|
||||
self.checksum,
|
||||
self.offset,
|
||||
self.length,
|
||||
},
|
||||
);
|
||||
}
|
||||
};
|
||||
};
|
||||
|
||||
directory: Directory,
|
||||
|
||||
data: []const u8,
|
||||
|
||||
/// Parse a font from raw data. The struct will keep a
|
||||
/// reference to `data` and use it for future operations.
|
||||
pub fn init(data: []const u8, alloc: Allocator) !SFNT {
|
||||
var fbs = std.io.fixedBufferStream(data);
|
||||
const reader = fbs.reader();
|
||||
|
||||
// SFNT files use big endian, if our native endian is
|
||||
// not big we'll need to byte swap the values we read.
|
||||
const byte_swap = native_endian != .big;
|
||||
|
||||
var directory: Directory = undefined;
|
||||
|
||||
try reader.readNoEof(std.mem.asBytes(&directory.offset));
|
||||
if (byte_swap) std.mem.byteSwapAllFields(
|
||||
Directory.OffsetSubtable,
|
||||
&directory.offset,
|
||||
);
|
||||
|
||||
directory.records = try alloc.alloc(Directory.TableRecord, directory.offset.num_tables);
|
||||
|
||||
try reader.readNoEof(std.mem.sliceAsBytes(directory.records));
|
||||
if (byte_swap) for (directory.records) |*record| {
|
||||
std.mem.byteSwapAllFields(
|
||||
Directory.TableRecord,
|
||||
record,
|
||||
);
|
||||
};
|
||||
|
||||
return .{
|
||||
.directory = directory,
|
||||
.data = data,
|
||||
};
|
||||
}
|
||||
|
||||
pub fn deinit(self: SFNT, alloc: Allocator) void {
|
||||
alloc.free(self.directory.records);
|
||||
}
|
||||
|
||||
/// Returns the bytes of the table with the provided tag if present.
|
||||
pub fn getTable(self: SFNT, tag: *const [4]u8) ?[]const u8 {
|
||||
for (self.directory.records) |record| {
|
||||
if (std.mem.eql(u8, tag, &record.tag)) {
|
||||
return self.data[record.offset..][0..record.length];
|
||||
}
|
||||
}
|
||||
|
||||
return null;
|
||||
}
|
||||
};
|
||||
|
||||
const native_endian = @import("builtin").target.cpu.arch.endian();
|
||||
|
||||
test "parse font" {
|
||||
const testing = std.testing;
|
||||
const alloc = testing.allocator;
|
||||
|
||||
const test_font = @import("../embedded.zig").julia_mono;
|
||||
|
||||
const sfnt = try SFNT.init(&test_font.*, alloc);
|
||||
defer sfnt.deinit(alloc);
|
||||
|
||||
try testing.expectEqual(19, sfnt.directory.offset.num_tables);
|
||||
try testing.expectEqualStrings("prep", &sfnt.directory.records[18].tag);
|
||||
}
|
||||
|
||||
test "get table" {
|
||||
const testing = std.testing;
|
||||
const alloc = testing.allocator;
|
||||
|
||||
const test_font = @import("../embedded.zig").julia_mono;
|
||||
|
||||
const sfnt = try SFNT.init(&test_font.*, alloc);
|
||||
defer sfnt.deinit(alloc);
|
||||
|
||||
const svg = sfnt.getTable("SVG ").?;
|
||||
|
||||
try testing.expectEqual(430, svg.len);
|
||||
}
|
||||
Reference in New Issue
Block a user