ref: 37580053b491b69284988ed25cbbf6e884151eb0
parent: ac335cd5865fcae031689e23c470907245aad4a0
author: Werner Lemberg <[email protected]>
date: Thu May 16 08:15:54 EDT 2019
[truetype] Use 26.6 format for storing unscaled CVT values. If `CVAR' data is applied to variation fonts, fractional values are possible. * include/freetype/internal/tttypes.h (TT_FaceRec): Change type of `cvt' from `FT_Short' to `FT_Int32'. * src/truetype/ttgxvar.c (FT_fdot6ToFixed): New macro. (tt_face_vary_cvt): Use it to update code to 26.6 format. * src/truetype/ttobjs.c (tt_size_run_prep): Update code to 26.6 format. * src/truetype/ttpload.c (tt_face_load_cvt): Stora data in 26.6 format.
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,24 @@
2019-05-16 Werner Lemberg <[email protected]>
+ [truetype] Use 26.6 format for storing unscaled CVT values.
+
+ If `CVAR' data is applied to variation fonts, fractional values are
+ possible.
+
+ * include/freetype/internal/tttypes.h (TT_FaceRec): Change type of
+ `cvt' from `FT_Short' to `FT_Int32'.
+
+ * src/truetype/ttgxvar.c (FT_fdot6ToFixed): New macro.
+ (tt_face_vary_cvt): Use it to update code to 26.6 format.
+
+ * src/truetype/ttobjs.c (tt_size_run_prep): Update code to 26.6
+ format.
+
+ * src/truetype/ttpload.c (tt_face_load_cvt): Stora data in 26.6
+ format.
+
+2019-05-16 Werner Lemberg <[email protected]>
+
* src/truetype/ttgload.c (load_truetype_glyph): Init `unrounded'.
This fixes linear advance width values for spacing glyphs. Bug
--- a/include/freetype/internal/tttypes.h
+++ b/include/freetype/internal/tttypes.h
@@ -1395,9 +1395,11 @@
*
* cvt ::
* The face's original control value table. Coordinates are expressed
- * in unscaled font units. Comes from the 'cvt~' table. Ignored for
- * Type 2 fonts.
+ * in unscaled font units (in 26.6 format). Comes from the 'cvt~'
+ * table. Ignored for Type 2 fonts.
*
+ * If varied by the `CVAR' table, non-integer values are possible.
+ *
* interpreter ::
* A pointer to the TrueType bytecode interpreters field is also used
* to hook the debugger in 'ttdebug'.
@@ -1633,7 +1635,7 @@
/* the original, unscaled, control value table */
FT_ULong cvt_size;
- FT_Short* cvt;
+ FT_Int32* cvt;
/* A pointer to the bytecode interpreter to use. This is also */
/* used to hook the debugger for the `ttdebug' utility. */
--- a/src/truetype/ttgxvar.c
+++ b/src/truetype/ttgxvar.c
@@ -72,6 +72,8 @@
( (FT_Fixed)( (FT_ULong)(x) << 2 ) )
#define FT_intToFixed( i ) \
( (FT_Fixed)( (FT_ULong)(i) << 16 ) )
+#define FT_fdot6ToFixed( i ) \
+ ( (FT_Fixed)( (FT_ULong)(i) << 10 ) )
#define FT_fixedToInt( x ) \
( (FT_Short)( ( (FT_ULong)(x) + 0x8000U ) >> 16 ) )
#define FT_fixedToFdot6( x ) \
@@ -3367,9 +3369,9 @@
{FT_TRACE7(( " %d: %f -> %f\n",
j,
- ( FT_intToFixed( face->cvt[j] ) +
+ ( FT_fdot6ToFixed( face->cvt[j] ) +
old_cvt_delta ) / 65536.0,
- ( FT_intToFixed( face->cvt[j] ) +
+ ( FT_fdot6ToFixed( face->cvt[j] ) +
cvt_deltas[j] ) / 65536.0 ));
count++;
}
@@ -3409,9 +3411,9 @@
{FT_TRACE7(( " %d: %f -> %f\n",
pindex,
- ( FT_intToFixed( face->cvt[pindex] ) +
+ ( FT_fdot6ToFixed( face->cvt[pindex] ) +
old_cvt_delta ) / 65536.0,
- ( FT_intToFixed( face->cvt[pindex] ) +
+ ( FT_fdot6ToFixed( face->cvt[pindex] ) +
cvt_deltas[pindex] ) / 65536.0 ));
count++;
}
@@ -3436,7 +3438,7 @@
FT_TRACE5(( "\n" ));
for ( i = 0; i < face->cvt_size; i++ )
- face->cvt[i] += FT_fixedToInt( cvt_deltas[i] );
+ face->cvt[i] += FT_fixedToFdot6( cvt_deltas[i] );
FExit:
FT_FRAME_EXIT();
--- a/src/truetype/ttobjs.c
+++ b/src/truetype/ttobjs.c
@@ -939,15 +939,18 @@
FT_Error error;
FT_UInt i;
+ /* unscaled CVT values are already stored in 26.6 format */
+ FT_Fixed scale = size->ttmetrics.scale >> 6;
+
/* Scale the cvt values to the new ppem. */
/* By default, we use the y ppem value for scaling. */
FT_TRACE6(( "CVT values:\n" ));
for ( i = 0; i < size->cvt_size; i++ )
{- size->cvt[i] = FT_MulFix( face->cvt[i], size->ttmetrics.scale );
- FT_TRACE6(( " %3d: %d (%f)\n",
- i, face->cvt[i], size->cvt[i] / 64.0 ));
+ size->cvt[i] = FT_MulFix( face->cvt[i], scale );
+ FT_TRACE6(( " %3d: %f (%f)\n",
+ i, face->cvt[i] / 64.0, size->cvt[i] / 64.0 ));
}
FT_TRACE6(( "\n" ));
--- a/src/truetype/ttpload.c
+++ b/src/truetype/ttpload.c
@@ -352,12 +352,12 @@
goto Exit;
{- FT_Short* cur = face->cvt;
- FT_Short* limit = cur + face->cvt_size;
+ FT_Int32* cur = face->cvt;
+ FT_Int32* limit = cur + face->cvt_size;
for ( ; cur < limit; cur++ )
- *cur = FT_GET_SHORT();
+ *cur = FT_GET_SHORT() * 64;
}
FT_FRAME_EXIT();