[truetype, snft] Add service methods for `DeltaSetIdxMap` and `VarStore`.

This will be needed for 'COLR' v1 variation support.

* src/truetype/ttgxvar.h (GX_ItemVarData, GX_AxisCoords, GX_VarRegion,
GX_VarItemStore, GX_DeltaSetIdxMap): Move structures to...
* include/freetype/internal/ftmmtypes.h: ... this new file.

* include/freetype/internal/service/svmm.h (MultiMasters): Include
`ftmmtypes.h`.
(FT_Var_Load_Delta_Set_Idx_Map_Func, FT_Var_Load_Item_Var_Store_Func,
FT_Var_Get_Item_Delta_Func, FT_Var_Done_Item_Var_Store_Func,
FT_Var_Done_Delta_Set_Idx_Map_Func): New function typedefs.
(MultiMasters): Add them.
(FT_DEFINE_SERVICE_MULTIMASTERSREC): Updated.

* src/cff/cffdrivr.c (cff_load_item_variation_store,
cff_load_delta_set_index_mapping, cff_get_item_delta,
cff_done_item_variation_store, cff_done_delta_set_index_map): New wrapper
methods calling into mm service.
(cff_service_multi_masters): Updated.

* src/truetype/ttgxvar.c (ft_var_load_item_variation_store,
ft_var_load_delta_set_index_mapping, ft_var_get_item_delta,
ft_var_done_item_variation_store, ft_var_done_delta_set_index_map): Renamed
to ...
(tt_var_load_item_variation_store, tt_var_load_delta_set_index_mapping,
tt_var_get_item_delta, tt_var_done_item_variation_store,
tt_var_done_delta_set_index_map): ... this for consistency.
Mark them as non-static.
* src/truetype/ttgxvar.h: Add corresponding prototypes.

* src/truetype/ttdriver.c (tt_service_gx_multi_masters): Updated.

* src/type1/t1driver.c (t1_service_multi_masters): Updated.

2 files changed, 165 insertions, 40 deletions

diff --git a/include/freetype/internal/ftmmtypes.h b/include/freetype/internal/ftmmtypes.h
new file mode 100644
index 000000000..74706bedb
--- /dev/null
+++ b/include/freetype/internal/ftmmtypes.h
@@ -0,0 +1,83 @@
+/****************************************************************************
+ *
+ * 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 struct  GX_ItemVarDataRec_
+  {
+    FT_UInt    itemCount;      /* number of delta sets per item         */
+    FT_UInt    regionIdxCount; /* number of region indices in this data */
+    FT_UInt*   regionIndices;  /* array of `regionCount' indices;       */
+                               /* these index `varRegionList'           */
+    FT_Short*  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 */
diff --git a/include/freetype/internal/services/svmm.h b/include/freetype/internal/services/svmm.h
index c6394890a..22ddc8c66 100644
--- a/include/freetype/internal/services/svmm.h
+++ b/include/freetype/internal/services/svmm.h
@@ -5,7 +5,7 @@
  *   The FreeType Multiple Masters and GX var services (specification).
  *
  * Copyright (C) 2003-2022 by
- * David Turner, Robert Wilhelm, and Werner Lemberg.
+ * David Turner, Robert Wilhelm, Werner Lemberg, 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
@@ -20,6 +20,7 @@
 #define SVMM_H_
 
 #include <freetype/internal/ftserv.h>
+#include <freetype/internal/ftmmtypes.h>
 
 
 FT_BEGIN_HEADER
@@ -96,53 +97,94 @@ FT_BEGIN_HEADER
                                   FT_UInt*   len,
                                   FT_Fixed*  weight_vector );
 
+  typedef FT_Error
+  (*FT_Var_Load_Delta_Set_Idx_Map_Func)( FT_Face            face,
+                                         FT_ULong           offset,
+                                         GX_DeltaSetIdxMap  map,
+                                         GX_ItemVarStore    itemStore,
+                                         FT_ULong           table_len );
+
+  typedef FT_Error
+  (*FT_Var_Load_Item_Var_Store_Func)( FT_Face          face,
+                                      FT_ULong         offset,
+                                      GX_ItemVarStore  itemStore );
+
+  typedef FT_Int
+  (*FT_Var_Get_Item_Delta_Func)( FT_Face          face,
+                                 GX_ItemVarStore  itemStore,
+                                 FT_UInt          outerIndex,
+                                 FT_UInt          innerIndex );
+
+  typedef void
+  (*FT_Var_Done_Item_Var_Store_Func)( FT_Face          face,
+                                      GX_ItemVarStore  itemStore );
+
+  typedef void
+  (*FT_Var_Done_Delta_Set_Idx_Map_Func)( FT_Face            face,
+                                         GX_DeltaSetIdxMap  deltaSetIdxMap );
+
 
