Minor documentation improvements.

include/freetype.h

@@ -4,7 +4,7 @@
 /*                                                                         */
 /*    FreeType high-level API and common types (specification only).       */
 /*                                                                         */
-/*  Copyright 1996-2013 by                                                 */
+/*  Copyright 1996-2014 by                                                 */
 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
 /*                                                                         */
 /*  This file is part of the FreeType project, and may only be used,       */
@@ -2305,6 +2305,8 @@ FT_BEGIN_HEADER
   /*    glyph relative to this size.  For more information refer to        */
   /*    `http://www.freetype.org/freetype2/docs/glyphs/glyphs-2.html'      */
   /*                                                                       */
+  /*    Don't use this function if you are using the FreeType cache API.   */
+  /*                                                                       */
   FT_EXPORT( FT_Error )
   FT_Request_Size( FT_Face          face,
                    FT_Size_Request  req );
@@ -2379,6 +2381,8 @@ FT_BEGIN_HEADER
   /*    constrained, to this pixel size.  Refer to @FT_Request_Size to     */
   /*    understand how requested sizes relate to actual sizes.             */
   /*                                                                       */
+  /*    Don't use this function if you are using the FreeType cache API.   */
+  /*                                                                       */
   FT_EXPORT( FT_Error )
   FT_Set_Pixel_Sizes( FT_Face  face,
                       FT_UInt  pixel_width,
@@ -2871,6 +2875,10 @@ FT_BEGIN_HEADER
   /* <Return>                                                              */
   /*    FreeType error code.  0~means success.                             */
   /*                                                                       */
+  /* <Note>                                                                */
+  /*    To get meaningful results, font scaling values must be set with    */
+  /*    functions like @FT_Set_Char_Size before calling FT_Render_Glyph.   */
+  /*                                                                       */
   FT_EXPORT( FT_Error )
   FT_Render_Glyph( FT_GlyphSlot    slot,
                    FT_Render_Mode  render_mode );

include/ftoutln.h

@@ -5,7 +5,7 @@
 /*    Support for the FT_Outline type used to store glyph shapes of        */
 /*    most scalable font formats (specification).                          */
 /*                                                                         */
-/*  Copyright 1996-2003, 2005-2013 by                                      */
+/*  Copyright 1996-2003, 2005-2014 by                                      */
 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
 /*                                                                         */
 /*  This file is part of the FreeType project, and may only be used,       */
@@ -355,6 +355,9 @@ FT_BEGIN_HEADER
   /*        FT_Outline_Embolden( &face->slot->outline, strength );         */
   /*    }                                                                  */
   /*                                                                       */
+  /*    To get meaningful results, font scaling values must be set with    */
+  /*    functions like @FT_Set_Char_Size before calling FT_Render_Glyph.   */
+  /*                                                                       */
   FT_EXPORT( FT_Error )
   FT_Outline_Embolden( FT_Outline*  outline,
                        FT_Pos       strength );