751 lines
20 KiB
C
751 lines
20 KiB
C
/****************************************************************************
|
|
*
|
|
* ftglyph.h
|
|
*
|
|
* FreeType convenience functions to handle glyphs (specification).
|
|
*
|
|
* Copyright (C) 1996-2022 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.
|
|
*
|
|
*/
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* This file contains the definition of several convenience functions that
|
|
* can be used by client applications to easily retrieve glyph bitmaps and
|
|
* outlines from a given face.
|
|
*
|
|
* These functions should be optional if you are writing a font server or
|
|
* text layout engine on top of FreeType. However, they are pretty handy
|
|
* for many other simple uses of the library.
|
|
*
|
|
*/
|
|
|
|
|
|
#ifndef FTGLYPH_H_
|
|
#define FTGLYPH_H_
|
|
|
|
|
|
#include <freetype/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:
|
|
* glyph_management
|
|
*
|
|
* @title:
|
|
* Glyph Management
|
|
*
|
|
* @abstract:
|
|
* Generic interface to manage individual glyph data.
|
|
*
|
|
* @description:
|
|
* This section contains definitions used to manage glyph data through
|
|
* generic @FT_Glyph objects. Each of them can contain a bitmap,
|
|
* a vector outline, or even images in other formats. These objects are
|
|
* detached from @FT_Face, contrary to @FT_GlyphSlot.
|
|
*
|
|
*/
|
|
|
|
|
|
/* forward declaration to a private type */
|
|
typedef struct FT_Glyph_Class_ FT_Glyph_Class;
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @type:
|
|
* FT_Glyph
|
|
*
|
|
* @description:
|
|
* Handle to an object used to model generic glyph images. It is a
|
|
* pointer to the @FT_GlyphRec structure and can contain a glyph bitmap
|
|
* or pointer.
|
|
*
|
|
* @note:
|
|
* Glyph objects are not owned by the library. You must thus release
|
|
* them manually (through @FT_Done_Glyph) _before_ calling
|
|
* @FT_Done_FreeType.
|
|
*/
|
|
typedef struct FT_GlyphRec_* FT_Glyph;
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @struct:
|
|
* FT_GlyphRec
|
|
*
|
|
* @description:
|
|
* The root glyph structure contains a given glyph image plus its advance
|
|
* width in 16.16 fixed-point format.
|
|
*
|
|
* @fields:
|
|
* library ::
|
|
* A handle to the FreeType library object.
|
|
*
|
|
* clazz ::
|
|
* A pointer to the glyph's class. Private.
|
|
*
|
|
* format ::
|
|
* The format of the glyph's image.
|
|
*
|
|
* advance ::
|
|
* A 16.16 vector that gives the glyph's advance width.
|
|
*/
|
|
typedef struct FT_GlyphRec_
|
|
{
|
|
FT_Library library;
|
|
const FT_Glyph_Class* clazz;
|
|
FT_Glyph_Format format;
|
|
FT_Vector advance;
|
|
|
|
} FT_GlyphRec;
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @type:
|
|
* FT_BitmapGlyph
|
|
*
|
|
* @description:
|
|
* A handle to an object used to model a bitmap glyph image. This is a
|
|
* 'sub-class' of @FT_Glyph, and a pointer to @FT_BitmapGlyphRec.
|
|
*/
|
|
typedef struct FT_BitmapGlyphRec_* FT_BitmapGlyph;
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @struct:
|
|
* FT_BitmapGlyphRec
|
|
*
|
|
* @description:
|
|
* A structure used for bitmap glyph images. This really is a
|
|
* 'sub-class' of @FT_GlyphRec.
|
|
*
|
|
* @fields:
|
|
* root ::
|
|
* The root fields of @FT_Glyph.
|
|
*
|
|
* left ::
|
|
* The left-side bearing, i.e., the horizontal distance from the
|
|
* current pen position to the left border of the glyph bitmap.
|
|
*
|
|
* top ::
|
|
* The top-side bearing, i.e., the vertical distance from the current
|
|
* pen position to the top border of the glyph bitmap. This distance
|
|
* is positive for upwards~y!
|
|
*
|
|
* bitmap ::
|
|
* A descriptor for the bitmap.
