VN Textbox updated

src/dawn/display/font/FontMeasure.cpp

@@ -19,6 +19,10 @@ int32_t FontMeasure::getQuadCount() {
   return this->realLength;
 }
 
+float_t FontMeasure::getHeightOfLineCount(int32_t lineCount) {
+  return this->lineHeight * lineCount;
+}
+
 size_t FontMeasure::getLineCount() {
   return this->lines.size();
 }