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1 /*
2  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1.  Redistributions of source code must retain the above copyright
9  *     notice, this list of conditions and the following disclaimer.
10  * 2.  Redistributions in binary form must reproduce the above copyright
11  *     notice, this list of conditions and the following disclaimer in the
12  *     documentation and/or other materials provided with the distribution.
13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14  *     its contributors may be used to endorse or promote products derived
15  *     from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "config.h"
30 #include "GlyphPageTreeNode.h"
31 
32 #include "CString.h"
33 #include "CharacterNames.h"
34 #include "SegmentedFontData.h"
35 #include "SimpleFontData.h"
36 #include <wtf/unicode/Unicode.h>
37 
38 namespace WebCore {
39 
40 using std::max;
41 using std::min;
42 
43 HashMap<int, GlyphPageTreeNode*>* GlyphPageTreeNode::roots = 0;
44 GlyphPageTreeNode* GlyphPageTreeNode::pageZeroRoot = 0;
45 
getRoot(unsigned pageNumber)46 GlyphPageTreeNode* GlyphPageTreeNode::getRoot(unsigned pageNumber)
47 {
48     static bool initialized;
49     if (!initialized) {
50         initialized = true;
51         roots = new HashMap<int, GlyphPageTreeNode*>;
52         pageZeroRoot = new GlyphPageTreeNode;
53     }
54 
55     GlyphPageTreeNode* node = pageNumber ? roots->get(pageNumber) : pageZeroRoot;
56     if (!node) {
57         node = new GlyphPageTreeNode;
58 #ifndef NDEBUG
59         node->m_pageNumber = pageNumber;
60 #endif
61         if (pageNumber)
62             roots->set(pageNumber, node);
63         else
64             pageZeroRoot = node;
65     }
66     return node;
67 }
68 
treeGlyphPageCount()69 size_t GlyphPageTreeNode::treeGlyphPageCount()
70 {
71     size_t count = 0;
72     if (roots) {
73         HashMap<int, GlyphPageTreeNode*>::iterator end = roots->end();
74         for (HashMap<int, GlyphPageTreeNode*>::iterator it = roots->begin(); it != end; ++it)
75             count += it->second->pageCount();
76     }
77 
78     if (pageZeroRoot)
79         count += pageZeroRoot->pageCount();
80 
81     return count;
82 }
83 
pageCount() const84 size_t GlyphPageTreeNode::pageCount() const
85 {
86     size_t count = m_page && m_page->owner() == this ? 1 : 0;
87     HashMap<const FontData*, GlyphPageTreeNode*>::const_iterator end = m_children.end();
88     for (HashMap<const FontData*, GlyphPageTreeNode*>::const_iterator it = m_children.begin(); it != end; ++it)
89         count += it->second->pageCount();
90 
91     return count;
92 }
93 
pruneTreeCustomFontData(const FontData * fontData)94 void GlyphPageTreeNode::pruneTreeCustomFontData(const FontData* fontData)
95 {
96     // Enumerate all the roots and prune any tree that contains our custom font data.
97     if (roots) {
98         HashMap<int, GlyphPageTreeNode*>::iterator end = roots->end();
99         for (HashMap<int, GlyphPageTreeNode*>::iterator it = roots->begin(); it != end; ++it)
100             it->second->pruneCustomFontData(fontData);
101     }
102 
103     if (pageZeroRoot)
104         pageZeroRoot->pruneCustomFontData(fontData);
105 }
106 
pruneTreeFontData(const SimpleFontData * fontData)107 void GlyphPageTreeNode::pruneTreeFontData(const SimpleFontData* fontData)
108 {
109     if (roots) {
110         HashMap<int, GlyphPageTreeNode*>::iterator end = roots->end();
111         for (HashMap<int, GlyphPageTreeNode*>::iterator it = roots->begin(); it != end; ++it)
112             it->second->pruneFontData(fontData);
113     }
114 
115     if (pageZeroRoot)
116         pageZeroRoot->pruneFontData(fontData);
117 }
118 
~GlyphPageTreeNode()119 GlyphPageTreeNode::~GlyphPageTreeNode()
120 {
121     deleteAllValues(m_children);
122     delete m_systemFallbackChild;
123 }
124 
initializePage(const FontData * fontData,unsigned pageNumber)125 void GlyphPageTreeNode::initializePage(const FontData* fontData, unsigned pageNumber)
126 {
127     ASSERT(!m_page);
128 
129     // This function must not be called for the root of the tree, because that
130     // level does not contain any glyphs.
