font: introduce GroupCacheSet, use it for descriptors to start

This commit is contained in:
Mitchell Hashimoto
2024-04-01 12:25:21 -07:00
parent 7fef1aa294
commit bfcd5f380a
3 changed files with 197 additions and 69 deletions

View File

@ -320,6 +320,12 @@ pub fn init(
.ydpi = @intFromFloat(y_dpi),
};
// Create our font group key. This is used to determine if we have
// a cached font group we can use already. Otherwise, this can be
// used to build the group.
var font_group_key = try font.GroupCacheSet.Key.init(alloc, config);
defer font_group_key.deinit();
// Find all the fonts for this surface
//
// Future: we can share the font group amongst all surfaces to save
@ -368,84 +374,41 @@ pub fn init(
// A buffer we use to store the font names for logging.
var name_buf: [256]u8 = undefined;
for (config.@"font-family".list.items) |family| {
var disco_it = try disco.discover(alloc, .{
.family = family,
.style = config.@"font-style".nameValue(),
.size = font_size.points,
.variations = config.@"font-variation".list.items,
});
inline for (@typeInfo(font.Style).Enum.fields) |field| {
const style = @field(font.Style, field.name);
for (font_group_key.descriptorsForStyle(style)) |desc| {
var disco_it = try disco.discover(alloc, desc);
defer disco_it.deinit();
if (try disco_it.next()) |face| {
log.info("font regular: {s}", .{try face.name(&name_buf)});
_ = try group.addFace(.regular, .{ .deferred = face });
} else log.warn("font-family not found: {s}", .{family});
log.info("font {s}: {s}", .{
field.name,
try face.name(&name_buf),
});
_ = try group.addFace(style, .{ .deferred = face });
} else log.warn("font-family {s} not found: {s}", .{
field.name,
desc.family.?,
});
}
// In all the styled cases below, we prefer to specify an exact
// style via the `font-style` configuration. If a style is not
// specified, we use the discovery mechanism to search for a
// style category such as bold, italic, etc. We can't specify both
// because the latter will restrict the search to only that. If
// a user says `font-style = italic` for the bold face for example,
// no results would be found if we restrict to ALSO searching for
// italic.
for (config.@"font-family-bold".list.items) |family| {
const style = config.@"font-style-bold".nameValue();
var disco_it = try disco.discover(alloc, .{
.family = family,
.style = style,
.size = font_size.points,
.bold = style == null,
.variations = config.@"font-variation-bold".list.items,
});
defer disco_it.deinit();
if (try disco_it.next()) |face| {
log.info("font bold: {s}", .{try face.name(&name_buf)});
_ = try group.addFace(.bold, .{ .deferred = face });
} else log.warn("font-family-bold not found: {s}", .{family});
}
for (config.@"font-family-italic".list.items) |family| {
const style = config.@"font-style-italic".nameValue();
var disco_it = try disco.discover(alloc, .{
.family = family,
.style = style,
.size = font_size.points,
.italic = style == null,
.variations = config.@"font-variation-italic".list.items,
});
defer disco_it.deinit();
if (try disco_it.next()) |face| {
log.info("font italic: {s}", .{try face.name(&name_buf)});
_ = try group.addFace(.italic, .{ .deferred = face });
} else log.warn("font-family-italic not found: {s}", .{family});
}
for (config.@"font-family-bold-italic".list.items) |family| {
const style = config.@"font-style-bold-italic".nameValue();
var disco_it = try disco.discover(alloc, .{
.family = family,
.style = style,
.size = font_size.points,
.bold = style == null,
.italic = style == null,
.variations = config.@"font-variation-bold-italic".list.items,
});
defer disco_it.deinit();
if (try disco_it.next()) |face| {
log.info("font bold+italic: {s}", .{try face.name(&name_buf)});
_ = try group.addFace(.bold_italic, .{ .deferred = face });
} else log.warn("font-family-bold-italic not found: {s}", .{family});
}
}
// Our built-in font will be used as a backup
_ = try group.addFace(
.regular,
.{ .fallback_loaded = try font.Face.init(font_lib, face_ttf, group.faceOptions()) },
.{ .fallback_loaded = try font.Face.init(
font_lib,
face_ttf,
group.faceOptions(),
) },
);
_ = try group.addFace(
.bold,
.{ .fallback_loaded = try font.Face.init(font_lib, face_bold_ttf, group.faceOptions()) },
.{ .fallback_loaded = try font.Face.init(
font_lib,
face_bold_ttf,
group.faceOptions(),
) },
);
// Auto-italicize if we have to.

