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// Copyright 2018 Google LLC.
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
#include "src/pdf/SkPDFSubsetFont.h"
#if defined(SK_PDF_USE_HARFBUZZ_SUBSET)
#include "include/private/base/SkTemplates.h"
#include "include/private/base/SkTo.h"
#include "src/utils/SkCallableTraits.h"
#include "hb.h" // NO_G3_REWRITE
#include "hb-subset.h" // NO_G3_REWRITE
using HBBlob = std::unique_ptr<hb_blob_t, SkFunctionObject<hb_blob_destroy>>;
using HBFace = std::unique_ptr<hb_face_t, SkFunctionObject<hb_face_destroy>>;
using HBSubsetInput = std::unique_ptr<hb_subset_input_t, SkFunctionObject<hb_subset_input_destroy>>;
using HBSet = std::unique_ptr<hb_set_t, SkFunctionObject<hb_set_destroy>>;
static HBBlob to_blob(sk_sp<SkData> data) {
using blob_size_t = SkCallableTraits<decltype(hb_blob_create)>::argument<1>::type;
if (!SkTFitsIn<blob_size_t>(data->size())) {
return nullptr;
}
const char* blobData = static_cast<const char*>(data->data());
blob_size_t blobSize = SkTo<blob_size_t>(data->size());
return HBBlob(hb_blob_create(blobData, blobSize,
HB_MEMORY_MODE_READONLY,
data.release(), [](void* p){ ((SkData*)p)->unref(); }));
}
static sk_sp<SkData> to_data(HBBlob blob) {
if (!blob) {
return nullptr;
}
unsigned int length;
const char* data = hb_blob_get_data(blob.get(), &length);
if (!data || !length) {
return nullptr;
}
return SkData::MakeWithProc(data, SkToSizeT(length),
[](const void*, void* ctx) { hb_blob_destroy((hb_blob_t*)ctx); },
blob.release());
}
template<typename...> using void_t = void;
template<typename T, typename = void>
struct SkPDFHarfBuzzSubset {
// This is the HarfBuzz 3.0 interface.
// hb_subset_flags_t does not exist in 2.0. It isn't dependent on T, so inline the value of
// HB_SUBSET_FLAGS_RETAIN_GIDS until 2.0 is no longer supported.
static HBFace Make(T input, hb_face_t* face, bool retainZeroGlyph) {
// TODO: When possible, check if a font is 'tricky' with FT_IS_TRICKY.
// If it isn't known if a font is 'tricky', retain the hints.
unsigned int flags = 0x2u/*HB_SUBSET_FLAGS_RETAIN_GIDS*/;
if (retainZeroGlyph) {
flags |= 0x40u/*HB_SUBSET_FLAGS_NOTDEF_OUTLINE*/;
}
hb_subset_input_set_flags(input, flags);
return HBFace(hb_subset_or_fail(face, input));
}
};
template<typename T>
struct SkPDFHarfBuzzSubset<T, void_t<
decltype(hb_subset_input_set_retain_gids(std::declval<T>(), std::declval<bool>())),
decltype(hb_subset_input_set_drop_hints(std::declval<T>(), std::declval<bool>())),
decltype(hb_subset(std::declval<hb_face_t*>(), std::declval<T>()))
>>
{
// This is the HarfBuzz 2.0 (non-public) interface, used if it exists.
// This code should be removed as soon as all users are migrated to the newer API.
static HBFace Make(T input, hb_face_t* face, bool) {
hb_subset_input_set_retain_gids(input, true);
// TODO: When possible, check if a font is 'tricky' with FT_IS_TRICKY.
