/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkFontDescriptor.h"
#include "SkFontMgr.h"
#include "SkOnce.h"
#include "SkStream.h"
#include "SkTypes.h"
class SkFontStyle;
class SkTypeface;
class SkEmptyFontStyleSet : public SkFontStyleSet {
public:
int count() override { return 0; }
void getStyle(int, SkFontStyle*, SkString*) override {
SkDEBUGFAIL("SkFontStyleSet::getStyle called on empty set");
}
SkTypeface* createTypeface(int index) override {
SkDEBUGFAIL("SkFontStyleSet::createTypeface called on empty set");
return nullptr;
}
SkTypeface* matchStyle(const SkFontStyle&) override {
return nullptr;
}
};
SkFontStyleSet* SkFontStyleSet::CreateEmpty() { return new SkEmptyFontStyleSet; }
///////////////////////////////////////////////////////////////////////////////
class SkEmptyFontMgr : public SkFontMgr {
protected:
int onCountFamilies() const override {
return 0;
}
void onGetFamilyName(int index, SkString* familyName) const override {
SkDEBUGFAIL("onGetFamilyName called with bad index");
}
SkFontStyleSet* onCreateStyleSet(int index) const override {
SkDEBUGFAIL("onCreateStyleSet called with bad index");
return nullptr;
}
SkFontStyleSet* onMatchFamily(const char[]) const override {
return SkFontStyleSet::CreateEmpty();
}
SkTypeface* onMatchFamilyStyle(const char[], const SkFontStyle&) const override {
return nullptr;
}
SkTypeface* onMatchFamilyStyleCharacter(const char familyName[],
const SkFontStyle& style,
const char* bcp47[],
int bcp47Count,
SkUnichar character) const override {
return nullptr;
}
SkTypeface* onMatchFaceStyle(const SkTypeface*, const SkFontStyle&) const override {
return nullptr;
}
sk_sp<SkTypeface> onMakeFromData(sk_sp<SkData>, int) const override {
return nullptr;
}
sk_sp<SkTypeface> onMakeFromStreamIndex(std::unique_ptr<SkStreamAsset>, int) const override {
return nullptr;
}
sk_sp<SkTypeface> onMakeFromStreamArgs(std::unique_ptr<SkStreamAsset>,
const SkFontArguments&) const override {
return nullptr;
}
sk_sp<SkTypeface> onMakeFromFontData(std::unique_ptr<SkFontData>) const override {
return nullptr;
}
sk_sp<SkTypeface> onMakeFromFile(const char[], int) const override {
return nullptr;
}
sk_sp<SkTypeface> onLegacyMakeTypeface(const char [], SkFontStyle) const override {
return nullptr;
}
};
static SkFontStyleSet* emptyOnNull(SkFontStyleSet* fsset) {
if (nullptr == fsset) {
fsset = SkFontStyleSet::CreateEmpty();
}
return fsset;
}
int SkFontMgr::countFamilies() const {
return this->onCountFamilies();
}
void SkFontMgr::getFamilyName(int index, SkString* familyName) const {
this->onGetFamilyName(index, familyName);
}
SkFontStyleSet* SkFontMgr::createStyleSet(int index) const {
return emptyOnNull(this->onCreateStyleSet(index));
}
SkFontStyleSet* SkFontMgr::matchFamily(const char familyName[]) const {
return emptyOnNull(this->onMatchFamily(familyName));
}
SkTypeface* SkFontMgr::matchFamilyStyle(const char familyName[],
const SkFontStyle& fs) const {
return this->onMatchFamilyStyle(familyName, fs);
}
SkTypeface* SkFontMgr::matchFamilyStyleCharacter(const char familyName[], const SkFontStyle& style,
const char* bcp47[], int bcp47Count,
SkUnichar character) const {
return this->onMatchFamilyStyleCharacter(familyName, style, bcp47, bcp47Count, character);
}
SkTypeface* SkFontMgr::matchFaceStyle(const SkTypeface* face,
const SkFontStyle& fs) const {
return this->onMatchFaceStyle(face, fs);
}
sk_sp<SkTypeface> SkFontMgr::makeFromData(sk_sp<SkData> data, int ttcIndex) const {
if (nullptr == data) {
return nullptr;
}
return this->onMakeFromData(std::move(data), ttcIndex);
}
sk_sp<SkTypeface> SkFontMgr::makeFromStream(std::unique_ptr<SkStreamAsset> stream,
int ttcIndex) const {
if (nullptr == stream) {
return nullptr;
}
return this->onMakeFromStreamIndex(std::move(stream), ttcIndex);
}
sk_sp<SkTypeface> SkFontMgr::makeFromStream(std::unique_ptr<SkStreamAsset> stream,
const SkFontArguments& args) const {
if (nullptr == stream) {
return nullptr;
}
return this->onMakeFromStreamArgs(std::move(stream), args);
}
sk_sp<SkTypeface> SkFontMgr::makeFromFontData(std::unique_ptr<SkFontData> data) const {
if (nullptr == data) {
return nullptr;
}
return this->onMakeFromFontData(std::move(data));
}
sk_sp<SkTypeface> SkFontMgr::makeFromFile(const char path[], int ttcIndex) const {
if (nullptr == path) {
return nullptr;
}
return this->onMakeFromFile(path, ttcIndex);
}
sk_sp<SkTypeface> SkFontMgr::legacyMakeTypeface(const char familyName[], SkFontStyle style) const {
return this->onLegacyMakeTypeface(familyName, style);
}
sk_sp<SkTypeface> SkFontMgr::onMakeFromStreamArgs(std::unique_ptr<SkStreamAsset> stream,
const SkFontArguments& args) const {
return this->makeFromStream(std::move(stream), args.getCollectionIndex());
}
sk_sp<SkTypeface> SkFontMgr::onMakeFromFontData(std::unique_ptr<SkFontData> data) const {
return this->makeFromStream(data->detachStream(), data->getIndex());
}
// A global function pointer that's not declared, but can be overriden at startup by test tools.