164
src/font/GroupCacheSet.zig Normal file
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@ -0,0 +1,164 @@
//! This structure contains a set of GroupCache instances keyed by
//! unique font configuration.
//!
//! Most terminals (surfaces) will share the same font configuration.
//! This structure allows expensive font information such as
//! the font atlas, glyph cache, font faces, etc. to be shared.
//!
//! The Ghostty renderers which use this information run on their
//! own threads so this structure is thread-safe. It expects that
//! the case where all glyphs are cached is the common case and
//! optimizes for that. When a glyph is not cached, all renderers
//! that share the same font configuration will be blocked until
//! the glyph is cached.
const GroupCacheSet = @This();
const std = @import("std");
const assert = std.debug.assert;
const Allocator = std.mem.Allocator;
const ArenaAllocator = std.heap.ArenaAllocator;
const Style = @import("main.zig").Style;
const discovery = @import("discovery.zig");
const configpkg = @import("../config.zig");
const Config = configpkg.Config;
/// The key used to uniquely identify a font configuration.
pub const Key = struct {
arena: ArenaAllocator,
/// The descriptors used for all the fonts added to the
/// initial group, including all styles. This is hashed
/// in order so the order matters. All users of the struct
/// should ensure that the order is consistent.
descriptors: []const discovery.Descriptor,
/// These are the offsets into the descriptors array for
/// each style. For example, bold is from
/// offsets[@intFromEnum(.bold) - 1] to
/// offsets[@intFromEnum(.bold)].
style_offsets: StyleOffsets = .{0} ** style_offsets_len,
const style_offsets_len = std.enums.directEnumArrayLen(Style, 0);
const StyleOffsets = [style_offsets_len]usize;
comptime {
// We assume this throughout this structure. If this changes
// we may need to change this structure.
assert(@intFromEnum(Style.regular) == 0);
assert(@intFromEnum(Style.bold) == 1);
assert(@intFromEnum(Style.italic) == 2);
assert(@intFromEnum(Style.bold_italic) == 3);
}
pub fn init(
alloc_gpa: Allocator,
config: *const Config,
) !Key {
var arena = ArenaAllocator.init(alloc_gpa);
errdefer arena.deinit();
const alloc = arena.allocator();
var descriptors = std.ArrayList(discovery.Descriptor).init(alloc);
defer descriptors.deinit();
for (config.@"font-family".list.items) |family| {
try descriptors.append(.{
.family = family,
.style = config.@"font-style".nameValue(),
.size = config.@"font-size",
.variations = config.@"font-variation".list.items,
});
}
// In all the styled cases below, we prefer to specify an exact
// style via the `font-style` configuration. If a style is not
// specified, we use the discovery mechanism to search for a
// style category such as bold, italic, etc. We can't specify both
// because the latter will restrict the search to only that. If
// a user says `font-style = italic` for the bold face for example,
// no results would be found if we restrict to ALSO searching for
// italic.
for (config.@"font-family-bold".list.items) |family| {
const style = config.@"font-style-bold".nameValue();
try descriptors.append(.{
.family = family,
.style = style,
.size = config.@"font-size",
.bold = style == null,
.variations = config.@"font-variation".list.items,
});
}
for (config.@"font-family-italic".list.items) |family| {
const style = config.@"font-style-italic".nameValue();
try descriptors.append(.{
.family = family,
.style = style,
.size = config.@"font-size",
.italic = style == null,
.variations = config.@"font-variation".list.items,
});
}
for (config.@"font-family-bold-italic".list.items) |family| {
const style = config.@"font-style-bold-italic".nameValue();
try descriptors.append(.{
.family = family,
.style = style,
.size = config.@"font-size",
.bold = style == null,
.italic = style == null,
.variations = config.@"font-variation".list.items,
});
}
return .{
.arena = arena,
.descriptors = try descriptors.toOwnedSlice(),
.style_offsets = .{
config.@"font-family".list.items.len,
config.@"font-family-bold".list.items.len,
config.@"font-family-italic".list.items.len,
config.@"font-family-bold-italic".list.items.len,
},
};
}
pub fn deinit(self: *Key) void {
self.arena.deinit();
}
/// Get the descriptors for the given font style that can be
/// used with discovery.
pub fn descriptorsForStyle(
self: Key,
style: Style,
) []const discovery.Descriptor {
const idx = @intFromEnum(style);
const start: usize = if (idx == 0) 0 else self.style_offsets[idx - 1];
const end = self.style_offsets[idx];
return self.descriptors[start..end];
}
/// Hash the key with the given hasher.
pub fn hash(self: Key, hasher: anytype) void {
const autoHash = std.hash.autoHash;
autoHash(hasher, self.descriptors.len);
for (self.descriptors) |d| d.hash(hasher);
}
/// Returns a hash code that can be used to uniquely identify this
/// action.
pub fn hashcode(self: Key) u64 {
var hasher = std.hash.Wyhash.init(0);
self.hash(&hasher);
return hasher.final();
}
};
test "Key" {
const testing = std.testing;
const alloc = testing.allocator;
var cfg = try Config.default(alloc);
defer cfg.deinit();
var k = try Key.init(alloc, &cfg);
defer k.deinit();
}

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@ -10,6 +10,7 @@ pub const DeferredFace = @import("DeferredFace.zig");
pub const Face = face.Face;
pub const Group = @import("Group.zig");
pub const GroupCache = @import("GroupCache.zig");
pub const GroupCacheSet = @import("GroupCacheSet.zig");
pub const Glyph = @import("Glyph.zig");
pub const shape = @import("shape.zig");
pub const Shaper = shape.Shaper;