   FT_DEFINE_SERVICE( MultiMasters )
   {
-    FT_Get_MM_Func               get_mm;
-    FT_Set_MM_Design_Func        set_mm_design;
-    FT_Set_MM_Blend_Func         set_mm_blend;
-    FT_Get_MM_Blend_Func         get_mm_blend;
-    FT_Get_MM_Var_Func           get_mm_var;
-    FT_Set_Var_Design_Func       set_var_design;
-    FT_Get_Var_Design_Func       get_var_design;
-    FT_Set_Instance_Func         set_instance;
-    FT_Set_MM_WeightVector_Func  set_mm_weightvector;
-    FT_Get_MM_WeightVector_Func  get_mm_weightvector;
+    FT_Get_MM_Func                        get_mm;
+    FT_Set_MM_Design_Func                 set_mm_design;
+    FT_Set_MM_Blend_Func                  set_mm_blend;
+    FT_Get_MM_Blend_Func                  get_mm_blend;
+    FT_Get_MM_Var_Func                    get_mm_var;
+    FT_Set_Var_Design_Func                set_var_design;
+    FT_Get_Var_Design_Func                get_var_design;
+    FT_Set_Instance_Func                  set_instance;
+    FT_Set_MM_WeightVector_Func           set_mm_weightvector;
+    FT_Get_MM_WeightVector_Func           get_mm_weightvector;
 
     /* for internal use; only needed for code sharing between modules */
-    FT_Get_Var_Blend_Func  get_var_blend;
-    FT_Done_Blend_Func     done_blend;
+    FT_Var_Load_Delta_Set_Idx_Map_Func    load_delta_set_idx_map;
+    FT_Var_Load_Item_Var_Store_Func       load_item_var_store;
+    FT_Var_Get_Item_Delta_Func            get_item_delta;
+    FT_Var_Done_Item_Var_Store_Func       done_item_var_store;
+    FT_Var_Done_Delta_Set_Idx_Map_Func    done_delta_set_idx_map;
+    FT_Get_Var_Blend_Func                 get_var_blend;
+    FT_Done_Blend_Func                    done_blend;
   };
 
 
-#define FT_DEFINE_SERVICE_MULTIMASTERSREC( class_,            \
-                                           get_mm_,           \
-                                           set_mm_design_,    \
-                                           set_mm_blend_,     \
-                                           get_mm_blend_,     \
-                                           get_mm_var_,       \
-                                           set_var_design_,   \
-                                           get_var_design_,   \
-                                           set_instance_,     \
-                                           set_weightvector_, \
-                                           get_weightvector_, \
-                                           get_var_blend_,    \
-                                           done_blend_ )      \
-  static const FT_Service_MultiMastersRec  class_ =           \
-  {                                                           \
-    get_mm_,                                                  \
-    set_mm_design_,                                           \
-    set_mm_blend_,                                            \
-    get_mm_blend_,                                            \
-    get_mm_var_,                                              \
-    set_var_design_,                                          \
-    get_var_design_,                                          \
-    set_instance_,                                            \
-    set_weightvector_,                                        \
-    get_weightvector_,                                        \
-    get_var_blend_,                                           \
-    done_blend_                                               \
+#define FT_DEFINE_SERVICE_MULTIMASTERSREC( class_,                  \
+                                           get_mm_,                 \
+                                           set_mm_design_,          \
+                                           set_mm_blend_,           \
+                                           get_mm_blend_,           \
+                                           get_mm_var_,             \
+                                           set_var_design_,         \
+                                           get_var_design_,         \
+                                           set_instance_,           \
+                                           set_weightvector_,       \
+                                           get_weightvector_,       \
+                                           load_delta_set_idx_map_, \
+                                           load_item_var_store_,    \
+                                           get_item_delta_,         \
+                                           done_item_var_store_,    \
+                                           done_delta_set_idx_map_, \
+                                           get_var_blend_,          \
+                                           done_blend_ )            \
+  static const FT_Service_MultiMastersRec  class_ =                 \
+  {                                                                 \
+    get_mm_,                                                        \
+    set_mm_design_,                                                 \
+    set_mm_blend_,                                                  \
+    get_mm_blend_,                                                  \
+    get_mm_var_,                                                    \
+    set_var_design_,                                                \
+    get_var_design_,                                                \
+    set_instance_,                                                  \
+    set_weightvector_,                                              \
+    get_weightvector_,                                              \
+    load_delta_set_idx_map_,                                        \
+    load_item_var_store_,                                           \
+    get_item_delta_,                                                \
+    done_item_var_store_,                                           \
+    done_delta_set_idx_map_,                                        \
+    get_var_blend_,                                                 \
+    done_blend_                                                     \
   };
 
   /* */