Bug fixes for variable fonts, especially to support the Decovar font.

4 files changed, 44 insertions, 58 deletions

diff --git a/src/libnrtype/FontFactory.cpp b/src/libnrtype/FontFactory.cpp
index a354d8915..f09bd3df3 100644
--- a/src/libnrtype/FontFactory.cpp
+++ b/src/libnrtype/FontFactory.cpp
@@ -703,15 +703,6 @@ font_instance *font_factory::Face(PangoFontDescription *descr, bool canFail)
             }
         }
 
-#ifndef USE_PANGO_WIN32
-        if (res) {
-            readOpenTypeGsubTable( res->theFace, res->openTypeTables, res->openTypeStylistic, res->openTypeLigatures );
-            std::map<Glib::ustring, OTVarAxis> axes;
-            std::map<Glib::ustring, OTVarInstance> named;
-            readOpenTypeFvarAxes( res->theFace, res->openTypeVarAxes );
-        }
-#endif
-
     } else {
         // already here
         res = loadedFaces[descr];
diff --git a/src/libnrtype/FontInstance.cpp b/src/libnrtype/FontInstance.cpp
index d55f919f1..47d4baa51 100644
--- a/src/libnrtype/FontInstance.cpp
+++ b/src/libnrtype/FontInstance.cpp
@@ -210,6 +210,10 @@ void font_instance::InitTheFace()
 #endif
 
 #ifndef USE_PANGO_WIN32
+
+        readOpenTypeGsubTable( theFace, openTypeTables, openTypeStylistic, openTypeLigatures );
+        readOpenTypeFvarAxes(  theFace, openTypeVarAxes );
+
 #if PANGO_VERSION_CHECK(1,41,1)
 #if FREETYPE_MAJOR == 2 && FREETYPE_MINOR >= 8  // 2.8 does not seem to work even though it has some support.
 
@@ -217,9 +221,8 @@ void font_instance::InitTheFace()
         //    The font returned from pango_fc_font_lock_face does not include variation settings. We must set them.
 
         // We need to:
-        //   Get a list of axes supported in the font with the range of allowed values.
         //   Extract axes with values from Pango font description.
-        //   Fill an array indexed by FT axis with values from Pango.
+        //   Replace default axis values with extracted values.
 
         char const *var = pango_font_description_get_variations( descr );
         if (var) {
@@ -235,55 +238,44 @@ void font_instance::InitTheFace()
                 // std::cout << "  Multiple Masters: variables: " << mmvar->num_axis
                 //           << "  named styles: " << mmvar->num_namedstyles << std::endl;
 
-                // Get a list of axis and their default values from the font.
-                std::map<Glib::ustring, int> axis_map;
-                std::vector<int> axis_value;
-                for (FT_UInt axisIndex = 0; axisIndex < mmvar->num_axis; ++axisIndex) {
-
-                    const FT_Var_Axis& ftAxis = mmvar->axis[axisIndex];
-                    const FT_Tag axisTag = ftAxis.tag;
-
-                    Glib::ustring axis_name;
-                    axis_name += (char)(axisTag>>24 & 0xff);
-                    axis_name += (char)(axisTag>>16 & 0xff);
-                    axis_name += (char)(axisTag>> 8 & 0xff);
-                    axis_name += (char)(axisTag     & 0xff);
-
-                    axis_map.insert(std::pair<Glib::ustring, int>(axis_name, axisIndex));
-                    axis_value.push_back(static_cast<FT_Int32>(ftAxis.def/65536.0));
-                }
-
                 // Get the required values from Pango Font Description
                 // Need to check format of values from Pango, for the moment accept any format.
                 Glib::RefPtr<Glib::Regex> regex = Glib::Regex::create("(\\w{4})=([-+]?\\d*\\.?\\d+([eE][-+]?\\d+)?)");
                 Glib::MatchInfo matchInfo;
 
+                const FT_UInt num_axis = openTypeVarAxes.size();
+                FT_Fixed w[num_axis];
+                for (int i = 0; i < num_axis; ++i) w[i] = 0;
+
                 std::vector<Glib::ustring> tokens = Glib::Regex::split_simple(",", variations);
                 for (auto token: tokens) {
 
                     regex->match(token, matchInfo);
                     if (matchInfo.matches()) {
+
                         float value = std::stod(matchInfo.fetch(2));  // Should clamp value
 
