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575 lines
36 KiB
575 lines
36 KiB
/***************************************************************************/ |
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/* */ |
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/* ftglyph.h */ |
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/* */ |
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/* FreeType convenience functions to handle glyphs (specification). */ |
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/* */ |
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/* Copyright 1996-2001, 2002, 2003, 2006 by */ |
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/* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
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/* */ |
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/* This file is part of the FreeType project, and may only be used, */ |
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/* modified, and distributed under the terms of the FreeType project */ |
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/* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
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/* this file you indicate that you have read the license and */ |
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/* understand and accept it fully. */ |
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/* */ |
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/***************************************************************************/ |
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/*************************************************************************/ |
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/* */ |
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/* This file contains the definition of several convenience functions */ |
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/* that can be used by client applications to easily retrieve glyph */ |
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/* bitmaps and outlines from a given face. */ |
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/* */ |
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/* These functions should be optional if you are writing a font server */ |
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/* or text layout engine on top of FreeType. However, they are pretty */ |
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/* handy for many other simple uses of the library. */ |
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/* */ |
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/*************************************************************************/ |
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#ifndef __FTGLYPH_H__ |
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#define __FTGLYPH_H__ |
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#include <ft2build.h> |
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#include FT_FREETYPE_H |
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#ifdef FREETYPE_H |
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#error "freetype.h of FreeType 1 has been loaded!" |
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#error "Please fix the directory search order for header files" |
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#error "so that freetype.h of FreeType 2 is found first." |
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#endif |
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FT_BEGIN_HEADER |
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/*************************************************************************/ |
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/* */ |
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/* <Section> */ |
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/* glyph_management */ |
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/* */ |
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/* <Title> */ |
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/* Glyph Management */ |
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/* */ |
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/* <Abstract> */ |
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/* Generic interface to manage individual glyph data. */ |
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/* */ |
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/* <Description> */ |
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/* This section contains definitions used to manage glyph data */ |
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/* through generic FT_Glyph objects. Each of them can contain a */ |
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/* bitmap, a vector outline, or even images in other formats. */ |
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/* */ |
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/*************************************************************************/ |
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/* forward declaration to a private type */ |
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typedef struct FT_Glyph_Class_ FT_Glyph_Class; |
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/*************************************************************************/ |
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/* */ |
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/* <Type> */ |
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/* FT_Glyph */ |
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/* */ |
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/* <Description> */ |
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/* Handle to an object used to model generic glyph images. It is a */ |
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/* pointer to the @FT_GlyphRec structure and can contain a glyph */ |
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/* bitmap or pointer. */ |
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/* */ |
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/* <Note> */ |
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/* Glyph objects are not owned by the library. You must thus release */ |
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/* them manually (through @FT_Done_Glyph) _before_ calling */ |
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/* @FT_Done_FreeType. */ |
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/* */ |
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typedef struct FT_GlyphRec_* FT_Glyph; |
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/*************************************************************************/ |
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/* */ |
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/* <Struct> */ |
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/* FT_GlyphRec */ |
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/* */ |
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/* <Description> */ |
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/* The root glyph structure contains a given glyph image plus its */ |
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/* advance width in 16.16 fixed float format. */ |
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/* */ |
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/* <Fields> */ |
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/* library :: A handle to the FreeType library object. */ |
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/* */ |
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/* clazz :: A pointer to the glyph's class. Private. */ |
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/* */ |
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/* format :: The format of the glyph's image. */ |
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/* */ |
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/* advance :: A 16.16 vector that gives the glyph's advance width. */ |
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/* */ |
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typedef struct FT_GlyphRec_ |
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{ |
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FT_Library library; |
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const FT_Glyph_Class* clazz; |
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FT_Glyph_Format format; |
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FT_Vector advance; |
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} FT_GlyphRec; |
