// return root node.
static sk_sp<SkPDFDict> generate_page_tree(SkTArray<sk_sp<SkPDFDict>>* pages) {
// PDF wants a tree describing all the pages in the document. We arbitrary
// choose 8 (kNodeSize) as the number of allowed children. The internal
// nodes have type "Pages" with an array of children, a parent pointer, and
// the number of leaves below the node as "Count." The leaves are passed
// into the method, have type "Page" and need a parent pointer. This method
// builds the tree bottom up, skipping internal nodes that would have only
// one child.
static const int kNodeSize = 8;
// curNodes takes a reference to its items, which it passes to pageTree.
int totalPageCount = pages->count();
SkTArray<sk_sp<SkPDFDict>> curNodes;
curNodes.swap(pages);
// nextRoundNodes passes its references to nodes on to curNodes.
int treeCapacity = kNodeSize;
do {
SkTArray<sk_sp<SkPDFDict>> nextRoundNodes;
for (int i = 0; i < curNodes.count(); ) {
if (i > 0 && i + 1 == curNodes.count()) {
SkASSERT(curNodes[i]);
nextRoundNodes.emplace_back(std::move(curNodes[i]));
break;
}
auto newNode = sk_make_sp<SkPDFDict>("Pages");
auto kids = sk_make_sp<SkPDFArray>();
kids->reserve(kNodeSize);
int count = 0;
for (; i < curNodes.count() && count < kNodeSize; i++, count++) {
SkASSERT(curNodes[i]);
curNodes[i]->insertObjRef("Parent", newNode);
kids->appendObjRef(std::move(curNodes[i]));
}
// treeCapacity is the number of leaf nodes possible for the
// current set of subtrees being generated. (i.e. 8, 64, 512, ...).
// It is hard to count the number of leaf nodes in the current
// subtree. However, by construction, we know that unless it's the
// last subtree for the current depth, the leaf count will be
// treeCapacity, otherwise it's what ever is left over after
// consuming treeCapacity chunks.
int pageCount = treeCapacity;
if (i == curNodes.count()) {
pageCount = ((totalPageCount - 1) % treeCapacity) + 1;
}
newNode->insertInt("Count", pageCount);
newNode->insertObject("Kids", std::move(kids));
nextRoundNodes.emplace_back(std::move(newNode));
}
SkDEBUGCODE( for (const auto& n : curNodes) { SkASSERT(!n); } );
curNodes.swap(&nextRoundNodes);
nextRoundNodes.reset();
treeCapacity *= kNodeSize;
} while (curNodes.count() > 1);
void SkPDFType0Font::getFontSubset(SkPDFCanon* canon) {
const SkAdvancedTypefaceMetrics* metricsPtr =
SkPDFFont::GetMetrics(this->typeface(), canon);
SkASSERT(metricsPtr);
if (!metricsPtr) { return; }
const SkAdvancedTypefaceMetrics& metrics = *metricsPtr;
SkASSERT(can_embed(metrics));
SkAdvancedTypefaceMetrics::FontType type = this->getType();
SkTypeface* face = this->typeface();
SkASSERT(face);
auto descriptor = sk_make_sp<SkPDFDict>("FontDescriptor");
uint16_t emSize = SkToU16(this->typeface()->getUnitsPerEm());
add_common_font_descriptor_entries(descriptor.get(), metrics, emSize , 0);
int ttcIndex;
std::unique_ptr<SkStreamAsset> fontAsset(face->openStream(&ttcIndex));
size_t fontSize = fontAsset ? fontAsset->getLength() : 0;
if (0 == fontSize) {
SkDebugf("Error: (SkTypeface)(%p)::openStream() returned "
"empty stream (%p) when identified as kType1CID_Font "
"or kTrueType_Font.\n", face, fontAsset.get());
} else {
switch (type) {
case SkAdvancedTypefaceMetrics::kTrueType_Font: {
#ifdef SK_PDF_USE_SFNTLY
if (!SkToBool(metrics.fFlags &
SkAdvancedTypefaceMetrics::kNotSubsettable_FontFlag)) {
sk_sp<SkPDFStream> subsetStream = get_subset_font_stream(
std::move(fontAsset), this->glyphUsage(),
metrics.fFontName.c_str(), ttcIndex);
if (subsetStream) {
descriptor->insertObjRef("FontFile2", std::move(subsetStream));
break;
}
// If subsetting fails, fall back to original font data.
fontAsset.reset(face->openStream(&ttcIndex));
SkASSERT(fontAsset);
SkASSERT(fontAsset->getLength() == fontSize);
if (!fontAsset || fontAsset->getLength() == 0) { break; }
}
#endif // SK_PDF_USE_SFNTLY
auto fontStream = sk_make_sp<SkPDFSharedStream>(std::move(fontAsset));
fontStream->dict()->insertInt("Length1", fontSize);
descriptor->insertObjRef("FontFile2", std::move(fontStream));
break;
}
case SkAdvancedTypefaceMetrics::kType1CID_Font: {
auto fontStream = sk_make_sp<SkPDFSharedStream>(std::move(fontAsset));
fontStream->dict()->insertName("Subtype", "CIDFontType0C");
descriptor->insertObjRef("FontFile3", std::move(fontStream));
break;
}
default:
SkASSERT(false);
}
}
auto newCIDFont = sk_make_sp<SkPDFDict>("Font");
newCIDFont->insertObjRef("FontDescriptor", std::move(descriptor));
newCIDFont->insertName("BaseFont", metrics.fPostScriptName);
switch (type) {
case SkAdvancedTypefaceMetrics::kType1CID_Font:
newCIDFont->insertName("Subtype", "CIDFontType0");
break;
case SkAdvancedTypefaceMetrics::kTrueType_Font:
newCIDFont->insertName("Subtype", "CIDFontType2");
newCIDFont->insertName("CIDToGIDMap", "Identity");
break;
default:
SkASSERT(false);
}
auto sysInfo = sk_make_sp<SkPDFDict>();
sysInfo->insertString("Registry", "Adobe");
sysInfo->insertString("Ordering", "Identity");
sysInfo->insertInt("Supplement", 0);
newCIDFont->insertObject("CIDSystemInfo", std::move(sysInfo));
int16_t defaultWidth = 0;
{
int emSize;
auto glyphCache = SkPDFFont::MakeVectorCache(face, &emSize);
sk_sp<SkPDFArray> widths = SkPDFMakeCIDGlyphWidthsArray(
glyphCache.get(), &this->glyphUsage(), SkToS16(emSize), &defaultWidth);
if (widths && widths->size() > 0) {
newCIDFont->insertObject("W", std::move(widths));
}
newCIDFont->insertScalar(
"DW", scaleFromFontUnits(defaultWidth, SkToS16(emSize)));
}
////////////////////////////////////////////////////////////////////////////
this->insertName("Subtype", "Type0");
this->insertName("BaseFont", metrics.fPostScriptName);
this->insertName("Encoding", "Identity-H");
auto descendantFonts = sk_make_sp<SkPDFArray>();
descendantFonts->appendObjRef(std::move(newCIDFont));
this->insertObject("DescendantFonts", std::move(descendantFonts));
if (metrics.fGlyphToUnicode.count() > 0) {
this->insertObjRef("ToUnicode",
SkPDFMakeToUnicodeCmap(metrics.fGlyphToUnicode,
&this->glyphUsage(),
multiByteGlyphs(),
firstGlyphID(),
lastGlyphID()));
}
SkDEBUGCODE(fPopulated = true);
return;
}