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freetype2/include/freetype/ftbitmap.h

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/****************************************************************************
*
* ftbitmap.h
*
* FreeType utility functions for bitmaps (specification).
*
* Copyright (C) 2004-2019 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
#include FT_COLOR_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,
* automatically adjusting the target's bitmap buffer size as needed.
*
* Note that none of the functions changes the bitmap's 'flow' (as
* indicated by the sign of the `pitch` field in @FT_Bitmap).
*
* To set the flow, assign an appropriate positive or negative value to
* the `pitch` field of the target @FT_Bitmap object after calling
* @FT_Bitmap_Init but before calling any of the other functions
* described here.
*/
/**************************************************************************
*
* @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.
*
* @note:
* `source->buffer` and `target->buffer` must neither be equal nor
* overlap.
*/
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.
*
* `source->buffer` and `target->buffer` must neither be equal nor
* overlap.
*/
FT_EXPORT( FT_Error )
FT_Bitmap_Convert( FT_Library library,
const FT_Bitmap *source,
FT_Bitmap *target,
FT_Int alignment );
/**************************************************************************
*
* @function:
* FT_Bitmap_Blend
*
* @description:
* Blend a bitmap onto another bitmap, using a given color.
*
* @input:
* library ::
* A handle to a library object.
*
* source ::
* The source bitmap, which can have any @FT_Pixel_Mode format.
*
* source_offset ::
* The offset vector to the upper left corner of the source bitmap in
* 26.6 pixel format. It should represent an integer offset; the
* function will set the lowest six bits to zero to enforce that.
*
* color ::
* The color used to draw `source` onto `target`.
*
* @inout:
* target ::
* A handle to an `FT_Bitmap` object. It should be either initialized
* as empty with a call to @FT_Bitmap_Init, or it should be of type
* @FT_PIXEL_MODE_BGRA.
*
* atarget_offset ::
* The offset vector to the upper left corner of the target bitmap in
* 26.6 pixel format. It should represent an integer offset; the
* function will set the lowest six bits to zero to enforce that.
*
* @return:
* FreeType error code. 0~means success.
*
* @note:
* This function doesn't perform clipping.
*
* The bitmap in `target` gets allocated or reallocated as needed; the
* vector `atarget_offset` is updated accordingly.
*
* In case of allocation or reallocation, the bitmap's pitch is set to
* `4 * width`. Both `source` and `target` must have the same bitmap
* flow (as indicated by the sign of the `pitch` field).
*
* `source->buffer` and `target->buffer` must neither be equal nor
* overlap.
*
* @since:
* 2.10
*/
FT_EXPORT( FT_Error )
FT_Bitmap_Blend( FT_Library library,
const FT_Bitmap* source,
const FT_Vector source_offset,
FT_Bitmap* target,
FT_Vector *atarget_offset,
FT_Color color );
/**************************************************************************
*
* @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 */
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