add Encoding::encode()

src/core/Encoding.cc

@@ -188,7 +188,48 @@ uint8_t Encoding::num_bytes_to_encode_code_point(uint32_t code_point, Type type)
         }
         break;
     case CP_1252:
-        return 1u;
+        if (code_point <= 0xFFu)
+        {
+            return 1u;
+        }
+        else
+        {
+            return 0u;
+        }
+        break;
+    }
+
+    return 0u;
+}
+
+uint8_t Encoding::encode(uint32_t code_point, Type type, uint8_t * buffer)
+{
+    switch (type)
+    {
+    case UTF_8:
+        {
+            uint8_t size = num_bytes_to_encode_code_point(code_point, type);
+            if (size == 1u)
+            {
+                *buffer = code_point;
+            }
+            else if (size > 1u)
+            {
+                *buffer = (0xFFu << (8u - size)) | (code_point >> (6u * (size - 1u)));
+                for (uint8_t i = 0u, end = size - 1u; i < end; i++)
+                {
+                    buffer[end - i] = 0x80u | (code_point >> (6u * i) & 0x3Fu);
+                }
+            }
+            return size;
+        }
+        break;
+    case CP_1252:
+        if (code_point <= 0xFFu)
+        {
+            *buffer = code_point;
+            return 1u;
+        }
         break;
     }