131     ASSERT(m_level > 0 && m_parent);
132 
133     // The parent's page will be 0 if we are level one or the parent's font data
134     // did not contain any glyphs for that page.
135     GlyphPage* parentPage = m_parent->page();
136 
137     // NULL FontData means we're being asked for the system fallback font.
138     if (fontData) {
139         if (m_level == 1) {
140             // Children of the root hold pure pages. These will cover only one
141             // font data's glyphs, and will have glyph index 0 if the font data does not
142             // contain the glyph.
143             unsigned start = pageNumber * GlyphPage::size;
144             UChar buffer[GlyphPage::size * 2 + 2];
145             unsigned bufferLength;
146             unsigned i;
147 
148             // Fill in a buffer with the entire "page" of characters that we want to look up glyphs for.
149             if (start < 0x10000) {
150                 bufferLength = GlyphPage::size;
151                 for (i = 0; i < GlyphPage::size; i++)
152                     buffer[i] = start + i;
153 
154                 if (start == 0) {
155                     // Control characters must not render at all.
156                     for (i = 0; i < 0x20; ++i)
157                         buffer[i] = zeroWidthSpace;
158                     for (i = 0x7F; i < 0xA0; i++)
159                         buffer[i] = zeroWidthSpace;
160 
161                     // \n, \t, and nonbreaking space must render as a space.
162                     buffer[(int)'\n'] = ' ';
163                     buffer[(int)'\t'] = ' ';
164                     buffer[noBreakSpace] = ' ';
165                 } else if (start == (leftToRightMark & ~(GlyphPage::size - 1))) {
166                     // LRM, RLM, LRE, RLE and PDF must not render at all.
167                     buffer[leftToRightMark - start] = zeroWidthSpace;
168                     buffer[rightToLeftMark - start] = zeroWidthSpace;
169                     buffer[leftToRightEmbed - start] = zeroWidthSpace;
170                     buffer[rightToLeftEmbed - start] = zeroWidthSpace;
171                     buffer[leftToRightOverride - start] = zeroWidthSpace;
172                     buffer[rightToLeftOverride - start] = zeroWidthSpace;
173                     buffer[popDirectionalFormatting - start] = zeroWidthSpace;
174                 } else if (start == (objectReplacementCharacter & ~(GlyphPage::size - 1))) {
175                     // Object replacement character must not render at all.
176                     buffer[objectReplacementCharacter - start] = zeroWidthSpace;
177                 }
178             } else {
179                 bufferLength = GlyphPage::size * 2;
180                 for (i = 0; i < GlyphPage::size; i++) {
181                     int c = i + start;
182                     buffer[i * 2] = U16_LEAD(c);
183                     buffer[i * 2 + 1] = U16_TRAIL(c);
184                 }
185             }
186 
187             m_page = GlyphPage::create(this);
188 
189             // Now that we have a buffer full of characters, we want to get back an array
190             // of glyph indices.  This part involves calling into the platform-specific
191             // routine of our glyph map for actually filling in the page with the glyphs.
192             // Success is not guaranteed. For example, Times fails to fill page 260, giving glyph data
193             // for only 128 out of 256 characters.
194             bool haveGlyphs;
195             if (fontData->isSegmented()) {
196                 haveGlyphs = false;
197 
198                 const SegmentedFontData* segmentedFontData = static_cast<const SegmentedFontData*>(fontData);
199                 unsigned numRanges = segmentedFontData->numRanges();
200                 bool zeroFilled = false;
201                 RefPtr<GlyphPage> scratchPage;
202                 GlyphPage* pageToFill = m_page.get();
203                 for (unsigned i = 0; i < numRanges; i++) {
204                     const FontDataRange& range = segmentedFontData->rangeAt(i);
205                     int from = max(0, range.from() - static_cast<int>(start));
206                     int to = 1 + min(range.to() - static_cast<int>(start), static_cast<int>(GlyphPage::size) - 1);
207                     if (from < static_cast<int>(GlyphPage::size) && to > 0) {
208                         if (haveGlyphs && !scratchPage) {
209                             scratchPage = GlyphPage::create(this);
210                             pageToFill = scratchPage.get();
211                         }
212 
213                         if (!zeroFilled) {
214                             if (from > 0 || to < static_cast<int>(GlyphPage::size)) {
215                                 for (unsigned i = 0; i < GlyphPage::size; i++)
216                                     pageToFill->setGlyphDataForIndex(i, 0, 0);
217                             }
218                             zeroFilled = true;
219                         }
220                         haveGlyphs |= pageToFill->fill(from, to - from, buffer + from * (start < 0x10000 ? 1 : 2), (to - from) * (start < 0x10000 ? 1 : 2), range.fontData());
221                         if (scratchPage) {
222                             ASSERT(to <=  static_cast<int>(GlyphPage::size));
223                             for (int j = from; j < to; j++) {
224                                 if (!m_page->glyphAt(j) && pageToFill->glyphAt(j))
225                                     m_page->setGlyphDataForIndex(j, pageToFill->glyphDataForIndex(j));
226                             }
227                         }
228                     }
229                 }
230             } else
231                 haveGlyphs = m_page->fill(0, GlyphPage::size, buffer, bufferLength, static_cast<const SimpleFontData*>(fontData));
232 
233             if (!haveGlyphs)
234                 m_page = 0;
235         } else if (parentPage && parentPage->owner() != m_parent) {
236             // The page we're overriding may not be owned by our parent node.
