gfx: font: begin adding text shaping via harfbuzz
Helps hexops/mach#877 Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
This commit is contained in:
Stephen Gutekanst
parent
3bcbdc4682
commit
87c3de78f5
7 changed files with 333 additions and 9 deletions
204
src/gfx/font/main.zig
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204
src/gfx/font/main.zig
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@ -0,0 +1,204 @@
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const mach = @import("../../main.zig");
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const testing = mach.testing;
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const math = mach.math;
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const vec2 = math.vec2;
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const Vec2 = math.Vec2;
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pub const Font = FontInterface(if (@import("builtin").cpu.arch == .wasm32) {
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@panic("TODO: implement wasm/Font.zig");
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} else @import("native/Font.zig"));
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pub const TextRun = TextRunInterface(if (@import("builtin").cpu.arch == .wasm32)
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{
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@panic("TODO: implement wasm/TextRun.zig");
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} else @import("native/TextRun.zig"));
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fn FontInterface(comptime T: type) type {
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assertDecl(T, "initBytes", fn (font_bytes: []const u8) anyerror!T);
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assertDecl(T, "shape", fn (f: *const T, r: *TextRun) anyerror!void);
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assertDecl(T, "deinit", fn (*const T) void);
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return T;
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}
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fn TextRunInterface(comptime T: type) type {
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assertField(T, "font_size_px", u32);
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assertField(T, "px_density", u8);
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assertDecl(T, "init", fn () anyerror!T);
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assertDecl(T, "addText", fn (s: *const T, []const u8) void);
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assertDecl(T, "next", fn (s: *T) ?Glyph);
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assertDecl(T, "deinit", fn (s: *const T) void);
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return T;
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}
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fn assertDecl(comptime T: anytype, comptime name: []const u8, comptime Decl: type) void {
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if (!@hasDecl(T, name)) @compileError("Interface missing declaration: " ++ name ++ @typeName(Decl));
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const Found = @TypeOf(@field(T, name));
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if (Found != Decl) @compileError("Interface decl '" ++ name ++ "'\n\texpected type: " ++ @typeName(Decl) ++ "\n\t found type: " ++ @typeName(Found));
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}
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fn assertField(comptime T: anytype, comptime name: []const u8, comptime Field: type) void {
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if (!@hasField(T, name)) @compileError("Interface missing field: ." ++ name ++ @typeName(Field));
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const Found = @TypeOf(@field(@as(T, undefined), name));
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if (Found != Field) @compileError("Interface field '" ++ name ++ "'\n\texpected type: " ++ @typeName(Field) ++ "\n\t found type: " ++ @typeName(Found));
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}
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/// The number of pixels per point, e.g. a 12pt font em box size multiplied by this number tells a
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/// the em box size is 16px.
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pub const px_per_pt = 4.0 / 3.0;
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pub const Glyph = struct {
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glyph_index: u21,
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cluster: u32,
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advance: Vec2,
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offset: Vec2,
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// TODO: https://github.com/hexops/mach/issues/1048
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// TODO: https://github.com/hexops/mach/issues/1049
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//
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// pub fn eql(a: Glyph, b: Glyph) bool {
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// if (a.glyph_index != b.glyph_index) return false;
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// if (a.cluster != b.cluster) return false;
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// // TODO: add Vec2.eql method
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// if (a.advance.v[0] != b.advance.v[0] or a.advance.v[1] != b.advance.v[1]) return false;
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// if (a.offset.v[0] != b.offset.v[0] or a.offset.v[1] != b.offset.v[1]) return false;
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// return true;
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// }
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};
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test {
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const std = @import("std");
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std.testing.refAllDeclsRecursive(@This());
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// Load a font
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const font_bytes = @import("font-assets").fira_sans_regular_ttf;
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const font = try Font.initBytes(font_bytes);
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defer font.deinit();
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// Create a text shaper
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var run = try TextRun.init();
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run.font_size_px = 12 * px_per_pt;
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run.px_density = 1;
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defer run.deinit();
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const text = "h👩🚀️ello world!";
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run.addText(text);
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try font.shape(&run);
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// TODO: https://github.com/hexops/mach/issues/1048
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// TODO: https://github.com/hexops/mach/issues/1049
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//
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// try testing.expect(Glyph, .{
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// .glyph_index = 176,
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// .cluster = 0,
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// .advance = vec2(7.03, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 0,
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// .cluster = 1,
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// .advance = vec2(7.99, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 3,
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// .cluster = 1,