|
|
*
|
|
* @note:
|
|
* You can typecast an @FT_Glyph to @FT_BitmapGlyph if you have
|
|
* `glyph->format == FT_GLYPH_FORMAT_BITMAP`. This lets you access the
|
|
* bitmap's contents easily.
|
|
*
|
|
* The corresponding pixel buffer is always owned by @FT_BitmapGlyph and
|
|
* is thus created and destroyed with it.
|
|
*/
|
|
typedef struct FT_BitmapGlyphRec_
|
|
{
|
|
FT_GlyphRec root;
|
|
FT_Int left;
|
|
FT_Int top;
|
|
FT_Bitmap bitmap;
|
|
|
|
} FT_BitmapGlyphRec;
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @type:
|
|
* FT_OutlineGlyph
|
|
*
|
|
* @description:
|
|
* A handle to an object used to model an outline glyph image. This is a
|
|
* 'sub-class' of @FT_Glyph, and a pointer to @FT_OutlineGlyphRec.
|
|
*/
|
|
typedef struct FT_OutlineGlyphRec_* FT_OutlineGlyph;
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @struct:
|
|
* FT_OutlineGlyphRec
|
|
*
|
|
* @description:
|
|
* A structure used for outline (vectorial) glyph images. This really is
|
|
* a 'sub-class' of @FT_GlyphRec.
|
|
*
|
|
* @fields:
|
|
* root ::
|
|
* The root @FT_Glyph fields.
|
|
*
|
|
* outline ::
|
|
* A descriptor for the outline.
|
|
*
|
|
* @note:
|
|
* You can typecast an @FT_Glyph to @FT_OutlineGlyph if you have
|
|
* `glyph->format == FT_GLYPH_FORMAT_OUTLINE`. This lets you access the
|
|
* outline's content easily.
|
|
*
|
|
* As the outline is extracted from a glyph slot, its coordinates are
|
|
* expressed normally in 26.6 pixels, unless the flag @FT_LOAD_NO_SCALE
|
|
* was used in @FT_Load_Glyph or @FT_Load_Char.
|
|
*
|
|
* The outline's tables are always owned by the object and are destroyed
|
|
* with it.
|
|
*/
|
|
typedef struct FT_OutlineGlyphRec_
|
|
{
|
|
FT_GlyphRec root;
|
|
FT_Outline outline;
|
|
|
|
} FT_OutlineGlyphRec;
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @type:
|
|
* FT_SvgGlyph
|
|
*
|
|
* @description:
|
|
* A handle to an object used to model an SVG glyph. This is a
|
|
* 'sub-class' of @FT_Glyph, and a pointer to @FT_SvgGlyphRec.
|
|
*
|
|
* @since:
|
|
* 2.12
|
|
*/
|
|
typedef struct FT_SvgGlyphRec_* FT_SvgGlyph;
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @struct:
|
|
* FT_SvgGlyphRec
|
|
*
|
|
* @description:
|
|
* A structure used for OT-SVG glyphs. This is a 'sub-class' of
|
|
* @FT_GlyphRec.
|
|
*
|
|
* @fields:
|
|
* root ::
|
|
* The root @FT_GlyphRec fields.
|
|
*
|
|
* svg_document ::
|
|
* A pointer to the SVG document.
|
|
*
|
|
* svg_document_length ::
|
|
* The length of `svg_document`.
|
|
*
|
|
* glyph_index ::
|
|
* The index of the glyph to be rendered.
|
|
*
|
|
* metrics ::
|
|
* A metrics object storing the size information.
|
|
*
|
|
* units_per_EM ::
|
|
* The size of the EM square.
|
|
*
|
|
* start_glyph_id ::
|
|
* The first glyph ID in the glyph range covered by this document.
|
|
*
|
|
* end_glyph_id ::
|
|
* The last glyph ID in the glyph range covered by this document.
|
|
*
|
|
* transform ::
|
|
* A 2x2 transformation matrix to apply to the glyph while rendering
|
|
* it.
|
|
*
|
|
* delta ::
|
|
* Translation to apply to the glyph while rendering.
|
|
*
|
|
* @note:
|
|
* The Glyph Management API requires @FT_Glyph or its 'sub-class' to have
|
|
* all the information needed to completely define the glyph's rendering.
