freetype2/include/freetype/ftbitmap.h

/****************************************************************************
 *
 * ftbitmap.h
 *
 *   FreeType utility functions for bitmaps (specification).
 *
 * Copyright 2004-2018 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 FTBITMAP_H_
#define FTBITMAP_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:
   *   bitmap_handling
   *
   * @Title:
   *   Bitmap Handling
   *
   * @Abstract:
   *   Handling FT_Bitmap objects.
   *
   * @Description:
   *   This section contains functions for handling @FT_Bitmap objects.
   *   Note that none of the functions changes the bitmap's `flow' (as
   *   indicated by the sign of the `pitch' field in `FT_Bitmap').
   *
   */


  /**************************************************************************
   *
   * @Function:
   *   FT_Bitmap_Init
   *
   * @Description:
   *   Initialize a pointer to an @FT_Bitmap structure.
   *
   * @InOut:
   *   abitmap ::
   *     A pointer to the bitmap structure.
   *
   * @Note:
   *   A deprecated name for the same function is `FT_Bitmap_New'.
   */
  FT_EXPORT( void )
  FT_Bitmap_Init( FT_Bitmap  *abitmap );


  /* deprecated */
  FT_EXPORT( void )
  FT_Bitmap_New( FT_Bitmap  *abitmap );


  /**************************************************************************
   *
   * @Function:
   *   FT_Bitmap_Copy
   *
   * @Description:
   *   Copy a bitmap into another one.
   *
   * @Input:
   *   library ::
   *     A handle to a library object.
   *
   *   source ::
   *     A handle to the source bitmap.
   *
   * @Output:
   *   target ::
   *     A handle to the target bitmap.
   *
   * @Return:
   *   FreeType error code.  0~means success.
   */
  FT_EXPORT( FT_Error )
  FT_Bitmap_Copy( FT_Library        library,
                  const FT_Bitmap  *source,
                  FT_Bitmap        *target );


  /**************************************************************************
   *
   * @Function:
   *   FT_Bitmap_Embolden
   *
   * @Description:
   *   Embolden a bitmap.  The new bitmap will be about `xStrength'
   *   pixels wider and `yStrength' pixels higher.  The left and bottom
   *   borders are kept unchanged.
   *
   * @Input:
   *   library ::
   *     A handle to a library object.
   *
   *   xStrength ::
   *     How strong the glyph is emboldened horizontally.
   *     Expressed in 26.6 pixel format.
   *
   *   yStrength ::
   *     How strong the glyph is emboldened vertically.
   *     Expressed in 26.6 pixel format.
   *
   * @InOut:
   *   bitmap ::
   *     A handle to the target bitmap.
   *
   * @Return:
   *   FreeType error code.  0~means success.
   *
   * @Note:
   *   The current implementation restricts `xStrength' to be less than
   *   or equal to~8 if bitmap is of pixel_mode @FT_PIXEL_MODE_MONO.
   *
   *   If you want to embolden the bitmap owned by a @FT_GlyphSlotRec,
   *   you should call @FT_GlyphSlot_Own_Bitmap on the slot first.
   *
   *   Bitmaps in @FT_PIXEL_MODE_GRAY2 and @FT_PIXEL_MODE_GRAY@ format
   *   are converted to @FT_PIXEL_MODE_GRAY format (i.e., 8bpp).
   */
  FT_EXPORT( FT_Error )
  FT_Bitmap_Embolden( FT_Library  library,
                      FT_Bitmap*  bitmap,
                      FT_Pos      xStrength,
                      FT_Pos      yStrength );


  /**************************************************************************
   *
   * @Function:
   *   FT_Bitmap_Convert
   *
   * @Description:
   *   Convert a bitmap object with depth 1bpp, 2bpp, 4bpp, 8bpp or 32bpp
   *   to a bitmap object with depth 8bpp, making the number of used
   *   bytes per line (a.k.a. the `pitch') a multiple of `alignment'.
   *
   * @Input:
   *   library ::
   *     A handle to a library object.
   *
   *   source ::
   *     The source bitmap.
   *
   *   alignment ::
   *     The pitch of the bitmap is a multiple of this
   *     argument.  Common values are 1, 2, or 4.
   *
   * @Output:
   *   target ::
   *     The target bitmap.
   *
   * @Return:
   *   FreeType error code.  0~means success.
   *
   * @Note:
   *   It is possible to call @FT_Bitmap_Convert multiple times without
   *   calling @FT_Bitmap_Done (the memory is simply reallocated).
   *
   *   Use @FT_Bitmap_Done to finally remove the bitmap object.
   *
   *   The `library' argument is taken to have access to FreeType's
   *   memory handling functions.
   */
  FT_EXPORT( FT_Error )
  FT_Bitmap_Convert( FT_Library        library,
                     const FT_Bitmap  *source,
                     FT_Bitmap        *target,
                     FT_Int            alignment );


  /**************************************************************************
   *
   * @Function:
   *   FT_GlyphSlot_Own_Bitmap
   *
   * @Description:
   *   Make sure that a glyph slot owns `slot->bitmap'.
   *
   * @Input:
   *   slot ::
   *     The glyph slot.
   *
   * @Return:
   *   FreeType error code.  0~means success.
   *
   * @Note:
   *   This function is to be used in combination with
   *   @FT_Bitmap_Embolden.
   */
  FT_EXPORT( FT_Error )
  FT_GlyphSlot_Own_Bitmap( FT_GlyphSlot  slot );


  /**************************************************************************
   *
   * @Function:
   *   FT_Bitmap_Done
   *
   * @Description:
   *   Destroy a bitmap object initialized with @FT_Bitmap_Init.
   *
   * @Input:
   *   library ::
   *     A handle to a library object.
   *
   *   bitmap ::
   *     The bitmap object to be freed.
   *
   * @Return:
   *   FreeType error code.  0~means success.
   *
   * @Note:
   *   The `library' argument is taken to have access to FreeType's
   *   memory handling functions.
   */
  FT_EXPORT( FT_Error )
  FT_Bitmap_Done( FT_Library  library,
                  FT_Bitmap  *bitmap );


  /* */


FT_END_HEADER

#endif /* FTBITMAP_H_ */


/* END */