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authorQt by Nokia <qt-info@nokia.com>2011-04-27 12:05:43 +0200
committeraxis <qt-info@nokia.com>2011-04-27 12:05:43 +0200
commit38be0d13830efd2d98281c645c3a60afe05ffece (patch)
tree6ea73f3ec77f7d153333779883e8120f82820abe /src/3rdparty/freetype/src/sfnt/ttkern.c
Initial import from the monolithic Qt.
This is the beginning of revision history for this module. If you want to look at revision history older than this, please refer to the Qt Git wiki for how to use Git history grafting. At the time of writing, this wiki is located here: http://qt.gitorious.org/qt/pages/GitIntroductionWithQt If you have already performed the grafting and you don't see any history beyond this commit, try running "git log" with the "--follow" argument. Branched from the monolithic repo, Qt master branch, at commit 896db169ea224deb96c59ce8af800d019de63f12
Diffstat (limited to 'src/3rdparty/freetype/src/sfnt/ttkern.c')
-rw-r--r--src/3rdparty/freetype/src/sfnt/ttkern.c305
1 files changed, 305 insertions, 0 deletions
diff --git a/src/3rdparty/freetype/src/sfnt/ttkern.c b/src/3rdparty/freetype/src/sfnt/ttkern.c
new file mode 100644
index 0000000000..67d5115e87
--- /dev/null
+++ b/src/3rdparty/freetype/src/sfnt/ttkern.c
@@ -0,0 +1,305 @@
+/***************************************************************************/
+/* */
+/* ttkern.c */
+/* */
+/* Load the basic TrueType kerning table. This doesn't handle */
+/* kerning data within the GPOS table at the moment. */
+/* */
+/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009 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. */
+/* */
+/***************************************************************************/
+
+
+#include <ft2build.h>
+#include FT_INTERNAL_DEBUG_H
+#include FT_INTERNAL_STREAM_H
+#include FT_TRUETYPE_TAGS_H
+#include "ttkern.h"
+#include "ttload.h"
+
+#include "sferrors.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 trace_ttkern
+
+
+#undef TT_KERN_INDEX
+#define TT_KERN_INDEX( g1, g2 ) ( ( (FT_ULong)(g1) << 16 ) | (g2) )
+
+
+ FT_LOCAL_DEF( FT_Error )
+ tt_face_load_kern( TT_Face face,
+ FT_Stream stream )
+ {
+ FT_Error error;
+ FT_ULong table_size;
+ FT_Byte* p;
+ FT_Byte* p_limit;
+ FT_UInt nn, num_tables;
+ FT_UInt32 avail = 0, ordered = 0;
+
+
+ /* the kern table is optional; exit silently if it is missing */
+ error = face->goto_table( face, TTAG_kern, stream, &table_size );
+ if ( error )
+ goto Exit;
+
+ if ( table_size < 4 ) /* the case of a malformed table */
+ {
+ FT_ERROR(( "kerning table is too small - ignored\n" ));
+ error = SFNT_Err_Table_Missing;
+ goto Exit;
+ }
+
+ if ( FT_FRAME_EXTRACT( table_size, face->kern_table ) )
+ {
+ FT_ERROR(( "could not extract kerning table\n" ));
+ goto Exit;
+ }
+
+ face->kern_table_size = table_size;
+
+ p = face->kern_table;
+ p_limit = p + table_size;
+
+ p += 2; /* skip version */
+ num_tables = FT_NEXT_USHORT( p );
+
+ if ( num_tables > 32 ) /* we only support up to 32 sub-tables */
+ num_tables = 32;
+
+ for ( nn = 0; nn < num_tables; nn++ )
+ {
+ FT_UInt num_pairs, length, coverage;
+ FT_Byte* p_next;
+ FT_UInt32 mask = 1UL << nn;
+
+
+ if ( p + 6 > p_limit )
+ break;
+
+ p_next = p;
+
+ p += 2; /* skip version */
+ length = FT_NEXT_USHORT( p );
+ coverage = FT_NEXT_USHORT( p );
+
+ if ( length <= 6 )
+ break;
+
+ p_next += length;
+
+ if ( p_next > p_limit ) /* handle broken table */
+ p_next = p_limit;
+
+ /* only use horizontal kerning tables */
+ if ( ( coverage & ~8 ) != 0x0001 ||
+ p + 8 > p_limit )
+ goto NextTable;
+
+ num_pairs = FT_NEXT_USHORT( p );
+ p += 6;
+
+ if ( ( p_next - p ) / 6 < (int)num_pairs ) /* handle broken count */
+ num_pairs = (FT_UInt)( ( p_next - p ) / 6 );
+
+ avail |= mask;
+
+ /*
+ * Now check whether the pairs in this table are ordered.
