ref: 119e8e41ef1c5ff00d41ac64f8b9eef3b79a1cee
parent: 533887a947b2be0c56734fd1906cc24b9088b881
author: Werner Lemberg <[email protected]>
date: Tue May 17 15:54:09 EDT 2016
[cff] Fix matrix scaling (#47848). * include/freetype/config/ftstdlib.h (FT_LONG_MIN): New macro. * src/cff/cffparse.c (cff_parse_font_matrix): Use largest scaling value of all matrix coefficients to scale matrix. * src/cff/cffobjs.c (cff_face_init): Use `matrix->yx' member for matrix normalization if `matrix->yy' is zero.
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2016-05-17 Werner Lemberg <[email protected]>
+
+ [cff] Fix matrix scaling (#47848).
+
+ * include/freetype/config/ftstdlib.h (FT_LONG_MIN): New macro.
+
+ * src/cff/cffparse.c (cff_parse_font_matrix): Use largest scaling
+ value of all matrix coefficients to scale matrix.
+
+ * src/cff/cffobjs.c (cff_face_init): Use `matrix->yx' member for
+ matrix normalization if `matrix->yy' is zero.
+
2016-05-16 Werner Lemberg <[email protected]>
[base] Reject invalid sfnt Mac resource (#47891).
--- a/include/freetype/config/ftstdlib.h
+++ b/include/freetype/config/ftstdlib.h
@@ -63,6 +63,7 @@
#define FT_INT_MAX INT_MAX
#define FT_INT_MIN INT_MIN
#define FT_UINT_MAX UINT_MAX
+#define FT_LONG_MIN LONG_MIN
#define FT_LONG_MAX LONG_MAX
#define FT_ULONG_MAX ULONG_MAX
--- a/src/cff/cffobjs.c
+++ b/src/cff/cffobjs.c
@@ -670,10 +670,11 @@
if ( !dict->has_font_matrix )
dict->units_per_em = pure_cff ? 1000 : face->root.units_per_EM;
- /* Normalize the font matrix so that `matrix->yy' is 1; the */
- /* scaling is done with `units_per_em' then (at this point, */
- /* it already contains the scaling factor, but without */
- /* normalization of the matrix). */
+ /* Normalize the font matrix so that `matrix->yy' is 1; if */
+ /* it is zero, we use `matrix->yx' instead. The scaling is */
+ /* done with `units_per_em' then (at this point, it already */
+ /* contains the scaling factor, but without normalization */
+ /* of the matrix). */
/* */
/* Note that the offsets must be expressed in integer font */
/* units. */
@@ -682,9 +683,12 @@
FT_Matrix* matrix = &dict->font_matrix;
FT_Vector* offset = &dict->font_offset;
FT_ULong* upm = &dict->units_per_em;
- FT_Fixed temp = FT_ABS( matrix->yy );
+ FT_Fixed temp;
+ temp = matrix->yy ? FT_ABS( matrix->yy )
+ : FT_ABS( matrix->yx );
+
if ( temp != 0x10000L )
{*upm = (FT_ULong)FT_DivFix( (FT_Long)*upm, temp );
@@ -752,7 +756,10 @@
matrix = &sub->font_matrix;
offset = &sub->font_offset;
upm = &sub->units_per_em;
- temp = FT_ABS( matrix->yy );
+
+ temp = matrix->yy ? FT_ABS( matrix->yy )
+ : FT_ABS( matrix->yx );
+
if ( temp != 0x10000L )
{--- a/src/cff/cffparse.c
+++ b/src/cff/cffparse.c
@@ -521,9 +521,13 @@
if ( parser->top >= parser->stack + 6 )
{- FT_Long scaling;
+ FT_Fixed values[6];
+ FT_Long scalings[6];
+ FT_Long min_scaling, max_scaling;
+ int i;
+
error = FT_Err_Ok;
dict->has_font_matrix = TRUE;
@@ -530,22 +534,36 @@
/* We expect a well-formed font matrix, this is, the matrix elements */
/* `xx' and `yy' are of approximately the same magnitude. To avoid */
- /* loss of precision, we use the magnitude of element `xx' to scale */
- /* all other elements. The scaling factor is then contained in the */
- /* `units_per_em' value. */
+ /* loss of precision, we use the magnitude of the largest matrix */
+ /* element to scale all other elements. The scaling factor is then */
+ /* contained in the `units_per_em' value. */
- matrix->xx = cff_parse_fixed_dynamic( data++, &scaling );
+ max_scaling = FT_LONG_MIN;
+ min_scaling = FT_LONG_MAX;
- scaling = -scaling;
+ for ( i = 0; i < 6; i++ )
+ {+ values[i] = cff_parse_fixed_dynamic( data++, &scalings[i] );
+ if ( values[i] )
+ {+ if ( scalings[i] > max_scaling )
+ max_scaling = scalings[i];
+ if ( scalings[i] < min_scaling )
+ min_scaling = scalings[i];
+ }
+ }
- if ( scaling < 0 || scaling > 9 )
+ if ( max_scaling < -9 ||
+ max_scaling > 0 ||
+ ( max_scaling - min_scaling ) < 0 ||
+ ( max_scaling - min_scaling ) > 9 )
{/* Return default matrix in case of unlikely values. */
FT_TRACE1(( "cff_parse_font_matrix:"
- " strange scaling value for xx element (%d),\n"
+ " strange scaling values (minimum %d, maximum %d),\n"
" "
- " using default matrix\n", scaling ));
+ " using default matrix\n", min_scaling, max_scaling ));
matrix->xx = 0x10000L;
matrix->yx = 0;
@@ -558,13 +576,42 @@
goto Exit;
}
- matrix->yx = cff_parse_fixed_scaled( data++, scaling );
- matrix->xy = cff_parse_fixed_scaled( data++, scaling );
- matrix->yy = cff_parse_fixed_scaled( data++, scaling );
- offset->x = cff_parse_fixed_scaled( data++, scaling );
- offset->y = cff_parse_fixed_scaled( data, scaling );
+ for ( i = 0; i < 6; i++ )
+ {+ FT_Fixed value = values[i];
+ FT_Long divisor, half_divisor;
- *upm = (FT_ULong)power_tens[scaling];
+
+ if ( !value )
+ continue;
+
+ divisor = power_tens[max_scaling - scalings[i]];
+ half_divisor = divisor >> 1;
+
+ if ( value < 0 )
+ {+ if ( FT_LONG_MIN + half_divisor < value )
+ values[i] = ( value - half_divisor ) / divisor;
+ else
+ values[i] = FT_LONG_MIN / divisor;
+ }
+ else
+ {+ if ( FT_LONG_MAX - half_divisor > value )
+ values[i] = ( value + half_divisor ) / divisor;
+ else
+ values[i] = FT_LONG_MAX / divisor;
+ }
+ }
+
+ matrix->xx = values[0];
+ matrix->yx = values[1];
+ matrix->xy = values[2];
+ matrix->yy = values[3];
+ offset->x = values[4];
+ offset->y = values[5];
+
+ *upm = (FT_ULong)power_tens[-max_scaling];
FT_TRACE4(( " [%f %f %f %f %f %f]\n",
(double)matrix->xx / *upm / 65536,