diff options
Diffstat (limited to 'modules/freetype2/include/freetype/ftadvanc.h')
| -rw-r--r-- | modules/freetype2/include/freetype/ftadvanc.h | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/modules/freetype2/include/freetype/ftadvanc.h b/modules/freetype2/include/freetype/ftadvanc.h new file mode 100644 index 0000000000..4560ded6dc --- /dev/null +++ b/modules/freetype2/include/freetype/ftadvanc.h @@ -0,0 +1,188 @@ +/**************************************************************************** + * + * ftadvanc.h + * + * Quick computation of advance widths (specification only). + * + * Copyright (C) 2008-2023 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 FTADVANC_H_ +#define FTADVANC_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: + * quick_advance + * + * @title: + * Quick retrieval of advance values + * + * @abstract: + * Retrieve horizontal and vertical advance values without processing + * glyph outlines, if possible. + * + * @description: + * This section contains functions to quickly extract advance values + * without handling glyph outlines, if possible. + * + * @order: + * FT_Get_Advance + * FT_Get_Advances + * + */ + + + /************************************************************************** + * + * @enum: + * FT_ADVANCE_FLAG_FAST_ONLY + * + * @description: + * A bit-flag to be OR-ed with the `flags` parameter of the + * @FT_Get_Advance and @FT_Get_Advances functions. + * + * If set, it indicates that you want these functions to fail if the + * corresponding hinting mode or font driver doesn't allow for very quick + * advance computation. + * + * Typically, glyphs that are either unscaled, unhinted, bitmapped, or + * light-hinted can have their advance width computed very quickly. + * + * Normal and bytecode hinted modes that require loading, scaling, and + * hinting of the glyph outline, are extremely slow by comparison. + */ +#define FT_ADVANCE_FLAG_FAST_ONLY 0x20000000L + + + /************************************************************************** + * + * @function: + * FT_Get_Advance + * + * @description: + * Retrieve the advance value of a given glyph outline in an @FT_Face. + * + * @input: + * face :: + * The source @FT_Face handle. + * + * gindex :: + * The glyph index. + * + * load_flags :: + * A set of bit flags similar to those used when calling + * @FT_Load_Glyph, used to determine what kind of advances you need. + * + * @output: + * padvance :: + * The advance value. If scaling is performed (based on the value of + * `load_flags`), the advance value is in 16.16 format. Otherwise, it + * is in font units. + * + * If @FT_LOAD_VERTICAL_LAYOUT is set, this is the vertical advance + * corresponding to a vertical layout. Otherwise, it is the horizontal + * advance in a horizontal layout. + * + * @return: + * FreeType error code. 0 means success. + * + * @note: + * This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and if + * the corresponding font backend doesn't have a quick way to retrieve + * the advances. + * + * A scaled advance is returned in 16.16 format but isn't transformed by + * the affine transformation specified by @FT_Set_Transform. + */ + FT_EXPORT( FT_Error ) + FT_Get_Advance( FT_Face face, + FT_UInt gindex, + FT_Int32 load_flags, + FT_Fixed *padvance ); + + + /************************************************************************** + * + * @function: + * FT_Get_Advances + * + * @description: + * Retrieve the advance values of several glyph outlines in an @FT_Face. + * + * @input: + * face :: + * The source @FT_Face handle. + * + * start :: + * The first glyph index. + * + * count :: + * The number of advance values you want to retrieve. + * + * load_flags :: + * A set of bit flags similar to those used when calling + * @FT_Load_Glyph. + * + * @output: + * padvance :: + * The advance values. This array, to be provided by the caller, must + * contain at least `count` elements. + * + * If scaling is performed (based on the value of `load_flags`), the + * advance values are in 16.16 format. Otherwise, they are in font + * units. + * + * If @FT_LOAD_VERTICAL_LAYOUT is set, these are the vertical advances + * corresponding to a vertical layout. Otherwise, they are the + * horizontal advances in a horizontal layout. + * + * @return: + * FreeType error code. 0 means success. + * + * @note: + * This function may fail if you use @FT_ADVANCE_FLAG_FAST_ONLY and if + * the corresponding font backend doesn't have a quick way to retrieve + * the advances. + * + * Scaled advances are returned in 16.16 format but aren't transformed by + * the affine transformation specified by @FT_Set_Transform. + */ + FT_EXPORT( FT_Error ) + FT_Get_Advances( FT_Face face, + FT_UInt start, + FT_UInt count, + FT_Int32 load_flags, + FT_Fixed *padvances ); + + /* */ + + +FT_END_HEADER + +#endif /* FTADVANC_H_ */ + + +/* END */ |