fix label font cache

src/graphics/core/Font.cpp

@@ -38,6 +38,10 @@ bool Font::isPrintableChar(uint codepoint) const {
     }
 }
 
+int FontMetrics::calcWidth(std::wstring_view text, size_t offset, size_t length) const {
+    return std::min(text.length() - offset, length) * glyphInterval;
+}
+
 int Font::calcWidth(std::wstring_view text, size_t length) const {
     return calcWidth(text, 0, length);
 }

src/graphics/core/Font.hpp

@@ -4,7 +4,9 @@
 #include <string>
 #include <vector>
 #include <glm/glm.hpp>
+
 #include "typedefs.hpp"
+#include "FontMetics.hpp"
 
 class Texture;
 class Batch2D;
@@ -90,4 +92,8 @@ public:
     ) const;
 
     const Texture* getPage(int page) const;
+
+    FontMetrics getMetrics() const {
+        return {lineHeight, yoffset, glyphInterval};
+    }
 };

src/graphics/core/FontMetics.hpp

@@ -0,0 +1,11 @@
+#pragma once
+
+#include <string>
+
+struct FontMetrics {
+    int lineHeight;
+    int yoffset;
+    int glyphInterval = 8;
+
+    int calcWidth(std::wstring_view text, size_t offset=0, size_t length=-1) const;
+};