summaryrefslogtreecommitdiff
path: root/vcl/source/font/FeatureCollector.cxx
blob: 3e8e2e76e8a5682c7e6b0d8b55996b0d4c7ea3e4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#include <font/FeatureCollector.hxx>
#include <font/OpenTypeFeatureDefinitionList.hxx>
#include <i18nlangtag/languagetag.hxx>

#include <font/OpenTypeFeatureStrings.hrc>
#include <svdata.hxx>

#include <hb-ot.h>
#include <hb-graphite2.h>

namespace vcl::font
{
bool FeatureCollector::collectGraphite()
{
    gr_face* grFace = hb_graphite2_face_get_gr_face(m_pHbFace);

    if (grFace == nullptr)
        return false;

    gr_uint16 nUILanguage = gr_uint16(m_rLanguageTag.getLanguageType());

    gr_uint16 nNumberOfFeatures = gr_face_n_fref(grFace);
    gr_feature_val* pfeatureValues
        = gr_face_featureval_for_lang(grFace, 0); // shame we don't know which lang

    for (gr_uint16 i = 0; i < nNumberOfFeatures; ++i)
    {
        const gr_feature_ref* pFeatureRef = gr_face_fref(grFace, i);
        gr_uint32 nFeatureCode = gr_fref_id(pFeatureRef);

        if (nFeatureCode == 0) // illegal feature code - skip
            continue;

        gr_uint16 nValue = gr_fref_feature_value(pFeatureRef, pfeatureValues);
        gr_uint32 nLabelLength = 0;
        void* pLabel = gr_fref_label(pFeatureRef, &nUILanguage, gr_utf8, &nLabelLength);
        OUString sLabel(OUString::createFromAscii(static_cast<char*>(pLabel)));
        gr_label_destroy(pLabel);

        std::vector<vcl::font::FeatureParameter> aParameters;
        gr_uint16 nNumberOfValues = gr_fref_n_values(pFeatureRef);

        if (nNumberOfValues > 0)
        {
            for (gr_uint16 j = 0; j < nNumberOfValues; ++j)
            {
                gr_uint32 nValueLabelLength = 0;
                void* pValueLabel = gr_fref_value_label(pFeatureRef, j, &nUILanguage, gr_utf8,
                                                        &nValueLabelLength);
                OUString sValueLabel(OUString::createFromAscii(static_cast<char*>(pValueLabel)));
                gr_uint16 nParamValue = gr_fref_value(pFeatureRef, j);
                aParameters.emplace_back(sal_uInt32(nParamValue), sValueLabel);
                gr_label_destroy(pValueLabel);
            }

            auto eFeatureParameterType = vcl::font::FeatureParameterType::ENUM;

            // Check if the parameters are boolean
            if (aParameters.size() == 2
                && (aParameters[0].getDescription() == "True"
                    || aParameters[0].getDescription() == "False"))
            {
                eFeatureParameterType = vcl::font::FeatureParameterType::BOOL;
                aParameters.clear();
            }

            m_rFontFeatures.emplace_back(nFeatureCode, vcl::font::FeatureType::Graphite);
            vcl::font::Feature& rFeature = m_rFontFeatures.back();
            rFeature.m_aDefinition = vcl::font::FeatureDefinition(
                nFeatureCode, std::move(sLabel), eFeatureParameterType, std::move(aParameters),
                int32_t(nValue));
        }
    }
    gr_featureval_destroy(pfeatureValues);
    return true;
}

void FeatureCollector::collectForTable(hb_tag_t aTableTag)
{
    unsigned int nFeatureCount
        = hb_ot_layout_table_get_feature_tags(m_pHbFace, aTableTag, 0, nullptr, nullptr);
    std::vector<hb_tag_t> aFeatureTags(nFeatureCount);
    hb_ot_layout_table_get_feature_tags(m_pHbFace, aTableTag, 0, &nFeatureCount,
                                        aFeatureTags.data());
    aFeatureTags.resize(nFeatureCount);

    for (hb_tag_t aFeatureTag : aFeatureTags)
    {
        if (OpenTypeFeatureDefinitionList().isRequired(aFeatureTag))
            continue;

        m_rFontFeatures.emplace_back();
        vcl::font::Feature& rFeature = m_rFontFeatures.back();
        rFeature.m_nCode = aFeatureTag;

