188 lines
10 KiB
C
188 lines
10 KiB
C
/***************************************************************************/
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/* */
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/* ftadvanc.h */
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/* */
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/* Quick computation of advance widths (specification only). */
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/* */
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/* Copyright 2008-2018 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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#ifndef FTADVANC_H_
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#define FTADVANC_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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* quick_advance
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*
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* @title:
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* Quick retrieval of advance values
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*
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* @abstract:
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* Retrieve horizontal and vertical advance values without processing
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* glyph outlines, if possible.
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*
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* @description:
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* This section contains functions to quickly extract advance values
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* without handling glyph outlines, if possible.
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*
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* @order:
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* FT_Get_Advance
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* FT_Get_Advances
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*
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*/
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/*************************************************************************/
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/* */
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/* <Const> */
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/* FT_ADVANCE_FLAG_FAST_ONLY */
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/* */
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/* <Description> */
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/* A bit-flag to be OR-ed with the `flags' parameter of the */
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/* @FT_Get_Advance and @FT_Get_Advances functions. */
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/* */
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/* If set, it indicates that you want these functions to fail if the */
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/* corresponding hinting mode or font driver doesn't allow for very */
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/* quick advance computation. */
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/* */
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/* Typically, glyphs that are either unscaled, unhinted, bitmapped, */
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/* or light-hinted can have their advance width computed very */
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/* quickly. */
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/* */
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/* Normal and bytecode hinted modes that require loading, scaling, */
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/* and hinting of the glyph outline, are extremely slow by */
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/* comparison. */
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/* */
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#define FT_ADVANCE_FLAG_FAST_ONLY 0x20000000L
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FT_Get_Advance */
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/* */
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/* <Description> */
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/* Retrieve the advance value of a given glyph outline in an */
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/* @FT_Face. */
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/* */
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/* <Input> */
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/* face :: The source @FT_Face handle. */
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/* */
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/* gindex :: The glyph index. */
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/* */
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/* load_flags :: A set of bit flags similar to those used when */
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/* calling @FT_Load_Glyph, used to determine what kind */
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/* of advances you need. */
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/* <Output> */
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/* padvance :: The advance value. If scaling is performed (based on */
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/* the value of `load_flags'), the advance value is in */
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/* 16.16 format. Otherwise, it is in font units. */
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/* */
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/* If @FT_LOAD_VERTICAL_LAYOUT is set, this is the */
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/* vertical advance corresponding to a vertical layout. */
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/* Otherwise, it is the horizontal advance in a */
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/* horizontal layout. */
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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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/* This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and */
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/* if the corresponding font backend doesn't have a quick way to */
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/* retrieve the advances. */
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/* */
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/* A scaled advance is returned in 16.16 format but isn't transformed */
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/* by the affine transformation specified by @FT_Set_Transform. */
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/* */
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FT_EXPORT( FT_Error )
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FT_Get_Advance( FT_Face face,
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FT_UInt gindex,
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FT_Int32 load_flags,
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FT_Fixed *padvance );
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FT_Get_Advances */
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/* */
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/* <Description> */
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/* Retrieve the advance values of several glyph outlines in an */
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/* @FT_Face. */
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/* */
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/* <Input> */
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/* face :: The source @FT_Face handle. */
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/* */
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/* start :: The first glyph index. */
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/* */
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/* count :: The number of advance values you want to retrieve. */
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/* */
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/* load_flags :: A set of bit flags similar to those used when */
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/* calling @FT_Load_Glyph. */
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/* */
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/* <Output> */
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/* padvance :: The advance values. This array, to be provided by the */
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/* caller, must contain at least `count' elements. */
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/* */
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/* If scaling is performed (based on the value of */
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/* `load_flags'), the advance values are in 16.16 format. */
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/* Otherwise, they are in font units. */
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/* */
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/* If @FT_LOAD_VERTICAL_LAYOUT is set, these are the */
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/* vertical advances corresponding to a vertical layout. */
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/* Otherwise, they are the horizontal advances in a */
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/* horizontal layout. */
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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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/* This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and */
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/* if the corresponding font backend doesn't have a quick way to */
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/* retrieve the advances. */
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/* */
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/* Scaled advances are returned in 16.16 format but aren't */
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/* transformed by the affine transformation specified by */
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/* @FT_Set_Transform. */
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/* */
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FT_EXPORT( FT_Error )
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FT_Get_Advances( FT_Face face,
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FT_UInt start,
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FT_UInt count,
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FT_Int32 load_flags,
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FT_Fixed *padvances );
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/* */
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FT_END_HEADER
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#endif /* FTADVANC_H_ */
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/* END */
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