Edit
kc3-lang/freetype/src/gxvalid/gxvopbd.c
Werner Lemberg
- src/gxvalid/gxvopbd.c
-
/**************************************************************************** * * gxvopbd.c * * TrueTypeGX/AAT opbd table validation (body). * * Copyright (C) 2004-2020 by * suzuki toshiya, Masatake YAMATO, Red Hat K.K., * 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. * */ /**************************************************************************** * * gxvalid is derived from both gxlayout module and otvalid module. * Development of gxlayout is supported by the Information-technology * Promotion Agency(IPA), Japan. * */ #include "gxvalid.h" #include "gxvcommn.h" /************************************************************************** * * The macro FT_COMPONENT is used in trace mode. It is an implicit * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log * messages during execution. */ #undef FT_COMPONENT #define FT_COMPONENT gxvopbd /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** Data and Types *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ typedef struct GXV_opbd_DataRec_ { FT_UShort format; FT_UShort valueOffset_min; } GXV_opbd_DataRec, *GXV_opbd_Data; #define GXV_OPBD_DATA( FIELD ) GXV_TABLE_DATA( opbd, FIELD ) /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** UTILITY FUNCTIONS *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ static void gxv_opbd_LookupValue_validate( FT_UShort glyph, GXV_LookupValueCPtr value_p, GXV_Validator gxvalid ) { /* offset in LookupTable is measured from the head of opbd table */ FT_Bytes p = gxvalid->root->base + value_p->u; FT_Bytes limit = gxvalid->root->limit; FT_Short delta_value; int i; if ( value_p->u < GXV_OPBD_DATA( valueOffset_min ) ) GXV_OPBD_DATA( valueOffset_min ) = value_p->u; for ( i = 0; i < 4; i++ ) { GXV_LIMIT_CHECK( 2 ); delta_value = FT_NEXT_SHORT( p ); if ( GXV_OPBD_DATA( format ) ) /* format 1, value is ctrl pt. */ { if ( delta_value == -1 ) continue; gxv_ctlPoint_validate( glyph, (FT_UShort)delta_value, gxvalid ); } else /* format 0, value is distance */ continue; } } /* opbd ---------------------+ | +===============+ | | lookup header | | +===============+ | | BinSrchHeader | | +===============+ | | lastGlyph[0] | | +---------------+ | | firstGlyph[0] | | head of opbd sfnt table +---------------+ | + | offset[0] | -> | offset [byte] +===============+ | + | lastGlyph[1] | | (glyphID - firstGlyph) * 4 * sizeof(FT_Short) [byte] +---------------+ | | firstGlyph[1] | | +---------------+ | | offset[1] | | +===============+ | | .... | | 48bit value array | +===============+ | | value | <-------+ | | | | | | +---------------+ .... */ static GXV_LookupValueDesc gxv_opbd_LookupFmt4_transit( FT_UShort relative_gindex, GXV_LookupValueCPtr base_value_p, FT_Bytes lookuptbl_limit, GXV_Validator gxvalid ) { GXV_LookupValueDesc value; FT_UNUSED( lookuptbl_limit ); FT_UNUSED( gxvalid ); /* XXX: check range? */ value.u = (FT_UShort)( base_value_p->u + relative_gindex * 4 * sizeof ( FT_Short ) ); return value; } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** opbd TABLE *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_LOCAL_DEF( void ) gxv_opbd_validate( FT_Bytes table, FT_Face face, FT_Validator ftvalid ) { GXV_ValidatorRec gxvalidrec; GXV_Validator gxvalid = &gxvalidrec; GXV_opbd_DataRec opbdrec; GXV_opbd_Data opbd = &opbdrec; FT_Bytes p = table; FT_Bytes limit = 0; FT_ULong version; gxvalid->root = ftvalid; gxvalid->table_data = opbd; gxvalid->face = face; FT_TRACE3(( "validating `opbd' table\n" )); GXV_INIT; GXV_OPBD_DATA( valueOffset_min ) = 0xFFFFU; GXV_LIMIT_CHECK( 4 + 2 ); version = FT_NEXT_ULONG( p ); GXV_OPBD_DATA( format ) = FT_NEXT_USHORT( p ); /* only 0x00010000 is defined (1996) */ GXV_TRACE(( "(version=0x%08x)\n", version )); if ( 0x00010000UL != version ) FT_INVALID_FORMAT; /* only values 0 and 1 are defined (1996) */ GXV_TRACE(( "(format=0x%04x)\n", GXV_OPBD_DATA( format ) )); if ( 0x0001 < GXV_OPBD_DATA( format ) ) FT_INVALID_FORMAT; gxvalid->lookupval_sign = GXV_LOOKUPVALUE_UNSIGNED; gxvalid->lookupval_func = gxv_opbd_LookupValue_validate; gxvalid->lookupfmt4_trans = gxv_opbd_LookupFmt4_transit; gxv_LookupTable_validate( p, limit, gxvalid ); p += gxvalid->subtable_length; if ( p > table + GXV_OPBD_DATA( valueOffset_min ) ) { GXV_TRACE(( "found overlap between LookupTable and opbd_value array\n" )); FT_INVALID_OFFSET; } FT_TRACE4(( "\n" )); } /* END */