gltk.Buffer.set_buffer_data() can take an arbitrary array.

src/gltk/buffer.d

@@ -38,4 +38,11 @@ class Buffer
         bind();
         glBufferData(target, size, ptr, usage);
     }
+
+    void set_buffer_data(T)(GLenum target, GLenum usage, T[] arr)
+    {
+        m_target = target;
+        bind();
+        glBufferData(target, arr.length * arr[0].sizeof, arr.ptr, usage);
+    }
 }

src/jes/gui/font.d

@@ -74,7 +74,7 @@ class Font
                 cast(GLfloat)left, cast(GLfloat)top,                      0.0,   t_max,
                 cast(GLfloat)(left + cglyph.width), cast(GLfloat)top,            s_max, t_max,
             ];
-            m_buffer.set_buffer_data(GL_ARRAY_BUFFER, GL_STATIC_DRAW, data.ptr, data.length * GLfloat.sizeof);
+            m_buffer.set_buffer_data(GL_ARRAY_BUFFER, GL_STATIC_DRAW, data);
 
             glEnableVertexAttribArray(0);
             glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, null);