        FeatureDefinition aDefinition = OpenTypeFeatureDefinitionList().getDefinition(rFeature);
        std::vector<vcl::font::FeatureParameter> aParameters{
            { 0, VclResId(STR_FONT_FEATURE_PARAM_NONE) }
        };

        unsigned int nFeatureIdx;
        if (hb_ot_layout_language_find_feature(m_pHbFace, aTableTag, 0,
                                               HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX, aFeatureTag,
                                               &nFeatureIdx))
        {
            // ssXX and cvXX can have name ID defined for them, check for
            // them and use as appropriate.
            hb_ot_name_id_t aLabelID;
            hb_ot_name_id_t aFirstParameterID;
            unsigned nNamedParameters;
            if (hb_ot_layout_feature_get_name_ids(m_pHbFace, aTableTag, nFeatureIdx, &aLabelID,
                                                  nullptr, nullptr, &nNamedParameters,
                                                  &aFirstParameterID))
            {
                OUString sLabel = m_pFace->GetName(NameID(aLabelID), m_rLanguageTag);
                if (!sLabel.isEmpty())
                    aDefinition = vcl::font::FeatureDefinition(aFeatureTag, sLabel);

                // cvXX features can have parameters name IDs, check for
                // them and populate feature parameters as appropriate.
                for (unsigned i = 0; i < nNamedParameters; i++)
                {
                    hb_ot_name_id_t aNameID = aFirstParameterID + i;
                    OUString sName = m_pFace->GetName(NameID(aNameID), m_rLanguageTag);
                    if (!sName.isEmpty())
                        aParameters.emplace_back(uint32_t(i + 1), sName);
                    else
                        aParameters.emplace_back(uint32_t(i + 1), OUString::number(i + 1));
                }
            }

            unsigned int nAlternates = 0;
            if (aTableTag == HB_OT_TAG_GSUB)
            {
                // Collect lookups in this feature, and input glyphs for each
                // lookup, and calculate the max number of alternates they have.
                unsigned int nLookups = hb_ot_layout_feature_get_lookups(
                    m_pHbFace, aTableTag, nFeatureIdx, 0, nullptr, nullptr);
                std::vector<unsigned int> aLookups(nLookups);
                hb_ot_layout_feature_get_lookups(m_pHbFace, aTableTag, nFeatureIdx, 0, &nLookups,
                                                 aLookups.data());

                hb_set_t* pGlyphs = hb_set_create();
                for (unsigned int nLookupIdx : aLookups)
                {
                    hb_set_clear(pGlyphs);
                    hb_ot_layout_lookup_collect_glyphs(m_pHbFace, aTableTag, nLookupIdx, nullptr,
                                                       pGlyphs, nullptr, nullptr);
                    hb_codepoint_t nGlyphIdx = HB_SET_VALUE_INVALID;
                    while (hb_set_next(pGlyphs, &nGlyphIdx))
                    {
                        nAlternates
                            = std::max(nAlternates,
                                       hb_ot_layout_lookup_get_glyph_alternates(
                                           m_pHbFace, nLookupIdx, nGlyphIdx, 0, nullptr, nullptr));
                    }
                }
                hb_set_destroy(pGlyphs);
            }

            // Append the alternates to the feature parameters, keeping any
            // existing ones calculated from cvXX features above.
            for (unsigned int i = aParameters.size() - 1; i < nAlternates; i++)
                aParameters.emplace_back(uint32_t(i + 1), OUString::number(i + 1));

            if (aParameters.size() > 1)
            {
                aDefinition = vcl::font::FeatureDefinition(
                    aFeatureTag, aDefinition.getDescription(),
                    vcl::font::FeatureParameterType::ENUM, std::move(aParameters), 0);
            }
        }

        if (aDefinition)
            rFeature.m_aDefinition = std::move(aDefinition);
    }
}

bool FeatureCollector::collect()
{
    gr_face* grFace = hb_graphite2_face_get_gr_face(m_pHbFace);

    if (grFace)
    {
        return collectGraphite();
    }
    else
    {
        collectForTable(HB_OT_TAG_GSUB); // substitution
        collectForTable(HB_OT_TAG_GPOS); // positioning
        return true;
    }
}

} // end namespace vcl::font

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */