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
referenceTable(hb_face_t *,hb_tag_t tag,void * userData)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:
HbFontCache()49 HbFontCache() : mCache(kMaxEntries) {
50 mCache.setOnEntryRemovedListener(this);
51 }
52
53 // callback for OnEntryRemoved
operator ()(int32_t &,hb_font_t * & value)54 void operator()(int32_t& /* key */, hb_font_t*& value) {
55 hb_font_destroy(value);
56 }
57
get(int32_t fontId)58 hb_font_t* get(int32_t fontId) {
59 return mCache.get(fontId);
60 }
61
put(int32_t fontId,hb_font_t * font)62 void put(int32_t fontId, hb_font_t* font) {
63 mCache.put(fontId, font);
64 }
65
clear()66 void clear() {
67 mCache.clear();
68 }
69
remove(int32_t fontId)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
getFontCacheLocked()80 HbFontCache* getFontCacheLocked() {
81 assertMinikinLocked();
82 static HbFontCache* cache = nullptr;
83 if (cache == nullptr) {
84 cache = new HbFontCache();
85 }
86 return cache;
87 }
88
purgeHbFontCacheLocked()89 void purgeHbFontCacheLocked() {
90 assertMinikinLocked();
91 getFontCacheLocked()->clear();
92 }
93
purgeHbFontLocked(const MinikinFont * minikinFont)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.
getHbFontLocked(MinikinFont * minikinFont)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