summaryrefslogtreecommitdiffstats
path: root/src/libnrtype/OpenTypeUtil.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/libnrtype/OpenTypeUtil.cpp')
-rw-r--r--src/libnrtype/OpenTypeUtil.cpp434
1 files changed, 434 insertions, 0 deletions
diff --git a/src/libnrtype/OpenTypeUtil.cpp b/src/libnrtype/OpenTypeUtil.cpp
new file mode 100644
index 0000000..a456626
--- /dev/null
+++ b/src/libnrtype/OpenTypeUtil.cpp
@@ -0,0 +1,434 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef USE_PANGO_WIN32
+
+#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>
+
+// SVG in OpenType
+#include "util/ziptool.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;
+}
+
+
+// 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
+void get_glyphs( hb_font_t* font, hb_set_t* set, Glib::ustring& characters) {
+
+ // There is a unicode to glyph mapping function but not the inverse!
+ hb_codepoint_t codepoint = -1;
+ while (hb_set_next (set, &codepoint)) {
+ 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) {
+ characters += (gunichar)unicode_i;
+ continue;
+ }
+ }
+ }
+}
+#endif
+
+// Make a list of all tables found in the GSUB
+// This list includes all tables regardless of script or language.
+void readOpenTypeGsubTable (const FT_Face ft_face,
+ std::map<Glib::ustring, OTSubstitution>& tables
+ ) {
+
+ // std::cout << "readOpenTypeGsubTable: Entrance: "
+ // << (ft_face->family_name?ft_face->family_name:"null") << std::endl;
+ tables.clear();
+
+ // Use Harfbuzz, Pango's equivalent calls are deprecated.
+ auto const hb_face = hb_ft_face_create(ft_face, nullptr);
+
+ // First time to get size of array
+ auto script_count = hb_ot_layout_table_get_script_tags(hb_face, HB_OT_TAG_GSUB, 0, nullptr, nullptr);
+ 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) {
+ // std::cout << " Script: " << extract_tag(&hb_scripts[i]) << std::endl;
+ auto language_count = hb_ot_layout_script_get_language_tags(hb_face, HB_OT_TAG_GSUB, i, 0, nullptr, nullptr);
+
+ 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) {
+ // std::cout << " Language: " << extract_tag(&hb_languages[j]) << std::endl;
+ auto feature_count = hb_ot_layout_language_get_feature_tags(hb_face, HB_OT_TAG_GSUB, i, j, 0, nullptr, nullptr);
+ 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) {
+ // std::cout << " Feature: " << extract_tag(&hb_features[k]) << std::endl;
+ 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.
+ // std::cout << " Language: " << " (dflt)" << std::endl;
+ auto feature_count = hb_ot_layout_language_get_feature_tags(hb_face, HB_OT_TAG_GSUB, i,
+ HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
+ 0, nullptr, nullptr);
+ 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) {
+ // std::cout << " Feature: " << extract_tag(&hb_features[k]) << std::endl;
+ 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').
+ // Also look at character substitution tables ('cv01', etc.).
+ bool style =
+ table.first == "case" /* Case-Sensitive Forms */ ||
+ table.first == "salt" /* Stylistic Alternatives */ ||
+ table.first == "swsh" /* Swash */ ||
+ table.first == "cwsh" /* Contextual Swash */ ||
+ table.first == "ornm" /* Ornaments */ ||
+ table.first == "nalt" /* Alternative Annotation */ ||
+ table.first == "hist" /* Historical Forms */ ||
+ (table.first[0] == 's' && table.first[1] == 's' && !(table.first[2] == 't')) ||
+ (table.first[0] == 'c' && table.first[1] == 'v');
+
+ bool ligature = ( table.first == "liga" || // Standard ligatures
+ table.first == "clig" || // Common ligatures
+ table.first == "dlig" || // Discretionary ligatures
+ table.first == "hlig" || // Historical ligatures
+ table.first == "calt" ); // Contextual alternatives
+
+ bool numeric = ( table.first == "lnum" || // Lining numerals
+ table.first == "onum" || // Old style
+ table.first == "pnum" || // Proportional
+ table.first == "tnum" || // Tabular
+ table.first == "frac" || // Diagonal fractions
+ table.first == "afrc" || // Stacked fractions
+ table.first == "ordn" || // Ordinal fractions
+ table.first == "zero" ); // Slashed zero
+
+ if (style || ligature || numeric) {
+
+ 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 << "Table: " << table.first << std::endl;
+ // 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;
+
+ hb_font_t *hb_font = hb_font_create (hb_face); // MOVE THIS OUT OF LOOPS?
