blob: de309d311bdfa910d2ed1fc698c66ed79924fd5e [file] [log] [blame]
/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkFontConfigInterface.h"
#include "SkFontConfigTypeface.h"
#include "SkFontMgr.h"
#include "SkFontStyle.h"
#include "SkMath.h"
#include "SkMutex.h"
#include "SkString.h"
#include "SkTDArray.h"
// for now we pull these in directly. eventually we will solely rely on the
// SkFontConfigInterface instance.
#include <fontconfig/fontconfig.h>
#include <unistd.h>
namespace {
// Fontconfig is not threadsafe before 2.10.91. Before that, we lock with a global mutex.
// See skia:1497 for background.
SK_DECLARE_STATIC_MUTEX(gFCMutex);
static bool gFCSafeToUse;
struct FCLocker {
FCLocker() {
if (FcGetVersion() < 21091) { // We assume FcGetVersion() has always been thread safe.
gFCMutex.acquire();
fUnlock = true;
} else {
fUnlock = false;
}
gFCSafeToUse = true;
}
~FCLocker() {
if (fUnlock) {
gFCSafeToUse = false;
gFCMutex.release();
}
}
private:
bool fUnlock;
};
} // namespace
// borrow this global from SkFontHost_fontconfig. eventually that file should
// go away, and be replaced with this one.
extern SkFontConfigInterface* SkFontHost_fontconfig_ref_global();
static SkFontConfigInterface* RefFCI() {
return SkFontHost_fontconfig_ref_global();
}
// look for the last substring after a '/' and return that, or return null.
static const char* find_just_name(const char* str) {
const char* last = strrchr(str, '/');
return last ? last + 1 : nullptr;
}
static bool is_lower(char c) {
return c >= 'a' && c <= 'z';
}
static int get_int(FcPattern* pattern, const char field[]) {
SkASSERT(gFCSafeToUse);
int value;
if (FcPatternGetInteger(pattern, field, 0, &value) != FcResultMatch) {
value = SK_MinS32;
}
return value;
}
static const char* get_name(FcPattern* pattern, const char field[]) {
SkASSERT(gFCSafeToUse);
const char* name;
if (FcPatternGetString(pattern, field, 0, (FcChar8**)&name) != FcResultMatch) {
name = "";
}
return name;
}
static bool valid_pattern(FcPattern* pattern) {
SkASSERT(gFCSafeToUse);
FcBool is_scalable;
if (FcPatternGetBool(pattern, FC_SCALABLE, 0, &is_scalable) != FcResultMatch || !is_scalable) {
return false;
}
// fontconfig can also return fonts which are unreadable
const char* c_filename = get_name(pattern, FC_FILE);
if (0 == *c_filename) {
return false;
}
if (access(c_filename, R_OK) != 0) {
return false;
}
return true;
}
static bool match_name(FcPattern* pattern, const char family_name[]) {
return !strcasecmp(family_name, get_name(pattern, FC_FAMILY));
}
static FcPattern** MatchFont(FcFontSet* font_set,
const char post_config_family[],
int* count) {
// Older versions of fontconfig have a bug where they cannot select
// only scalable fonts so we have to manually filter the results.
FcPattern** iter = font_set->fonts;
FcPattern** stop = iter + font_set->nfont;
// find the first good match
for (; iter < stop; ++iter) {
if (valid_pattern(*iter)) {
break;
}
}
if (iter == stop || !match_name(*iter, post_config_family)) {
return nullptr;
}
FcPattern** firstIter = iter++;
for (; iter < stop; ++iter) {
if (!valid_pattern(*iter) || !match_name(*iter, post_config_family)) {
break;
}
}
*count = iter - firstIter;
return firstIter;
}
class SkFontStyleSet_FC : public SkFontStyleSet {
public:
SkFontStyleSet_FC(FcPattern** matches, int count);
virtual ~SkFontStyleSet_FC();
int count() override { return fRecCount; }
void getStyle(int index, SkFontStyle*, SkString* style) override;
SkTypeface* createTypeface(int index) override;
SkTypeface* matchStyle(const SkFontStyle& pattern) override;
private:
struct Rec {
SkString fStyleName;
SkString fFileName;
SkFontStyle fStyle;
};
Rec* fRecs;
int fRecCount;
};
static int map_range(int value,
int old_min, int old_max, int new_min, int new_max) {
SkASSERT(old_min < old_max);
SkASSERT(new_min < new_max);
return new_min + SkMulDiv(value - old_min,
new_max - new_min, old_max - old_min);
}
static SkFontStyle make_fontconfig_style(FcPattern* match) {
int weight = get_int(match, FC_WEIGHT);
int width = get_int(match, FC_WIDTH);
int slant = get_int(match, FC_SLANT);
// SkDebugf("old weight %d new weight %d\n", weight, map_range(weight, 0, 80, 0, 400));
// fontconfig weight seems to be 0..200 or so, so we remap it here
weight = map_range(weight, 0, 80, 0, 400);
