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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 "platform/fonts/GlyphPageTreeNode.h"
     31 
     32 #include <stdio.h>
     33 #include "platform/fonts/SegmentedFontData.h"
     34 #include "platform/fonts/SimpleFontData.h"
     35 #include "platform/fonts/opentype/OpenTypeVerticalData.h"
     36 #include "wtf/text/CString.h"
     37 #include "wtf/text/WTFString.h"
     38 #include "wtf/unicode/CharacterNames.h"
     39 
     40 namespace WebCore {
     41 
     42 using std::max;
     43 using std::min;
     44 
     45 HashMap<int, GlyphPageTreeNode*>* GlyphPageTreeNode::roots = 0;
     46 GlyphPageTreeNode* GlyphPageTreeNode::pageZeroRoot = 0;
     47 
     48 GlyphPageTreeNode* GlyphPageTreeNode::getRoot(unsigned pageNumber)
     49 {
     50     static bool initialized;
     51     if (!initialized) {
     52         initialized = true;
     53         roots = new HashMap<int, GlyphPageTreeNode*>;
     54         pageZeroRoot = new GlyphPageTreeNode;
     55     }
     56 
     57     if (!pageNumber)
     58         return pageZeroRoot;
     59 
     60     if (GlyphPageTreeNode* foundNode = roots->get(pageNumber))
     61         return foundNode;
     62 
     63     GlyphPageTreeNode* node = new GlyphPageTreeNode;
     64 #ifndef NDEBUG
     65     node->m_pageNumber = pageNumber;
     66 #endif
     67     roots->set(pageNumber, node);
     68     return node;
     69 }
     70 
     71 size_t GlyphPageTreeNode::treeGlyphPageCount()
     72 {
     73     size_t count = 0;
     74     if (roots) {
     75         HashMap<int, GlyphPageTreeNode*>::iterator end = roots->end();
     76         for (HashMap<int, GlyphPageTreeNode*>::iterator it = roots->begin(); it != end; ++it)
     77             count += it->value->pageCount();
     78     }
     79 
     80     if (pageZeroRoot)
     81         count += pageZeroRoot->pageCount();
     82 
     83     return count;
     84 }
     85 
     86 size_t GlyphPageTreeNode::pageCount() const
     87 {
     88     size_t count = m_page && m_page->owner() == this ? 1 : 0;
     89     GlyphPageTreeNodeMap::const_iterator end = m_children.end();
     90     for (GlyphPageTreeNodeMap::const_iterator it = m_children.begin(); it != end; ++it)
     91         count += it->value->pageCount();
     92 
     93     return count;
     94 }
     95 
     96 void GlyphPageTreeNode::pruneTreeCustomFontData(const FontData* fontData)
     97 {
     98     // Enumerate all the roots and prune any tree that contains our custom font data.
     99     if (roots) {
    100         HashMap<int, GlyphPageTreeNode*>::iterator end = roots->end();
    101         for (HashMap<int, GlyphPageTreeNode*>::iterator it = roots->begin(); it != end; ++it)
    102             it->value->pruneCustomFontData(fontData);
    103     }
    104 
    105     if (pageZeroRoot)
    106         pageZeroRoot->pruneCustomFontData(fontData);
    107 }
    108 
    109 void GlyphPageTreeNode::pruneTreeFontData(const SimpleFontData* fontData)
    110 {
    111     if (roots) {
    112         HashMap<int, GlyphPageTreeNode*>::iterator end = roots->end();
    113         for (HashMap<int, GlyphPageTreeNode*>::iterator it = roots->begin(); it != end; ++it)
    114             it->value->pruneFontData(fontData);
    115     }
    116 
    117     if (pageZeroRoot)
    118         pageZeroRoot->pruneFontData(fontData);
    119 }
    120 
    121 static bool fill(GlyphPage* pageToFill, unsigned offset, unsigned length, UChar* buffer, unsigned bufferLength, const SimpleFontData* fontData)
    122 {
    123 #if ENABLE(SVG_FONTS)
    124     if (fontData->isSVGFont())
    125         return fontData->customFontData()->fillSVGGlyphPage(pageToFill, offset, length, buffer, bufferLength, fontData);
    126 #endif
    127     bool hasGlyphs = pageToFill->fill(offset, length, buffer, bufferLength, fontData);
    128 #if ENABLE(OPENTYPE_VERTICAL)
    129     if (hasGlyphs && fontData->verticalData())
    130         fontData->verticalData()->substituteWithVerticalGlyphs(fontData, pageToFill, offset, length);
    131 #endif
    132     return hasGlyphs;
    133 }
    134 
    135 void GlyphPageTreeNode::initializePage(const FontData* fontData, unsigned pageNumber)
    136 {
    137     ASSERT(!m_page);
    138 
    139     // This function must not be called for the root of the tree, because that
    140     // level does not contain any glyphs.
    141     ASSERT(m_level > 0 && m_parent);
    142 
    143     // The parent's page will be 0 if we are level one or the parent's font data
    144     // did not contain any glyphs for that page.
    145     GlyphPage* parentPage = m_parent->page();
    146 
    147     // NULL FontData means we're being asked for the system fallback font.
    148     if (fontData) {
    149         if (m_level == 1) {
    150             // Children of the root hold pure pages. These will cover only one
    151             // font data's glyphs, and will have glyph index 0 if the font data does not
    152             // contain the glyph.
    153             unsigned start = pageNumber * GlyphPage::size;
    154             UChar buffer[GlyphPage::size * 2 + 2];
    155             unsigned bufferLength;
    156             unsigned i;
    157 
    158             // Fill in a buffer with the entire "page" of characters that we want to look up glyphs for.
    159             if (start < 0x10000) {
    160                 bufferLength = GlyphPage::size;
    161                 for (i = 0; i < GlyphPage::size; i++)
    162                     buffer[i] = start + i;
    163 
    164                 if (start == 0) {
    165                     // Control characters must not render at all.
    166                     for (i = 0; i < 0x20; ++i)
    167                         buffer[i] = zeroWidthSpace;
    168                     for (i = 0x7F; i < 0xA0; i++)
    169                         buffer[i] = zeroWidthSpace;
    170                     buffer[softHyphen] = zeroWidthSpace;
    171 
    172                     // \n, \t, and nonbreaking space must render as a space.
    173                     buffer[(int)'\n'] = ' ';
    174                     buffer[(int)'\t'] = ' ';
    175                     buffer[noBreakSpace] = ' ';
    176                 } else if (start == (leftToRightMark & ~(GlyphPage::size - 1))) {
    177                     // LRM, RLM, LRE, RLE, ZWNJ, ZWJ, and PDF must not render at all.
    178                     buffer[leftToRightMark - start] = zeroWidthSpace;
    179                     buffer[rightToLeftMark - start] = zeroWidthSpace;
    180                     buffer[leftToRightEmbed - start] = zeroWidthSpace;
    181                     buffer[rightToLeftEmbed - start] = zeroWidthSpace;
    182                     buffer[leftToRightOverride - start] = zeroWidthSpace;
    183                     buffer[rightToLeftOverride - start] = zeroWidthSpace;
    184                     buffer[zeroWidthNonJoiner - start] = zeroWidthSpace;
    185                     buffer[zeroWidthJoiner - start] = zeroWidthSpace;
    186                     buffer[popDirectionalFormatting - start] = zeroWidthSpace;
    187                 } else if (start == (objectReplacementCharacter & ~(GlyphPage::size - 1))) {
    188                     // Object replacement character must not render at all.
    189                     buffer[objectReplacementCharacter - start] = zeroWidthSpace;
    190                 } else if (start == (zeroWidthNoBreakSpace & ~(GlyphPage::size - 1))) {
    191                     // ZWNBS/BOM must not render at all.