+
+ for (int i = 0; i < count; ++i) {
+ hb_set_t* glyphs_before = hb_set_create();
+ hb_set_t* glyphs_input = hb_set_create();
+ hb_set_t* glyphs_after = hb_set_create();
+ hb_set_t* glyphs_output = hb_set_create();
+
+ hb_ot_layout_lookup_collect_glyphs (hb_face, HB_OT_TAG_GSUB,
+ lookup_indexes[i],
+ glyphs_before,
+ glyphs_input,
+ glyphs_after,
+ glyphs_output );
+
+ // std::cout << " Populations: "
+ // << " " << hb_set_get_population (glyphs_before)
+ // << " " << hb_set_get_population (glyphs_input)
+ // << " " << hb_set_get_population (glyphs_after)
+ // << " " << hb_set_get_population (glyphs_output)
+ // << std::endl;
+
+ // Without this, all functions return 0, etc.
+ hb_ft_font_set_funcs (hb_font);
+
+ get_glyphs (hb_font, glyphs_before, tables[table.first].before);
+ get_glyphs (hb_font, glyphs_input, tables[table.first].input );
+ get_glyphs (hb_font, glyphs_after, tables[table.first].after );
+ get_glyphs (hb_font, glyphs_output, tables[table.first].output);
+
+ // std::cout << " Before: " << tables[table.first].before.c_str() << std::endl;
+ // std::cout << " Input: " << tables[table.first].input.c_str() << std::endl;
+ // std::cout << " After: " << tables[table.first].after.c_str() << std::endl;
+ // std::cout << " Output: " << tables[table.first].output.c_str() << std::endl;
+
+ hb_set_destroy (glyphs_before);
+ hb_set_destroy (glyphs_input);
+ hb_set_destroy (glyphs_after);
+ hb_set_destroy (glyphs_output);
+
+ } // End count (lookups)
+
+ hb_font_destroy (hb_font);
+
+ } else {
+ // std::cout << " Did not find '" << table.first << "'!" << 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);
+}
+
+// Harfbuzz now as API for variations (Version 2.2, Nov 29 2018).
+// Make a list of all Variation axes with ranges.
+void readOpenTypeFvarAxes(const FT_Face ft_face,
+ std::map<Glib::ustring, OTVarAxis>& axes) {
+
+#if FREETYPE_MAJOR *10000 + FREETYPE_MINOR*100 + FREETYPE_MICRO >= 20701
+ FT_MM_Var* mmvar = nullptr;
+ FT_Multi_Master mmtype;
+ if (FT_HAS_MULTIPLE_MASTERS( ft_face ) && // Font has variables
+ FT_Get_MM_Var( ft_face, &mmvar) == 0 && // We found the data
+ FT_Get_Multi_Master( ft_face, &mmtype) !=0) { // It's not an Adobe MM font
+
+ FT_Fixed coords[mmvar->num_axis];
+ FT_Get_Var_Design_Coordinates( ft_face, mmvar->num_axis, coords );
+
+ for (size_t i = 0; i < mmvar->num_axis; ++i) {
+ FT_Var_Axis* axis = &mmvar->axis[i];
+ axes[axis->name] = OTVarAxis(FTFixedToDouble(axis->minimum),
+ FTFixedToDouble(axis->maximum),
+ FTFixedToDouble(coords[i]),
+ i);
+ }
+
+ // for (auto a: axes) {
+ // std::cout << " " << a.first
+ // << " min: " << a.second.minimum
+ // << " max: " << a.second.maximum
+ // << " set: " << a.second.set_val << std::endl;
+ // }
+
+ }
+
+#endif /* FREETYPE Version */
+}
+
+
+// Harfbuzz now as API for named variations (Version 2.2, Nov 29 2018).
+// Make a list of all Named instances with axis values.
+void readOpenTypeFvarNamed(const FT_Face ft_face,
+ std::map<Glib::ustring, OTVarInstance>& named) {
+
+#if FREETYPE_MAJOR *10000 + FREETYPE_MINOR*100 + FREETYPE_MICRO >= 20701
+ FT_MM_Var* mmvar = nullptr;
+ FT_Multi_Master mmtype;
+ if (FT_HAS_MULTIPLE_MASTERS( ft_face ) && // Font has variables
+ FT_Get_MM_Var( ft_face, &mmvar) == 0 && // We found the data
+ FT_Get_Multi_Master( ft_face, &mmtype) !=0) { // It's not an Adobe MM font
+
+ std::cout << " Multiple Masters: variables: " << mmvar->num_axis
+ << " named styles: " << mmvar->num_namedstyles << std::endl;
+
+ // const FT_UInt numNames = FT_Get_Sfnt_Name_Count(ft_face);
+ // std::cout << " number of names: " << numNames << std::endl;
+ // FT_SfntName ft_name;
+ // for (FT_UInt i = 0; i < numNames; ++i) {
+
+ // if (FT_Get_Sfnt_Name(ft_face, i, &ft_name) != 0) {
+ // continue;
+ // }
+
+ // Glib::ustring name;
+ // for (size_t j = 0; j < ft_name.string_len; ++j) {
+ // name += (char)ft_name.string[j];
+ // }
+ // std::cout << " " << i << ": " << name << std::endl;
+ // }
+
+ }
+
+#endif /* FREETYPE Version */
+}
+
+#define HB_OT_TAG_SVG HB_TAG('S','V','G',' ')
+
+// Get SVG glyphs out of an OpenType font.
