implement dynamic text wrapping based on pixel width

src/render/TextRenderer.cpp

@@ -347,6 +347,38 @@ bool TextRenderer::loadGlyphs(const std::string& ttfPath, int pixelSize, const s
     return true;
 }
 
+float TextRenderer::measureTextWidth(const std::string& text, float scale) const
+{
+    if (text.empty()) {
+        return 0.0f;
+    }
+
+    float penX = 0.0f;
+    float maxLineWidth = 0.0f;
+
+    size_t textPos = 0;
+    while (textPos < text.size()) {
+        uint32_t cp = nextUtf8Codepoint(text, textPos);
+
+        if (cp == '\n') {
+            maxLineWidth = max(maxLineWidth, penX);
+            penX = 0.0f;
+            continue;
+        }
+
+        auto it = glyphs.find(cp);
+        if (it == glyphs.end()) {
+            continue;
+        }
+
+        const GlyphInfo& g = it->second;
+        penX += static_cast<float>(g.advance >> 6) * scale;
+    }
+
+    maxLineWidth = max(maxLineWidth, penX);
+    return maxLineWidth;
+}
+
 void TextRenderer::drawText(const std::string& text, float x, float y, float scale, bool centered, std::array<float, 4> color)
 {
     if (!r || text.empty() || !atlasTexture) return;

src/render/TextRenderer.h

@@ -29,6 +29,8 @@ public:
     bool init(Renderer& renderer, const std::string& ttfPath, int pixelSize, const std::string& zipfilename);
     void drawText(const std::string& text, float x, float y, float scale, bool centered, std::array<float, 4> color = { 1.f,1.f,1.f,1.f });
 
+    float measureTextWidth(const std::string& text, float scale = 1.0f) const;
+
     // Clear cached meshes (call on window resize / DPI change)
     void ClearCache();