    192                     buffer[zeroWidthNoBreakSpace - start] = zeroWidthSpace;
    193                 }
    194             } else {
    195                 bufferLength = GlyphPage::size * 2;
    196                 for (i = 0; i < GlyphPage::size; i++) {
    197                     int c = i + start;
    198                     buffer[i * 2] = U16_LEAD(c);
    199                     buffer[i * 2 + 1] = U16_TRAIL(c);
    200                 }
    201             }
    202 
    203             // Now that we have a buffer full of characters, we want to get back an array
    204             // of glyph indices.  This part involves calling into the platform-specific
    205             // routine of our glyph map for actually filling in the page with the glyphs.
    206             // Success is not guaranteed. For example, Times fails to fill page 260, giving glyph data
    207             // for only 128 out of 256 characters.
    208             bool haveGlyphs;
    209             if (!fontData->isSegmented()) {
    210                 m_page = GlyphPage::createForSingleFontData(this, static_cast<const SimpleFontData*>(fontData));
    211                 haveGlyphs = fill(m_page.get(), 0, GlyphPage::size, buffer, bufferLength, static_cast<const SimpleFontData*>(fontData));
    212             } else {
    213                 m_page = GlyphPage::createForMixedFontData(this);
    214                 haveGlyphs = false;
    215 
    216                 const SegmentedFontData* segmentedFontData = static_cast<const SegmentedFontData*>(fontData);
    217                 unsigned numRanges = segmentedFontData->numRanges();
    218                 bool zeroFilled = false;
    219                 RefPtr<GlyphPage> scratchPage;
    220                 GlyphPage* pageToFill = m_page.get();
    221                 for (unsigned i = 0; i < numRanges; i++) {
    222                     const FontDataRange& range = segmentedFontData->rangeAt(i);
    223                     // all this casting is to ensure all the parameters to min and max have the same type,
    224                     // to avoid ambiguous template parameter errors on Windows
    225                     int from = max(0, static_cast<int>(range.from()) - static_cast<int>(start));
    226                     int to = 1 + min(static_cast<int>(range.to()) - static_cast<int>(start), static_cast<int>(GlyphPage::size) - 1);
    227                     if (from < static_cast<int>(GlyphPage::size) && to > 0) {
    228                         // If this is a custom font needs to be loaded, kick off
    229                         // the load here, and do not fill the page so that
    230                         // font fallback is used while loading.
    231                         RefPtr<CustomFontData> customData = range.fontData()->customFontData();
    232                         if (customData && customData->isLoadingFallback()) {
    233                             customData->beginLoadIfNeeded();
    234                             continue;
    235                         }
    236 
    237                         if (haveGlyphs && !scratchPage) {
    238                             scratchPage = GlyphPage::createForMixedFontData(this);
    239                             pageToFill = scratchPage.get();
    240                         }
    241 
    242                         if (!zeroFilled) {
    243                             if (from > 0 || to < static_cast<int>(GlyphPage::size)) {
    244                                 for (unsigned i = 0; i < GlyphPage::size; i++)
    245                                     pageToFill->setGlyphDataForIndex(i, 0, 0);
    246                             }
    247                             zeroFilled = true;
    248                         }
    249                         haveGlyphs |= fill(pageToFill, from, to - from, buffer + from * (start < 0x10000 ? 1 : 2), (to - from) * (start < 0x10000 ? 1 : 2), range.fontData().get());
    250                         if (scratchPage) {
    251                             ASSERT_WITH_SECURITY_IMPLICATION(to <=  static_cast<int>(GlyphPage::size));
    252                             for (int j = from; j < to; j++) {
    253                                 if (!m_page->glyphAt(j) && pageToFill->glyphAt(j))
    254                                     m_page->setGlyphDataForIndex(j, pageToFill->glyphDataForIndex(j));
    255                             }
    256                         }
    257                     }
    258                 }
    259             }
    260 
    261             if (!haveGlyphs)
    262                 m_page = 0;
    263         } else if (parentPage && parentPage->owner() != m_parent) {
    264             // The page we're overriding may not be owned by our parent node.