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/*************************************************************************/ |
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/* */ |
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/* <Type> */ |
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/* FT_BitmapGlyph */ |
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/* */ |
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/* <Description> */ |
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/* A handle to an object used to model a bitmap glyph image. This is */ |
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/* a sub-class of @FT_Glyph, and a pointer to @FT_BitmapGlyphRec. */ |
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/* */ |
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typedef struct FT_BitmapGlyphRec_* FT_BitmapGlyph; |
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/*************************************************************************/ |
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/* */ |
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/* <Struct> */ |
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/* FT_BitmapGlyphRec */ |
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/* */ |
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/* <Description> */ |
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/* A structure used for bitmap glyph images. This really is a */ |
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/* `sub-class' of @FT_GlyphRec. */ |
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/* */ |
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/* <Fields> */ |
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/* root :: The root @FT_Glyph fields. */ |
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/* */ |
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/* left :: The left-side bearing, i.e., the horizontal distance */ |
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/* from the current pen position to the left border of the */ |
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/* glyph bitmap. */ |
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/* */ |
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/* top :: The top-side bearing, i.e., the vertical distance from */ |
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/* the current pen position to the top border of the glyph */ |
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/* bitmap. This distance is positive for upwards-y! */ |
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/* */ |
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/* bitmap :: A descriptor for the bitmap. */ |
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/* */ |
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/* <Note> */ |
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/* You can typecast an @FT_Glyph to @FT_BitmapGlyph if you have */ |
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/* `glyph->format == FT_GLYPH_FORMAT_BITMAP'. This lets you access */ |
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/* the bitmap's contents easily. */ |
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/* */ |
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/* The corresponding pixel buffer is always owned by @FT_BitmapGlyph */ |
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/* and is thus created and destroyed with it. */ |
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/* */ |
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typedef struct FT_BitmapGlyphRec_ |
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{ |
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FT_GlyphRec root; |
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FT_Int left; |
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FT_Int top; |
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FT_Bitmap bitmap; |
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} FT_BitmapGlyphRec; |
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/*************************************************************************/ |
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/* */ |
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/* <Type> */ |
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/* FT_OutlineGlyph */ |
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/* */ |
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/* <Description> */ |
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/* A handle to an object used to model an outline glyph image. This */ |
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/* is a sub-class of @FT_Glyph, and a pointer to @FT_OutlineGlyphRec. */ |
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/* */ |
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typedef struct FT_OutlineGlyphRec_* FT_OutlineGlyph; |
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/*************************************************************************/ |
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/* */ |
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/* <Struct> */ |
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/* FT_OutlineGlyphRec */ |
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/* */ |
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/* <Description> */ |
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/* A structure used for outline (vectorial) glyph images. This */ |
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/* really is a `sub-class' of @FT_GlyphRec. */ |
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/* */ |
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/* <Fields> */ |
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/* root :: The root @FT_Glyph fields. */ |
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/* */ |
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/* outline :: A descriptor for the outline. */ |
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/* */ |
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/* <Note> */ |
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/* You can typecast a @FT_Glyph to @FT_OutlineGlyph if you have */ |
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/* `glyph->format == FT_GLYPH_FORMAT_OUTLINE'. This lets you access */ |
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/* the outline's content easily. */ |
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/* */ |
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/* As the outline is extracted from a glyph slot, its coordinates are */ |
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/* expressed normally in 26.6 pixels, unless the flag */ |
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/* @FT_LOAD_NO_SCALE was used in @FT_Load_Glyph() or @FT_Load_Char(). */ |
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/* */ |
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/* The outline's tables are always owned by the object and are */ |
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/* destroyed with it. */ |
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/* */ |
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typedef struct FT_OutlineGlyphRec_ |
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{ |
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FT_GlyphRec root; |
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FT_Outline outline; |
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} FT_OutlineGlyphRec; |
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/*************************************************************************/ |
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/* */ |
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/* <Function> */ |
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/* FT_Get_Glyph */ |
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/* */ |
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/* <Description> */ |
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/* A function used to extract a glyph image from a slot. */ |
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/* */ |
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/* <Input> */ |
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/* slot :: A handle to the source glyph slot. */ |
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/* */ |
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/* <Output> */ |
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/* aglyph :: A handle to the glyph object. */ |
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/* */ |
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/* <Return> */ |
