gecko-dev/gfx/2d/ScaledFontMac.cpp

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2012-05-21 11:12:37 +00:00
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "ScaledFontMac.h"
#ifdef USE_SKIA
#include "PathSkia.h"
#include "skia/SkPaint.h"
#include "skia/SkPath.h"
#include "skia/SkTypeface_mac.h"
#endif
#include "DrawTargetCG.h"
#include <vector>
#include <dlfcn.h>
// prototype for private API
extern "C" {
CGPathRef CGFontGetGlyphPath(CGFontRef fontRef, CGAffineTransform *textTransform, int unknown, CGGlyph glyph);
};
namespace mozilla {
namespace gfx {
ScaledFontMac::CTFontDrawGlyphsFuncT* ScaledFontMac::CTFontDrawGlyphsPtr = nullptr;
bool ScaledFontMac::sSymbolLookupDone = false;
ScaledFontMac::ScaledFontMac(CGFontRef aFont, Float aSize)
: ScaledFontBase(aSize)
{
if (!sSymbolLookupDone) {
CTFontDrawGlyphsPtr =
(CTFontDrawGlyphsFuncT*)dlsym(RTLD_DEFAULT, "CTFontDrawGlyphs");
sSymbolLookupDone = true;
}
// XXX: should we be taking a reference
mFont = CGFontRetain(aFont);
if (CTFontDrawGlyphsPtr != nullptr) {
// only create mCTFont if we're going to be using the CTFontDrawGlyphs API
mCTFont = CTFontCreateWithGraphicsFont(aFont, aSize, nullptr, nullptr);
} else {
mCTFont = nullptr;
}
}
ScaledFontMac::~ScaledFontMac()
{
if (mCTFont) {
CFRelease(mCTFont);
}
CGFontRelease(mFont);
}
#ifdef USE_SKIA
SkTypeface* ScaledFontMac::GetSkTypeface()
{
if (!mTypeface) {
if (mCTFont) {
mTypeface = SkCreateTypefaceFromCTFont(mCTFont);
} else {
CTFontRef fontFace = CTFontCreateWithGraphicsFont(mFont, mSize, nullptr, nullptr);
mTypeface = SkCreateTypefaceFromCTFont(fontFace);
CFRelease(fontFace);
}
}
return mTypeface;
}
#endif
// private API here are the public options on OS X
// CTFontCreatePathForGlyph
// ATSUGlyphGetCubicPaths
// we've used this in cairo sucessfully for some time.
// Note: cairo dlsyms it. We could do that but maybe it's
// safe just to use?
TemporaryRef<Path>
ScaledFontMac::GetPathForGlyphs(const GlyphBuffer &aBuffer, const DrawTarget *aTarget)
{
if (aTarget->GetBackendType() == BackendType::COREGRAPHICS ||
aTarget->GetBackendType() == BackendType::COREGRAPHICS_ACCELERATED) {
CGMutablePathRef path = CGPathCreateMutable();
for (unsigned int i = 0; i < aBuffer.mNumGlyphs; i++) {
// XXX: we could probably fold both of these transforms together to avoid extra work
CGAffineTransform flip = CGAffineTransformMakeScale(1, -1);
CGPathRef glyphPath = ::CGFontGetGlyphPath(mFont, &flip, 0, aBuffer.mGlyphs[i].mIndex);
CGAffineTransform matrix = CGAffineTransformMake(mSize, 0, 0, mSize,
aBuffer.mGlyphs[i].mPosition.x,
aBuffer.mGlyphs[i].mPosition.y);
CGPathAddPath(path, &matrix, glyphPath);
CGPathRelease(glyphPath);
}
TemporaryRef<Path> ret = new PathCG(path, FillRule::FILL_WINDING);
CGPathRelease(path);
return ret;
}
return ScaledFontBase::GetPathForGlyphs(aBuffer, aTarget);
}
void
ScaledFontMac::CopyGlyphsToBuilder(const GlyphBuffer &aBuffer, PathBuilder *aBuilder, BackendType aBackendType, const Matrix *aTransformHint)
{
if (!(aBackendType == BackendType::COREGRAPHICS || aBackendType == BackendType::COREGRAPHICS_ACCELERATED)) {
ScaledFontBase::CopyGlyphsToBuilder(aBuffer, aBuilder, aBackendType, aTransformHint);
return;
}
PathBuilderCG *pathBuilderCG =
static_cast<PathBuilderCG*>(aBuilder);
// XXX: check builder type
for (unsigned int i = 0; i < aBuffer.mNumGlyphs; i++) {
// XXX: we could probably fold both of these transforms together to avoid extra work
CGAffineTransform flip = CGAffineTransformMakeScale(1, -1);
CGPathRef glyphPath = ::CGFontGetGlyphPath(mFont, &flip, 0, aBuffer.mGlyphs[i].mIndex);
CGAffineTransform matrix = CGAffineTransformMake(mSize, 0, 0, mSize,
aBuffer.mGlyphs[i].mPosition.x,
aBuffer.mGlyphs[i].mPosition.y);
CGPathAddPath(pathBuilderCG->mCGPath, &matrix, glyphPath);
