/**************************************************************************** * * ftotval.h * * FreeType API for validating OpenType tables (specification). * * Copyright (C) 2004-2020 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. * */ /**************************************************************************** * * * Warning: This module might be moved to a different library in the * future to avoid a tight dependency between FreeType and the * OpenType specification. * * */ #ifndef FTOTVAL_H_ #define FTOTVAL_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: * ot_validation * * @title: * OpenType Validation * * @abstract: * An API to validate OpenType tables. * * @description: * This section contains the declaration of functions to validate some * OpenType tables (BASE, GDEF, GPOS, GSUB, JSTF, MATH). * * @order: * FT_OpenType_Validate * FT_OpenType_Free * * FT_VALIDATE_OTXXX * */ /************************************************************************** * * @enum: * FT_VALIDATE_OTXXX * * @description: * A list of bit-field constants used with @FT_OpenType_Validate to * indicate which OpenType tables should be validated. * * @values: * FT_VALIDATE_BASE :: * Validate BASE table. * * FT_VALIDATE_GDEF :: * Validate GDEF table. * * FT_VALIDATE_GPOS :: * Validate GPOS table. * * FT_VALIDATE_GSUB :: * Validate GSUB table. * * FT_VALIDATE_JSTF :: * Validate JSTF table. * * FT_VALIDATE_MATH :: * Validate MATH table. * * FT_VALIDATE_OT :: * Validate all OpenType tables (BASE, GDEF, GPOS, GSUB, JSTF, MATH). * */ #define FT_VALIDATE_BASE 0x0100 #define FT_VALIDATE_GDEF 0x0200 #define FT_VALIDATE_GPOS 0x0400 #define FT_VALIDATE_GSUB 0x0800 #define FT_VALIDATE_JSTF 0x1000 #define FT_VALIDATE_MATH 0x2000 #define FT_VALIDATE_OT ( FT_VALIDATE_BASE | \ FT_VALIDATE_GDEF | \ FT_VALIDATE_GPOS | \ FT_VALIDATE_GSUB | \ FT_VALIDATE_JSTF | \ FT_VALIDATE_MATH ) /************************************************************************** * * @function: * FT_OpenType_Validate * * @description: * Validate various OpenType tables to assure that all offsets and * indices are valid. The idea is that a higher-level library that * actually does the text layout can access those tables without error * checking (which can be quite time consuming). * * @input: * face :: * A handle to the input face. * * validation_flags :: * A bit field that specifies the tables to be validated. See * @FT_VALIDATE_OTXXX for possible values. * * @output: * BASE_table :: * A pointer to the BASE table. * * GDEF_table :: * A pointer to the GDEF table. * * GPOS_table :: * A pointer to the GPOS table. * * GSUB_table :: * A pointer to the GSUB table. * * JSTF_table :: * A pointer to the JSTF table. * * @return: * FreeType error code. 0~means success. * * @note: * This function only works with OpenType fonts, returning an error * otherwise. * * After use, the application should deallocate the five tables with * @FT_OpenType_Free. A `NULL` value indicates that the table either * doesn't exist in the font, or the application hasn't asked for * validation. */ FT_EXPORT( FT_Error ) FT_OpenType_Validate( FT_Face face, FT_UInt validation_flags, FT_Bytes *BASE_table, FT_Bytes *GDEF_table, FT_Bytes *GPOS_table, FT_Bytes *GSUB_table, FT_Bytes *JSTF_table ); /************************************************************************** * * @function: * FT_OpenType_Free * * @description: * Free the buffer allocated by OpenType validator. * * @input: * face :: * A handle to the input face. * * table :: * The pointer to the buffer that is allocated by * @FT_OpenType_Validate. * * @note: * This function must be used to free the buffer allocated by * @FT_OpenType_Validate only. */ FT_EXPORT( void ) FT_OpenType_Free( FT_Face face, FT_Bytes table ); /* */ FT_END_HEADER #endif /* FTOTVAL_H_ */ /* END */