Move OpenType functions to separate file.

4 files changed, 255 insertions, 174 deletions

diff --git a/src/libnrtype/CMakeLists.txt b/src/libnrtype/CMakeLists.txt
index c39eecbbc..3061e9304 100644
--- a/src/libnrtype/CMakeLists.txt
+++ b/src/libnrtype/CMakeLists.txt
@@ -9,6 +9,7 @@ set(nrtype_SRC
 	Layout-TNG-OutIter.cpp
 	Layout-TNG-Output.cpp
 	Layout-TNG-Scanline-Makers.cpp
+        OpenTypeUtil.cpp
 
 	# -------
 	# Headers
@@ -19,6 +20,7 @@ set(nrtype_SRC
 	FontFactory.h
 	Layout-TNG-Scanline-Maker.h
 	Layout-TNG.h
+        OpenTypeUtil.cpp
 )
 
 add_inkscape_lib(nrtype_LIB "${nrtype_SRC}")
diff --git a/src/libnrtype/FontFactory.cpp b/src/libnrtype/FontFactory.cpp
index 9b39f9e9b..d17a8a310 100644
--- a/src/libnrtype/FontFactory.cpp
+++ b/src/libnrtype/FontFactory.cpp
@@ -17,18 +17,19 @@
 #endif
 
 #include <glibmm/i18n.h>
+
 #include <fontconfig/fontconfig.h>
+
 #include <pango/pangofc-fontmap.h>
 #include <pango/pangoft2.h>
 #include <pango/pango-ot.h>
+
 #include "io/sys.h"
-#include "libnrtype/FontFactory.h"
-#include "libnrtype/font-instance.h"
 #include "util/unordered-containers.h"
-#include <map>
 
-#include <harfbuzz/hb-ft.h>
-#include <harfbuzz/hb-ot.h>
+#include "libnrtype/FontFactory.h"
+#include "libnrtype/font-instance.h"
+#include "libnrtype/OpenTypeUtil.h"
 
 typedef INK_UNORDERED_MAP<PangoFontDescription*, font_instance*, font_descr_hash, font_descr_equal> FaceMapType;
 
@@ -472,6 +473,7 @@ GList* font_factory::GetUIStyles(PangoFontFamily * in)
         std::cerr << "font_factory::GetUIStyles(): PangoFontFamily is NULL" << std::endl;
         return ret;
     }
+
     pango_font_family_list_faces(in, &faces, &numFaces);
 
     for (int currentFace = 0; currentFace < numFaces; currentFace++) {
@@ -490,6 +492,7 @@ GList* font_factory::GetUIStyles(PangoFontFamily * in)
             Glib::ustring familyUIName = GetUIFamilyString(faceDescr);
             Glib::ustring styleUIName = GetUIStyleString(faceDescr);
             // std::cout << "  " << familyUIName << "  styleUIName: " << styleUIName << "  displayName: " << displayName << std::endl;
+
             // Disable synthesized (faux) font faces except for CSS generic faces
             if (pango_font_face_is_synthesized(faces[currentFace]) ) {
                 if (familyUIName.compare( "sans-serif" ) != 0 &&
@@ -633,174 +636,6 @@ font_instance* font_factory::FaceFromFontSpecification(char const *fontSpecifica
     return font;
 }
 
