From be15811c4602a1c2584684eb7ed5242e2bf16a5e Mon Sep 17 00:00:00 2001 From: suzuki toshiya Date: Wed, 3 May 2023 01:31:37 +0000 Subject: [t1cid] Improve cid_get_cid_from_glyph_index(). Update cid_get_cid_from_glyph_index() to return an error and CID=0 in the case that the specified glyph index points to an invalid entry. cidgload.h (cid_compute_fd_and_offsets): Declare new helper function to set the fd_select and 2 offsets to access the glyph description data. cidgload.c (cid_compute_fd_and_offsets): Move the part loading fd_select and 2 offsets from cid_load_glyph() to here. If the loaded parameters are broken, return the Invalid_Offset error. This function does not load the glyph data, only fills these parameters. (cid_load_glyph): Use new helper function in above. cidriver.c (cid_get_cid_from_glyph_index): Check whether the requested glyph index points to a valid entry, by calling cid_compute_fd_and_offsets(). If it is valid, fill the cid by the glyph index (=CID). If it is invalid, return an error and fill the cid by 0. --- src/cid/cidgload.c | 161 ++++++++++++++++++++++++++++++++++------------------- src/cid/cidgload.h | 8 +++ src/cid/cidriver.c | 18 +++++- 3 files changed, 128 insertions(+), 59 deletions(-) diff --git a/src/cid/cidgload.c b/src/cid/cidgload.c index f4fe582be..babaf957c 100644 --- a/src/cid/cidgload.c +++ b/src/cid/cidgload.c @@ -40,6 +40,108 @@ #define FT_COMPONENT cidgload + /* + * A helper function to compute FD number (fd_select), + * the offset to the head of the glyph data (off1), + * and the offset to the and of the glyph data (off2). + * + * The number how many times cid_get_offset() is invoked + * can be controlled by the number how many non-NULL + * arguments are given. If fd_select is non-NULL but + * off1 and off2 are NULL, cid_get_offset() is invoked + * only for fd_select, off1/off2 are not validated. + * + */ + FT_LOCAL_DEF( FT_Error ) + cid_compute_fd_and_offsets( CID_Face face, + FT_UInt glyph_index, + FT_ULong* fd_select_p, + FT_ULong* off1_p, + FT_ULong* off2_p ) + { + FT_Error error = FT_Err_Ok; + CID_FaceInfo cid = &face->cid; + FT_Stream stream = face->cid_stream; + FT_UInt entry_len = cid->fd_bytes + cid->gd_bytes; + FT_Byte* p; + FT_Bool need_frame_exit = 0; + FT_ULong fd_select, off1, off2; + + + /* For ordinary fonts read the CID font dictionary index */ + /* and charstring offset from the CIDMap. */ + + if ( FT_STREAM_SEEK( cid->data_offset + cid->cidmap_offset + + glyph_index * entry_len ) || + FT_FRAME_ENTER( 2 * entry_len ) ) + goto Exit; + + need_frame_exit = 1; + + p = (FT_Byte*)stream->cursor; + fd_select = cid_get_offset( &p, cid->fd_bytes ); + off1 = cid_get_offset( &p, cid->gd_bytes ); + + p += cid->fd_bytes; + off2 = cid_get_offset( &p, cid->gd_bytes ); + + if (fd_select_p) + *fd_select_p = fd_select; + + if (off1_p) + *off1_p = off1; + + if (off2_p) + *off2_p = off2; + + if ( fd_select >= cid->num_dicts ) + { + /* + * fd_select == 0xFF is often used to indicate that the CID + * has no charstring to be rendered, similar to GID = 0xFFFF + * in TrueType fonts. + */ + if ( (cid->fd_bytes == 1 && fd_select == 0xFFU ) || + (cid->fd_bytes == 2 && fd_select == 0xFFFFU ) ) + { + FT_TRACE1(( "cid_load_glyph: fail for glyph_index=%d, " + "FD number %ld is the max integer fitting into %d byte%s\n", + glyph_index, fd_select, cid->fd_bytes, + cid->fd_bytes == 1 ? "" : "s" )); + } + else + { + FT_TRACE0(( "cid_load_glyph: fail for glyph_index=%d, " + "FD number %ld > number of dicts %d\n", + glyph_index, fd_select, cid->num_dicts )); + } + error = FT_THROW( Invalid_Offset ); + goto Exit; + } + else if ( off2 > stream->size ) + { + FT_TRACE0(( "cid_load_glyph: fail for glyph_index=%d, " + "end of the glyph data is beyond the data stream\n", + glyph_index )); + error = FT_THROW( Invalid_Offset ); + goto Exit; + } + else if ( off1 > off2 ) + { + FT_TRACE0(( "cid_load_glyph: fail for glyph_index=%d, " + "the end position of glyph data is set before the start position\n", + glyph_index )); + error = FT_THROW( Invalid_Offset ); + } + + Exit: + if ( need_frame_exit ) + FT_FRAME_EXIT(); + + return error; + } + + FT_CALLBACK_DEF( FT_Error ) cid_load_glyph( T1_Decoder decoder, FT_UInt glyph_index ) @@ -97,67 +199,14 @@ else #endif /* FT_CONFIG_OPTION_INCREMENTAL */ - - /* For ordinary fonts read the CID font dictionary index */ - /* and charstring offset from the CIDMap. */ { - FT_UInt entry_len = cid->fd_bytes + cid->gd_bytes; FT_ULong off1, off2; - if ( FT_STREAM_SEEK( cid->data_offset + cid->cidmap_offset + - glyph_index * entry_len ) || - FT_FRAME_ENTER( 2 * entry_len ) ) - goto Exit; - - p = (FT_Byte*)stream->cursor; - fd_select = cid_get_offset( &p, cid->fd_bytes ); - off1 = cid_get_offset( &p, cid->gd_bytes ); - p += cid->fd_bytes; - off2 = cid_get_offset( &p, cid->gd_bytes ); - FT_FRAME_EXIT(); - - - if ( fd_select >= cid->num_dicts ) - { - /* - * fd_select == 0xFF is often used to indicate that the CID - * has no charstring to be rendered, similar to GID = 0xFFFF - * in TrueType fonts. - */ - if ( (cid->fd_bytes == 1 && fd_select == 0xFFU ) || - (cid->fd_bytes == 2 && fd_select == 0xFFFFU ) ) - { - FT_TRACE1(( "cid_load_glyph: fail for glyph_index=%d, " - "FD number %ld is the max integer fitting into %d byte%s\n", - glyph_index, fd_select, cid->fd_bytes, - cid->fd_bytes == 1 ? "" : "s" )); - } - else - { - FT_TRACE0(( "cid_load_glyph: fail for glyph_index=%d, " - "FD number %ld > number of dicts %d\n", - glyph_index, fd_select, cid->num_dicts )); - } - error = FT_THROW( Invalid_Offset ); - goto Exit; - } - else if ( off2 > stream->size ) - { - FT_TRACE0(( "cid_load_glyph: fail for glyph_index=%d, " - "end of the glyph data is beyond the data stream\n", - glyph_index )); - error = FT_THROW( Invalid_Offset ); - goto Exit; - } - else if ( off1 > off2 ) - { - FT_TRACE0(( "cid_load_glyph: fail for glyph_index=%d, " - "the end position of glyph data is set before the start position\n", - glyph_index )); - error = FT_THROW( Invalid_Offset ); + error = cid_compute_fd_and_offsets( face, glyph_index, + &fd_select, &off1, &off2 ); + if ( error ) goto Exit; - } glyph_length = off2 - off1; diff --git a/src/cid/cidgload.h b/src/cid/cidgload.h index 97954d418..edd622923 100644 --- a/src/cid/cidgload.h +++ b/src/cid/cidgload.h @@ -42,6 +42,14 @@ FT_BEGIN_HEADER FT_Int32 load_flags ); + FT_LOCAL( FT_Error ) + cid_compute_fd_and_offsets( CID_Face face, + FT_UInt glyph_index, + FT_ULong* fd_select_p, + FT_ULong* off1_p, + FT_ULong* off2_p ); + + FT_END_HEADER #endif /* CIDGLOAD_H_ */ diff --git a/src/cid/cidriver.c b/src/cid/cidriver.c index f7499237d..10cb8c1fd 100644 --- a/src/cid/cidriver.c +++ b/src/cid/cidriver.c @@ -150,11 +150,23 @@ FT_UInt *cid ) { FT_Error error = FT_Err_Ok; - FT_UNUSED( face ); - if ( cid ) - *cid = glyph_index; /* identity mapping */ + /* + * Currently, FreeType does not support an incrementally- + * defined CID-keyed font that stores the glyph description + * data in /GlyphDirectory array or dictionary. + * Thus the font loaded by the incremental loading feature + * is not handled in here. + */ + error = cid_compute_fd_and_offsets( face, glyph_index, + NULL, NULL, NULL ); + + + if ( error ) + *cid = 0; + else + *cid = glyph_index; return error; } -- cgit v1.2.1