Commit 45524679c6798b3d8b75ab03d54a53bf46912871
2018-08-22T10:31:05
[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.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161
diff --git a/ChangeLog b/ChangeLog
index 9ddfad2..69cdc1d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2018-08-22 Werner Lemberg <wl@gnu.org>
+
+ [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 <wl@gnu.org>
* 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 0a436a2..d767584 100644
--- a/src/truetype/ttgload.c
+++ b/src/truetype/ttgload.c
@@ -50,6 +50,21 @@
/**************************************************************************
*
+ * 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.
*/
#define ARGS_ARE_WORDS 0x0001
@@ -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;