Track recent freetype commit for now

There was some UB (see !207 on FreeType) which was a blocking issue for
certain use cases. The issue has been fixed on freetype master, so for
now we'll track a recent commit until a new release is tagged.

freetype/include/freetype/freetype.h

@@ -1892,13 +1892,13 @@ FT_BEGIN_HEADER
    *     The advance width of the unhinted glyph.  Its value is expressed in
    *     16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when
    *     loading the glyph.  This field can be important to perform correct
-   *     WYSIWYG layout.  Only relevant for outline glyphs.
+   *     WYSIWYG layout.  Only relevant for scalable glyphs.
    *
    *   linearVertAdvance ::
    *     The advance height of the unhinted glyph.  Its value is expressed in
    *     16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when
    *     loading the glyph.  This field can be important to perform correct
-   *     WYSIWYG layout.  Only relevant for outline glyphs.
+   *     WYSIWYG layout.  Only relevant for scalable glyphs.
    *
    *   advance ::
    *     This shorthand is, depending on @FT_LOAD_IGNORE_TRANSFORM, the
@@ -2593,8 +2593,8 @@ FT_BEGIN_HEADER
    *   stream attachments.
    */
   FT_EXPORT( FT_Error )
-  FT_Attach_Stream( FT_Face        face,
-                    FT_Open_Args*  parameters );
+  FT_Attach_Stream( FT_Face              face,
+                    const FT_Open_Args*  parameters );
 
 
   /**************************************************************************

freetype/include/freetype/ftcolor.h

@@ -521,9 +521,10 @@ FT_BEGIN_HEADER
    *
    * @description:
    *   This iterator object is needed for @FT_Get_Colorline_Stops.  It keeps
-   *   state while iterating over the stops of an @FT_ColorLine,
-   *   representing the `ColorLine` struct of the v1 extensions to 'COLR',
-   *   see 'https://github.com/googlefonts/colr-gradients-spec'.
+   *   state while iterating over the stops of an @FT_ColorLine, representing
+   *   the `ColorLine` struct of the v1 extensions to 'COLR', see
+   *   'https://github.com/googlefonts/colr-gradients-spec'.  Do not manually
+   *   modify fields of this iterator.
    *
    * @fields:
    *   num_color_stops ::
@@ -537,6 +538,10 @@ FT_BEGIN_HEADER
    *     An opaque pointer into 'COLR' table data.  Set by @FT_Get_Paint.
    *     Updated by @FT_Get_Colorline_Stops.
    *
+   *   read_variable ::
+   *     A boolean keeping track of whether variable color lines are to be
+   *     read.  Set by @FT_Get_Paint.
+   *
    * @since:
    *   2.11 -- **currently experimental only!**  There might be changes
    *   without retaining backward compatibility of both the API and ABI.
@@ -549,6 +554,8 @@ FT_BEGIN_HEADER
 
     FT_Byte*  p;
 
+    FT_Bool  read_variable;
+
   } FT_ColorStopIterator;
 
 
@@ -592,7 +599,8 @@ FT_BEGIN_HEADER
    *
    * @fields:
    *   stop_offset ::
-   *     The stop offset between 0 and 1 along the gradient.
+   *     The stop offset along the gradient, expressed as a 16.16 fixed-point
+   *     coordinate.
    *
    *   color ::
    *     The color information for this stop, see @FT_ColorIndex.
@@ -604,7 +612,7 @@ FT_BEGIN_HEADER
    */
   typedef struct  FT_ColorStop_
   {
-    FT_F2Dot14     stop_offset;
+    FT_Fixed       stop_offset;
     FT_ColorIndex  color;
 
   } FT_ColorStop;

freetype/include/freetype/ftdriver.h

@@ -214,9 +214,9 @@ FT_BEGIN_HEADER
    *   itself, it is possible to control its behaviour with @FT_Property_Set
    *   and @FT_Property_Get.
    *
-   *   The TrueType driver's module name is 'truetype'; a single property
-   *   @interpreter-version is available, as documented in the @properties
-   *   section.
+   *   The TrueType driver's module name is 'truetype'; two properties are
+   *   available, @interpreter-version and @TEMPORARY-enable-variable-colrv1, as
+   *   documented in the @properties section.
    *
    *   To help understand the differences between interpreter versions, we
    *   introduce a list of definitions, kindly provided by Greg Hitchcock.
@@ -820,6 +820,48 @@ FT_BEGIN_HEADER
    *   2.5
    */
 