237             // This happens when our parent node provides no useful overrides
238             // and just copies the pointer to an already-existing page (see
239             // below).
240             //
241             // We want our override to be shared by all nodes that reference
242             // that page to avoid duplication, and so standardize on having the
243             // page's owner collect all the overrides.  Call getChild on the
244             // page owner with the desired font data (this will populate
245             // the page) and then reference it.
246             m_page = parentPage->owner()->getChild(fontData, pageNumber)->page();
247         } else {
248             // Get the pure page for the fallback font (at level 1 with no
249             // overrides). getRootChild will always create a page if one
250             // doesn't exist, but the page doesn't necessarily have glyphs
251             // (this pointer may be 0).
252             GlyphPage* fallbackPage = getRootChild(fontData, pageNumber)->page();
253             if (!parentPage) {
254                 // When the parent has no glyphs for this page, we can easily
255                 // override it just by supplying the glyphs from our font.
256                 m_page = fallbackPage;
257             } else if (!fallbackPage) {
258                 // When our font has no glyphs for this page, we can just reference the
259                 // parent page.
260                 m_page = parentPage;
261             } else {
262                 // Combine the parent's glyphs and ours to form a new more complete page.
263                 m_page = GlyphPage::create(this);
264 
265                 // Overlay the parent page on the fallback page. Check if the fallback font
266                 // has added anything.
267                 bool newGlyphs = false;
268                 for (unsigned i = 0; i < GlyphPage::size; i++) {
269                     if (parentPage->glyphAt(i))
270                         m_page->setGlyphDataForIndex(i, parentPage->glyphDataForIndex(i));
271                     else  if (fallbackPage->glyphAt(i)) {
272                         m_page->setGlyphDataForIndex(i, fallbackPage->glyphDataForIndex(i));
273                         newGlyphs = true;
274                     } else
275                         m_page->setGlyphDataForIndex(i, 0, 0);
276                 }
277 
278                 if (!newGlyphs)
279                     // We didn't override anything, so our override is just the parent page.
280                     m_page = parentPage;
281             }
282         }
283     } else {
284         m_page = GlyphPage::create(this);
285         // System fallback. Initialized with the parent's page here, as individual
286         // entries may use different fonts depending on character. If the Font
287         // ever finds it needs a glyph out of the system fallback page, it will
288         // ask the system for the best font to use and fill that glyph in for us.
289         if (parentPage)
290             m_page->copyFrom(*parentPage);
291         else
292             m_page->clear();
293     }
294 }
295 
getChild(const FontData * fontData,unsigned pageNumber)296 GlyphPageTreeNode* GlyphPageTreeNode::getChild(const FontData* fontData, unsigned pageNumber)
297 {
298     ASSERT(fontData || !m_isSystemFallback);
299     ASSERT(pageNumber == m_pageNumber);
300 
301     GlyphPageTreeNode* child = fontData ? m_children.get(fontData) : m_systemFallbackChild;
302     if (!child) {
303         child = new GlyphPageTreeNode;
304         child->m_parent = this;
305         child->m_level = m_level + 1;
306         if (fontData && fontData->isCustomFont()) {
307             for (GlyphPageTreeNode* curr = this; curr; curr = curr->m_parent)
308                 curr->m_customFontCount++;
309         }
310 
311 #ifndef NDEBUG
312         child->m_pageNumber = m_pageNumber;
313 #endif
314         if (fontData) {
315             m_children.set(fontData, child);
316             fontData->setMaxGlyphPageTreeLevel(max(fontData->maxGlyphPageTreeLevel(), child->m_level));
317         } else {
318             m_systemFallbackChild = child;
319             child->m_isSystemFallback = true;
320         }
321         child->initializePage(fontData, pageNumber);
322     }
323     return child;
324 }
325 
pruneCustomFontData(const FontData * fontData)326 void GlyphPageTreeNode::pruneCustomFontData(const FontData* fontData)
327 {
328     if (!fontData || !m_customFontCount)
329         return;
330 
331     // Prune any branch that contains this FontData.
