Add Freetype2 to includes and lib folders, update CMakeLists.txt to

properly build the text_rendering example as just one more project.

includes/freetype/ftadvanc.h

@@ -0,0 +1,188 @@
+/****************************************************************************
+ *
+ * ftadvanc.h
+ *
+ *   Quick computation of advance widths (specification only).
+ *
+ * Copyright (C) 2008-2020 by
+ * David Turner, Robert Wilhelm, and Werner Lemberg.
+ *
+ * This file is part of the FreeType project, and may only be used,
+ * modified, and distributed under the terms of the FreeType project
+ * license, LICENSE.TXT.  By continuing to use, modify, or distribute
+ * this file you indicate that you have read the license and
+ * understand and accept it fully.
+ *
+ */
+
+
+#ifndef FTADVANC_H_
+#define FTADVANC_H_
+
+
+#include <ft2build.h>
+#include FT_FREETYPE_H
+
+#ifdef FREETYPE_H
+#error "freetype.h of FreeType 1 has been loaded!"
+#error "Please fix the directory search order for header files"
+#error "so that freetype.h of FreeType 2 is found first."
+#endif
+
+
+FT_BEGIN_HEADER
+
+
+  /**************************************************************************
+   *
+   * @section:
+   *   quick_advance
+   *
+   * @title:
+   *   Quick retrieval of advance values
+   *
+   * @abstract:
+   *   Retrieve horizontal and vertical advance values without processing
+   *   glyph outlines, if possible.
+   *
+   * @description:
+   *   This section contains functions to quickly extract advance values
+   *   without handling glyph outlines, if possible.
+   *
+   * @order:
+   *   FT_Get_Advance
+   *   FT_Get_Advances
+   *
+   */
+
+
+  /**************************************************************************
+   *
+   * @enum:
+   *   FT_ADVANCE_FLAG_FAST_ONLY
+   *
+   * @description:
+   *   A bit-flag to be OR-ed with the `flags` parameter of the
+   *   @FT_Get_Advance and @FT_Get_Advances functions.
+   *
+   *   If set, it indicates that you want these functions to fail if the
+   *   corresponding hinting mode or font driver doesn't allow for very quick
+   *   advance computation.
+   *
+   *   Typically, glyphs that are either unscaled, unhinted, bitmapped, or
+   *   light-hinted can have their advance width computed very quickly.
+   *
+   *   Normal and bytecode hinted modes that require loading, scaling, and
+   *   hinting of the glyph outline, are extremely slow by comparison.
+   */
+#define FT_ADVANCE_FLAG_FAST_ONLY  0x20000000L
+
+
+  /**************************************************************************
+   *
+   * @function:
+   *   FT_Get_Advance
+   *
+   * @description:
+   *   Retrieve the advance value of a given glyph outline in an @FT_Face.
+   *
+   * @input:
+   *   face ::
+   *     The source @FT_Face handle.
+   *
+   *   gindex ::
+   *     The glyph index.
+   *
+   *   load_flags ::
+   *     A set of bit flags similar to those used when calling
+   *     @FT_Load_Glyph, used to determine what kind of advances you need.
+   * @output:
+   *   padvance ::
+   *     The advance value.  If scaling is performed (based on the value of
+   *     `load_flags`), the advance value is in 16.16 format.  Otherwise, it
+   *     is in font units.
+   *
+   *     If @FT_LOAD_VERTICAL_LAYOUT is set, this is the vertical advance
+   *     corresponding to a vertical layout.  Otherwise, it is the horizontal
+   *     advance in a horizontal layout.
+   *
+   * @return:
+   *   FreeType error code.  0 means success.
+   *
+   * @note:
+   *   This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and if
+   *   the corresponding font backend doesn't have a quick way to retrieve
+   *   the advances.
+   *
+   *   A scaled advance is returned in 16.16 format but isn't transformed by
+   *   the affine transformation specified by @FT_Set_Transform.
+   */
+  FT_EXPORT( FT_Error )
+  FT_Get_Advance( FT_Face    face,
+                  FT_UInt    gindex,
+                  FT_Int32   load_flags,
+                  FT_Fixed  *padvance );
+
+
+  /**************************************************************************
+   *
+   * @function:
+   *   FT_Get_Advances
+   *
+   * @description:
+   *   Retrieve the advance values of several glyph outlines in an @FT_Face.
+   *
+   * @input:
+   *   face ::
+   *     The source @FT_Face handle.
+   *
+   *   start ::
+   *     The first glyph index.
+   *
+   *   count ::
+   *     The number of advance values you want to retrieve.
+   *
+   *   load_flags ::
+   *     A set of bit flags similar to those used when calling
+   *     @FT_Load_Glyph.
+   *
+   * @output:
+   *   padvance ::
+   *     The advance values.  This array, to be provided by the caller, must
+   *     contain at least `count` elements.
+   *
+   *     If scaling is performed (based on the value of `load_flags`), the
+   *     advance values are in 16.16 format.  Otherwise, they are in font
+   *     units.
+   *
+   *     If @FT_LOAD_VERTICAL_LAYOUT is set, these are the vertical advances
+   *     corresponding to a vertical layout.  Otherwise, they are the
+   *     horizontal advances in a horizontal layout.
+   *
+   * @return:
+   *   FreeType error code.  0 means success.
+   *
+   * @note:
+   *   This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and if
+   *   the corresponding font backend doesn't have a quick way to retrieve
+   *   the advances.
+   *
+   *   Scaled advances are returned in 16.16 format but aren't transformed by
+   *   the affine transformation specified by @FT_Set_Transform.
+   */
+  FT_EXPORT( FT_Error )
+  FT_Get_Advances( FT_Face    face,
+                   FT_UInt    start,
+                   FT_UInt    count,
+                   FT_Int32   load_flags,
+                   FT_Fixed  *padvances );
+
+  /* */
+
+
+FT_END_HEADER
+
+#endif /* FTADVANC_H_ */
+
+
+/* END */