[sdf] Added raster params struct.

* src/sdf/ftsdf.h (SDF_Raster_Params): Added struct which is used to pass 
  params to both `sdf' and `bsdf' rasterizer.

* src/sdf/sdf.c (*): Include source files in order to make a single object of the
  module.

* src/sdf/ftsdfrend.h (SDF_Renderer_Module): Add a '*' to make the comment
  similar to the rest in the module.

src/sdf/ftsdf.h

@@ -2,6 +2,69 @@
 #ifndef FTSDF_H_
 #define FTSDF_H_
 
+#include <ft2build.h>
+#include FT_CONFIG_CONFIG_H
+#include <freetype/ftimage.h>
+
+/* common properties and function */
+#include "ftsdfcommon.h"
+
+FT_BEGIN_HEADER
+
+  /**************************************************************************
+   *
+   * @struct:
+   *   SDF_Raster_Params
+   *
+   * @description:
+   *   This struct must be passed to the raster render function
+   *   `FT_Raster_Render_Func' instead of `FT_Raster_Params' because
+   *   the rasterizer require some addition information to render properly.
+   *   So, this struct is used to pass additional parameter to the
+   *   rasterizer.
+   *
+   * @fields:
+   *   root ::
+   *     The native raster params struct.
+   *
+   *   spread ::
+   *     This is and essential parameter/property required by the
+   *     rendere. `spread' defines the maximum unsigned value that
+   *     will be present in the final SDF output. For default value
+   *     check `ftsdfcommon.h'.
+   *
+   *   flip_sign ::
+   *     By default the position values are inside the contours i.e.
+   *     filled by a contour. If this property is true then that output
+   *     will be opposite from the default i.e. negative will be filled
+   *     by a contour.
+   *
+   *   flip_y ::
+   *     Setting this parameter to true maked the output image flipped
+   *     along the y-axis.
+   *
+   *   overlaps ::
+   *     Set this to true to generate SDF for glyphs having overlapping
+   *     contours. The overlapping support is limited to glyph which do
+   *     not have self intersecting contours. Also, removing overlaps
+   *     require a considerable amount of extra memory and this is not
+   *     valid while generating SDF from bitmap.
+   *
+   * @note:
+   *   It is valid for both `sdf' and `bsdf' renderer.
+   *
+   */
+  typedef struct  SDF_Raster_Params_
+  {
+    FT_Raster_Params  root;
+    FT_UInt           spread;
+    FT_Bool           flip_sign;
+    FT_Bool           flip_y;
+    FT_Bool           overlaps;
+
+  } SDF_Raster_Params;
+
+FT_END_HEADER
 
 #endif /* FTSDF_H_ */
 

src/sdf/ftsdfrend.h

@@ -50,6 +50,7 @@ FT_BEGIN_HEADER
    * @note:
    *   All properties except `overlaps' is valid for both `sdf' and
    *   `bsdf' renderer.
+   *
    */
   typedef struct  SDF_Renderer_Module_
   {

src/sdf/sdf.c

@@ -1,3 +1,8 @@
 
+#define FT_MAKE_OPTION_SINGLE_OBJECT
+
+#include "ftsdfrend.c"
+#include "ftbsdf.c"
+#include "ftsdf.c"
 
 /* END */