+void readOpenTypeSVGTable(const FT_Face ft_face,
+ std::map<int, SVGTableEntry>& glyphs) {
+
+ // Harfbuzz has some support for SVG fonts but it is not exposed until version 2.1 (Oct 30, 2018).
+ // We do it the hard way!
+ hb_face_t *hb_face = hb_ft_face_create_cached (ft_face);
+ hb_blob_t *hb_blob = hb_face_reference_table (hb_face, HB_OT_TAG_SVG);
+
+ if (!hb_blob) {
+ // No SVG table in font!
+ return;
+ }
+
+ unsigned int svg_length = hb_blob_get_length (hb_blob);
+ if (svg_length == 0) {
+ // No SVG glyphs in table!
+ return;
+ }
+
+ const char* data = hb_blob_get_data(hb_blob, &svg_length);
+ if (!data) {
+ std::cerr << "readOpenTypeSVGTable: Failed to get data! "
+ << (ft_face->family_name?ft_face->family_name:"Unknown family") << std::endl;
+ return;
+ }
+
+ // OpenType fonts use Big Endian
+#if 0
+ uint16_t version = ((data[0] & 0xff) << 8) + (data[1] & 0xff);
+ // std::cout << "Version: " << version << std::endl;
+#endif
+ uint32_t offset = ((data[2] & 0xff) << 24) + ((data[3] & 0xff) << 16) + ((data[4] & 0xff) << 8) + (data[5] & 0xff);
+
+ // std::cout << "Offset: " << offset << std::endl;
+ // Bytes 6-9 are reserved.
+
+ uint16_t entries = ((data[offset] & 0xff) << 8) + (data[offset+1] & 0xff);
+ // std::cout << "Number of entries: " << entries << std::endl;
+
+ for (int entry = 0; entry < entries; ++entry) {
+ uint32_t base = offset + 2 + entry * 12;
+
+ uint16_t startGlyphID = ((data[base ] & 0xff) << 8) + (data[base+1] & 0xff);
+ uint16_t endGlyphID = ((data[base+2] & 0xff) << 8) + (data[base+3] & 0xff);
+ uint32_t offsetGlyph = ((data[base+4] & 0xff) << 24) + ((data[base+5] & 0xff) << 16) +((data[base+6] & 0xff) << 8) + (data[base+7] & 0xff);
+ uint32_t lengthGlyph = ((data[base+8] & 0xff) << 24) + ((data[base+9] & 0xff) << 16) +((data[base+10] & 0xff) << 8) + (data[base+11] & 0xff);
+
+ // std::cout << "Entry " << entry << ": Start: " << startGlyphID << " End: " << endGlyphID
+ // << " Offset: " << offsetGlyph << " Length: " << lengthGlyph << std::endl;
+
+ std::string svg;
+
+ // static cast is needed as hb_blob_get_length returns char but we are comparing to a value greater than allowed by char.
+ if (lengthGlyph > 1 && data[offsetGlyph] == 0x1f && static_cast<unsigned char>(data[offsetGlyph + 1]) == 0x8b) {
+ // Glyph is gzipped
+
+ std::vector<unsigned char> buffer;
+ for (unsigned int c = offsetGlyph; c < offsetGlyph + lengthGlyph; ++c) {
+ buffer.push_back(data[offset + c]);
+ }
+
+ GzipFile zipped;
+ zipped.readBuffer(buffer);
+
+ std::vector<unsigned char> unzipped_data = zipped.getData();
+ for (auto i : unzipped_data) {
+ svg += (char)i;
+ }
+
+ } else {
+ // Glyph is not compressed
+
+ for (unsigned int c = offsetGlyph; c < offsetGlyph + lengthGlyph; ++c) {
+ svg += (unsigned char) data[offset + c];
+ }
+ }
+
+ for (unsigned int i = startGlyphID; i < endGlyphID+1; ++i) {
+ glyphs[i].svg = svg;
+ }
+
+ // for (auto glyph : glyphs) {
+ // std::cout << "Glyph: " << glyph.first << std::endl;
+ // std::cout << glyph.second.svg << std::endl;
+ // }
+ }
+}
+
+#endif /* !USE_PANGO_WIND32 */
+
+/*
+ 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 :
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-03 03:19:20 +0000