1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #define LOG_TAG "Minikin" 18 19 #include "HbFontCache.h" 20 21 #include <cutils/log.h> 22 #include <hb.h> 23 #include <hb-ot.h> 24 #include <utils/LruCache.h> 25 26 #include <minikin/MinikinFont.h> 27 #include "MinikinInternal.h" 28 29 namespace android { 30 31 static hb_blob_t* referenceTable(hb_face_t* /* face */, hb_tag_t tag, void* userData) { 32 MinikinFont* font = reinterpret_cast<MinikinFont*>(userData); 33 MinikinDestroyFunc destroy = 0; 34 size_t size = 0; 35 const void* buffer = font->GetTable(tag, &size, &destroy); 36 if (buffer == nullptr) { 37 return nullptr; 38 } 39 #ifdef VERBOSE_DEBUG 40 ALOGD("referenceTable %c%c%c%c length=%zd", 41 (tag >>24)&0xff, (tag>>16)&0xff, (tag>>8)&0xff, tag&0xff, size); 42 #endif 43 return hb_blob_create(reinterpret_cast<const char*>(buffer), size, 44 HB_MEMORY_MODE_READONLY, const_cast<void*>(buffer), destroy); 45 } 46 47 class HbFontCache : private OnEntryRemoved<int32_t, hb_font_t*> { 48 public: 49 HbFontCache() : mCache(kMaxEntries) { 50 mCache.setOnEntryRemovedListener(this); 51 } 52 53 // callback for OnEntryRemoved 54 void operator()(int32_t& /* key */, hb_font_t*& value) { 55 hb_font_destroy(value); 56 } 57 58 hb_font_t* get(int32_t fontId) { 59 return mCache.get(fontId); 60 } 61 62 void put(int32_t fontId, hb_font_t* font) { 63 mCache.put(fontId, font); 64 } 65 66 void clear() { 67 mCache.clear(); 68 } 69 70 void remove(int32_t fontId) { 71 mCache.remove(fontId); 72 } 73 74 private: 75 static const size_t kMaxEntries = 100; 76 77 LruCache<int32_t, hb_font_t*> mCache; 78 }; 79 80 HbFontCache* getFontCacheLocked() { 81 assertMinikinLocked(); 82 static HbFontCache* cache = nullptr; 83 if (cache == nullptr) { 84 cache = new HbFontCache(); 85 } 86 return cache; 87 } 88 89 void purgeHbFontCacheLocked() { 90 assertMinikinLocked(); 91 getFontCacheLocked()->clear(); 92 } 93 94 void purgeHbFontLocked(const MinikinFont* minikinFont) { 95 assertMinikinLocked(); 96 const int32_t fontId = minikinFont->GetUniqueId(); 97 getFontCacheLocked()->remove(fontId); 98 } 99 100 // Returns a new reference to a hb_font_t object, caller is 101 // responsible for calling hb_font_destroy() on it. 102 hb_font_t* getHbFontLocked(MinikinFont* minikinFont) { 103 assertMinikinLocked(); 104 // TODO: get rid of nullFaceFont 105 static hb_font_t* nullFaceFont = nullptr; 106 if (minikinFont == nullptr) { 107 if (nullFaceFont == nullptr) { 108 nullFaceFont = hb_font_create(nullptr); 109 } 110 return hb_font_reference(nullFaceFont); 111 } 112 113 HbFontCache* fontCache = getFontCacheLocked(); 114 const int32_t fontId = minikinFont->GetUniqueId(); 115 hb_font_t* font = fontCache->get(fontId); 116 if (font != nullptr) { 117 return hb_font_reference(font); 118 } 119 120 hb_face_t* face; 121 const void* buf = minikinFont->GetFontData(); 122 if (buf == nullptr) { 123 face = hb_face_create_for_tables(referenceTable, minikinFont, nullptr); 124 } else { 125 size_t size = minikinFont->GetFontSize(); 126 hb_blob_t* blob = hb_blob_create(reinterpret_cast<const char*>(buf), size, 127 HB_MEMORY_MODE_READONLY, nullptr, nullptr); 128 face = hb_face_create(blob, minikinFont->GetFontIndex()); 129 hb_blob_destroy(blob); 130 } 131 hb_font_t* parent_font = hb_font_create(face); 132 hb_ot_font_set_funcs(parent_font); 133 134 unsigned int upem = hb_face_get_upem(face); 135 hb_font_set_scale(parent_font, upem, upem); 136 137 font = hb_font_create_sub_font(parent_font); 138 hb_font_destroy(parent_font); 139 hb_face_destroy(face); 140 fontCache->put(fontId, font); 141 return hb_font_reference(font); 142 } 143 144 } // namespace android 145