From 5b081c0b0be025c9c46b651bdf40bb9123c2259b Mon Sep 17 00:00:00 2001
From: zhenyan121 <3367366583@qq.com>
Date: Mon, 20 Jul 2026 10:39:20 +0800
Subject: [PATCH] feat(ui): add word wrap for chat messages with font width
 measurement

---
 include/Cubed/tools/font.hpp  |  1 +
 include/Cubed/ui/chat_box.hpp |  1 +
 src/tools/font.cpp            | 22 +++++++++++++++++++
 src/ui/chat_box.cpp           | 40 +++++++++++++++++++++++++++++++++--
 4 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/include/Cubed/tools/font.hpp b/include/Cubed/tools/font.hpp
index 55d6d7f..27c823f 100644
--- a/include/Cubed/tools/font.hpp
+++ b/include/Cubed/tools/font.hpp
@@ -56,6 +56,7 @@ public:
     TextMesh vertices(const std::string& text);
     const Texture* text_texture();
     static const std::string& font_path();
+    static float text_width(const std::string& text);
 
 private:
     FT_Library m_ft;
diff --git a/include/Cubed/ui/chat_box.hpp b/include/Cubed/ui/chat_box.hpp
index 0ee7416..cbb47fb 100644
--- a/include/Cubed/ui/chat_box.hpp
+++ b/include/Cubed/ui/chat_box.hpp
@@ -51,5 +51,6 @@ private:
     void on_render(Renderer& renderer) override;
     bool handle_text_input_event(const TextInputEvent& e) override;
     bool handle_key_event(const KeyEvent& e) override;
+    std::vector<std::string> wrap_message(const std::string& text) const;
 };
 } // namespace Cubed
\ No newline at end of file
diff --git a/src/tools/font.cpp b/src/tools/font.cpp
index fd986a2..1c53c18 100644
--- a/src/tools/font.cpp
+++ b/src/tools/font.cpp
@@ -154,6 +154,28 @@ TextMesh Font::vertices(const std::string& text) {
     return {std::move(vertices), max_x - min_x, max_y - min_y, 0, 0};
 }
 
+float Font::text_width(const std::string& text) {
+    auto& f = Font::get();
+
+    hb_buffer_t* buffer = hb_buffer_create();
+
+    hb_buffer_add_utf8(buffer, text.c_str(), text.size(), 0, text.size());
+    hb_buffer_guess_segment_properties(buffer);
+    hb_shape(f.m_hb_font, buffer, nullptr, 0);
+
+    unsigned int count = 0;
+    auto* positions = hb_buffer_get_glyph_positions(buffer, &count);
+
+    hb_position_t advance = 0;
+    for (unsigned int i = 0; i < count; ++i) {
+        advance += positions[i].x_advance;
+    }
+
+    hb_buffer_destroy(buffer);
+
+    return static_cast<float>(advance) / 64.0f;
+}
+
 const Texture* Font::text_texture() { return m_text_texture.get(); }
 
 const std::string& Font::font_path() { return m_font_path; }
diff --git a/src/ui/chat_box.cpp b/src/ui/chat_box.cpp
index 3ccf6f6..5200c11 100644
--- a/src/ui/chat_box.cpp
+++ b/src/ui/chat_box.cpp
@@ -1,7 +1,9 @@
 #include "Cubed/ui/chat_box.hpp"
 
-#include "Cubed/tools/text_tools.hpp"
+#include "Cubed/tools/font.hpp"
 #include "Cubed/tools/time_tools.hpp"
+
+#include <utf8cpp/utf8.h>
 namespace Cubed {
 ChatBox::ChatBox(Widget* parent) : Widget(parent) {}
 
@@ -12,7 +14,7 @@ void ChatBox::add_message(ChatMessage& message) {
 
     std::string str = std::format("<{}>{}", message.player, message.text);
 
-    auto split_str = split_utf8(str, 20);
+    auto split_str = wrap_message(str);
     for (auto it = split_str.begin(); it != split_str.end(); ++it) {
         auto lable = std::make_unique<Label>(this);
         lable->set_text(*it).set_scale(m_text_scale);
@@ -158,5 +160,39 @@ bool ChatBox::handle_key_event(const KeyEvent& e) {
     }
     return Widget::handle_key_event(e);
 }
+std::vector<std::string> ChatBox::wrap_message(const std::string& text) const {
+    std::vector<std::string> lines;
 
+    std::string line;
+    size_t last_space = std::string::npos;
+
+    auto it = text.begin();
+    while (it != text.end()) {
+        auto begin = it;
+        utf8::next(it, text.end());
+
+        line.append(begin, it);
+
+        if (*begin == ' ')
+            last_space = line.size() - 1;
+
+        if (Font::text_width(line) * m_text_scale > text_label_width()) {
+            if (last_space != std::string::npos) {
+                lines.emplace_back(line.substr(0, last_space));
+                line.erase(0, last_space + 1);
+                last_space = std::string::npos;
+            } else {
+
+                line.erase(line.size() - (it - begin));
+                lines.emplace_back(line);
+                line.assign(begin, it);
+            }
+        }
+    }
+
+    if (!line.empty())
+        lines.emplace_back(std::move(line));
+
+    return lines;
+}
 } // namespace Cubed
\ No newline at end of file