diff --git a/ChangeLog b/ChangeLog index 9ddfad2c4..69cdc1d1f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2018-08-22 Werner Lemberg + + [truetype] Improve legibility of `glyf' parsing. + + * src/truetype/ttgload.c (ON_CURVE_POINT, X_SHORT_VECTOR, + Y_SHORT_VECTOR, REPEAT_FLAG, X_POSITIVE, SAME_X, Y_POSITIVE, SAME_Y, + OVERLAP_SIMPLE): New macros. + (TT_Load_Simple_Glyph): Use new macros to make code more readable. + Remove useless adjustment of `outline->tags' elements. + 2018-08-21 Werner Lemberg * src/sfnt/ttcpal.c (tt_face_load_cpal): Add missing safety check. diff --git a/src/truetype/ttgload.c b/src/truetype/ttgload.c index 0a436a2ac..d76758465 100644 --- a/src/truetype/ttgload.c +++ b/src/truetype/ttgload.c @@ -48,6 +48,21 @@ #define FT_COMPONENT ttgload + /************************************************************************** + * + * Simple glyph flags. + */ +#define ON_CURVE_POINT 0x01 /* same value as FT_CURVE_TAG_ON */ +#define X_SHORT_VECTOR 0x02 +#define Y_SHORT_VECTOR 0x04 +#define REPEAT_FLAG 0x08 +#define X_POSITIVE 0x10 /* two meanings depending on X_SHORT_VECTOR */ +#define SAME_X 0x10 +#define Y_POSITIVE 0x20 /* two meanings depending on Y_SHORT_VECTOR */ +#define SAME_Y 0x20 +#define OVERLAP_SIMPLE 0x40 /* we ignore this value */ + + /************************************************************************** * * Composite glyph flags. @@ -62,7 +77,7 @@ #define WE_HAVE_A_2X2 0x0080 #define WE_HAVE_INSTR 0x0100 #define USE_MY_METRICS 0x0200 -#define OVERLAP_COMPOUND 0x0400 +#define OVERLAP_COMPOUND 0x0400 /* we ignore this value */ #define SCALED_COMPONENT_OFFSET 0x0800 #define UNSCALED_COMPONENT_OFFSET 0x1000 @@ -337,7 +352,7 @@ FT_Byte *flag, *flag_limit; FT_Byte c, count; FT_Vector *vec, *vec_limit; - FT_Pos x; + FT_Pos x, y; FT_Short *cont, *cont_limit, prev_cont; FT_Int xy_size = 0; @@ -454,7 +469,7 @@ goto Invalid_Outline; *flag++ = c = FT_NEXT_BYTE( p ); - if ( c & 8 ) + if ( c & REPEAT_FLAG ) { if ( p + 1 > limit ) goto Invalid_Outline; @@ -480,31 +495,29 @@ for ( ; vec < vec_limit; vec++, flag++ ) { - FT_Pos y = 0; - FT_Byte f = *flag; + FT_Pos delta = 0; + FT_Byte f = *flag; - if ( f & 2 ) + if ( f & X_SHORT_VECTOR ) { if ( p + 1 > limit ) goto Invalid_Outline; - y = (FT_Pos)FT_NEXT_BYTE( p ); - if ( ( f & 16 ) == 0 ) - y = -y; + delta = (FT_Pos)FT_NEXT_BYTE( p ); + if ( !( f & X_POSITIVE ) ) + delta = -delta; } - else if ( ( f & 16 ) == 0 ) + else if ( !( f & SAME_X ) ) { if ( p + 2 > limit ) goto Invalid_Outline; - y = (FT_Pos)FT_NEXT_SHORT( p ); + delta = (FT_Pos)FT_NEXT_SHORT( p ); } - x += y; + x += delta; vec->x = x; - /* the cast is for stupid compilers */ - *flag = (FT_Byte)( f & ~( 2 | 16 ) ); } /* reading the Y coordinates */ @@ -512,35 +525,36 @@ vec = gloader->current.outline.points; vec_limit = vec + n_points; flag = (FT_Byte*)outline->tags; - x = 0; + y = 0; for ( ; vec < vec_limit; vec++, flag++ ) { - FT_Pos y = 0; - FT_Byte f = *flag; + FT_Pos delta = 0; + FT_Byte f = *flag; - if ( f & 4 ) + if ( f & Y_SHORT_VECTOR ) { if ( p + 1 > limit ) goto Invalid_Outline; - y = (FT_Pos)FT_NEXT_BYTE( p ); - if ( ( f & 32 ) == 0 ) - y = -y; + delta = (FT_Pos)FT_NEXT_BYTE( p ); + if ( !( f & Y_POSITIVE ) ) + delta = -delta; } - else if ( ( f & 32 ) == 0 ) + else if ( !( f & SAME_Y ) ) { if ( p + 2 > limit ) goto Invalid_Outline; - y = (FT_Pos)FT_NEXT_SHORT( p ); + delta = (FT_Pos)FT_NEXT_SHORT( p ); } - x += y; - vec->y = x; + y += delta; + vec->y = y; + /* the cast is for stupid compilers */ - *flag = (FT_Byte)( f & FT_CURVE_TAG_ON ); + *flag = (FT_Byte)( f & ON_CURVE_POINT ); } outline->n_points = (FT_Short)n_points;