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 <log/log.h>
22 #include <utils/LruCache.h>
23
24 #include <hb.h>
25 #include <hb-ot.h>
26
27 #include <minikin/MinikinFont.h>
28 #include "MinikinInternal.h"
29
30 namespace minikin {
31
32 class HbFontCache : private android::OnEntryRemoved<int32_t, hb_font_t*> {
33 public:
HbFontCache()34 HbFontCache() : mCache(kMaxEntries) {
35 mCache.setOnEntryRemovedListener(this);
36 }
37
38 // callback for OnEntryRemoved
operator ()(int32_t &,hb_font_t * & value)39 void operator()(int32_t& /* key */, hb_font_t*& value) {
40 hb_font_destroy(value);
41 }
42
get(int32_t fontId)43 hb_font_t* get(int32_t fontId) {
44 return mCache.get(fontId);
45 }
46
put(int32_t fontId,hb_font_t * font)47 void put(int32_t fontId, hb_font_t* font) {
48 mCache.put(fontId, font);
49 }
50
clear()51 void clear() {
52 mCache.clear();
53 }
54
remove(int32_t fontId)55 void remove(int32_t fontId) {
56 mCache.remove(fontId);
57 }
58
59 private:
60 static const size_t kMaxEntries = 100;
61
62 android::LruCache<int32_t, hb_font_t*> mCache;
63 };
64
getFontCacheLocked()65 HbFontCache* getFontCacheLocked() {
66 assertMinikinLocked();
67 static HbFontCache* cache = nullptr;
68 if (cache == nullptr) {
69 cache = new HbFontCache();
70 }
71 return cache;
72 }
73
purgeHbFontCacheLocked()74 void purgeHbFontCacheLocked() {
75 assertMinikinLocked();
76 getFontCacheLocked()->clear();
77 }
78
purgeHbFontLocked(const MinikinFont * minikinFont)79 void purgeHbFontLocked(const MinikinFont* minikinFont) {
80 assertMinikinLocked();
81 const int32_t fontId = minikinFont->GetUniqueId();
82 getFontCacheLocked()->remove(fontId);
83 }
84
85 // Returns a new reference to a hb_font_t object, caller is
86 // responsible for calling hb_font_destroy() on it.
getHbFontLocked(const MinikinFont * minikinFont)87 hb_font_t* getHbFontLocked(const MinikinFont* minikinFont) {
88 assertMinikinLocked();
89 // TODO: get rid of nullFaceFont
90 static hb_font_t* nullFaceFont = nullptr;
91 if (minikinFont == nullptr) {
92 if (nullFaceFont == nullptr) {
93 nullFaceFont = hb_font_create(nullptr);
94 }
95 return hb_font_reference(nullFaceFont);
96 }
97
98 HbFontCache* fontCache = getFontCacheLocked();
99 const int32_t fontId = minikinFont->GetUniqueId();
100 hb_font_t* font = fontCache->get(fontId);
101 if (font != nullptr) {
102 return hb_font_reference(font);
103 }
104
105 hb_face_t* face;
106 const void* buf = minikinFont->GetFontData();
107 size_t size = minikinFont->GetFontSize();
108 hb_blob_t* blob = hb_blob_create(reinterpret_cast<const char*>(buf), size,
109 HB_MEMORY_MODE_READONLY, nullptr, nullptr);
110 face = hb_face_create(blob, minikinFont->GetFontIndex());
111 hb_blob_destroy(blob);
112
113 hb_font_t* parent_font = hb_font_create(face);
114 hb_ot_font_set_funcs(parent_font);
115
116 unsigned int upem = hb_face_get_upem(face);
117 hb_font_set_scale(parent_font, upem, upem);
118
119 font = hb_font_create_sub_font(parent_font);
120 std::vector<hb_variation_t> variations;
121 for (const FontVariation& variation : minikinFont->GetAxes()) {
122 variations.push_back({variation.axisTag, variation.value});
123 }
124 hb_font_set_variations(font, variations.data(), variations.size());
125 hb_font_destroy(parent_font);
126 hb_face_destroy(face);
127 fontCache->put(fontId, font);
128 return hb_font_reference(font);
129 }
130
131 } // namespace minikin
132