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/* FreeType error code. 0 means success. */ |
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/* */ |
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FT_EXPORT( FT_Error ) |
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FT_Get_Glyph( FT_GlyphSlot slot, |
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FT_Glyph *aglyph ); |
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/*************************************************************************/ |
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/* */ |
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/* <Function> */ |
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/* FT_Glyph_Copy */ |
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/* */ |
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/* <Description> */ |
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/* A function used to copy a glyph image. Note that the created */ |
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/* @FT_Glyph object must be released with @FT_Done_Glyph. */ |
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/* */ |
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/* <Input> */ |
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/* source :: A handle to the source glyph object. */ |
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/* */ |
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/* <Output> */ |
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/* target :: A handle to the target glyph object. 0 in case of */ |
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/* error. */ |
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/* */ |
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/* <Return> */ |
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/* FreeType error code. 0 means success. */ |
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/* */ |
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FT_EXPORT( FT_Error ) |
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FT_Glyph_Copy( FT_Glyph source, |
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FT_Glyph *target ); |
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/*************************************************************************/ |
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/* */ |
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/* <Function> */ |
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/* FT_Glyph_Transform */ |
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/* */ |
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/* <Description> */ |
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/* Transforms a glyph image if its format is scalable. */ |
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/* */ |
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/* <InOut> */ |
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/* glyph :: A handle to the target glyph object. */ |
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/* */ |
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/* <Input> */ |
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/* matrix :: A pointer to a 2x2 matrix to apply. */ |
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/* */ |
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/* delta :: A pointer to a 2d vector to apply. Coordinates are */ |
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/* expressed in 1/64th of a pixel. */ |
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/* */ |
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/* <Return> */ |
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/* FreeType error code (if not 0, the glyph format is not scalable). */ |
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/* */ |
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/* <Note> */ |
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/* The 2x2 transformation matrix is also applied to the glyph's */ |
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/* advance vector. */ |
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/* */ |
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FT_EXPORT( FT_Error ) |
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FT_Glyph_Transform( FT_Glyph glyph, |
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FT_Matrix* matrix, |
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FT_Vector* delta ); |
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/*************************************************************************/ |
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/* */ |
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/* <Enum> */ |
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/* FT_Glyph_BBox_Mode */ |
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/* */ |
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/* <Description> */ |
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/* The mode how the values of @FT_Glyph_Get_CBox are returned. */ |
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/* */ |
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/* <Values> */ |
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/* FT_GLYPH_BBOX_UNSCALED :: */ |
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/* Return unscaled font units. */ |
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/* */ |
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/* FT_GLYPH_BBOX_SUBPIXELS :: */ |
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/* Return unfitted 26.6 coordinates. */ |
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/* */ |
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/* FT_GLYPH_BBOX_GRIDFIT :: */ |
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/* Return grid-fitted 26.6 coordinates. */ |
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/* */ |
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/* FT_GLYPH_BBOX_TRUNCATE :: */ |
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/* Return coordinates in integer pixels. */ |
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/* */ |
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/* FT_GLYPH_BBOX_PIXELS :: */ |
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/* Return grid-fitted pixel coordinates. */ |
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/* */ |
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typedef enum FT_Glyph_BBox_Mode_ |
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{ |
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FT_GLYPH_BBOX_UNSCALED = 0, |
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FT_GLYPH_BBOX_SUBPIXELS = 0, |
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FT_GLYPH_BBOX_GRIDFIT = 1, |
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FT_GLYPH_BBOX_TRUNCATE = 2, |
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FT_GLYPH_BBOX_PIXELS = 3 |
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} FT_Glyph_BBox_Mode; |
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/*************************************************************************/ |
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/* */ |
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/* <Enum> */ |
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/* ft_glyph_bbox_xxx */ |
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/* */ |
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/* <Description> */ |
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/* These constants are deprecated. Use the corresponding */ |
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/* @FT_Glyph_BBox_Mode values instead. */ |
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/* */ |
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/* <Values> */ |
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/* ft_glyph_bbox_unscaled :: See @FT_GLYPH_BBOX_UNSCALED. */ |
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/* ft_glyph_bbox_subpixels :: See @FT_GLYPH_BBOX_SUBPIXELS. */ |
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/* ft_glyph_bbox_gridfit :: See @FT_GLYPH_BBOX_GRIDFIT. */ |
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/* ft_glyph_bbox_truncate :: See @FT_GLYPH_BBOX_TRUNCATE. */ |
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/* ft_glyph_bbox_pixels :: See @FT_GLYPH_BBOX_PIXELS. */ |
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/* */ |
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#define ft_glyph_bbox_unscaled FT_GLYPH_BBOX_UNSCALED |
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#define ft_glyph_bbox_subpixels FT_GLYPH_BBOX_SUBPIXELS |
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#define ft_glyph_bbox_gridfit FT_GLYPH_BBOX_GRIDFIT |
