gfx/2d/ScaledFontMac.cpp@97036ab72558
gfx/2d/ScaledFontMac.cpp
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 * This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 #include "ScaledFontMac.h"
7 #ifdef USE_SKIA
8 #include "PathSkia.h"
9 #include "skia/SkPaint.h"
10 #include "skia/SkPath.h"
11 #include "skia/SkTypeface_mac.h"
12 #endif
13 #include "DrawTargetCG.h"
14 #include <vector>
15 #include <dlfcn.h>
17 // prototype for private API
18 extern "C" {
19 CGPathRef CGFontGetGlyphPath(CGFontRef fontRef, CGAffineTransform *textTransform, int unknown, CGGlyph glyph);
20 };
23 namespace mozilla {
24 namespace gfx {
26 ScaledFontMac::CTFontDrawGlyphsFuncT* ScaledFontMac::CTFontDrawGlyphsPtr = nullptr;
27 bool ScaledFontMac::sSymbolLookupDone = false;
29 ScaledFontMac::ScaledFontMac(CGFontRef aFont, Float aSize)
30 : ScaledFontBase(aSize)
31 {
32 if (!sSymbolLookupDone) {
33 CTFontDrawGlyphsPtr =
34 (CTFontDrawGlyphsFuncT*)dlsym(RTLD_DEFAULT, "CTFontDrawGlyphs");
35 sSymbolLookupDone = true;
36 }
38 // XXX: should we be taking a reference
39 mFont = CGFontRetain(aFont);
40 if (CTFontDrawGlyphsPtr != nullptr) {
41 // only create mCTFont if we're going to be using the CTFontDrawGlyphs API
42 mCTFont = CTFontCreateWithGraphicsFont(aFont, aSize, nullptr, nullptr);
43 } else {
44 mCTFont = nullptr;
45 }
46 }
48 ScaledFontMac::~ScaledFontMac()
49 {
50 if (mCTFont) {
51 CFRelease(mCTFont);
52 }
53 CGFontRelease(mFont);
54 }
56 #ifdef USE_SKIA
57 SkTypeface* ScaledFontMac::GetSkTypeface()
58 {
59 if (!mTypeface) {
60 if (mCTFont) {
61 mTypeface = SkCreateTypefaceFromCTFont(mCTFont);
62 } else {
63 CTFontRef fontFace = CTFontCreateWithGraphicsFont(mFont, mSize, nullptr, nullptr);
64 mTypeface = SkCreateTypefaceFromCTFont(fontFace);
65 CFRelease(fontFace);
66 }
67 }
68 return mTypeface;
69 }
70 #endif
72 // private API here are the public options on OS X
73 // CTFontCreatePathForGlyph
74 // ATSUGlyphGetCubicPaths
75 // we've used this in cairo sucessfully for some time.
76 // Note: cairo dlsyms it. We could do that but maybe it's
77 // safe just to use?
79 TemporaryRef<Path>
80 ScaledFontMac::GetPathForGlyphs(const GlyphBuffer &aBuffer, const DrawTarget *aTarget)
81 {
82 if (aTarget->GetType() == BackendType::COREGRAPHICS || aTarget->GetType() == BackendType::COREGRAPHICS_ACCELERATED) {
83 CGMutablePathRef path = CGPathCreateMutable();
85 for (unsigned int i = 0; i < aBuffer.mNumGlyphs; i++) {
86 // XXX: we could probably fold both of these transforms together to avoid extra work
87 CGAffineTransform flip = CGAffineTransformMakeScale(1, -1);
88 CGPathRef glyphPath = ::CGFontGetGlyphPath(mFont, &flip, 0, aBuffer.mGlyphs[i].mIndex);
90 CGAffineTransform matrix = CGAffineTransformMake(mSize, 0, 0, mSize,
91 aBuffer.mGlyphs[i].mPosition.x,
92 aBuffer.mGlyphs[i].mPosition.y);
93 CGPathAddPath(path, &matrix, glyphPath);
94 CGPathRelease(glyphPath);
95 }
96 TemporaryRef<Path> ret = new PathCG(path, FillRule::FILL_WINDING);
97 CGPathRelease(path);
98 return ret;
99 } else {
100 return ScaledFontBase::GetPathForGlyphs(aBuffer, aTarget);
101 }
102 }
104 void
105 ScaledFontMac::CopyGlyphsToBuilder(const GlyphBuffer &aBuffer, PathBuilder *aBuilder, BackendType aBackendType, const Matrix *aTransformHint)
106 {
107 if (!(aBackendType == BackendType::COREGRAPHICS || aBackendType == BackendType::COREGRAPHICS_ACCELERATED)) {
108 ScaledFontBase::CopyGlyphsToBuilder(aBuffer, aBuilder, aBackendType, aTransformHint);
109 return;
110 }
112 PathBuilderCG *pathBuilderCG =
113 static_cast<PathBuilderCG*>(aBuilder);
114 // XXX: check builder type
115 for (unsigned int i = 0; i < aBuffer.mNumGlyphs; i++) {
116 // XXX: we could probably fold both of these transforms together to avoid extra work
117 CGAffineTransform flip = CGAffineTransformMakeScale(1, -1);
118 CGPathRef glyphPath = ::CGFontGetGlyphPath(mFont, &flip, 0, aBuffer.mGlyphs[i].mIndex);
120 CGAffineTransform matrix = CGAffineTransformMake(mSize, 0, 0, mSize,
121 aBuffer.mGlyphs[i].mPosition.x,
122 aBuffer.mGlyphs[i].mPosition.y);
123 CGPathAddPath(pathBuilderCG->mCGPath, &matrix, glyphPath);
124 CGPathRelease(glyphPath);
125 }
126 }
128 uint32_t