|
|
* Outline-based glyphs can directly apply transformations to the outline
|
|
* but this is not possible for an SVG document that hasn't been parsed.
|
|
* Therefore, the transformation is stored along with the document. In
|
|
* the absence of a 'ViewBox' or 'Width'/'Height' attribute, the size of
|
|
* the ViewPort should be assumed to be 'units_per_EM'.
|
|
*/
|
|
typedef struct FT_SvgGlyphRec_
|
|
{
|
|
FT_GlyphRec root;
|
|
|
|
FT_Byte* svg_document;
|
|
FT_ULong svg_document_length;
|
|
|
|
FT_UInt glyph_index;
|
|
|
|
FT_Size_Metrics metrics;
|
|
FT_UShort units_per_EM;
|
|
|
|
FT_UShort start_glyph_id;
|
|
FT_UShort end_glyph_id;
|
|
|
|
FT_Matrix transform;
|
|
FT_Vector delta;
|
|
|
|
} FT_SvgGlyphRec;
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @function:
|
|
* FT_New_Glyph
|
|
*
|
|
* @description:
|
|
* A function used to create a new empty glyph image. Note that the
|
|
* created @FT_Glyph object must be released with @FT_Done_Glyph.
|
|
*
|
|
* @input:
|
|
* library ::
|
|
* A handle to the FreeType library object.
|
|
*
|
|
* format ::
|
|
* The format of the glyph's image.
|
|
*
|
|
* @output:
|
|
* aglyph ::
|
|
* A handle to the glyph object.
|
|
*
|
|
* @return:
|
|
* FreeType error code. 0~means success.
|
|
*
|
|
* @since:
|
|
* 2.10
|
|
*/
|
|
FT_EXPORT( FT_Error )
|
|
FT_New_Glyph( FT_Library library,
|
|
FT_Glyph_Format format,
|
|
FT_Glyph *aglyph );
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @function:
|
|
* FT_Get_Glyph
|
|
*
|
|
* @description:
|
|
* A function used to extract a glyph image from a slot. Note that the
|
|
* created @FT_Glyph object must be released with @FT_Done_Glyph.
|
|
*
|
|
* @input:
|
|
* slot ::
|
|
* A handle to the source glyph slot.
|
|
*
|
|
* @output:
|
|
* aglyph ::
|
|
* A handle to the glyph object.
|
|
*
|
|
* @return:
|
|
* FreeType error code. 0~means success.
|
|
*
|
|
* @note:
|
|
* Because `*aglyph->advance.x` and `*aglyph->advance.y` are 16.16
|
|
* fixed-point numbers, `slot->advance.x` and `slot->advance.y` (which
|
|
* are in 26.6 fixed-point format) must be in the range ]-32768;32768[.
|
|
*/
|
|
FT_EXPORT( FT_Error )
|
|
FT_Get_Glyph( FT_GlyphSlot slot,
|
|
FT_Glyph *aglyph );
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @function:
|
|
* FT_Glyph_Copy
|
|
*
|
|
* @description:
|
|
* A function used to copy a glyph image. Note that the created
|
|
* @FT_Glyph object must be released with @FT_Done_Glyph.
|
|
*
|
|
* @input:
|
|
* source ::
|
|
* A handle to the source glyph object.
|
|
*
|
|
* @output:
|
|
* target ::
|
|
* A handle to the target glyph object. 0~in case of error.
|
|
*
|
|
* @return:
|
|
* FreeType error code. 0~means success.
|
|
*/
|
|
FT_EXPORT( FT_Error )
|
|
FT_Glyph_Copy( FT_Glyph source,
|
|
FT_Glyph *target );
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @function:
|
|
* FT_Glyph_Transform
|
|
*
|
|
* @description:
|
|
* Transform a glyph image if its format is scalable.
|
|
*
|
|
* @inout:
|
|
* glyph ::
|
|
* A handle to the target glyph object.
|
|
*
|
|
* @input:
|
|
* matrix ::
|
|
* A pointer to a 2x2 matrix to apply.
|
|
*
|
|
* delta ::
|
|
* A pointer to a 2d vector to apply. Coordinates are expressed in
|
|
* 1/64th of a pixel.
|
|
*
|
|
* @return:
|
|
* FreeType error code (if not 0, the glyph format is not scalable).
|
|
*
|
|
* @note:
|
|
* The 2x2 transformation matrix is also applied to the glyph's advance
|
|
* vector.
|
|
*/
|
|
FT_EXPORT( FT_Error )
|
|
FT_Glyph_Transform( FT_Glyph glyph,
|
|
const FT_Matrix* matrix,
|
|
const FT_Vector* delta );
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @enum:
|
|
* FT_Glyph_BBox_Mode
|
|
*
|
|
* @description:
|
|
* The mode how the values of @FT_Glyph_Get_CBox are returned.
|
|
*
|
|
* @values:
|
|
* FT_GLYPH_BBOX_UNSCALED ::
|
|
* Return unscaled font units.
|
|
*
|
|
* FT_GLYPH_BBOX_SUBPIXELS ::
|
|
* Return unfitted 26.6 coordinates.
|
|
*
|
|
* FT_GLYPH_BBOX_GRIDFIT ::
|
|
* Return grid-fitted 26.6 coordinates.
|
|
*
|
|
* FT_GLYPH_BBOX_TRUNCATE ::
|
|
* Return coordinates in integer pixels.
|
|
*
|
|
* FT_GLYPH_BBOX_PIXELS ::
|
|
* Return grid-fitted pixel coordinates.
|
|
*/
|
|
typedef enum FT_Glyph_BBox_Mode_
|
|
{
|
|
FT_GLYPH_BBOX_UNSCALED = 0,
|
|
FT_GLYPH_BBOX_SUBPIXELS = 0,
|
|
FT_GLYPH_BBOX_GRIDFIT = 1,
|
|
FT_GLYPH_BBOX_TRUNCATE = 2,
|
|
FT_GLYPH_BBOX_PIXELS = 3
|
|
|
|
} FT_Glyph_BBox_Mode;
|
|
|
|
|
|
/* these constants are deprecated; use the corresponding */
|
|
/* `FT_Glyph_BBox_Mode` values instead */
|
|
#define ft_glyph_bbox_unscaled FT_GLYPH_BBOX_UNSCALED
|
|
#define ft_glyph_bbox_subpixels FT_GLYPH_BBOX_SUBPIXELS
|
|
#define ft_glyph_bbox_gridfit FT_GLYPH_BBOX_GRIDFIT
|
|
#define ft_glyph_bbox_truncate FT_GLYPH_BBOX_TRUNCATE
|
|
#define ft_glyph_bbox_pixels FT_GLYPH_BBOX_PIXELS
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @function:
|
|
* FT_Glyph_Get_CBox
|
|
*
|
|
* @description:
|
|
* Return a glyph's 'control box'. The control box encloses all the
|
|
* outline's points, including Bezier control points. Though it
|
|
* coincides with the exact bounding box for most glyphs, it can be
|
|
* slightly larger in some situations (like when rotating an outline that
|
|
* contains Bezier outside arcs).
|
|
*
|
|
* Computing the control box is very fast, while getting the bounding box
|
|
* can take much more time as it needs to walk over all segments and arcs
|
|
* in the outline. To get the latter, you can use the 'ftbbox'
|
|
* component, which is dedicated to this single task.
|
|
*
|
|
* @input:
|
|
* glyph ::
|
|
* A handle to the source glyph object.
|
|
*
|
|
* mode ::
|
|
* The mode that indicates how to interpret the returned bounding box
|
|
* values.
|
|
*
|
|
* @output:
|
|
* acbox ::
|
|
* The glyph coordinate bounding box. Coordinates are expressed in
|
|
* 1/64th of pixels if it is grid-fitted.
|
|
*
|
|
* @note:
|
|
* Coordinates are relative to the glyph origin, using the y~upwards
|
|
* convention.
|
|
*
|
|
* If the glyph has been loaded with @FT_LOAD_NO_SCALE, `bbox_mode` must
|
|
* be set to @FT_GLYPH_BBOX_UNSCALED to get unscaled font units in 26.6
|
|
* pixel format. The value @FT_GLYPH_BBOX_SUBPIXELS is another name for
|
|
* this constant.
|
|
*
|
|
* If the font is tricky and the glyph has been loaded with
|
|
* @FT_LOAD_NO_SCALE, the resulting CBox is meaningless. To get
|
|
* reasonable values for the CBox it is necessary to load the glyph at a
|
|
* large ppem value (so that the hinting instructions can properly shift
|
|
* and scale the subglyphs), then extracting the CBox, which can be
|
|
* eventually converted back to font units.
|
|
*
|
|
* Note that the maximum coordinates are exclusive, which means that one
|
|
* can compute the width and height of the glyph image (be it in integer
|
|
* or 26.6 pixels) as:
|
|
*
|
|
* ```
|
|
* width = bbox.xMax - bbox.xMin;
|
|
* height = bbox.yMax - bbox.yMin;
|
|
* ```
|
|
*
|
|
* Note also that for 26.6 coordinates, if `bbox_mode` is set to
|
|
* @FT_GLYPH_BBOX_GRIDFIT, the coordinates will also be grid-fitted,
|
|
* which corresponds to:
|
|
*
|
|
* ```
|
|
* bbox.xMin = FLOOR(bbox.xMin);
|
|
* bbox.yMin = FLOOR(bbox.yMin);
|
|
* bbox.xMax = CEILING(bbox.xMax);
|
|
* bbox.yMax = CEILING(bbox.yMax);
|
|
* ```
|
|
*
|
|
* To get the bbox in pixel coordinates, set `bbox_mode` to
|
|
* @FT_GLYPH_BBOX_TRUNCATE.
|
|
*
|
|
* To get the bbox in grid-fitted pixel coordinates, set `bbox_mode` to
|
|
* @FT_GLYPH_BBOX_PIXELS.
|
|
*/
|
|
FT_EXPORT( void )
|
|
FT_Glyph_Get_CBox( FT_Glyph glyph,
|
|
FT_UInt bbox_mode,
|
|
FT_BBox *acbox );
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @function:
|
|
* FT_Glyph_To_Bitmap
|
|
*
|
|
* @description:
|
|
* Convert a given glyph object to a bitmap glyph object.
|
|
*
|
|
* @inout:
|
|
* the_glyph ::
|
|
* A pointer to a handle to the target glyph.
|
|
*
|
|
* @input:
|
|
* render_mode ::
|
|
* An enumeration that describes how the data is rendered.
|
|
*
|
|
* origin ::
|
|
* A pointer to a vector used to translate the glyph image before
|
|
* rendering. Can be~0 (if no translation). The origin is expressed
|
|
* in 26.6 pixels.
|
|
*
|
|
* destroy ::
|
|
* A boolean that indicates that the original glyph image should be
|
|
* destroyed by this function. It is never destroyed in case of error.
|
|
*
|
|
* @return:
|
|
* FreeType error code. 0~means success.
|
|
*
|
|
* @note:
|
|
* This function does nothing if the glyph format isn't scalable.
|
|
*
|
|
* The glyph image is translated with the `origin` vector before
|
|
* rendering.
|
|
*
|
|
* The first parameter is a pointer to an @FT_Glyph handle, that will be
|
|
* _replaced_ by this function (with newly allocated data). Typically,
|
|
* you would use (omitting error handling):
|
|
*
|
|
* ```
|
|
* FT_Glyph glyph;
|
|
* FT_BitmapGlyph glyph_bitmap;
|
|
*
|
|
*
|
|
* // load glyph
|
|
* error = FT_Load_Char( face, glyph_index, FT_LOAD_DEFAULT );
|
|
*
|
|
* // extract glyph image
|
|
* error = FT_Get_Glyph( face->glyph, &glyph );
|
|
*
|
|
* // convert to a bitmap (default render mode + destroying old)
|
|
* if ( glyph->format != FT_GLYPH_FORMAT_BITMAP )
|
|
* {
|
|
* error = FT_Glyph_To_Bitmap( &glyph, FT_RENDER_MODE_NORMAL,
|
|
* 0, 1 );
|
|
* if ( error ) // `glyph' unchanged
|
|
* ...
|
|
* }
|
|
*
|
|
* // access bitmap content by typecasting
|
|
* glyph_bitmap = (FT_BitmapGlyph)glyph;
|
|
*
|
|
* // do funny stuff with it, like blitting/drawing
|
|
* ...
|
|
*
|
|
* // discard glyph image (bitmap or not)
|
|
* FT_Done_Glyph( glyph );
|
|
* ```
|
|
*
|
|
* Here is another example, again without error handling:
|
|
*
|
|
* ```
|
|
* FT_Glyph glyphs[MAX_GLYPHS]
|
|
*
|
|
*
|
|
* ...
|
|
*
|
|
* for ( idx = 0; i < MAX_GLYPHS; i++ )
|
|
* error = FT_Load_Glyph( face, idx, FT_LOAD_DEFAULT ) ||
|
|
* FT_Get_Glyph ( face->glyph, &glyphs[idx] );
|
|
*
|
|
* ...
|
|
*
|
|
* for ( idx = 0; i < MAX_GLYPHS; i++ )
|
|
* {
|
|
* FT_Glyph bitmap = glyphs[idx];
|
|
*
|
|
*
|
|
* ...
|
|
*
|
|
* // after this call, `bitmap' no longer points into
|
|
* // the `glyphs' array (and the old value isn't destroyed)
|
|
* FT_Glyph_To_Bitmap( &bitmap, FT_RENDER_MODE_MONO, 0, 0 );
|
|
*
|
|
* ...
|
|
*
|
|
* FT_Done_Glyph( bitmap );
|
|
* }
|
|
*
|
|
* ...
|
|
*
|
|
* for ( idx = 0; i < MAX_GLYPHS; i++ )
|
|
* FT_Done_Glyph( glyphs[idx] );
|
|
* ```
|
|
*/
|
|
FT_EXPORT( FT_Error )
|
|
FT_Glyph_To_Bitmap( FT_Glyph* the_glyph,
|
|
FT_Render_Mode render_mode,
|
|
const FT_Vector* origin,
|
|
FT_Bool destroy );
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @function:
|
|
* FT_Done_Glyph
|
|
*
|
|
* @description:
|
|
* Destroy a given glyph.
|
|
*
|
|
* @input:
|
|
* glyph ::
|
|
* A handle to the target glyph object.
|
|
*/
|
|
FT_EXPORT( void )
|
|
FT_Done_Glyph( FT_Glyph glyph );
|
|
|
|
/* */
|
|
|
|
|
|
/* other helpful functions */
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @section:
|
|
* computations
|
|
*
|
|
*/
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @function:
|
|
* FT_Matrix_Multiply
|
|
*
|
|
* @description:
|
|
* Perform the matrix operation `b = a*b`.
|
|
*
|
|
* @input:
|
|
* a ::
|
|
* A pointer to matrix `a`.
|
|
*
|
|
* @inout:
|
|
* b ::
|
|
* A pointer to matrix `b`.
|
|
*
|
|
* @note:
|
|
* The result is undefined if either `a` or `b` is zero.
|
|
*
|
|
* Since the function uses wrap-around arithmetic, results become
|
|
* meaningless if the arguments are very large.
|
|
*/
|
|
FT_EXPORT( void )
|
|
FT_Matrix_Multiply( const FT_Matrix* a,
|
|
FT_Matrix* b );
|
|
|
|
|
|
/**************************************************************************
|
|
*
|
|
* @function:
|
|
* FT_Matrix_Invert
|
|
*
|
|
* @description:
|
|
* Invert a 2x2 matrix. Return an error if it can't be inverted.
|
|
*
|
|
* @inout:
|
|
* matrix ::
|
|
* A pointer to the target matrix. Remains untouched in case of error.
|
|
*
|
|
* @return:
|
|
* FreeType error code. 0~means success.
|
|
*/
|
|
FT_EXPORT( FT_Error )
|
|
FT_Matrix_Invert( FT_Matrix* matrix );
|
|
|
|
/* */
|
|
|
|
|
|
FT_END_HEADER
|
|
|
|
#endif /* FTGLYPH_H_ */
|
|
|
|
|
|
/* END */
|
|
|
|
|
|
/* Local Variables: */
|
|
/* coding: utf-8 */
|
|
/* End: */
|