+ * We then can use binary search.
+ */
+ if ( num_pairs > 0 )
+ {
+ FT_UInt count;
+ FT_UInt old_pair;
+
+
+ old_pair = FT_NEXT_ULONG( p );
+ p += 2;
+
+ for ( count = num_pairs - 1; count > 0; count-- )
+ {
+ FT_UInt32 cur_pair;
+
+
+ cur_pair = FT_NEXT_ULONG( p );
+ if ( cur_pair <= old_pair )
+ break;
+
+ p += 2;
+ old_pair = cur_pair;
+ }
+
+ if ( count == 0 )
+ ordered |= mask;
+ }
+
+ NextTable:
+ p = p_next;
+ }
+
+ face->num_kern_tables = nn;
+ face->kern_avail_bits = avail;
+ face->kern_order_bits = ordered;
+
+ Exit:
+ return error;
+ }
+
+
+ FT_LOCAL_DEF( void )
+ tt_face_done_kern( TT_Face face )
+ {
+ FT_Stream stream = face->root.stream;
+
+
+ FT_FRAME_RELEASE( face->kern_table );
+ face->kern_table_size = 0;
+ face->num_kern_tables = 0;
+ face->kern_avail_bits = 0;
+ face->kern_order_bits = 0;
+ }
+
+
+ FT_LOCAL_DEF( FT_Int )
+ tt_face_get_kerning( TT_Face face,
+ FT_UInt left_glyph,
+ FT_UInt right_glyph )
+ {
+ FT_Int result = 0;
+ FT_UInt count, mask = 1;
+ FT_Byte* p = face->kern_table;
+ FT_Byte* p_limit = p + face->kern_table_size;
+
+
+ p += 4;
+ mask = 0x0001;
+
+ for ( count = face->num_kern_tables;
+ count > 0 && p + 6 <= p_limit;
+ count--, mask <<= 1 )
+ {
+ FT_Byte* base = p;
+ FT_Byte* next = base;
+ FT_UInt version = FT_NEXT_USHORT( p );
+ FT_UInt length = FT_NEXT_USHORT( p );
+ FT_UInt coverage = FT_NEXT_USHORT( p );
+ FT_UInt num_pairs;
+ FT_Int value = 0;
+
+ FT_UNUSED( version );
+
+
+ next = base + length;
+
+ if ( next > p_limit ) /* handle broken table */
+ next = p_limit;
+
+ if ( ( face->kern_avail_bits & mask ) == 0 )
+ goto NextTable;
+
+ if ( p + 8 > next )
+ goto NextTable;
+
+ num_pairs = FT_NEXT_USHORT( p );
+ p += 6;
+
+ if ( ( next - p ) / 6 < (int)num_pairs ) /* handle broken count */
+ num_pairs = (FT_UInt)( ( next - p ) / 6 );
+
+ switch ( coverage >> 8 )
+ {
+ case 0:
+ {
+ FT_ULong key0 = TT_KERN_INDEX( left_glyph, right_glyph );
+
+
+ if ( face->kern_order_bits & mask ) /* binary search */
+ {
+ FT_UInt min = 0;
+ FT_UInt max = num_pairs;
+
+
+ while ( min < max )
+ {
+ FT_UInt mid = ( min + max ) >> 1;
+ FT_Byte* q = p + 6 * mid;
+ FT_ULong key;
+
+
+ key = FT_NEXT_ULONG( q );
+
+ if ( key == key0 )
+ {
+ value = FT_PEEK_SHORT( q );
+ goto Found;
+ }
+ if ( key < key0 )
+ min = mid + 1;
+ else
+ max = mid;
+ }
+ }
+ else /* linear search */
+ {
+ FT_UInt count2;
+
+
+ for ( count2 = num_pairs; count2 > 0; count2-- )
+ {
+ FT_ULong key = FT_NEXT_ULONG( p );
+
+
+ if ( key == key0 )
+ {
+ value = FT_PEEK_SHORT( p );
+ goto Found;
+ }
+ p += 2;
+ }
+ }
+ }
+ break;
+
+ /*
+ * We don't support format 2 because we haven't seen a single font
+ * using it in real life...
+ */
+
+ default:
+ ;
+ }
+
+ goto NextTable;
+
+ Found:
+ if ( coverage & 8 ) /* override or add */
+ result = value;
+ else
+ result += value;
+
+ NextTable:
+ p = next;
+ }
+
+ return result;
+ }
+
+#undef TT_KERN_INDEX
+
+/* END */