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// .advance = vec2(0.00, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 0,
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// .cluster = 1,
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// .advance = vec2(7.99, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 3,
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// .cluster = 1,
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// .advance = vec2(0.00, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 160,
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// .cluster = 15,
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// .advance = vec2(6.60, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 197,
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// .cluster = 16,
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// .advance = vec2(3.52, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 197,
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// .cluster = 17,
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// .advance = vec2(3.39, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 211,
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// .cluster = 18,
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// .advance = vec2(7.01, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 3,
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// .cluster = 19,
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// .advance = vec2(3.18, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 254,
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// .cluster = 20,
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// .advance = vec2(8.48, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 211,
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// .cluster = 21,
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// .advance = vec2(7.01, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 226,
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// .cluster = 22,
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// .advance = vec2(4.63, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 197,
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// .cluster = 23,
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// .advance = vec2(3.39, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 156,
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// .cluster = 24,
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// .advance = vec2(7.18, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// try testing.expect(Glyph, .{
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// .glyph_index = 988,
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// .cluster = 25,
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// .advance = vec2(2.89, 0.00),
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// .offset = vec2(0.00, 0.00),
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// }).eql(run.next().?);
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// var cluster_start: usize = 0;
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// while (run.next()) |glyph| {
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// if (glyph.cluster != cluster_start) {
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// const str = text[cluster_start..glyph.cluster];
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// cluster_start = glyph.cluster;
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// std.debug.print("^ string: '{s}' (hex: {s})\n", .{ str, std.fmt.fmtSliceHexUpper(str) });
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// }
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// std.debug.print(".{{ .glyph_index={}, .cluster={}, .advance=vec2({d:.2},{d:.2}), .offset=vec2({d:.2},{d:.2}), }}\n", .{
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// glyph.glyph_index,
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// glyph.cluster,
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// glyph.advance.x(),
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// glyph.advance.y(),
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// glyph.offset.x(),
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// glyph.offset.y(),
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// });
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// }
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}
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57
src/gfx/font/native/Font.zig
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57
src/gfx/font/native/Font.zig
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@ -0,0 +1,57 @@
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const std = @import("std");
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const ft = @import("mach-freetype");
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const harfbuzz = @import("mach-harfbuzz");
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const TextRun = @import("TextRun.zig");
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const px_per_pt = @import("../main.zig").px_per_pt;
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const Font = @This();
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var freetype_ready_mu: std.Thread.Mutex = .{};
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var freetype_ready: bool = false;
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var freetype: ft.Library = undefined;
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face: ft.Face,
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pub fn initFreetype() !void {
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freetype_ready_mu.lock();
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defer freetype_ready_mu.unlock();
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if (!freetype_ready) {
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freetype = try ft.Library.init();
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freetype_ready = true;
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}
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}
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pub fn initBytes(font_bytes: []const u8) anyerror!Font {
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try initFreetype();
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return .{
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.face = try freetype.createFaceMemory(font_bytes, 0),
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};
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}
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pub fn shape(f: *const Font, r: *TextRun) anyerror!void {
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// Guess text segment properties.
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r.buffer.guessSegmentProps();
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// TODO: Optionally override specific text segment properties?
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// buffer.setDirection(.ltr);
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// buffer.setScript(.latin);
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// buffer.setLanguage(harfbuzz.Language.fromString("en"));
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const hb_face = harfbuzz.Face.fromFreetypeFace(f.face);
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const hb_font = harfbuzz.Font.init(hb_face);
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defer hb_font.deinit();
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const font_size_pt = @as(f32, @floatFromInt(r.font_size_px)) / px_per_pt;
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hb_font.setScale(@as(i32, @intFromFloat(font_size_pt)) * 256, @as(i32, @intFromFloat(font_size_pt)) * 256);
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hb_font.setPTEM(font_size_pt);
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// TODO: optionally pass shaping features?