-void dump_tag( guint32 *tag, Glib::ustring prefix = "", bool lf=true ) {
-    std::cout << prefix
-              << ((char)((*tag & 0xff000000)>>24))
-              << ((char)((*tag & 0x00ff0000)>>16))
-              << ((char)((*tag & 0x0000ff00)>>8))
-              << ((char)((*tag & 0x000000ff)>>0));
-    if( lf ) {
-        std::cout << std::endl;
-    }
-}
-
-Glib::ustring extract_tag( guint32 *tag ) {
-    Glib::ustring tag_name;
-    tag_name += ((char)((*tag & 0xff000000)>>24));
-    tag_name += ((char)((*tag & 0x00ff0000)>>16));
-    tag_name += ((char)((*tag & 0x0000ff00)>>8));
-    tag_name += ((char)((*tag & 0x000000ff)>>0));
-    return tag_name;
-}
-
-// Extract which OpenType tables are in the font. A list of all tables (regardless of which script and langauge
-// they are in) will be stored as a std::map in the openTypeTables field of the font_instance
-// This Harfbuzz code replaces an earlier Pango version as the Pango functions are deprecated.
-void extract_openTypeTables(font_instance *res) {
-    // Empty map... bitmap fonts seem to be loaded multiple times.
-    res->openTypeTables.clear();
-
-#ifndef USE_PANGO_WIN32
-    auto const face = hb_ft_face_create(res->theFace, NULL);
-
-    // First time to get size of array
-    auto script_count = hb_ot_layout_table_get_script_tags(face, HB_OT_TAG_GSUB, 0, NULL, NULL);
-    auto const scripts_hb = g_new(hb_tag_t, script_count + 1);
-
-    // Second time to fill array (this two step process was not necessary with Pango).
-    hb_ot_layout_table_get_script_tags(face, HB_OT_TAG_GSUB, 0, &script_count, scripts_hb);
-
-    for(unsigned int i = 0; i < script_count; ++i) {
-        auto language_count = hb_ot_layout_script_get_language_tags(face, HB_OT_TAG_GSUB, i, 0, NULL, NULL);
-
-        if(language_count > 0) {
-            auto const languages_hb = g_new(hb_tag_t, language_count + 1);
-            hb_ot_layout_script_get_language_tags(face, HB_OT_TAG_GSUB, i, 0, &language_count, languages_hb);
-
-            for(unsigned int j = 0; j < language_count; ++j) {
-                auto feature_count = hb_ot_layout_language_get_feature_tags(face, HB_OT_TAG_GSUB, i, j, 0, NULL, NULL);
-                auto const features_hb = g_new(hb_tag_t, feature_count + 1);
-                hb_ot_layout_language_get_feature_tags(face, HB_OT_TAG_GSUB, i, j, 0, &feature_count, features_hb);
-
-                for(unsigned int k = 0; k < feature_count; ++k) {
-                    ++(res->openTypeTables[ extract_tag(&features_hb[k])]);
-                }
-
-                g_free(features_hb);
-            }
-
-            g_free(languages_hb);
-        }
-        else {
-            // Even if no languages are present there is still the default.
-            auto feature_count = hb_ot_layout_language_get_feature_tags(face, HB_OT_TAG_GSUB, i,
-                                                                        HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
-                                                                        0, NULL, NULL);
-            auto const features_hb = g_new(hb_tag_t, feature_count + 1); 
-            hb_ot_layout_language_get_feature_tags(face, HB_OT_TAG_GSUB, i,
-                                                   HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
-                                                   0, &feature_count, features_hb);
-
-            for(unsigned int k = 0; k < feature_count; ++k) {
-                ++(res->openTypeTables[ extract_tag(&features_hb[k])]);
-            }
-
-            g_free(features_hb);
-        }
-    }
-
-// TODO: Ideally, we should use the HB_VERSION_ATLEAST macro here,
-// but this was only released in harfbuzz >= 0.9.30
-// #if HB_VERSION_ATLEAST(1,2,3)
-#if HB_VERSION_MAJOR*10000 + HB_VERSION_MINOR*100 + HB_VERSION_MICRO >= 10203
-    // Find glyphs in OpenType substitution tables ('gsub').
-    // Note that pango's functions are just dummies. Must use harfbuzz.
-
-    // Loop over all tables
-    for (auto table: res->openTypeTables) {
-
-        // Only look at style substitution tables ('salt', 'ss01', etc. but not 'ssty').
-        if (table.first == "salt" ||
-            (table.first[0] == 's' && table.first[1] == 's' && !(table.first[2] == 't') ) ) {
