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      1 
      2 /*
      3  * Copyright 2010 Google Inc.
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 
     10 
     11 #ifndef GrTextStrike_impl_DEFINED
     12 #define GrTextStrike_impl_DEFINED
     13 
     14 class GrFontCache::Key {
     15 public:
     16     explicit Key(const GrKey* fontScalarKey) {
     17         fFontScalerKey = fontScalarKey;
     18     }
     19 
     20     intptr_t getHash() const { return fFontScalerKey->getHash(); }
     21 
     22     static bool LessThan(const GrTextStrike& strike, const Key& key) {
     23         return *strike.getFontScalerKey() < *key.fFontScalerKey;
     24     }
     25     static bool Equals(const GrTextStrike& strike, const Key& key) {
     26         return *strike.getFontScalerKey() == *key.fFontScalerKey;
     27     }
     28 
     29 private:
     30     const GrKey* fFontScalerKey;
     31 };
     32 
     33 void GrFontCache::detachStrikeFromList(GrTextStrike* strike) {
     34     if (strike->fPrev) {
     35         SkASSERT(fHead != strike);
     36         strike->fPrev->fNext = strike->fNext;
     37     } else {
     38         SkASSERT(fHead == strike);
     39         fHead = strike->fNext;
     40     }
     41 
     42     if (strike->fNext) {
     43         SkASSERT(fTail != strike);
     44         strike->fNext->fPrev = strike->fPrev;
     45     } else {
     46         SkASSERT(fTail == strike);
     47         fTail = strike->fPrev;
     48     }
     49 }
     50 
     51 GrTextStrike* GrFontCache::getStrike(GrFontScaler* scaler, bool useDistanceField) {
     52     this->validate();
     53 
     54     const Key key(scaler->getKey());
     55     GrTextStrike* strike = fCache.find(key);
     56     if (NULL == strike) {
     57         strike = this->generateStrike(scaler, key);
     58     } else if (strike->fPrev) {
     59         // Need to put the strike at the head of its dllist, since that is how
     60         // we age the strikes for purging (we purge from the back of the list)
     61         this->detachStrikeFromList(strike);
     62         // attach at the head
     63         fHead->fPrev = strike;
     64         strike->fNext = fHead;
     65         strike->fPrev = NULL;
     66         fHead = strike;
     67     }
     68     strike->fUseDistanceField = useDistanceField;
     69     this->validate();
     70     return strike;
     71 }
     72 
     73 ///////////////////////////////////////////////////////////////////////////////
     74 
     75 /**
     76  *  This Key just wraps a glyphID, and matches the protocol need for
     77  *  GrTHashTable
     78  */
     79 class GrTextStrike::Key {
     80 public:
     81     Key(GrGlyph::PackedID id) : fPackedID(id) {}
     82 
     83     uint32_t getHash() const { return fPackedID; }
     84 
     85     static bool LessThan(const GrGlyph& glyph, const Key& key) {
     86         return glyph.fPackedID < key.fPackedID;
     87     }
     88     static bool Equals(const GrGlyph& glyph, const Key& key) {
     89         return glyph.fPackedID == key.fPackedID;
     90     }
     91 
     92 private:
     93     GrGlyph::PackedID fPackedID;
     94 };
     95 
     96 GrGlyph* GrTextStrike::getGlyph(GrGlyph::PackedID packed,
     97                                 GrFontScaler* scaler) {
     98     GrGlyph* glyph = fCache.find(packed);
     99     if (NULL == glyph) {
    100         glyph = this->generateGlyph(packed, scaler);
    101     }
    102     return glyph;
    103 }
    104 
    105 #endif
    106