added new meaasure_text() and measure_glyph() methods

libraries/badger2040/badger2040.cpp

@@ -205,7 +205,6 @@ namespace pimoroni {
   }
 
   int32_t Badger2040::glyph(unsigned char c, int32_t x, int32_t y, float s, float a) {
-    // if space character then return a width to move the caret by
     const hershey_font_glyph_t *gd = glyph_data(c);
 
     // if glyph data not found (id too great) then skip
@@ -266,6 +265,26 @@ namespace pimoroni {
     }
   }
 
+  int32_t Badger2040::measure_text(std::string message, float s) {
+    int32_t width = 0;
+    for(auto &c : message) {
+      width += measure_glyph(c, s);
+    }
+    return width;
+  }
+
+  int32_t Badger2040::measure_glyph(unsigned char c, float s) {
+    const hershey_font_glyph_t *gd = glyph_data(c);
+
+    // if glyph data not found (id too great) then skip
+    if(!gd) {
+      return 0;
+    }
+
+    return gd->width * s;
+  }
+
+
   void Badger2040::font(std::string name) {
     // check that font exists and assign it
     if(fonts.find(name) != fonts.end()) {

libraries/badger2040/badger2040.hpp

@@ -56,9 +56,13 @@ namespace pimoroni {
     void image(const uint8_t *data);
 
     // text (fonts: sans, sans_bold, gothic, cursive_bold, cursive, serif_italic, serif, serif_bold)
-    void text(std::string message, int32_t x, int32_t y, float s = 1.0f, float a = 0.0f);
     const hershey_font_glyph_t* glyph_data(unsigned char c);
-    int32_t glyph(unsigned char c, int32_t x, int32_t y, float s, float a = 0.0f);
+
+    void text(std::string message, int32_t x, int32_t y, float s = 1.0f, float a = 0.0f);
+    int32_t glyph(unsigned char c, int32_t x, int32_t y, float s = 1.0f, float a = 0.0f);
+
+    int32_t measure_text(std::string message, float s = 1.0f);
+    int32_t measure_glyph(unsigned char c, float s = 1.0f);
 
     void debug_command(uint8_t command, size_t len, const uint8_t *data);
     void dump_otp(uint8_t *otp_data);