blob: ce32d8976b8ae7ddd53fd9b0b735410aa3bb26fb [file] [log] [blame]
// 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"
#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,
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); },
static HBFace make_subset(hb_subset_input_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 = HB_SUBSET_FLAGS_RETAIN_GIDS;
if (retainZeroGlyph) {
hb_subset_input_set_flags(input, flags);
return HBFace(hb_subset_or_fail(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));
HBSubsetInput input(hb_subset_input_create_or_fail());
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 = make_subset(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));
sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData> fontData,
const SkPDFGlyphUse& glyphUsage,
int ttcIndex) {
return subset_harfbuzz(std::move(fontData), glyphUsage, ttcIndex);
sk_sp<SkData> SkPDFSubsetFont(sk_sp<SkData>, const SkPDFGlyphUse&, SkPDF::Metadata::Subsetter, int){
return nullptr;
#endif // defined(SK_PDF_USE_HARFBUZZ_SUBSET)