    265             // This happens when our parent node provides no useful overrides
    266             // and just copies the pointer to an already-existing page (see
    267             // below).
    268             //
    269             // We want our override to be shared by all nodes that reference
    270             // that page to avoid duplication, and so standardize on having the
    271             // page's owner collect all the overrides.  Call getChild on the
    272             // page owner with the desired font data (this will populate
    273             // the page) and then reference it.
    274             m_page = parentPage->owner()->getChild(fontData, pageNumber)->page();
    275         } else {
    276             // Get the pure page for the fallback font (at level 1 with no
    277             // overrides). getRootChild will always create a page if one
    278             // doesn't exist, but the page doesn't necessarily have glyphs
    279             // (this pointer may be 0).
    280             GlyphPage* fallbackPage = getRootChild(fontData, pageNumber)->page();
    281             if (!parentPage) {
    282                 // When the parent has no glyphs for this page, we can easily
    283                 // override it just by supplying the glyphs from our font.
    284                 m_page = fallbackPage;
    285             } else if (!fallbackPage) {
    286                 // When our font has no glyphs for this page, we can just reference the
    287                 // parent page.
    288                 m_page = parentPage;
    289             } else {
    290                 // Combine the parent's glyphs and ours to form a new more complete page.
    291                 m_page = GlyphPage::createForMixedFontData(this);
    292 
    293                 // Overlay the parent page on the fallback page. Check if the fallback font
    294                 // has added anything.
    295                 bool newGlyphs = false;
    296                 for (unsigned i = 0; i < GlyphPage::size; i++) {
    297                     if (parentPage->glyphAt(i))
    298                         m_page->setGlyphDataForIndex(i, parentPage->glyphDataForIndex(i));
    299                     else  if (fallbackPage->glyphAt(i)) {
    300                         m_page->setGlyphDataForIndex(i, fallbackPage->glyphDataForIndex(i));
    301                         newGlyphs = true;
    302                     } else
    303                         m_page->setGlyphDataForIndex(i, 0, 0);
    304                 }
    305 
    306                 if (!newGlyphs)
    307                     // We didn't override anything, so our override is just the parent page.
    308                     m_page = parentPage;
    309             }
    310         }
    311     } else {
    312         // System fallback. Initialized with the parent's page here, as individual
    313         // entries may use different fonts depending on character. If the Font
    314         // ever finds it needs a glyph out of the system fallback page, it will
    315         // ask the system for the best font to use and fill that glyph in for us.
    316         if (parentPage)
    317             m_page = parentPage->createCopiedSystemFallbackPage(this);
    318         else
    319             m_page = GlyphPage::createForMixedFontData(this);
    320     }
    321 }
    322 
    323 GlyphPageTreeNode* GlyphPageTreeNode::getChild(const FontData* fontData, unsigned pageNumber)
    324 {
    325     ASSERT(fontData || !m_isSystemFallback);
    326     ASSERT(pageNumber == m_pageNumber);
    327 
    328     if (GlyphPageTreeNode* foundChild = fontData ? m_children.get(fontData) : m_systemFallbackChild.get())
    329         return foundChild;
    330 
    331     GlyphPageTreeNode* child = new GlyphPageTreeNode;
    332     child->m_parent = this;
    333     child->m_level = m_level + 1;
    334     if (fontData && fontData->isCustomFont()) {
    335         for (GlyphPageTreeNode* curr = this; curr; curr = curr->m_parent)
    336             curr->m_customFontCount++;
    337     }
    338 
    339 #ifndef NDEBUG
    340     child->m_pageNumber = m_pageNumber;
    341 #endif
    342     if (fontData) {
    343         m_children.set(fontData, adoptPtr(child));
    344         fontData->setMaxGlyphPageTreeLevel(max(fontData->maxGlyphPageTreeLevel(), child->m_level));
    345     } else {
    346         m_systemFallbackChild = adoptPtr(child);
    347         child->m_isSystemFallback = true;
    348     }
    349     child->initializePage(fontData, pageNumber);
    350     return child;
    351 }
    352 
    353 void GlyphPageTreeNode::pruneCustomFontData(const FontData* fontData)
    354 {
    355     if (!fontData || !m_customFontCount)
    356         return;
    357 
    358     // Prune any branch that contains this FontData.