CGPathRelease(glyphPath);
}
}
uint32_t
CalcTableChecksum(const uint32_t *tableStart, uint32_t length, bool skipChecksumAdjust = false)
{
uint32_t sum = 0L;
const uint32_t *table = tableStart;
const uint32_t *end = table+((length+3) & ~3) / sizeof(uint32_t);
while (table < end) {
if (skipChecksumAdjust && (table - tableStart) == 2) {
table++;
} else {
sum += CFSwapInt32BigToHost(*table++);
}
}
return sum;
}
struct TableRecord {
uint32_t tag;
uint32_t checkSum;
uint32_t offset;
uint32_t length;
CFDataRef data;
};
int maxPow2LessThan(int a)
{
int x = 1;
int shift = 0;
while ((x<<(shift+1)) < a) {
shift++;
}
return shift;
}
struct writeBuf
{
explicit writeBuf(int size)
{
this->data = new unsigned char [size];
this->offset = 0;
}
~writeBuf() {
delete this->data;
}
template <class T>
void writeElement(T a)
{
*reinterpret_cast<T*>(&this->data[this->offset]) = a;
this->offset += sizeof(T);
}
void writeMem(const void *data, unsigned long length)
{
memcpy(&this->data[this->offset], data, length);
this->offset += length;
}
void align()
{
while (this->offset & 3) {
this->data[this->offset] = 0;
this->offset++;
}
}
unsigned char *data;
int offset;
};
bool
ScaledFontMac::GetFontFileData(FontFileDataOutput aDataCallback, void *aBaton)
{
// We'll reconstruct a TTF font from the tables we can get from the CGFont
CFArrayRef tags = CGFontCopyTableTags(mFont);
CFIndex count = CFArrayGetCount(tags);
TableRecord *records = new TableRecord[count];
uint32_t offset = 0;
offset += sizeof(uint32_t)*3;
offset += sizeof(uint32_t)*4*count;
bool CFF = false;
for (CFIndex i = 0; i<count; i++) {
uint32_t tag = (uint32_t)(uintptr_t)CFArrayGetValueAtIndex(tags, i);
if (tag == 0x43464620) // 'CFF '
CFF = true;
CFDataRef data = CGFontCopyTableForTag(mFont, tag);
records[i].tag = tag;
records[i].offset = offset;
records[i].data = data;
records[i].length = CFDataGetLength(data);
bool skipChecksumAdjust = (tag == 0x68656164); // 'head'
records[i].checkSum = CalcTableChecksum(reinterpret_cast<const uint32_t*>(CFDataGetBytePtr(data)),
records[i].length, skipChecksumAdjust);
offset += records[i].length;
// 32 bit align the tables
offset = (offset + 3) & ~3;
}
CFRelease(tags);
struct writeBuf buf(offset);
// write header/offset table
if (CFF) {
buf.writeElement(CFSwapInt32HostToBig(0x4f54544f));
} else {
buf.writeElement(CFSwapInt32HostToBig(0x00010000));
}
buf.writeElement(CFSwapInt16HostToBig(count));
buf.writeElement(CFSwapInt16HostToBig((1<<maxPow2LessThan(count))*16));
buf.writeElement(CFSwapInt16HostToBig(maxPow2LessThan(count)));
buf.writeElement(CFSwapInt16HostToBig(count*16-((1<<maxPow2LessThan(count))*16)));
// write table record entries
for (CFIndex i = 0; i<count; i++) {
buf.writeElement(CFSwapInt32HostToBig(records[i].tag));
buf.writeElement(CFSwapInt32HostToBig(records[i].checkSum));
buf.writeElement(CFSwapInt32HostToBig(records[i].offset));
buf.writeElement(CFSwapInt32HostToBig(records[i].length));
}
// write tables
int checkSumAdjustmentOffset = 0;
for (CFIndex i = 0; i<count; i++) {
if (records[i].tag == 0x68656164) {
checkSumAdjustmentOffset = buf.offset + 2*4;
}
buf.writeMem(CFDataGetBytePtr(records[i].data), CFDataGetLength(records[i].data));
buf.align();
CFRelease(records[i].data);
}
delete[] records;
// clear the checksumAdjust field before checksumming the whole font
memset(&buf.data[checkSumAdjustmentOffset], 0, sizeof(uint32_t));
uint32_t fontChecksum = CFSwapInt32HostToBig(0xb1b0afba - CalcTableChecksum(reinterpret_cast<const uint32_t*>(buf.data), offset));
// set checkSumAdjust to the computed checksum
memcpy(&buf.data[checkSumAdjustmentOffset], &fontChecksum, sizeof(fontChecksum));
// we always use an index of 0
aDataCallback(buf.data, buf.offset, 0, mSize, aBaton);
return true;
}
}
}