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hb_font.shape(r.buffer, null);
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r.index = 0;
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r.infos = r.buffer.getGlyphInfos();
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r.positions = r.buffer.getGlyphPositions() orelse return error.OutOfMemory;
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}
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pub fn deinit(f: *const Font) void {
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f.face.deinit();
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}
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48
src/gfx/font/native/TextRun.zig
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48
src/gfx/font/native/TextRun.zig
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@ -0,0 +1,48 @@
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const std = @import("std");
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const harfbuzz = @import("mach-harfbuzz");
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const math = @import("../../../main.zig").math;
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const vec2 = math.vec2;
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const Vec2 = math.Vec2;
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const Glyph = @import("../main.zig").Glyph;
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const TextRun = @This();
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font_size_px: u32 = 16.0,
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px_density: u8 = 1,
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// Internal / private fields.
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buffer: harfbuzz.Buffer,
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index: usize = 0,
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infos: []harfbuzz.GlyphInfo = undefined,
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positions: []harfbuzz.GlyphPosition = undefined,
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pub fn init() anyerror!TextRun {
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return TextRun{
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.buffer = harfbuzz.Buffer.init() orelse return error.OutOfMemory,
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};
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}
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pub fn addText(s: *const TextRun, utf8_text: []const u8) void {
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s.buffer.addUTF8(utf8_text, 0, null);
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}
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pub fn next(s: *TextRun) ?Glyph {
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if (s.index >= s.infos.len) return null;
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const info = s.infos[s.index];
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const pos = s.positions[s.index];
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s.index += 1;
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return Glyph{
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.glyph_index = @intCast(info.codepoint),
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// TODO: should we expose this? Is there a browser equivalent? do we need it?
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// .var1 = @intCast(info.var1),
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// .var2 = @intCast(info.var2),
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.cluster = info.cluster,
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.advance = vec2(@floatFromInt(pos.x_advance), @floatFromInt(pos.y_advance)).div(&Vec2.splat(256.0)),
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.offset = vec2(@floatFromInt(pos.x_offset), @floatFromInt(pos.y_offset)).div(&Vec2.splat(256.0)),
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};
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}
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pub fn deinit(s: *const TextRun) void {
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s.buffer.deinit();
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return;
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}
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@ -1,11 +1,17 @@
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pub const util = @import("util.zig");
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pub const util = @import("util.zig"); // TODO: banish 2-level deep namespaces
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pub const Sprite = @import("Sprite.zig");
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pub const Atlas = @import("atlas/Atlas.zig");
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pub const Text = @import("Text.zig");
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pub const FontRenderer = @import("font.zig").FontRenderer;
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pub const RGBA32 = @import("font.zig").RGBA32;
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pub const Glyph = @import("font.zig").Glyph;
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pub const GlyphMetrics = @import("font.zig").GlyphMetrics;
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// TODO: integrate font rendering
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// pub const RGBA32 = @import("font.zig").RGBA32;
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// pub const FontRenderer = @import("font.zig").FontRenderer;
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// pub const Glyph = @import("font.zig").Glyph;
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// pub const GlyphMetrics = @import("font.zig").GlyphMetrics;
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pub const Font = @import("font/main.zig").Font;
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pub const TextRun = @import("font/main.zig").TextRun;
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pub const Glyph = @import("font/main.zig").Glyph;
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test {
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const std = @import("std");
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@ -13,9 +19,9 @@ test {
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// std.testing.refAllDeclsRecursive(@This());
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std.testing.refAllDeclsRecursive(util);
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// std.testing.refAllDeclsRecursive(Sprite);
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std.testing.refAllDeclsRecursive(Atlas);
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// std.testing.refAllDeclsRecursive(Text);
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std.testing.refAllDeclsRecursive(FontRenderer);
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std.testing.refAllDeclsRecursive(RGBA32);
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std.testing.refAllDeclsRecursive(Font);
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std.testing.refAllDeclsRecursive(TextRun);
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std.testing.refAllDeclsRecursive(Glyph);
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std.testing.refAllDeclsRecursive(GlyphMetrics);
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}
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