s/this is,/that is,/

10 files changed, 14 insertions, 14 deletions

diff --git a/src/autofit/afblue.dat b/src/autofit/afblue.dat
index b7efe8be6..8299baa25 100644
--- a/src/autofit/afblue.dat
+++ b/src/autofit/afblue.dat
@@ -89,7 +89,7 @@ AF_BLUE_STRING_ENUM AF_BLUE_STRINGS_ARRAY AF_BLUE_STRING_MAX_LEN:
     "ت ث ط ظ ك"
   // We don't necessarily have access to medial forms via Unicode in case
   // Arabic presentational forms are missing.  The only character that is
-  // guaranteed to have the same vertical position with joining (this is,
+  // guaranteed to have the same vertical position with joining (that is,
   // non-isolated) forms is U+0640, ARABIC TATWEEL, which must join both
   // round and flat curves.
   AF_BLUE_STRING_ARABIC_JOIN
diff --git a/src/autofit/aflatin.c b/src/autofit/aflatin.c
index 1082fee9a..d84579238 100644
--- a/src/autofit/aflatin.c
+++ b/src/autofit/aflatin.c
@@ -2038,7 +2038,7 @@
             max = seg2->max_coord;
 
           /* compute maximum coordinate difference of the two segments */
-          /* (this is, how much they overlap)                          */
+          /* (that is, how much they overlap)                          */
           len = max - min;
           if ( len >= len_threshold )
           {
diff --git a/src/autofit/afshaper.c b/src/autofit/afshaper.c
index 1b8b870e8..abc6f1d29 100644
--- a/src/autofit/afshaper.c
+++ b/src/autofit/afshaper.c
@@ -258,7 +258,7 @@
     /*
      * We now check whether we can construct blue zones, using glyphs
      * covered by the feature only.  In case there is not a single zone
-     * (this is, not a single character is covered), we skip this coverage.
+     * (that is, not a single character is covered), we skip this coverage.
      *
      */
     if ( style_class->coverage != AF_COVERAGE_DEFAULT )
@@ -313,9 +313,9 @@
      * hinted and usually rendered glyph.
      *
      * Consider the superscript feature of font `pala.ttf': Some of the
-     * glyphs are `real', this is, they have a zero vertical offset, but
+     * glyphs are `real', that is, they have a zero vertical offset, but
      * most of them are small caps glyphs shifted up to the superscript
-     * position (this is, the `sups' feature is present in both the GSUB and
+     * position (that is, the `sups' feature is present in both the GSUB and
      * GPOS tables).  The code for blue zones computation actually uses a
      * feature's y offset so that the `real' glyphs get correct hints.  But
      * later on it is impossible to decide whether a glyph index belongs to,
diff --git a/src/base/ftcalc.c b/src/base/ftcalc.c
index 997921883..442b08ddf 100644
--- a/src/base/ftcalc.c
+++ b/src/base/ftcalc.c
@@ -1061,7 +1061,7 @@
     /*                                                           */
     /* This approach has the advantage that the angle between    */
     /* `in' and `out' is not checked.  In case one of the two    */
-    /* vectors is `dominant', this is, much larger than the      */
+    /* vectors is `dominant', that is, much larger than the      */
     /* other vector, we thus always have a flat corner.          */
     /*                                                           */
     /*                hypotenuse                                 */
diff --git a/src/base/ftsystem.c b/src/base/ftsystem.c
index 98c046b83..61c99e363 100644
--- a/src/base/ftsystem.c
+++ b/src/base/ftsystem.c
@@ -206,7 +206,7 @@
    *     The number of bytes to read from the stream.
    *
    * @Return:
-   *   The number of bytes actually read.  If `count' is zero (this is,
+   *   The number of bytes actually read.  If `count' is zero (that is,
    *   the function is used for seeking), a non-zero return value
    *   indicates an error.
    */
diff --git a/src/cff/cffload.c b/src/cff/cffload.c
index f0e1977e2..fa2c29b28 100644
--- a/src/cff/cffload.c
+++ b/src/cff/cffload.c
@@ -400,7 +400,7 @@
 
   /* Allocate a table containing pointers to an index's elements. */
   /* The `pool' argument makes this function convert the index    */
-  /* entries to C-style strings (this is, null-terminated).       */
+  /* entries to C-style strings (that is, null-terminated).       */
   static FT_Error
   cff_index_get_pointers( CFF_Index   idx,
                           FT_Byte***  table,
diff --git a/src/cff/cffparse.c b/src/cff/cffparse.c
index a31f085d9..89a0263b7 100644
--- a/src/cff/cffparse.c
+++ b/src/cff/cffparse.c
@@ -622,7 +622,7 @@
 
       dict->has_font_matrix = TRUE;
 
-      /* We expect a well-formed font matrix, this is, the matrix elements */
+      /* We expect a well-formed font matrix, that is, the matrix elements */
       /* `xx' and `yy' are of approximately the same magnitude.  To avoid  */
       /* loss of precision, we use the magnitude of the largest matrix     */
       /* element to scale all other elements.  The scaling factor is then  */
diff --git a/src/pshinter/pshalgo.c b/src/pshinter/pshalgo.c
index a7f321291..4f622e1e4 100644
--- a/src/pshinter/pshalgo.c
+++ b/src/pshinter/pshalgo.c
@@ -516,7 +516,7 @@
             if ( !psh_hint_is_fitted( parent ) )
               psh_hint_align( parent, globals, dimension, glyph );
 
-            /* keep original relation between hints, this is, use the */
+            /* keep original relation between hints, that is, use the */
             /* scaled distance between the centers of the hints to    */
             /* compute the new position                               */
             par_org_center = parent->org_pos + ( parent->org_len >> 1 );
diff --git a/src/sdf/ftsdf.c b/src/sdf/ftsdf.c
index d8479af10..0a43e9be6 100644
--- a/src/sdf/ftsdf.c
+++ b/src/sdf/ftsdf.c
@@ -2371,7 +2371,7 @@
      *     ```
      *
      * (6) Our task is to find a value of `t` such that the above equation
-     *     `Q(t)` becomes zero, this is, the point-to-curve vector makes
+     *     `Q(t)` becomes zero, that is, the point-to-curve vector makes
      *     90~degrees with the curve.  We solve this with the Newton-Raphson
      *     method.
      *
@@ -2684,7 +2684,7 @@
      *     ```
      *
      * (6) Our task is to find a value of `t` such that the above equation
-     *     `Q(t)` becomes zero, this is, the point-to-curve vector makes
+     *     `Q(t)` becomes zero, that is, the point-to-curve vector makes
      *     90~degree with curve.  We solve this with the Newton-Raphson
      *     method.
      *
diff --git a/src/truetype/ttinterp.c b/src/truetype/ttinterp.c
index c6a6cde6b..3b7b21cca 100644
--- a/src/truetype/ttinterp.c
+++ b/src/truetype/ttinterp.c
@@ -7837,7 +7837,7 @@
         /* a variable number of arguments             */
 
         /* it is the job of the application to `activate' GX handling, */
-        /* this is, calling any of the GX API functions on the current */
+        /* that is, calling any of the GX API functions on the current */
         /* font to select a variation instance                         */
         if ( exc->face->blend )
           exc->new_top = exc->args + exc->face->blend->num_axis;
@@ -8397,7 +8397,7 @@
 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
         case 0x91:
           /* it is the job of the application to `activate' GX handling, */
-          /* this is, calling any of the GX API functions on the current */
+          /* that is, calling any of the GX API functions on the current */
           /* font to select a variation instance                         */
           if ( exc->face->blend )
             Ins_GETVARIATION( exc, args );