-            // std::cout << " Table: " << table.first << std::endl;
-
-            Glib::ustring unicode_characters;
-
-            unsigned int feature_index;
-            if (  hb_ot_layout_language_find_feature (face, HB_OT_TAG_GSUB,
-                                                      0,  // Assume one script exists with index 0
-                                                      HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
-                                                      HB_TAG(table.first[0],
-                                                             table.first[1],
-                                                             table.first[2],
-                                                             table.first[3]),
-                                                      &feature_index ) ) {
-
-                // std::cout << "  Found feature, number: " << feature_index << std::endl;
-                unsigned int lookup_indexes[32]; 
-                unsigned int lookup_count = 32;
-                int count = hb_ot_layout_feature_get_lookups (face, HB_OT_TAG_GSUB,
-                                                              feature_index,
-                                                              0, // Start
-                                                              &lookup_count,
-                                                              lookup_indexes );
-                // std::cout << "  Lookup count: " << count << " total: " << lookup_count << std::endl;
-
-                if (count > 0) {
-                    hb_set_t* glyphs_before = NULL; // hb_set_create();
-                    hb_set_t* glyphs_input  = hb_set_create();
-                    hb_set_t* glyphs_after  = NULL; // hb_set_create();
-                    hb_set_t* glyphs_output = NULL; // hb_set_create();
-
-                    // For now, just look at first index
-                    hb_ot_layout_lookup_collect_glyphs (face, HB_OT_TAG_GSUB,
-                                                        lookup_indexes[0],
-                                                        glyphs_before,
-                                                        glyphs_input,
-                                                        glyphs_after,
-                                                        glyphs_output );
-
-                    hb_font_t *font = hb_font_create (face);
-
-                    // Without this, all functions return 0, etc.
-                    hb_ft_font_set_funcs (font);
-
-                    hb_codepoint_t codepoint = -1;
-                    while (hb_set_next (glyphs_input, &codepoint)) {
-
-                        // There is a unicode to glyph mapping function but not the inverse!
-                        for (hb_codepoint_t unicode_i = 0; unicode_i < 0xffff; ++unicode_i) {
-                            hb_codepoint_t glyph = 0;
-                            hb_font_get_nominal_glyph (font, unicode_i, &glyph);
-                            if ( glyph == codepoint) {
-                                unicode_characters += (gunichar)unicode_i;
-                                continue;
-                            }
-                        }
-                    }
-                    res->openTypeSubstitutions[table.first] = unicode_characters;
-
-                    hb_set_destroy (glyphs_input);
-                    hb_font_destroy (font);
-                }
-            } else {
-                // std::cout << "  Did not find '" << table.first << "'!" << std::endl;
-            }
-        }
-    }
-    // for (auto table: res->openTypeSubstitutions) {
-    //     std::cout << table.first << ": " << table.second << std::endl;
-    // }
-#else
-    std::cerr << "Requires Harfbuzz 1.2.3 for visualizing alternative glyph OpenType tables. "
-              << "Compiled with: " << HB_VERSION_STRING << "." << std::endl;
-#endif
-
-    hb_face_destroy (face);
-    g_free(scripts_hb);
-#endif // USE_PANGO_WIN32
-}
-
 font_instance *font_factory::Face(PangoFontDescription *descr, bool canFail)
 {
 #ifdef USE_PANGO_WIN32
@@ -869,8 +704,9 @@ font_instance *font_factory::Face(PangoFontDescription *descr, bool canFail)
         }
 
