Font variations.

src/ports/SkFontHost_FreeType.cpp

Index: src/ports/SkFontHost_FreeType.cpp
diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp
index 5c53b9d9136320973c3c63b81f8a822a048d1b84..a4305bfa872b9b0aa160e82e0a36fa17b16e9962 100644
--- a/src/ports/SkFontHost_FreeType.cpp
+++ b/src/ports/SkFontHost_FreeType.cpp
@@ -11,6 +11,7 @@
 #include "SkColorPriv.h"
 #include "SkDescriptor.h"
 #include "SkFDot6.h"
+#include "SkFontDescriptor.h"
 #include "SkFontHost_FreeType_common.h"
 #include "SkGlyph.h"
 #include "SkMask.h"
@@ -33,6 +34,7 @@
 #include FT_FREETYPE_H
 #include FT_LCD_FILTER_H
 #include FT_MODULE_H
+#include FT_MULTIPLE_MASTERS_H
 #include FT_OUTLINE_H
 #include FT_SIZES_H
 #include FT_SYSTEM_H
@@ -273,6 +275,37 @@ SkFaceRec::SkFaceRec(SkStreamAsset* stream, uint32_t fontID)
     fFTStream.close = sk_ft_stream_close;
 }
 
+static void ft_face_setup_axes(FT_Face face, const SkFontData& data) {
+    if (!(face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS)) {
+        return;
+    }
+
+    SkDEBUGCODE(
+        FT_MM_Var* variations = NULL;
+        if (FT_Get_MM_Var(face, &variations)) {

[bungeman-skia, 2015/05/13 23:04:44]

The Android Framework build died here because, while it builds all of the code
to do this (and if you know the right hackery to get the function pointer it
works), it doesn't build the ftmm.c file which is tiny and exports FT_Get_MM_Var
and several other calls which are basically just forwards through the
appropriate vtable. This will need to be added. 

+            SkDEBUGF(("INFO: font %s claims variations, but none found.\n", face->family_name));
+            return;
+        }
+        SkAutoFree autoFreeVariations(variations);
+
+        if (static_cast<FT_UInt>(data.getAxisCount()) != variations->num_axis) {
+            SkDEBUGF(("INFO: font %s has %d variations, but %d were specified.\n",
+                    face->family_name, variations->num_axis, data.getAxisCount()));
+            return;
+        }
+    )
+
+    SkAutoSTMalloc<4, FT_Fixed> coords(data.getAxisCount());
+    for (int i = 0; i < data.getAxisCount(); ++i) {
+        coords[i] = data.getAxis()[i];
+    }
+    if (FT_Set_Var_Design_Coordinates(face, data.getAxisCount(), coords.get())) {
+        SkDEBUGF(("INFO: font %s has variations, but specified variations could not be set.\n",
+                  face->family_name));
+        return;
+    }
+}
+
 // Will return 0 on failure
 // Caller must lock gFTMutex before calling this function.
 static SkFaceRec* ref_ft_face(const SkTypeface* typeface) {
@@ -289,34 +322,36 @@ static SkFaceRec* ref_ft_face(const SkTypeface* typeface) {
         rec = rec->fNext;
     }
 
-    int face_index;
-    SkStreamAsset* stream = typeface->openStream(&face_index);
-    if (NULL == stream) {
+    SkAutoTDelete<SkFontData> data(typeface->createFontData());
+    if (NULL == data || !data->hasStream()) {
         return NULL;
     }
 
     // this passes ownership of stream to the rec
-    rec = SkNEW_ARGS(SkFaceRec, (stream, fontID));
+    rec = SkNEW_ARGS(SkFaceRec, (data->detachStream(), fontID));
 
     FT_Open_Args args;
     memset(&args, 0, sizeof(args));
-    const void* memoryBase = stream->getMemoryBase();
+    const void* memoryBase = rec->fSkStream->getMemoryBase();
     if (memoryBase) {
         args.flags = FT_OPEN_MEMORY;
         args.memory_base = (const FT_Byte*)memoryBase;
-        args.memory_size = stream->getLength();
+        args.memory_size = rec->fSkStream->getLength();
     } else {
         args.flags = FT_OPEN_STREAM;
         args.stream = &rec->fFTStream;
     }
 
-    FT_Error err = FT_Open_Face(gFTLibrary->library(), &args, face_index, &rec->fFace);
-    if (err) {    // bad filename, try the default font
+    FT_Error err = FT_Open_Face(gFTLibrary->library(), &args, data->getIndex(), &rec->fFace);
+    if (err) {
         SkDEBUGF(("ERROR: unable to open font '%x'\n", fontID));
         SkDELETE(rec);
         return NULL;
     }
     SkASSERT(rec->fFace);
+
+    ft_face_setup_axes(rec->fFace, *data);
+
     rec->fNext = gFaceRecHead;
     gFaceRecHead = rec;
     return rec;
@@ -1649,7 +1684,8 @@ bool SkTypeface_FreeType::Scanner::recognizedFont(SkStream* stream, int* numFace
 
 #include "SkTSearch.h"
 bool SkTypeface_FreeType::Scanner::scanFont(
-    SkStream* stream, int ttcIndex, SkString* name, SkFontStyle* style, bool* isFixedPitch) const
+    SkStream* stream, int ttcIndex,
+    SkString* name, SkFontStyle* style, bool* isFixedPitch, AxisDefinitions* axes) const
 {
     SkAutoMutexAcquire libraryLock(fLibraryMutex);
 
@@ -1725,6 +1761,26 @@ bool SkTypeface_FreeType::Scanner::scanFont(
         *isFixedPitch = FT_IS_FIXED_WIDTH(face);
     }
 
+    if (axes && face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS) {
+        FT_MM_Var* variations = NULL;
+        FT_Error err = FT_Get_MM_Var(face, &variations);
+        if (err) {
+            SkDEBUGF(("INFO: font %s claims to have variations, but none found.\n",
+                      face->family_name));
+            return false;
+        }
+        SkAutoFree autoFreeVariations(variations);
+
+        axes->reset(variations->num_axis);
+        for (FT_UInt i = 0; i < variations->num_axis; ++i) {
+            const FT_Var_Axis& ftAxis = variations->axis[i];
+            (*axes)[i].fTag = ftAxis.tag;
+            (*axes)[i].fMinimum = ftAxis.minimum;
+            (*axes)[i].fDefault = ftAxis.def;
+            (*axes)[i].fMaximum = ftAxis.maximum;
+        }
+    }
+
     FT_Done_Face(face);
     return true;
 }