129 CalcTableChecksum(const uint32_t *tableStart, uint32_t length, bool skipChecksumAdjust = false)
130 {
131 uint32_t sum = 0L;
132 const uint32_t *table = tableStart;
133 const uint32_t *end = table+((length+3) & ~3) / sizeof(uint32_t);
134 while (table < end) {
135 if (skipChecksumAdjust && (table - tableStart) == 2) {
136 table++;
137 } else {
138 sum += CFSwapInt32BigToHost(*table++);
139 }
140 }
141 return sum;
142 }
144 struct TableRecord {
145 uint32_t tag;
146 uint32_t checkSum;
147 uint32_t offset;
148 uint32_t length;
149 CFDataRef data;
150 };
152 int maxPow2LessThan(int a)
153 {
154 int x = 1;
155 int shift = 0;
156 while ((x<<(shift+1)) < a) {
157 shift++;
158 }
159 return shift;
160 }
162 struct writeBuf
163 {
164 writeBuf(int size)
165 {
166 this->data = new unsigned char [size];
167 this->offset = 0;
168 }
169 ~writeBuf() {
170 delete this->data;
171 }
173 template <class T>
174 void writeElement(T a)
175 {
176 *reinterpret_cast<T*>(&this->data[this->offset]) = a;
177 this->offset += sizeof(T);
178 }
180 void writeMem(const void *data, unsigned long length)
181 {
182 memcpy(&this->data[this->offset], data, length);
183 this->offset += length;
184 }
186 void align()
187 {
188 while (this->offset & 3) {
189 this->data[this->offset] = 0;
190 this->offset++;
191 }
192 }
194 unsigned char *data;
195 int offset;
196 };
198 bool
199 ScaledFontMac::GetFontFileData(FontFileDataOutput aDataCallback, void *aBaton)
200 {
201 // We'll reconstruct a TTF font from the tables we can get from the CGFont
202 CFArrayRef tags = CGFontCopyTableTags(mFont);
203 CFIndex count = CFArrayGetCount(tags);
205 TableRecord *records = new TableRecord[count];
206 uint32_t offset = 0;
207 offset += sizeof(uint32_t)*3;
208 offset += sizeof(uint32_t)*4*count;
209 bool CFF = false;
210 for (CFIndex i = 0; i<count; i++) {
211 uint32_t tag = (uint32_t)(uintptr_t)CFArrayGetValueAtIndex(tags, i);
212 if (tag == 0x43464620) // 'CFF '
213 CFF = true;
214 CFDataRef data = CGFontCopyTableForTag(mFont, tag);
215 records[i].tag = tag;
216 records[i].offset = offset;
217 records[i].data = data;
218 records[i].length = CFDataGetLength(data);
219 bool skipChecksumAdjust = (tag == 0x68656164); // 'head'
220 records[i].checkSum = CalcTableChecksum(reinterpret_cast<const uint32_t*>(CFDataGetBytePtr(data)),
221 records[i].length, skipChecksumAdjust);
222 offset += records[i].length;
223 // 32 bit align the tables
224 offset = (offset + 3) & ~3;
225 }
226 CFRelease(tags);
228 struct writeBuf buf(offset);
229 // write header/offset table
230 if (CFF) {
231 buf.writeElement(CFSwapInt32HostToBig(0x4f54544f));
232 } else {
233 buf.writeElement(CFSwapInt32HostToBig(0x00010000));
234 }
235 buf.writeElement(CFSwapInt16HostToBig(count));
236 buf.writeElement(CFSwapInt16HostToBig((1<<maxPow2LessThan(count))*16));
237 buf.writeElement(CFSwapInt16HostToBig(maxPow2LessThan(count)));
238 buf.writeElement(CFSwapInt16HostToBig(count*16-((1<<maxPow2LessThan(count))*16)));
240 // write table record entries
241 for (CFIndex i = 0; i<count; i++) {
242 buf.writeElement(CFSwapInt32HostToBig(records[i].tag));
243 buf.writeElement(CFSwapInt32HostToBig(records[i].checkSum));
244 buf.writeElement(CFSwapInt32HostToBig(records[i].offset));
245 buf.writeElement(CFSwapInt32HostToBig(records[i].length));
246 }
248 // write tables
249 int checkSumAdjustmentOffset = 0;
250 for (CFIndex i = 0; i<count; i++) {
251 if (records[i].tag == 0x68656164) {
252 checkSumAdjustmentOffset = buf.offset + 2*4;
253 }
254 buf.writeMem(CFDataGetBytePtr(records[i].data), CFDataGetLength(records[i].data));
255 buf.align();
256 CFRelease(records[i].data);
257 }
258 delete[] records;
260 // clear the checksumAdjust field before checksumming the whole font
261 memset(&buf.data[checkSumAdjustmentOffset], 0, sizeof(uint32_t));
262 uint32_t fontChecksum = CFSwapInt32HostToBig(0xb1b0afba - CalcTableChecksum(reinterpret_cast<const uint32_t*>(buf.data), offset));
263 // set checkSumAdjust to the computed checksum
264 memcpy(&buf.data[checkSumAdjustmentOffset], &fontChecksum, sizeof(fontChecksum));
266 // we always use an index of 0
267 aDataCallback(buf.data, buf.offset, 0, mSize, aBaton);
269 return true;
271 }
273 }
274 }