332     GlyphPageTreeNode* node = m_children.get(fontData);
333     if (node) {
334         m_children.remove(fontData);
335         unsigned fontCount = node->m_customFontCount + 1;
336         delete node;
337         for (GlyphPageTreeNode* curr = this; curr; curr = curr->m_parent)
338             curr->m_customFontCount -= fontCount;
339     }
340 
341     // Check any branches that remain that still have custom fonts underneath them.
342     if (!m_customFontCount)
343         return;
344     HashMap<const FontData*, GlyphPageTreeNode*>::iterator end = m_children.end();
345     for (HashMap<const FontData*, GlyphPageTreeNode*>::iterator it = m_children.begin(); it != end; ++it)
346         it->second->pruneCustomFontData(fontData);
347 }
348 
pruneFontData(const SimpleFontData * fontData,unsigned level)349 void GlyphPageTreeNode::pruneFontData(const SimpleFontData* fontData, unsigned level)
350 {
351     ASSERT(fontData);
352     if (!fontData)
353         return;
354 
355     // Prune any branch that contains this FontData.
356     HashMap<const FontData*, GlyphPageTreeNode*>::iterator child = m_children.find(fontData);
357     if (child == m_children.end()) {
358         // If there is no level-1 node for fontData, then there is no deeper node for it in this tree.
359         if (!level)
360             return;
361     } else {
362         GlyphPageTreeNode* node = child->second;
363         m_children.remove(fontData);
364         unsigned customFontCount = node->m_customFontCount;
365         delete node;
366         if (customFontCount) {
367             for (GlyphPageTreeNode* curr = this; curr; curr = curr->m_parent)
368                 curr->m_customFontCount -= customFontCount;
369         }
370     }
371 
372     level++;
373     if (level > fontData->maxGlyphPageTreeLevel())
374         return;
375 
376     HashMap<const FontData*, GlyphPageTreeNode*>::iterator end = m_children.end();
377     for (HashMap<const FontData*, GlyphPageTreeNode*>::iterator it = m_children.begin(); it != end; ++it)
378         it->second->pruneFontData(fontData, level);
379 }
380 
381 #ifndef NDEBUG
showSubtree()382     void GlyphPageTreeNode::showSubtree()
383     {
384         Vector<char> indent(level());
385         indent.fill('\t', level());
386         indent.append(0);
387 
388         HashMap<const FontData*, GlyphPageTreeNode*>::iterator end = m_children.end();
389         for (HashMap<const FontData*, GlyphPageTreeNode*>::iterator it = m_children.begin(); it != end; ++it) {
390             printf("%s\t%p %s\n", indent.data(), it->first, it->first->description().utf8().data());
391             it->second->showSubtree();
392         }
393         if (m_systemFallbackChild) {
394             printf("%s\t* fallback\n", indent.data());
395             m_systemFallbackChild->showSubtree();
396         }
397     }
398 #endif
399 
400 }
401 
402 #ifndef NDEBUG
showGlyphPageTrees()403 void showGlyphPageTrees()
404 {
405     printf("Page 0:\n");
406     showGlyphPageTree(0);
407     HashMap<int, WebCore::GlyphPageTreeNode*>::iterator end = WebCore::GlyphPageTreeNode::roots->end();
408     for (HashMap<int, WebCore::GlyphPageTreeNode*>::iterator it = WebCore::GlyphPageTreeNode::roots->begin(); it != end; ++it) {
409         printf("\nPage %d:\n", it->first);
410         showGlyphPageTree(it->first);
411     }
412 }
413 
showGlyphPageTree(unsigned pageNumber)414 void showGlyphPageTree(unsigned pageNumber)
415 {
416     WebCore::GlyphPageTreeNode::getRoot(pageNumber)->showSubtree();
417 }
418 #endif
419