         if (res) {
-            extract_openTypeTables(res);
+            readOpenTypeGsubTable( res->theFace, res->openTypeTables, res->openTypeSubstitutions );
         }
+
     } else {
         // already here
         res = loadedFaces[descr];
diff --git a/src/libnrtype/OpenTypeUtil.cpp b/src/libnrtype/OpenTypeUtil.cpp
new file mode 100644
index 000000000..d1d1dea82
--- /dev/null
+++ b/src/libnrtype/OpenTypeUtil.cpp
@@ -0,0 +1,207 @@
+
+#include "OpenTypeUtil.h"
+
+#include <iostream>  // For debugging
+
+// FreeType
+#include FT_FREETYPE_H
+#include FT_MULTIPLE_MASTERS_H
+#include FT_SFNT_NAMES_H
+
+// Harfbuzz
+#include <harfbuzz/hb-ft.h>
+#include <harfbuzz/hb-ot.h>
+
+
+// Utilities used in this file
+
+void dump_tag( guint32 *tag, Glib::ustring prefix = "", bool lf=true ) {
+    std::cout << prefix
+              << ((char)((*tag & 0xff000000)>>24))
+              << ((char)((*tag & 0x00ff0000)>>16))
+              << ((char)((*tag & 0x0000ff00)>> 8))
+              << ((char)((*tag & 0x000000ff)    ));
+    if( lf ) {
+        std::cout << std::endl;
+    }
+}
+
+Glib::ustring extract_tag( guint32 *tag ) {
+    Glib::ustring tag_name;
+    tag_name += ((char)((*tag & 0xff000000)>>24));
+    tag_name += ((char)((*tag & 0x00ff0000)>>16));
+    tag_name += ((char)((*tag & 0x0000ff00)>> 8));
+    tag_name += ((char)((*tag & 0x000000ff)    ));
+    return tag_name;
+}
+
+inline double FTFixedToDouble (FT_Fixed value) {
+    return static_cast<FT_Int32>(value) / 65536.0;
+}
+
+inline FT_Fixed FTDoubleToFixed (double value) {
+    return static_cast<FT_Fixed>(value * 65536);
+}
+
+
+// Make a list of all tables fount in the GSUB
+// This list includes all tables regardless of script or language.
+void readOpenTypeGsubTable (const FT_Face ft_face,
+                            std::map<Glib::ustring, int>& tables,
+                            std::map<Glib::ustring, Glib::ustring>& substitutions) {
+
+    tables.clear();
+    substitutions.clear();
+
+    // Use Harfbuzz, Pango's equivalent calls are deprecated.
+    auto const hb_face = hb_ft_face_create(ft_face, NULL);
+
+    // First time to get size of array
+    auto script_count = hb_ot_layout_table_get_script_tags(hb_face, HB_OT_TAG_GSUB, 0, NULL, NULL);
+    auto const hb_scripts = g_new(hb_tag_t, script_count + 1);
+
+    // Second time to fill array (this two step process was not necessary with Pango).
+    hb_ot_layout_table_get_script_tags(hb_face, HB_OT_TAG_GSUB, 0, &script_count, hb_scripts);
+
+    for(unsigned int i = 0; i < script_count; ++i) {
+        auto language_count = hb_ot_layout_script_get_language_tags(hb_face, HB_OT_TAG_GSUB, i, 0, NULL, NULL);
+
+        if(language_count > 0) {
+            auto const hb_languages = g_new(hb_tag_t, language_count + 1);
+            hb_ot_layout_script_get_language_tags(hb_face, HB_OT_TAG_GSUB, i, 0, &language_count, hb_languages);
+
+            for(unsigned int j = 0; j < language_count; ++j) {
+                auto feature_count = hb_ot_layout_language_get_feature_tags(hb_face, HB_OT_TAG_GSUB, i, j, 0, NULL, NULL);
+                auto const hb_features = g_new(hb_tag_t, feature_count + 1);
+                hb_ot_layout_language_get_feature_tags(hb_face, HB_OT_TAG_GSUB, i, j, 0, &feature_count, hb_features);
+
+                for(unsigned int k = 0; k < feature_count; ++k) {
+                    ++(tables[ extract_tag(&hb_features[k])]);
+                }
+
+                g_free(hb_features);
+            }
+
+            g_free(hb_languages);
+
+        } else {
+
+            // Even if no languages are present there is still the default.
+            auto feature_count = hb_ot_layout_language_get_feature_tags(hb_face, HB_OT_TAG_GSUB, i,
+                                                                        HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
+                                                                        0, NULL, NULL);
+            auto const hb_features = g_new(hb_tag_t, feature_count + 1); 
+            hb_ot_layout_language_get_feature_tags(hb_face, HB_OT_TAG_GSUB, i,
+                                                   HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
+                                                   0, &feature_count, hb_features);
+
+            for(unsigned int k = 0; k < feature_count; ++k) {
+                ++(tables[ extract_tag(&hb_features[k])]);
+            }
+
+            g_free(hb_features);
+        }
+    }
+
+// TODO: Ideally, we should use the HB_VERSION_ATLEAST macro here,
+// but this was only released in harfbuzz >= 0.9.30
+// #if HB_VERSION_ATLEAST(1,2,3)
+#if HB_VERSION_MAJOR*10000 + HB_VERSION_MINOR*100 + HB_VERSION_MICRO >= 10203
+    // Find glyphs in OpenType substitution tables ('gsub').
+    // Note that pango's functions are just dummies. Must use harfbuzz.
+
+    // Loop over all tables
+    for (auto table: tables) {
+
+        // Only look at style substitution tables ('salt', 'ss01', etc. but not 'ssty').