    359     if (OwnPtr<GlyphPageTreeNode> node = m_children.take(fontData)) {
    360         if (unsigned customFontCount = node->m_customFontCount + 1) {
    361             for (GlyphPageTreeNode* curr = this; curr; curr = curr->m_parent)
    362                 curr->m_customFontCount -= customFontCount;
    363         }
    364     }
    365 
    366     // Check any branches that remain that still have custom fonts underneath them.
    367     if (!m_customFontCount)
    368         return;
    369 
    370     GlyphPageTreeNodeMap::iterator end = m_children.end();
    371     for (GlyphPageTreeNodeMap::iterator it = m_children.begin(); it != end; ++it)
    372         it->value->pruneCustomFontData(fontData);
    373 }
    374 
    375 void GlyphPageTreeNode::pruneFontData(const SimpleFontData* fontData, unsigned level)
    376 {
    377     ASSERT(fontData);
    378 
    379     // Prune fall back child (if any) of this font.
    380     if (m_systemFallbackChild && m_systemFallbackChild->m_page)
    381         m_systemFallbackChild->m_page->removeFontDataFromSystemFallbackPage(fontData);
    382 
    383     // Prune any branch that contains this FontData.
    384     if (OwnPtr<GlyphPageTreeNode> node = m_children.take(fontData)) {
    385         if (unsigned customFontCount = node->m_customFontCount) {
    386             for (GlyphPageTreeNode* curr = this; curr; curr = curr->m_parent)
    387                 curr->m_customFontCount -= customFontCount;
    388         }
    389     }
    390 
    391     level++;
    392     if (level > fontData->maxGlyphPageTreeLevel())
    393         return;
    394 
    395     GlyphPageTreeNodeMap::iterator end = m_children.end();
    396     for (GlyphPageTreeNodeMap::iterator it = m_children.begin(); it != end; ++it)
    397         it->value->pruneFontData(fontData, level);
    398 }
    399 
    400 #ifndef NDEBUG
    401     void GlyphPageTreeNode::showSubtree()
    402     {
    403         Vector<char> indent(level());
    404         indent.fill('\t', level());
    405         indent.append(0);
    406 
    407         GlyphPageTreeNodeMap::iterator end = m_children.end();
    408         for (GlyphPageTreeNodeMap::iterator it = m_children.begin(); it != end; ++it) {
    409             printf("%s\t%p %s\n", indent.data(), it->key, it->key->description().utf8().data());
    410             it->value->showSubtree();
    411         }
    412         if (m_systemFallbackChild) {
    413             printf("%s\t* fallback\n", indent.data());
    414             m_systemFallbackChild->showSubtree();
    415         }
    416     }
    417 #endif
    418 
    419 }
    420 
    421 #ifndef NDEBUG
    422 void showGlyphPageTrees()
    423 {
    424     printf("Page 0:\n");
    425     showGlyphPageTree(0);
    426     HashMap<int, WebCore::GlyphPageTreeNode*>::iterator end = WebCore::GlyphPageTreeNode::roots->end();
    427     for (HashMap<int, WebCore::GlyphPageTreeNode*>::iterator it = WebCore::GlyphPageTreeNode::roots->begin(); it != end; ++it) {
    428         printf("\nPage %d:\n", it->key);
    429         showGlyphPageTree(it->key);
    430     }
    431 }
    432 
    433 void showGlyphPageTree(unsigned pageNumber)
    434 {
    435     WebCore::GlyphPageTreeNode::getRoot(pageNumber)->showSubtree();
    436 }
    437 #endif
    438