add Init_FreeType() in Font.cc

src/Font.cc

@@ -1,9 +1,29 @@
 #include "Font.h"
+#include "ruby.h"
 #include <iostream>
 #include <stdint.h>
+#include <ft2build.h>
+#include FT_FREETYPE_H
 
 #define round_up_26_6(val) (((val) + 63) >> 6u)
 
+static FT_Library ft;
+
+static void Init_FreeType()
+{
+    static bool initialized = false;
+
+    if (initialized)
+        return;
+
+    if (FT_Init_FreeType(&ft) != 0)
+    {
+        rb_raise(rb_eRuntimeError, "Error initializing FreeType");
+    }
+
+    initialized = true;
+}
+
 Font::Font()
 {
     m_loaded = false;

src/Window.cc

@@ -13,7 +13,7 @@ typedef struct
 
 static VALUE ruby_class;
 
-static void Init_SDL(void)
+static void Init_SDL()
 {
     static bool initialized = false;