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#define ft_glyph_bbox_truncate FT_GLYPH_BBOX_TRUNCATE |
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#define ft_glyph_bbox_pixels FT_GLYPH_BBOX_PIXELS |
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/*************************************************************************/ |
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/* */ |
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/* <Function> */ |
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/* FT_Glyph_Get_CBox */ |
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/* */ |
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/* <Description> */ |
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/* Return a glyph's `control box'. The control box encloses all the */ |
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/* outline's points, including Bézier control points. Though it */ |
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/* coincides with the exact bounding box for most glyphs, it can be */ |
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/* slightly larger in some situations (like when rotating an outline */ |
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/* which contains Bézier outside arcs). */ |
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/* */ |
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/* Computing the control box is very fast, while getting the bounding */ |
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/* box can take much more time as it needs to walk over all segments */ |
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/* and arcs in the outline. To get the latter, you can use the */ |
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/* `ftbbox' component which is dedicated to this single task. */ |
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/* */ |
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/* <Input> */ |
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/* glyph :: A handle to the source glyph object. */ |
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/* */ |
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/* mode :: The mode which indicates how to interpret the returned */ |
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/* bounding box values. */ |
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/* */ |
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/* <Output> */ |
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/* acbox :: The glyph coordinate bounding box. Coordinates are */ |
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/* expressed in 1/64th of pixels if it is grid-fitted. */ |
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/* */ |
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/* <Note> */ |
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/* Coordinates are relative to the glyph origin, using the Y-upwards */ |
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/* convention. */ |
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/* */ |
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/* If the glyph has been loaded with @FT_LOAD_NO_SCALE, `bbox_mode' */ |
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/* must be set to @FT_GLYPH_BBOX_UNSCALED to get unscaled font */ |
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/* units in 26.6 pixel format. The value @FT_GLYPH_BBOX_SUBPIXELS */ |
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/* is another name for this constant. */ |
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/* */ |
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/* Note that the maximum coordinates are exclusive, which means that */ |
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/* one can compute the width and height of the glyph image (be it in */ |
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/* integer or 26.6 pixels) as: */ |
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/* */ |
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/* { */ |
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/* width = bbox.xMax - bbox.xMin; */ |
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/* height = bbox.yMax - bbox.yMin; */ |
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/* } */ |
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/* */ |
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/* Note also that for 26.6 coordinates, if `bbox_mode' is set to */ |
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/* @FT_GLYPH_BBOX_GRIDFIT, the coordinates will also be grid-fitted, */ |
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/* which corresponds to: */ |
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/* */ |
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/* { */ |
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/* bbox.xMin = FLOOR(bbox.xMin); */ |
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/* bbox.yMin = FLOOR(bbox.yMin); */ |
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/* bbox.xMax = CEILING(bbox.xMax); */ |
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/* bbox.yMax = CEILING(bbox.yMax); */ |
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/* } */ |
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/* */ |
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/* To get the bbox in pixel coordinates, set `bbox_mode' to */ |
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/* @FT_GLYPH_BBOX_TRUNCATE. */ |
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/* */ |
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/* To get the bbox in grid-fitted pixel coordinates, set `bbox_mode' */ |
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/* to @FT_GLYPH_BBOX_PIXELS. */ |
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/* */ |
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FT_EXPORT( void ) |
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FT_Glyph_Get_CBox( FT_Glyph glyph, |
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FT_UInt bbox_mode, |
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FT_BBox *acbox ); |
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/*************************************************************************/ |
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/* */ |
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/* <Function> */ |
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/* FT_Glyph_To_Bitmap */ |
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/* */ |
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/* <Description> */ |
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/* Converts a given glyph object to a bitmap glyph object. */ |
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/* */ |
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/* <InOut> */ |
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/* the_glyph :: A pointer to a handle to the target glyph. */ |
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/* */ |
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/* <Input> */ |
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/* render_mode :: An enumeration that describe how the data is */ |
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/* rendered. */ |
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/* */ |
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/* origin :: A pointer to a vector used to translate the glyph */ |
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/* image before rendering. Can be 0 (if no */ |
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/* translation). The origin is expressed in */ |
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/* 26.6 pixels. */ |
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/* */ |
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/* destroy :: A boolean that indicates that the original glyph */ |
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/* image should be destroyed by this function. It is */ |
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/* never destroyed in case of error. */ |
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/* */ |
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/* <Return> */ |
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/* FreeType error code. 0 means success. */ |
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/* */ |
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/* <Note> */ |
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/* The glyph image is translated with the `origin' vector before */ |
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/* rendering. */ |