// If it isn't known if a font is 'tricky', retain the hints.
hb_subset_input_set_drop_hints(input, false);
return HBFace(hb_subset(face, input));
}
};
static sk_sp<SkData> subset_harfbuzz(sk_sp<SkData> fontData,
const SkPDFGlyphUse& glyphUsage,
int ttcIndex) {
if (!fontData) {
return nullptr;
}
HBFace face(hb_face_create(to_blob(std::move(fontData)).get(), ttcIndex));
SkASSERT(face);
HBSubsetInput input(hb_subset_input_create_or_fail());
SkASSERT(input);
if (!face || !input) {
return nullptr;
}
hb_set_t* glyphs = hb_subset_input_glyph_set(input.get());
glyphUsage.getSetValues([&glyphs](unsigned gid) { hb_set_add(glyphs, gid);});
HBFace subset = SkPDFHarfBuzzSubset<hb_subset_input_t*>::Make(input.get(), face.get(),
glyphUsage.has(0));
if (!subset) {
return nullptr;
}
HBBlob result(hb_face_reference_blob(subset.get()));
return to_data(std::move(result));
}
#endif // defined(SK_PDF_USE_HARFBUZZ_SUBSET)
////////////////////////////////////////////////////////////////////////////////
#if defined(SK_PDF_USE_SFNTLY)
#include "sample/chromium/font_subsetter.h"
#include <vector>
#if defined(SK_USING_THIRD_PARTY_ICU)
#include "third_party/icu/SkLoadICU.h"
#endif
static sk_sp<SkData> subset_sfntly(sk_sp<SkData> fontData,
const SkPDFGlyphUse& glyphUsage,
const char* fontName,
int ttcIndex) {
#if defined(SK_USING_THIRD_PARTY_ICU)
if (!SkLoadICU()) {
return nullptr;
}
#endif
// Generate glyph id array in format needed by sfntly.
// TODO(halcanary): sfntly should take a more compact format.
std::vector<unsigned> subset;
glyphUsage.getSetValues([&subset](unsigned v) { subset.push_back(v); });
unsigned char* subsetFont{nullptr};
#if defined(SK_BUILD_FOR_GOOGLE3)
// TODO(halcanary): update SK_BUILD_FOR_GOOGLE3 to newest version of Sfntly.
(void)ttcIndex;
int subsetFontSize = SfntlyWrapper::SubsetFont(fontName,
fontData->bytes(),
fontData->size(),
subset.data(),
subset.size(),
&subsetFont);
#else // defined(SK_BUILD_FOR_GOOGLE3)
(void)fontName;
int subsetFontSize = SfntlyWrapper::SubsetFont(ttcIndex,
fontData->bytes(),
fontData->size(),
subset.data(),
subset.size(),
&subsetFont);
#endif // defined(SK_BUILD_FOR_GOOGLE3)
SkASSERT(subsetFontSize > 0 || subsetFont == nullptr);
if (subsetFontSize < 1 || subsetFont == nullptr) {
return nullptr;
}
return SkData::MakeWithProc(subsetFont, subsetFontSize,
[](const void* p, void*) { delete[] (unsigned char*)p; },
nullptr);
}
#endif // defined(SK_PDF_USE_SFNTLY)
////////////////////////////////////////////////////////////////////////////////
#if defined(SK_PDF_USE_SFNTLY) && defined(SK_PDF_USE_HARFBUZZ_SUBSET)
sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData> fontData,
const SkPDFGlyphUse& glyphUsage,
SkPDF::Metadata::Subsetter subsetter,
const char* fontName,
int ttcIndex) {
switch (subsetter) {
case SkPDF::Metadata::kHarfbuzz_Subsetter:
return subset_harfbuzz(std::move(fontData), glyphUsage, ttcIndex);
case SkPDF::Metadata::kSfntly_Subsetter:
return subset_sfntly(std::move(fontData), glyphUsage, fontName, ttcIndex);
}
return nullptr;
}
#elif defined(SK_PDF_USE_SFNTLY)
sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData> fontData,
const SkPDFGlyphUse& glyphUsage,
SkPDF::Metadata::Subsetter,
const char* fontName,
int ttcIndex) {
return subset_sfntly(std::move(fontData), glyphUsage, fontName, ttcIndex);
}
#elif defined(SK_PDF_USE_HARFBUZZ_SUBSET)
sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData> fontData,
const SkPDFGlyphUse& glyphUsage,
SkPDF::Metadata::Subsetter,
const char*,
int ttcIndex) {
return subset_harfbuzz(std::move(fontData), glyphUsage, ttcIndex);
}
#else
sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData>, const SkPDFGlyphUse&, SkPDF::Metadata::Subsetter,
const char*, int) {
return nullptr;
}
#endif // defined(SK_PDF_USE_SFNTLY)