+  /**************************************************************************
+   *
+   * @property:
+   *   TEMPORARY-enable-variable-colrv1
+   *
+   * @description:
+   *   Controls experimental support of variable COLRv1 and whether the COLRv1
+   *   implementation should take into account variation deltas. This tells the
+   *   COLRv1 API methods whether they should read from the font and apply
+   *   variable deltas to COLRv1 properties. The feature is default off.  When
+   *   on, variable COLRv1 deltas are applied for COLRv1 features for which they
+   *   are already implemented. When off, variable deltas are ignored even if
+   *   the respective PaintVar* table may already be understood.
+   *
+   *   WARNING: Temporary flag during development of variable COLRv1. This flag
+   *   will be removed, do not rely on it. Full variable COLRv1 support will be
+   *   announced separately.
+   *
+   * @note:
+   *   This property cannot be set via the `FREETYPE_PROPERTIES` environment
+   *   variable.
+   *
+   * @example:
+   *   The following example code demonstrates how to enable variable
+   *   COLRv1.
+   *
+   *   ```
+   *     FT_Library  library;
+   *     FT_Face     face;
+   *     FT_Bool     variable_colrv1 = TRUE;
+   *
+   *
+   *     FT_Init_FreeType( &library );
+   *
+   *     FT_Property_Set( library, "truetype",
+   *                               "TEMPORARY-enable-variable-colrv1",
+   *                               &variable_colr_v1 );
+   *   ```
+   *
+   * @since:
+   *   2.12.2
+   */
 
   /**************************************************************************
    *

freetype/include/freetype/ftglyph.h

@@ -355,7 +355,7 @@ FT_BEGIN_HEADER
    *
    * @output:
    *   aglyph ::
-   *     A handle to the glyph object.
+   *     A handle to the glyph object.  `NULL` in case of error.
    *
    * @return:
    *   FreeType error code.  0~means success.
@@ -385,7 +385,7 @@ FT_BEGIN_HEADER
    *
    * @output:
    *   target ::
-   *     A handle to the target glyph object.  0~in case of error.
+   *     A handle to the target glyph object.  `NULL` in case of error.
    *
    * @return:
    *   FreeType error code.  0~means success.
@@ -671,7 +671,7 @@ FT_BEGIN_HEADER
    *
    * @input:
    *   glyph ::
-   *     A handle to the target glyph object.
+   *     A handle to the target glyph object.  Can be `NULL`.
    */
   FT_EXPORT( void )
   FT_Done_Glyph( FT_Glyph  glyph );

freetype/include/freetype/ftmm.h

@@ -398,6 +398,10 @@ FT_BEGIN_HEADER
    *   FreeType error code.  0~means success.
    *
    * @note:
+   *   The design coordinates are 16.16 fractional values for TrueType GX and
+   *   OpenType variation fonts.  For Adobe MM fonts, the values are
+   *   integers.
+   *
    *   [Since 2.8.1] To reset all axes to the default values, call the
    *   function with `num_coords` set to zero and `coords` set to `NULL`.
    *   [Since 2.9] 'Default values' means the currently selected named
@@ -440,6 +444,11 @@ FT_BEGIN_HEADER
    * @return:
    *   FreeType error code.  0~means success.
    *
+   * @note:
+   *   The design coordinates are 16.16 fractional values for TrueType GX and
+   *   OpenType variation fonts.  For Adobe MM fonts, the values are
+   *   integers.
+   *
    * @since:
    *   2.7.1
    */
@@ -471,9 +480,9 @@ FT_BEGIN_HEADER
    *     the number of axes, use default values for the remaining axes.
    *
    *   coords ::
-   *     The design coordinates array (each element must be between 0 and 1.0
-   *     for Adobe MM fonts, and between -1.0 and 1.0 for TrueType GX and
-   *     OpenType variation fonts).
+   *     The design coordinates array.  Each element is a 16.16 fractional
+   *     value and must be between 0 and 1.0 for Adobe MM fonts, and between
+   *     -1.0 and 1.0 for TrueType GX and OpenType variation fonts.
    *
    * @return:
    *   FreeType error code.  0~means success.
@@ -518,7 +527,7 @@ FT_BEGIN_HEADER
    *
    * @output:
    *   coords ::
-   *     The normalized blend coordinates array.
+   *     The normalized blend coordinates array (as 16.16 fractional values).
    *
    * @return:
    *   FreeType error code.  0~means success.

freetype/include/freetype/ftstroke.h

@@ -293,7 +293,7 @@ FT_BEGIN_HEADER
    *
    *   miter_limit ::
    *     The maximum reciprocal sine of half-angle at the miter join,
-   *     expressed as 16.16 fixed point value.
+   *     expressed as 16.16 fixed-point value.
    *
    * @note:
    *   The `radius` is expressed in the same units as the outline

freetype/include/freetype/ftsystem.h

@@ -229,7 +229,8 @@ FT_BEGIN_HEADER
    *     A handle to the source stream.
    *
    *   offset ::
-   *     The offset of read in stream (always from start).
+   *     The offset from the start of the stream to seek to if this is a seek
+   *     operation (see note).
    *
    *   buffer ::
    *     The address of the read buffer.
@@ -241,8 +242,13 @@ FT_BEGIN_HEADER
    *   The number of bytes effectively read by the stream.
    *
    * @note:
-   *   This function might be called to perform a seek or skip operation with
-   *   a `count` of~0.  A non-zero return value then indicates an error.
+   *   This function performs a seek *or* a read operation depending on the
+   *   argument values.  If `count` is zero, the operation is a seek to
+   *   `offset` bytes.  If `count` is >~0, the operation is a read of `count`
+   *   bytes from the current position in the stream, and the `offset` value
+   *   should be ignored.
+   *
+   *   For seek operations, a non-zero return value indicates an error.
    *
    */
   typedef unsigned long

freetype/include/freetype/internal/cfftypes.h

@@ -315,7 +315,7 @@ FT_BEGIN_HEADER
     /* The normal stack then points to these values instead of the DICT   */
     /* because all other operators in Private DICT clear the stack.       */
     /* `blend_stack' could be cleared at each operator other than blend.  */
-    /* Blended values are stored as 5-byte fixed point values.            */
+    /* Blended values are stored as 5-byte fixed-point values.            */
 
