feat: add font management

Author: RossComputerGuy

src/phantom/fonts.zig

@@ -1 +1,11 @@
+const std = @import("std");
+
 pub const Font = @import("fonts/font.zig");
+pub const Manager = @import("fonts/manager.zig");
+
+pub const backends = @import("fonts/backends.zig");
+pub const BackendType = std.meta.DeclEnum(backends);
+
+pub fn Backend(comptime T: BackendType) type {
+    return @field(backends, @tagName(T));
+}

src/phantom/fonts/backends.zig

@@ -0,0 +1,3 @@
+const root = @import("root");
+
+pub usingnamespace if (@hasDecl(root, "phantomOptions")) if (@hasDecl(root.phantomOptions, "fontBackends")) root.phantomOptions.fontBackends else struct {} else struct {};

src/phantom/fonts/manager.zig

@@ -0,0 +1,34 @@
+const std = @import("std");
+const metap = @import("meta+");
+const Font = @import("font.zig");
+const Self = @This();
+
+const BaseVTable = struct {
+    loadBuffer: *const fn (*anyopaque, []const u8) anyerror!*Font,
+    deinit: ?*const fn (*anyopaque) void = null,
+};
+
+const FsVTable = struct {
+    loadFile: ?*const fn (*anyopaque, std.fs.File) anyerror!*Font = null,
+};
+
+pub const VTable = metap.structs.fields.mix(BaseVTable, if (@hasDecl(std.os.system, "fd_t")) FsVTable else struct {});
+
+ptr: *anyopaque,
+vtable: *const VTable,
+
+pub inline fn loadBuffer(self: *Self, buff: []const u8) !*Font {
+    return self.vtable.loadBuffer(self.ptr, buff);
+}
+
+pub inline fn loadFile(self: *Self, file: std.fs.File) !*Font {
+    if (@hasDecl(std.os.system, "fd_t")) {
+        if (self.vtable.loadFile) |f| return f(self.ptr, file);
+        return error.NotImplemented;
+    }
+    return error.NotSupported;
+}
+
+pub inline fn deinit(self: *Self) void {
+    return if (self.vtable.deinit) |f| f(self.ptr) else {};
+}