+        if (table.first == "salt" ||
+            (table.first[0] == 's' && table.first[1] == 's' && !(table.first[2] == 't') ) ) {
+            // std::cout << " Table: " << table.first << std::endl;
+
+            Glib::ustring unicode_characters;
+
+            unsigned int feature_index;
+            if (  hb_ot_layout_language_find_feature (hb_face, HB_OT_TAG_GSUB,
+                                                      0,  // Assume one script exists with index 0
+                                                      HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
+                                                      HB_TAG(table.first[0],
+                                                             table.first[1],
+                                                             table.first[2],
+                                                             table.first[3]),
+                                                      &feature_index ) ) {
+
+                // std::cout << "  Found feature, number: " << feature_index << std::endl;
+                unsigned int lookup_indexes[32]; 
+                unsigned int lookup_count = 32;
+                int count = hb_ot_layout_feature_get_lookups (hb_face, HB_OT_TAG_GSUB,
+                                                              feature_index,
+                                                              0, // Start
+                                                              &lookup_count,
+                                                              lookup_indexes );
+                // std::cout << "  Lookup count: " << count << " total: " << lookup_count << std::endl;
+
+                if (count > 0) {
+                    hb_set_t* glyphs_before = NULL; // hb_set_create();
+                    hb_set_t* glyphs_input  = hb_set_create();
+                    hb_set_t* glyphs_after  = NULL; // hb_set_create();
+                    hb_set_t* glyphs_output = NULL; // hb_set_create();
+
+                    // For now, just look at first index
+                    hb_ot_layout_lookup_collect_glyphs (hb_face, HB_OT_TAG_GSUB,
+                                                        lookup_indexes[0],
+                                                        glyphs_before,
+                                                        glyphs_input,
+                                                        glyphs_after,
+                                                        glyphs_output );
+
+                    hb_font_t *hb_font = hb_font_create (hb_face);
+
+                    // Without this, all functions return 0, etc.
+                    hb_ft_font_set_funcs (hb_font);
+
+                    hb_codepoint_t codepoint = -1;
+                    while (hb_set_next (glyphs_input, &codepoint)) {
+
+                        // There is a unicode to glyph mapping function but not the inverse!
+                        for (hb_codepoint_t unicode_i = 0; unicode_i < 0xffff; ++unicode_i) {
+                            hb_codepoint_t glyph = 0;
+                            hb_font_get_nominal_glyph (hb_font, unicode_i, &glyph);
+                            if ( glyph == codepoint) {
+                                unicode_characters += (gunichar)unicode_i;
+                                continue;
+                            }
+                        }
+                    }
+                    substitutions[table.first] = unicode_characters;
+
+                    hb_set_destroy (glyphs_input);
+                    hb_font_destroy (hb_font);
+                }
+            } else {
+                // std::cout << "  Did not find '" << table.first << "'!" << std::endl;
+            }
+        }
+    }
+    // for (auto table: res->openTypeSubstitutions) {
+    //     std::cout << table.first << ": " << table.second << std::endl;
+    // }
+#else
+    std::cerr << "Requires Harfbuzz 1.2.3 for visualizing alternative glyph OpenType tables. "
+              << "Compiled with: " << HB_VERSION_STRING << "." << std::endl;
+#endif
+
+    g_free(hb_scripts);
+    hb_face_destroy (hb_face);
+}
+
+  
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/libnrtype/OpenTypeUtil.h b/src/libnrtype/OpenTypeUtil.h
new file mode 100644
index 000000000..6d9ac9b3b
--- /dev/null
+++ b/src/libnrtype/OpenTypeUtil.h
@@ -0,0 +1,36 @@
+
+#ifndef SEEN_OPENTYPEUTIL_H
+#define SEEN_OPENTYPEUTIL_H
+
+#include <map>
+
+#include <ft2build.h>
+#include FT_FREETYPE_H
+
+#include <glibmm/ustring.h>
+
+/*
+ * A set of utilities to extract data from OpenType fonts.
+ *
+ * Isolates dependencies on FreeType, Harfbuzz, and Pango.
+ * All three provide variable amounts of access to data.
+ */
+
+
+void readOpenTypeGsubTable (const FT_Face ft_face,
+                            std::map<Glib::ustring, int>& tables,
+                            std::map<Glib::ustring, Glib::ustring>& substitutions);
+
+
+#endif /* !SEEN_OPENTYPEUTIL_H */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :