ref: 43a2f656a71aea4d735dcdff201fed120479f707
dir: /include/freetype/ftglyph.h/
/***************************************************************************/
/* */
/* ftglyph.h */
/* */
/* FreeType convenience functions to handle glyphs.. */
/* */
/* Copyright 1996-2000 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're 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 __cplusplus
extern "C" {
#endif
/* forward declaration to a private type */
typedef struct FT_Glyph_Class_ FT_Glyph_Class;
/***********************************************************************
*
* <Struct>
* FT_GlyphRec
*
* <Description>
* The root glyph structure contains a given glyph image plus its
* advance width in 16.16 fixed float format..
*
* <Field>
* 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, *FT_Glyph;
/***********************************************************************
*
* <Struct>
* FT_BitmapGlyphRec
*
* <Description>
* A structure used for bitmap glyph images.. This really is
* a "sub-class" of "FT_GlyphRec".
*
* <Field>
* root :: the root FT_Glyph fields
* left :: left-side bearing, i.e. the horizontal distance from
* the current pen position to the left border of the glyph
* bitmap.
* top :: 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 a FT_Glyph to FT_BitmapGlyph when you have
* glyph->format == ft_glyph_format_bitmap. This lets you access
* the bitmap's content easily..
*
* the corresponding pixel buffer is always owned by the 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, *FT_BitmapGlyph;
/***********************************************************************
*
* <Struct>
* FT_OutlineGlyphRec
*
* <Description>
* A structure used for outline (vectorial) glyph images..
* This really is a "sub-class" of FT_GlyphRec.
*
* <Field>
* root :: the root FT_Glyph fields.
* outline :: a descriptor for the outline
*
* <Note>
* You can typecast a FT_Glyph to FT_OutlineGlyph when 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 / 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, *FT_OutlineGlyph;
/***********************************************************************
*
* <Function>
* FT_Get_Glyph
*
* <Description>
* A function used to extract one glyph image from a slot..
*
* <Input>
* slot :: handle to source glyph slot.
*
* <Output>
* aglyph :: handle to the glyph object.
*
* <Return>
* Error code. 0 means success.
*
* <Note>
*
*
***********************************************************************/
FT_EXPORT_DEF(FT_Error) FT_Get_Glyph( FT_GlyphSlot slot,
FT_Glyph *aglyph );
/***********************************************************************
*
* <Function>
* FT_Glyph_Copy
*
* <Description>
* A function used to copy one glyph image.
*
* <Input>
* source :: handle to source glyph object
*
* <Output>
* target :: handle to target glyph object. 0 in case of error
*
* <Return>
* Error code. 0 means success.
*
***********************************************************************/
FT_EXPORT_DEF(FT_Error) FT_Glyph_Copy( FT_Glyph source,
FT_Glyph *target );
/***********************************************************************
*
* <Function>
* FT_Glyph_Transform
*
* <Description>
* Transforms a glyph image, when it's format is scalable
*
* <Input>
* glyph :: handle to target glyph object
*
* matrix :: pointer to 2x2 matrix to apply
*
* delta :: pointer to a 2d vector to apply. coordinates are
* expressed in 1/64th of a pixel..
*
* <Return>
* error code (is not 0, the glyph format is not scalable).
*
* <Note>
* the 2x2 transform matrix is also applied to the glyph's
* advance vector
*
***********************************************************************/
FT_EXPORT_DEF(FT_Error) FT_Glyph_Transform( FT_Glyph glyph,
FT_Matrix* matrix,
FT_Vector* delta );
/***********************************************************************
*
* <Function>
* FT_Glyph_Get_CBox
*
* <Description>
* Returns the glyph image's bounding box.
*
* <Input>
* glyph :: handle to source glyph object
* mode :: a set of bit flags that indicate how to interpret
* the meaning of the box's coordinates
*
* <Output>
* box :: the glyph bounding box. Coordinates are expressed in
* 1/64th of pixels, it is grid-fitted..
*
* <Note>
* Coordinates are relative to the glyph origin, using the Y-upwards
* convention..
*
* if 'ft_glyph_bbox_subpixels' is set in "mode", the bbox coordinates
* are returned in 26.6 pixels (i.e. 1/64th of pixels).
*
* otherwise, coordinates are in integer pixels.
*
* note that the maximum coordinates are exclusive, which means that
* once 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 the 'ft_glyph_bbox_gridfit'
* flag is set in "mode", 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);
*
***********************************************************************/
enum
{
ft_glyph_bbox_pixels = 0,
ft_glyph_bbox_subpixels = 1,
ft_glyph_bbox_gridfit = 2
};
FT_EXPORT_DEF(void) FT_Glyph_Get_CBox( FT_Glyph glyph,
FT_UInt bbox_mode,
FT_BBox *cbox );
/***********************************************************************
*
* <Function>
* FT_Glyph_To_Bitmap
*
* <Description>
* converts a given glyph object to a bitmap glyph object
*
* <InOut>
* glyph :: pointer to a handle to the target glyph
*
* <Input>
* render_mode :: a set of bit flags that describe how
*
* origin :: pointer to a vector used to translate the glyph image
* before rendering. Can be 0 (for 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. The glyph is
* never destroyed in case of error..
*
* <Return>
* Error code. 0 means success
*
* <Note>
* the glyph image is translated with the "origin" vector before
* rendering.. In case of error, it it translated back to its original
* position and the glyph is untouched..
*
* The first parameter is a pointer to a FT_Glyph handle, that
* will be replaced by this function. Typically, you would use:
*
* {
* FT_Glyph glyph;
* FT_BitmapGlyph glyph_bitmap;
*
* // load glyph
* error = FT_Load_Char( face, glyph_index, FT_LOAD_DEFAUT );
*
* // extract glyph image
* error = FT_Get_Glyph( face->glyph, &glyph );
*
* // convert to a bitmap (default render mode + destroy old)
* if (glyph->format != ft_glyph_format_bitmap)
* {
* error = FT_Glyph_To_Bitmap( &glyph, ft_render_mode_default, 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 );
*
*
* This function will always fail if the glyph's format isn't scalable
*
***********************************************************************/
FT_EXPORT_DEF(FT_Error) FT_Glyph_To_Bitmap( FT_Glyph *the_glyph,
FT_ULong render_mode,
FT_Vector* origin,
FT_Bool destroy );
/***********************************************************************
*
* <Function>
* FT_Done_Glyph
*
* <Description>
* Destroys a given glyph..
*
* <Input>
* glyph :: handle to target glyph object
*
***********************************************************************/
FT_EXPORT_DEF(void) FT_Done_Glyph( FT_Glyph glyph );
/* other helpful functions */
/*************************************************************************/
/* */
/* <Function> */
/* FT_Matrix_Multiply */
/* */
/* <Description> */
/* Performs the matrix operation `b = a*b'. */
/* */
/* <Input> */
/* a :: A pointer to matrix `a'. */
/* */
/* <InOut> */
/* b :: A pointer to matrix `b'. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
FT_EXPORT_DEF(void) FT_Matrix_Multiply( FT_Matrix* a,
FT_Matrix* b );
/*************************************************************************/
/* */
/* <Function> */
/* FT_Matrix_Invert */
/* */
/* <Description> */
/* Inverts a 2x2 matrix. Returns 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. */
/* */
/* <MT-Note> */
/* Yes. */
/* */
FT_EXPORT_DEF(FT_Error) FT_Matrix_Invert( FT_Matrix* matrix );
#ifdef __cplusplus
}
#endif
#endif /* FTGLYPH_H */