-                        auto it = axis_map.find(matchInfo.fetch(1));
-                        if (it != axis_map.end()) {
-                            axis_value[it->second] = value;
+                        // Translate the "named" axes.
+                        Glib::ustring name = matchInfo.fetch(1);
+                        if (name == "wdth") name = "Width"       ; // 'font-stretch'
+                        if (name == "wght") name = "Weight"      ; // 'font-weight'
+                        if (name == "opsz") name = "Optical size"; // 'font-optical-sizing'
+                        if (name == "slnt") name = "Slant"       ; // 'font-style'
+                        if (name == "ital") name = "Italic"      ; // 'font-style'
+
+                        auto it = openTypeVarAxes.find(name);
+                        if (it != openTypeVarAxes.end()) {
+                            it->second.set_val = value;
+                            w[it->second.index] = value * 65536;
                         }
                     }
                 }
 
-                // Fill coordinate array
-                const FT_UInt num_axis = axis_map.size();
-                FT_Fixed w[num_axis];
-                for (FT_UInt axisIndex = 0; axisIndex < num_axis; ++axisIndex) {
-                    w[axisIndex] = axis_value[axisIndex] * 65536;
-                }
-
                 // Set design coordinates
                 FT_Error err;
-                err = FT_Set_Var_Design_Coordinates (theFace, 2, w);
+                err = FT_Set_Var_Design_Coordinates (theFace, num_axis, w);
                 if (err) {
-                    std::cout << "font_instance::InitTheFace(): Error in call to FT_Set_Var_Design_Coordinates(): " << err << std::endl;
+                    std::cerr << "font_instance::InitTheFace(): Error in call to FT_Set_Var_Design_Coordinates(): " << err << std::endl;
                 }
 
                 // FT_Done_MM_Var(mmlib, mmvar);
diff --git a/src/libnrtype/OpenTypeUtil.cpp b/src/libnrtype/OpenTypeUtil.cpp
index 5324392d9..a2506e1d7 100644
--- a/src/libnrtype/OpenTypeUtil.cpp
+++ b/src/libnrtype/OpenTypeUtil.cpp
@@ -222,8 +222,7 @@ void readOpenTypeGsubTable (const FT_Face ft_face,
     hb_face_destroy (hb_face);
 }
 
-// Make a list of all Variaration axes with ranges.
-// Make a list of all Named instances with axis values.
+// Make a list of all Variation axes with ranges.
 void readOpenTypeFvarAxes(const FT_Face ft_face,
                           std::map<Glib::ustring, OTVarAxis>& axes) {
 
@@ -241,7 +240,8 @@ void readOpenTypeFvarAxes(const FT_Face ft_face,
             FT_Var_Axis* axis = &mmvar->axis[i];
             axes[axis->name] =  OTVarAxis(FTFixedToDouble(axis->minimum),
                                           FTFixedToDouble(axis->maximum),
-                                          FTFixedToDouble(coords[i]));
+                                          FTFixedToDouble(coords[i]),
+                                          i);
         }
 
         // for (auto a: axes) {
diff --git a/src/libnrtype/OpenTypeUtil.h b/src/libnrtype/OpenTypeUtil.h
index 59ffe0045..48d97b0f7 100644
--- a/src/libnrtype/OpenTypeUtil.h
+++ b/src/libnrtype/OpenTypeUtil.h
@@ -20,20 +20,23 @@
 
 // An OpenType fvar axis.
 class OTVarAxis {
- public:
-  OTVarAxis()
-    : minimum(0)
-    , maximum(1000)
-    , set_val(500) {};
-
-  OTVarAxis(double _minimum, double _maximum, double _set_val)
-    : minimum(_minimum)
-    , maximum(_maximum)
-    , set_val(_set_val) {};
-
-  double minimum;
-  double maximum;
-  double set_val;
+public:
+    OTVarAxis()
+        : minimum(0)
+        , maximum(1000)
+        , set_val(500)
+        , index(-1) {};
+
+    OTVarAxis(double _minimum, double _maximum, double _set_val, int _index)
+        : minimum(_minimum)
+        , maximum(_maximum)
+        , set_val(_set_val)
+        , index  (_index) {};
+
+    double minimum;
+    double maximum;
+    double set_val;
+    int    index;  // Index in OpenType file (since we use a map).
 };
 
 // A particular instance of a variable font.