xref: /aosp_15_r20/external/skia/src/ports/SkFontScanner_fontations.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2024 The Android Open Source Project
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 #include "src/ports/SkFontScanner_fontations_priv.h"
8 #include "src/ports/SkTypeface_fontations_priv.h"
9 #include "src/ports/fontations/src/skpath_bridge.h"
10 #include "src/sfnt/SkOTUtils.h"
11 
12 using namespace skia_private;
13 
14 namespace {
make_bridge_font_ref(SkData * fontData,uint32_t index)15 rust::Box<::fontations_ffi::BridgeFontRef> make_bridge_font_ref(SkData* fontData, uint32_t index) {
16     rust::Slice<const uint8_t> slice{fontData->bytes(), fontData->size()};
17     return fontations_ffi::make_font_ref(slice, index);
18 }
19   // TODO(drott): Remove this once SkData::MakeFromStream is able to do this itself.
make_data_avoiding_copy(SkStreamAsset * stream)20 sk_sp<SkData> make_data_avoiding_copy(SkStreamAsset* stream) {
21     if (!stream) {
22         return SkData::MakeEmpty();
23     }
24     if (stream->getData()) {
25         return stream->getData();
26     }
27     if (stream->getMemoryBase() && stream->getLength()) {
28         return SkData::MakeWithoutCopy(stream->getMemoryBase(), stream->getLength());
29     }
30 
31     return SkData::MakeFromStream(stream, stream->getLength());
32 }
33 }  // namespace
34 
SkFontScanner_Fontations()35 SkFontScanner_Fontations::SkFontScanner_Fontations() {}
36 
~SkFontScanner_Fontations()37 SkFontScanner_Fontations::~SkFontScanner_Fontations() {}
38 
scanFile(SkStreamAsset * stream,int * numFaces) const39 bool SkFontScanner_Fontations::scanFile(SkStreamAsset* stream, int* numFaces) const {
40     sk_sp<SkData> fontData = make_data_avoiding_copy(stream);
41     stream->rewind();
42     rust::Slice<const uint8_t> slice{fontData->bytes(), fontData->size()};
43     ::std::uint32_t num_fonts;
44     if (!fontations_ffi::font_or_collection(slice, num_fonts)) {
45         return false;
46     }
47     *numFaces = num_fonts == 0 ? 1 : num_fonts;
48     return true;
49 }
50 
scanFace(SkStreamAsset * stream,int faceIndex,int * numInstances) const51 bool SkFontScanner_Fontations::scanFace(SkStreamAsset* stream,
52                                         int faceIndex,
53                                         int* numInstances) const {
54     sk_sp<SkData> fontData = make_data_avoiding_copy(stream);
55     rust::Box<fontations_ffi::BridgeFontRef> fontRef =
56             make_bridge_font_ref(fontData.get(), faceIndex);
57     stream->rewind();
58     if (!fontations_ffi::font_ref_is_valid(*fontRef)) {
59         return false;
60     }
61 
62     if (numInstances) {
63         *numInstances = fontations_ffi::num_named_instances(*fontRef);
64     }
65     return true;
66 }
67 
make_normalized_coords(fontations_ffi::BridgeFontRef const & bridgeFontRef,const SkFontArguments::VariationPosition & variationPosition)68 rust::Box<fontations_ffi::BridgeNormalizedCoords> make_normalized_coords(
69         fontations_ffi::BridgeFontRef const& bridgeFontRef,
70         const SkFontArguments::VariationPosition& variationPosition) {
71     // Cast is safe because of static_assert matching the structs above.