width = map_range(width, 0, 200, 0, 9);
return SkFontStyle(weight, width, slant > 0 ? SkFontStyle::kItalic_Slant
: SkFontStyle::kUpright_Slant);
}
SkFontStyleSet_FC::SkFontStyleSet_FC(FcPattern** matches, int count) {
fRecCount = count;
fRecs = new Rec[count];
for (int i = 0; i < count; ++i) {
fRecs[i].fStyleName.set(get_name(matches[i], FC_STYLE));
fRecs[i].fFileName.set(get_name(matches[i], FC_FILE));
fRecs[i].fStyle = make_fontconfig_style(matches[i]);
}
}
SkFontStyleSet_FC::~SkFontStyleSet_FC() { delete[] fRecs; }
void SkFontStyleSet_FC::getStyle(int index, SkFontStyle* style,
SkString* styleName) {
SkASSERT((unsigned)index < (unsigned)fRecCount);
if (style) {
*style = fRecs[index].fStyle;
}
if (styleName) {
*styleName = fRecs[index].fStyleName;
}
}
SkTypeface* SkFontStyleSet_FC::createTypeface(int index) {
return nullptr;
}
SkTypeface* SkFontStyleSet_FC::matchStyle(const SkFontStyle& pattern) {
return nullptr;
}
class SkFontMgr_fontconfig : public SkFontMgr {
SkAutoTUnref<SkFontConfigInterface> fFCI;
SkDataTable* fFamilyNames;
SkTypeface_FreeType::Scanner fScanner;
public:
SkFontMgr_fontconfig(SkFontConfigInterface* fci)
: fFCI(fci)
, fFamilyNames(fFCI->getFamilyNames()) {}
virtual ~SkFontMgr_fontconfig() {
SkSafeUnref(fFamilyNames);
}
protected:
int onCountFamilies() const override {
return fFamilyNames->count();
}
void onGetFamilyName(int index, SkString* familyName) const override {
familyName->set(fFamilyNames->atStr(index));
}
SkFontStyleSet* onCreateStyleSet(int index) const override {
return this->onMatchFamily(fFamilyNames->atStr(index));
}
SkFontStyleSet* onMatchFamily(const char familyName[]) const override {
FCLocker lock;
FcPattern* pattern = FcPatternCreate();
FcPatternAddString(pattern, FC_FAMILY, (FcChar8*)familyName);
#if 0
FcPatternAddBool(pattern, FC_SCALABLE, FcTrue);
#endif
FcConfigSubstitute(nullptr, pattern, FcMatchPattern);
FcDefaultSubstitute(pattern);
const char* post_config_family = get_name(pattern, FC_FAMILY);
FcResult result;
FcFontSet* font_set = FcFontSort(0, pattern, 0, 0, &result);
if (!font_set) {
FcPatternDestroy(pattern);
return nullptr;
}
int count;
FcPattern** match = MatchFont(font_set, post_config_family, &count);
if (!match) {
FcPatternDestroy(pattern);
FcFontSetDestroy(font_set);
return nullptr;
}
FcPatternDestroy(pattern);
SkTDArray<FcPattern*> trimmedMatches;
for (int i = 0; i < count; ++i) {
const char* justName = find_just_name(get_name(match[i], FC_FILE));
if (!is_lower(*justName)) {
*trimmedMatches.append() = match[i];
}
}
SkFontStyleSet_FC* sset =
new SkFontStyleSet_FC(trimmedMatches.begin(), trimmedMatches.count());
return sset;
}
SkTypeface* onMatchFamilyStyle(const char familyName[],
const SkFontStyle&) const override { return nullptr; }
SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
const char* bcp47[], int bcp47Count,
SkUnichar character) const override {
return nullptr;
}
SkTypeface* onMatchFaceStyle(const SkTypeface*,
const SkFontStyle&) const override { return nullptr; }
SkTypeface* onCreateFromData(SkData*, int ttcIndex) const override { return nullptr; }
SkTypeface* onCreateFromStream(SkStreamAsset* bareStream, int ttcIndex) const override {
SkAutoTDelete<SkStreamAsset> stream(bareStream);
const size_t length = stream->getLength();
if (!length) {
return nullptr;
}
if (length >= 1024 * 1024 * 1024) {
return nullptr; // don't accept too large fonts (>= 1GB) for safety.
}
// TODO should the caller give us the style or should we get it from freetype?
SkFontStyle style;
bool isFixedWidth = false;
if (!fScanner.scanFont(stream, 0, nullptr, &style, &isFixedWidth, nullptr)) {
return nullptr;
}
SkTypeface* face = FontConfigTypeface::Create(style, isFixedWidth, stream.detach());
return face;
}
SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const override {
SkAutoTDelete<SkStreamAsset> stream(SkStream::NewFromFile(path));
return stream.get() ? this->createFromStream(stream.detach(), ttcIndex) : nullptr;
}
SkTypeface* onLegacyCreateTypeface(const char familyName[],
unsigned styleBits) const override {
FCLocker lock;
return FontConfigTypeface::LegacyCreateTypeface(familyName, (SkTypeface::Style)styleBits);
}
};
SkFontMgr* SkFontMgr::Factory() {
SkFontConfigInterface* fci = RefFCI();
return fci ? new SkFontMgr_fontconfig(fci) : nullptr;
}