examples/gkurve: support for UTF32 characters

examples/gkurve/label.zig

@@ -21,7 +21,7 @@ const GlyphInfo = struct {
 
 face: ft.Face,
 size: i32,
-char_map: std.AutoHashMap(u8, GlyphInfo),
+char_map: std.AutoHashMap(u21, GlyphInfo),
 allocator: std.mem.Allocator,
 
 const WriterContext = struct {
@@ -48,7 +48,7 @@ pub fn init(lib: ft.Library, font_path: []const u8, face_index: i32, char_size:
     return Label{
         .face = try lib.newFace(font_path, face_index),
         .size = char_size,
-        .char_map = std.AutoHashMap(u8, GlyphInfo).init(allocator),
+        .char_map = std.AutoHashMap(u21, GlyphInfo).init(allocator),
         .allocator = allocator,
     };
 }
@@ -60,7 +60,11 @@ pub fn deinit(label: *Label) void {
 
 fn write(ctx: WriterContext, bytes: []const u8) WriterError!usize {
     var offset = Vec2{ 0, 0 };
-    for (bytes) |char| {
+    var j: usize = 0;
+    while (j < bytes.len) {
+        const len = std.unicode.utf8ByteSequenceLength(bytes[j]) catch unreachable;
+        const char = std.unicode.utf8Decode(bytes[j..(j + len)]) catch unreachable;
+        j += len;
         switch (char) {
             '\n' => {
                 offset[0] = 0;

examples/gkurve/main.zig

@@ -94,15 +94,16 @@ pub fn init(app: *App, engine: *mach.Engine) !void {
     defer lib.deinit();
 
     const size_multiplier = 5;
-    const character = 'e';
+    const character = "è";
     var label = try Label.init(lib, "freetype/upstream/assets/FiraSans-Regular.ttf", 0, 110 * size_multiplier, engine.allocator);
     defer label.deinit();
-    try label.print(app, &.{character}, .{}, @Vector(2, f32){ 50 * size_multiplier, 40 }, @Vector(4, f32){ 1, 1, 1, 1 });
+    // try label.print(app, "All your game's bases are belong to us èçòà", .{}, @Vector(2, f32){ 0, 420 }, @Vector(4, f32){ 1, 1, 1, 1 });
+    try label.print(app, character, .{}, @Vector(2, f32){ 50 * size_multiplier, 40 }, @Vector(4, f32){ 1, 1, 1, 1 });
 
     var resizable_label: ResizableLabel = undefined;
     try resizable_label.init(lib, "freetype/upstream/assets/FiraSans-Regular.ttf", 0, engine.allocator, white_texture_uv_data);
     defer resizable_label.deinit();
-    try resizable_label.print(app, &.{character}, .{}, @Vector(4, f32){ 0, 40, 0, 0 }, @Vector(4, f32){ 1, 1, 1, 1 }, 80 * size_multiplier);
+    try resizable_label.print(app, character, .{}, @Vector(4, f32){ 0, 40, 0, 0 }, @Vector(4, f32){ 1, 1, 1, 1 }, 80 * size_multiplier);
 
     queue.writeTexture(
         &.{ .texture = texture },

examples/gkurve/resizable_label.zig

@@ -34,7 +34,7 @@ const CharVertices = struct {
 };
 
 face: ft.Face,
-char_map: std.AutoHashMap(u8, CharVertices),
+char_map: std.AutoHashMap(u21, CharVertices),
 allocator: std.mem.Allocator,
 tessellator: Tessellator,
 white_texture: UVData,
@@ -66,7 +66,7 @@ pub fn writer(label: *ResizableLabel, app: *App, position: Vec4, text_color: Vec
 pub fn init(self: *ResizableLabel, lib: ft.Library, font_path: []const u8, face_index: i32, allocator: std.mem.Allocator, white_texture: UVData) !void {
     self.* = ResizableLabel{
         .face = try lib.newFace(font_path, face_index),
-        .char_map = std.AutoHashMap(u8, CharVertices).init(allocator),
+        .char_map = std.AutoHashMap(u21, CharVertices).init(allocator),
         .allocator = allocator,
         .tessellator = undefined,
         .white_texture = white_texture,
@@ -94,7 +94,11 @@ pub fn deinit(label: *ResizableLabel) void {
 // FIXME: many useless allocations for the arraylists
 fn write(ctx: WriterContext, bytes: []const u8) WriterError!usize {
     var offset = Vec4{ 0, 0, 0, 0 };
-    for (bytes) |char| {
+    var c: usize = 0;
+    while (c < bytes.len) {
+        const len = std.unicode.utf8ByteSequenceLength(bytes[c]) catch unreachable;
+        const char = std.unicode.utf8Decode(bytes[c..(c + len)]) catch unreachable;
+        c += len;
         switch (char) {
             '\n' => {
                 offset[0] = 0;