72     rust::Slice<const fontations_ffi::SkiaDesignCoordinate> coordinates(
73             reinterpret_cast<const fontations_ffi::SkiaDesignCoordinate*>(
74                     variationPosition.coordinates),
75             variationPosition.coordinateCount);
76     return resolve_into_normalized_coords(bridgeFontRef, coordinates);
77 }
78 
scanInstance(SkStreamAsset * stream,int faceIndex,int instanceIndex,SkString * name,SkFontStyle * style,bool * isFixedPitch,AxisDefinitions * axes) const79 bool SkFontScanner_Fontations::scanInstance(SkStreamAsset* stream,
80                                             int faceIndex,
81                                             int instanceIndex,
82                                             SkString* name,
83                                             SkFontStyle* style,
84                                             bool* isFixedPitch,
85                                             AxisDefinitions* axes) const {
86     sk_sp<SkData> fontData = make_data_avoiding_copy(stream);
87     rust::Box<fontations_ffi::BridgeFontRef> bridgeFontFaceRef =
88             make_bridge_font_ref(fontData.get(), faceIndex);
89     stream->rewind();
90     if (!fontations_ffi::font_ref_is_valid(*bridgeFontFaceRef)) {
91         return false;
92     }
93 
94     if (name != nullptr) {
95         rust::String readFamilyName = fontations_ffi::family_name(*bridgeFontFaceRef);
96         *name = SkString(readFamilyName.data(), readFamilyName.size());
97     }
98 
99     if (isFixedPitch != nullptr) {
100         *isFixedPitch = false;  // TODO
101     }
102 
103     if (style != nullptr) {
104         auto num = SkToInt(fontations_ffi::num_named_instances(*bridgeFontFaceRef));
105         if (instanceIndex > num) {
106             return false;
107         } else if (instanceIndex == 0) {
108             // This is the default instance
109             rust::Slice<const fontations_ffi::SkiaDesignCoordinate> coordinates;
110             rust::Box<fontations_ffi::BridgeNormalizedCoords> normalizedCoords =
111                     resolve_into_normalized_coords(*bridgeFontFaceRef, coordinates);
112             fontations_ffi::BridgeFontStyle fontStyle;
113             if (fontations_ffi::get_font_style(*bridgeFontFaceRef, *normalizedCoords, fontStyle)) {
114                 *style = SkFontStyle(fontStyle.weight, fontStyle.width, (SkFontStyle::Slant)fontStyle.slant);
115             } else {
116                 *style = SkFontStyle::Normal();
117             }
118         } else {
119             std::unique_ptr<SkFontArguments::VariationPosition::Coordinate[]> extractedCoords =
120                     nullptr;
121             size_t numNamedInstanceCoords =
122                     fontations_ffi::coordinates_for_shifted_named_instance_index(
123                             *bridgeFontFaceRef,
124                             instanceIndex << 16,
125                             rust::cxxbridge1::Slice<fontations_ffi::SkiaDesignCoordinate>());
126             extractedCoords.reset(new SkFontArguments::VariationPosition::Coordinate[numNamedInstanceCoords]);
127 
128             rust::cxxbridge1::Slice<fontations_ffi::SkiaDesignCoordinate> targetSlice(
129                     reinterpret_cast<fontations_ffi::SkiaDesignCoordinate*>(extractedCoords.get()),
130                     numNamedInstanceCoords);
131             size_t retrievedNamedInstanceCoords =
132                     fontations_ffi::coordinates_for_shifted_named_instance_index(
133                             *bridgeFontFaceRef, faceIndex + (instanceIndex << 16), targetSlice);
134             if (numNamedInstanceCoords != retrievedNamedInstanceCoords) {
135                 return false;
136             }
137 
138             SkFontArguments::VariationPosition variationPosition;
139             variationPosition.coordinateCount = numNamedInstanceCoords;
140             variationPosition.coordinates = extractedCoords.get();
141 
142             rust::Box<fontations_ffi::BridgeNormalizedCoords> normalizedCoords =
143                     make_normalized_coords(*bridgeFontFaceRef, variationPosition);
144             fontations_ffi::BridgeFontStyle fontStyle;
145             if (fontations_ffi::get_font_style(*bridgeFontFaceRef, *normalizedCoords, fontStyle)) {
146                 *style = SkFontStyle(fontStyle.weight,
147                                      fontStyle.width,
148                                      static_cast<SkFontStyle::Slant>(fontStyle.slant));
149             }
150         }
151     }
152 
153     if (axes != nullptr) {
154         rust::Box<fontations_ffi::BridgeFontRef> bridgeFontNamedInstanceRef =
155                 make_bridge_font_ref(fontData.get(), faceIndex + (instanceIndex << 16));
156         stream->rewind();
157         auto size = SkToInt(fontations_ffi::num_axes(*bridgeFontNamedInstanceRef));
158         axes->reset(size);
159         auto variationAxes = std::make_unique<SkFontParameters::Variation::Axis[]>(size);
160         sk_fontations::AxisWrapper axisWrapper(variationAxes.get(), size);
161         auto size1 = fontations_ffi::populate_axes(*bridgeFontNamedInstanceRef, axisWrapper);
162         SkASSERT(size == size1);
163         for (auto i = 0; i < size; ++i) {
164             const auto var = variationAxes[i];
165             (*axes)[i].fTag = var.tag;
166             (*axes)[i].fMinimum = var.min;
167             (*axes)[i].fDefault = var.def;
168             (*axes)[i].fMaximum = var.max;
169         }
170     }
171 
172     return true;
173 }
174 
MakeFromStream(std::unique_ptr<SkStreamAsset> stream,const SkFontArguments & args) const175 sk_sp<SkTypeface> SkFontScanner_Fontations::MakeFromStream(std::unique_ptr<SkStreamAsset> stream,
176                                                            const SkFontArguments& args) const {
177     return SkTypeface_Fontations::MakeFromStream(std::move(stream), args);
178 }
179 
getFactoryId() const180 SkTypeface::FactoryId SkFontScanner_Fontations::getFactoryId() const {
181     return SkTypeface_Fontations::FactoryId;
182 }
183 
SkFontScanner_Make_Fontations()184 std::unique_ptr<SkFontScanner> SkFontScanner_Make_Fontations() {
185     return std::make_unique<SkFontScanner_Fontations>();
186 }
187