sk_sp<SkFontMgr> (*gSkFontMgr_DefaultFactory)() = nullptr;
sk_sp<SkFontMgr> SkFontMgr::RefDefault() {
static SkOnce once;
static sk_sp<SkFontMgr> singleton;
once([]{
sk_sp<SkFontMgr> fm = gSkFontMgr_DefaultFactory ? gSkFontMgr_DefaultFactory()
: SkFontMgr::Factory();
singleton = fm ? std::move(fm) : sk_make_sp<SkEmptyFontMgr>();
});
return singleton;
}
/**
* Width has the greatest priority.
* If the value of pattern.width is 5 (normal) or less,
* narrower width values are checked first, then wider values.
* If the value of pattern.width is greater than 5 (normal),
* wider values are checked first, followed by narrower values.
*
* Italic/Oblique has the next highest priority.
* If italic requested and there is some italic font, use it.
* If oblique requested and there is some oblique font, use it.
* If italic requested and there is some oblique font, use it.
* If oblique requested and there is some italic font, use it.
*
* Exact match.
* If pattern.weight < 400, weights below pattern.weight are checked
* in descending order followed by weights above pattern.weight
* in ascending order until a match is found.
* If pattern.weight > 500, weights above pattern.weight are checked
* in ascending order followed by weights below pattern.weight
* in descending order until a match is found.
* If pattern.weight is 400, 500 is checked first
* and then the rule for pattern.weight < 400 is used.
* If pattern.weight is 500, 400 is checked first
* and then the rule for pattern.weight < 400 is used.
*/
SkTypeface* SkFontStyleSet::matchStyleCSS3(const SkFontStyle& pattern) {
int count = this->count();
if (0 == count) {
return nullptr;
}
struct Score {
int score;
int index;
Score& operator +=(int rhs) { this->score += rhs; return *this; }
Score& operator <<=(int rhs) { this->score <<= rhs; return *this; }
bool operator <(const Score& that) { return this->score < that.score; }
};
Score maxScore = { 0, 0 };
for (int i = 0; i < count; ++i) {
SkFontStyle current;
this->getStyle(i, ¤t, nullptr);
Score currentScore = { 0, i };
// CSS stretch / SkFontStyle::Width
// Takes priority over everything else.
if (pattern.width() <= SkFontStyle::kNormal_Width) {
if (current.width() <= pattern.width()) {
currentScore += 10 - pattern.width() + current.width();
} else {
currentScore += 10 - current.width();
}
} else {
if (current.width() > pattern.width()) {
currentScore += 10 + pattern.width() - current.width();
} else {
currentScore += current.width();
}
}
currentScore <<= 8;
// CSS style (normal, italic, oblique) / SkFontStyle::Slant (upright, italic, oblique)
// Takes priority over all valid weights.
static_assert(SkFontStyle::kUpright_Slant == 0 &&
SkFontStyle::kItalic_Slant == 1 &&
SkFontStyle::kOblique_Slant == 2,
"SkFontStyle::Slant values not as required.");
SkASSERT(0 <= pattern.slant() && pattern.slant() <= 2 &&
0 <= current.slant() && current.slant() <= 2);
static const int score[3][3] = {
/* Upright Italic Oblique [current]*/
/* Upright */ { 3 , 1 , 2 },
/* Italic */ { 1 , 3 , 2 },
/* Oblique */ { 1 , 2 , 3 },
/* [pattern] */
};
currentScore += score[pattern.slant()][current.slant()];
currentScore <<= 8;
// Synthetics (weight, style) [no stretch synthetic?]
// CSS weight / SkFontStyle::Weight
// The 'closer' to the target weight, the higher the score.
// 1000 is the 'heaviest' recognized weight
if (pattern.weight() == current.weight()) {
currentScore += 1000;
} else if (pattern.weight() <= 500) {
if (400 <= pattern.weight() && pattern.weight() < 450) {
if (450 <= current.weight() && current.weight() <= 500) {
// Artificially boost the 500 weight.
// TODO: determine correct number to use.
currentScore += 500;
}
}
if (current.weight() <= pattern.weight()) {
currentScore += 1000 - pattern.weight() + current.weight();
} else {
currentScore += 1000 - current.weight();
}
} else if (pattern.weight() > 500) {
if (current.weight() > pattern.weight()) {
currentScore += 1000 + pattern.weight() - current.weight();
} else {
currentScore += current.weight();
}
}
if (maxScore < currentScore) {
maxScore = currentScore;
}
}
return this->createTypeface(maxScore.index);
}