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/* */ |
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/* The first parameter is a pointer to an @FT_Glyph handle, that will */ |
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/* be replaced by this function. Typically, you would use (omitting */ |
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/* error handling): */ |
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/* */ |
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/* */ |
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/* { */ |
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/* FT_Glyph glyph; */ |
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/* FT_BitmapGlyph glyph_bitmap; */ |
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/* */ |
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/* */ |
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/* // load glyph */ |
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/* error = FT_Load_Char( face, glyph_index, FT_LOAD_DEFAUT ); */ |
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/* */ |
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/* // extract glyph image */ |
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/* error = FT_Get_Glyph( face->glyph, &glyph ); */ |
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/* */ |
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/* // convert to a bitmap (default render mode + destroy old) */ |
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/* if ( glyph->format != FT_GLYPH_FORMAT_BITMAP ) */ |
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/* { */ |
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/* error = FT_Glyph_To_Bitmap( &glyph, FT_RENDER_MODE_DEFAULT, */ |
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/* 0, 1 ); */ |
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/* if ( error ) // glyph unchanged */ |
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/* ... */ |
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/* } */ |
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/* */ |
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/* // access bitmap content by typecasting */ |
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/* glyph_bitmap = (FT_BitmapGlyph)glyph; */ |
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/* */ |
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/* // do funny stuff with it, like blitting/drawing */ |
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/* ... */ |
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/* */ |
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/* // discard glyph image (bitmap or not) */ |
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/* FT_Done_Glyph( glyph ); */ |
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/* } */ |
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/* */ |
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/* */ |
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/* This function does nothing if the glyph format isn't scalable. */ |
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/* */ |
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FT_EXPORT( FT_Error ) |
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FT_Glyph_To_Bitmap( FT_Glyph* the_glyph, |
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FT_Render_Mode render_mode, |
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FT_Vector* origin, |
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FT_Bool destroy ); |
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/*************************************************************************/ |
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/* */ |
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/* <Function> */ |
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/* FT_Done_Glyph */ |
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/* */ |
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/* <Description> */ |
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/* Destroys a given glyph. */ |
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/* */ |
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/* <Input> */ |
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/* glyph :: A handle to the target glyph object. */ |
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/* */ |
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FT_EXPORT( void ) |
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FT_Done_Glyph( FT_Glyph glyph ); |
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/* */ |
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/* other helpful functions */ |
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/*************************************************************************/ |
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/* */ |
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/* <Section> */ |
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/* computations */ |
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/* */ |
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/*************************************************************************/ |
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/*************************************************************************/ |
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/* */ |
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/* <Function> */ |
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/* FT_Matrix_Multiply */ |
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/* */ |
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/* <Description> */ |
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/* Performs the matrix operation `b = a*b'. */ |
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/* */ |
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/* <Input> */ |
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/* a :: A pointer to matrix `a'. */ |
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/* */ |
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/* <InOut> */ |
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/* b :: A pointer to matrix `b'. */ |
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/* */ |
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/* <Note> */ |
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/* The result is undefined if either `a' or `b' is zero. */ |
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/* */ |
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FT_EXPORT( void ) |
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FT_Matrix_Multiply( const FT_Matrix* a, |
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FT_Matrix* b ); |
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/*************************************************************************/ |
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/* */ |
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/* <Function> */ |
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/* FT_Matrix_Invert */ |
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/* */ |
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/* <Description> */ |
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/* Inverts a 2x2 matrix. Returns an error if it can't be inverted. */ |
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/* */ |
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/* <InOut> */ |
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/* matrix :: A pointer to the target matrix. Remains untouched in */ |
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/* case of error. */ |
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/* */ |
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/* <Return> */ |
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/* FreeType error code. 0 means success. */ |
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/* */ |
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FT_EXPORT( FT_Error ) |
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FT_Matrix_Invert( FT_Matrix* matrix ); |
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/* */ |
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FT_END_HEADER |
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#endif /* __FTGLYPH_H__ */ |
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/* END */ |
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/* Local Variables: */ |
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/* coding: utf-8 */ |
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/* End: */
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