Render font variants (ligatures, postions, caps, numerics).

Requires Pango 1.37.1.

(bzr r14206)

3 files changed, 83 insertions, 0 deletions

diff --git a/src/libnrtype/Layout-TNG-Compute.cpp b/src/libnrtype/Layout-TNG-Compute.cpp
index beff3734b..8c12f235c 100644
--- a/src/libnrtype/Layout-TNG-Compute.cpp
+++ b/src/libnrtype/Layout-TNG-Compute.cpp
@@ -958,6 +958,10 @@ void Layout::Calculator::ParagraphInfo::free()
  */
 void  Layout::Calculator::_buildPangoItemizationForPara(ParagraphInfo *para) const
 {
+    TRACE(("pango version string: %s\n", pango_version_string() ));
+#if PANGO_VERSION_CHECK(1,37,1)
+    TRACE((" ... compiled for font features\n"));
+#endif
     Glib::ustring para_text;
     PangoAttrList *attributes_list;
     unsigned input_index;
@@ -986,9 +990,22 @@ void  Layout::Calculator::_buildPangoItemizationForPara(ParagraphInfo *para) con
 
             PangoAttribute *attribute_font_description = pango_attr_font_desc_new(font->descr);
             attribute_font_description->start_index = para_text.bytes();
+
+#if PANGO_VERSION_CHECK(1,37,1)
+            PangoAttribute *attribute_font_features =
+                pango_attr_font_features_new( text_source->style->getFontFeatureString().c_str());
+//                pango_attr_font_features_new( "hlig 1, dlig 1");
+            attribute_font_features->start_index = para_text.bytes();
+#endif
             para_text.append(&*text_source->text_begin.base(), text_source->text_length);     // build the combined text
             attribute_font_description->end_index = para_text.bytes();
             pango_attr_list_insert(attributes_list, attribute_font_description);
+
+#if PANGO_VERSION_CHECK(1,37,1)
+            attribute_font_features->end_index = para_text.bytes();
+            pango_attr_list_insert(attributes_list, attribute_font_features);
+#endif
+
             // ownership of attribute is assumed by the list
             font->Unref();
         }
diff --git a/src/style.cpp b/src/style.cpp
index 1668646b6..e7316525b 100644
--- a/src/style.cpp
+++ b/src/style.cpp
@@ -1190,6 +1190,66 @@ SPStyle::_mergeObjectStylesheet( SPObject const *const object ) {
     }
 }
 
+std::string
+SPStyle::getFontFeatureString() {
+
+    std::string feature_string;
+
+    if ( font_variant_ligatures.value & SP_CSS_FONT_VARIANT_LIGATURES_COMMON )
+        feature_string += "liga, clig, ";
+    else
+        feature_string += "liga 0, clig 0, ";
+    if (   font_variant_ligatures.value & SP_CSS_FONT_VARIANT_LIGATURES_DISCRETIONARY )
+        feature_string += "dlig, ";
+    if (   font_variant_ligatures.value & SP_CSS_FONT_VARIANT_LIGATURES_HISTORICAL )
+        feature_string += "hlig, ";
+    if ( font_variant_ligatures.value & SP_CSS_FONT_VARIANT_LIGATURES_CONTEXTUAL )
+        feature_string += "calt, ";
+    else
+        feature_string += "calt 0, ";
+
+    if ( font_variant_position.value & SP_CSS_FONT_VARIANT_POSITION_SUB )
+        feature_string += "subs, ";
+    if ( font_variant_position.value & SP_CSS_FONT_VARIANT_POSITION_SUPER )
+        feature_string += "sups, ";
+
+    if ( font_variant_caps.value & SP_CSS_FONT_VARIANT_CAPS_SMALL )
+        feature_string += "smcp, ";
+    if ( font_variant_caps.value & SP_CSS_FONT_VARIANT_CAPS_ALL_SMALL )
+        feature_string += "smcp, c2sc, ";
+    if ( font_variant_caps.value & SP_CSS_FONT_VARIANT_CAPS_PETITE )
+        feature_string += "pcap, ";
+    if ( font_variant_caps.value & SP_CSS_FONT_VARIANT_CAPS_ALL_PETITE )
+        feature_string += "pcap, c2pc, ";
+    if ( font_variant_caps.value & SP_CSS_FONT_VARIANT_CAPS_UNICASE )
+        feature_string += "unic, ";
+    if ( font_variant_caps.value & SP_CSS_FONT_VARIANT_CAPS_TITLING )
+        feature_string += "titl, ";
+
+    if ( font_variant_numeric.value & SP_CSS_FONT_VARIANT_NUMERIC_LINING_NUMS )
+        feature_string += "lnum, ";
+    if ( font_variant_numeric.value & SP_CSS_FONT_VARIANT_NUMERIC_OLDSTYLE_NUMS )
+        feature_string += "onum, ";
+    if ( font_variant_numeric.value & SP_CSS_FONT_VARIANT_NUMERIC_PROPORTIONAL_NUMS )
+        feature_string += "pnum, ";
+    if ( font_variant_numeric.value & SP_CSS_FONT_VARIANT_NUMERIC_TABULAR_NUMS )
+        feature_string += "tnum, ";
+    if ( font_variant_numeric.value & SP_CSS_FONT_VARIANT_NUMERIC_DIAGONAL_FRACTIONS )
+        feature_string += "frac, ";
+    if ( font_variant_numeric.value & SP_CSS_FONT_VARIANT_NUMERIC_STACKED_FRACTIONS )
+        feature_string += "afrc, ";
+    if ( font_variant_numeric.value & SP_CSS_FONT_VARIANT_NUMERIC_ORDINAL )
+        feature_string += "ordn, ";
+    if ( font_variant_numeric.value & SP_CSS_FONT_VARIANT_NUMERIC_SLASHED_ZERO )
+        feature_string += "zero, ";
+
+    feature_string.erase( feature_string.size() - 1 );
+    feature_string.erase( feature_string.size() - 1 );
+
+    return feature_string;
+}
+
+
 // Internal
 /**
  * Release callback.
diff --git a/src/style.h b/src/style.h
index 8e22b3121..02432d3e7 100644
--- a/src/style.h
+++ b/src/style.h
@@ -303,6 +303,12 @@ public:
     SPPaintServer       *getStrokePaintServer()       { return (stroke.value.href) ? stroke.value.href->getObject() : NULL; }
     SPPaintServer const *getStrokePaintServer() const { return (stroke.value.href) ? stroke.value.href->getObject() : NULL; }
     char        const  *getStrokeURI()         const { return (stroke.value.href) ? stroke.value.href->getURI()->toString() : NULL; }
+
+    /**
+     * Return a font feature string useful for Pango.
+     */
+    std::string getFontFeatureString();
+
 };
 
 SPStyle *sp_style_ref(SPStyle *style); // SPStyle::ref();