     FT_Byte*  blend_stack;    /* base of stack allocation     */
     FT_Byte*  blend_top;      /* first empty slot             */

freetype/include/freetype/internal/ftcalc.h

@@ -278,6 +278,40 @@ FT_BEGIN_HEADER
                       FT_Long  c );
 
 
+  /**************************************************************************
+   *
+   * @function:
+   *   FT_MulAddFix
+   *
+   * @description:
+   *   Compute `(s[0] * f[0] + s[1] * f[1] + ...) / 0x10000`, where `s[n]` is
+   *   usually a 16.16 scalar.
+   *
+   * @input:
+   *   s ::
+   *     The array of scalars.
+   *   f ::
+   *     The array of factors.
+   *   count ::
+   *     The number of entries in the array.
+   *
+   * @return:
+   *   The result of `(s[0] * f[0] + s[1] * f[1] + ...) / 0x10000`.
+   *
+   * @note:
+   *   This function is currently used for the scaled delta computation of
+   *   variation stores.  It internally uses 64-bit data types when
+   *   available, otherwise it emulates 64-bit math by using 32-bit
+   *   operations, which produce a correct result but most likely at a slower
+   *   performance in comparison to the implementation base on `int64_t`.
+   *
+   */
+  FT_BASE( FT_Int32 )
+  FT_MulAddFix( FT_Fixed*  s,
+                FT_Int32*  f,
+                FT_UInt    count );
+
+
   /*
    * A variant of FT_Matrix_Multiply which scales its result afterwards.  The
    * idea is that both `a' and `b' are scaled by factors of 10 so that the

freetype/include/freetype/internal/ftmmtypes.h

@@ -0,0 +1,85 @@
+/****************************************************************************
+ *
+ * ftmmtypes.h
+ *
+ *   OpenType Variations type definitions for internal use
+ *   with the multi-masters service (specification).
+ *
+ * Copyright (C) 2022 by
+ * David Turner, Robert Wilhelm, Werner Lemberg, George Williams, and
+ * Dominik Röttsches.
+ *
+ * This file is part of the FreeType project, and may only be used,
+ * modified, and distributed under the terms of the FreeType project
+ * license, LICENSE.TXT.  By continuing to use, modify, or distribute
+ * this file you indicate that you have read the license and
+ * understand and accept it fully.
+ *
+ */
+
+
+#ifndef FTMMTYPES_H_
+#define FTMMTYPES_H_
+
+FT_BEGIN_HEADER
+
+
+  typedef FT_Int32  FT_ItemVarDelta;
+
+  typedef struct  GX_ItemVarDataRec_
+  {
+    FT_UInt            itemCount;       /* number of delta sets per item    */
+    FT_UInt            regionIdxCount;  /* number of region indices         */
+    FT_UInt*           regionIndices;   /* array of `regionCount' indices;  */
+                                        /* these index `varRegionList'      */
+    FT_ItemVarDelta*   deltaSet;        /* array of `itemCount' deltas      */
+                                        /* use `innerIndex' for this array  */
+
+  } GX_ItemVarDataRec, *GX_ItemVarData;
+
+
+  /* contribution of one axis to a region */
+  typedef struct  GX_AxisCoordsRec_
+  {
+    FT_Fixed  startCoord;
+    FT_Fixed  peakCoord;      /* zero means no effect (factor = 1) */
+    FT_Fixed  endCoord;
+
+  } GX_AxisCoordsRec, *GX_AxisCoords;
+
+
+  typedef struct  GX_VarRegionRec_
+  {
+    GX_AxisCoords  axisList;               /* array of axisCount records */
+
+  } GX_VarRegionRec, *GX_VarRegion;
+
+
+  /* item variation store */
+  typedef struct  GX_ItemVarStoreRec_
+  {
+    FT_UInt         dataCount;
+    GX_ItemVarData  varData;            /* array of dataCount records;     */
+                                        /* use `outerIndex' for this array */
+    FT_UShort     axisCount;
+    FT_UInt       regionCount;          /* total number of regions defined */
+    GX_VarRegion  varRegionList;
+
+  } GX_ItemVarStoreRec, *GX_ItemVarStore;
+
+
+  typedef struct  GX_DeltaSetIdxMapRec_
+  {
+    FT_ULong  mapCount;
+    FT_UInt*  outerIndex;               /* indices to item var data */
+    FT_UInt*  innerIndex;               /* indices to delta set     */
+
+  } GX_DeltaSetIdxMapRec, *GX_DeltaSetIdxMap;
+
+
+FT_END_HEADER
+
+#endif /* FTMMTYPES_H_ */
+
+
+/* END */