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      1 /*
      2  * Copyright (C) 2014 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 // Definitions internal to Minikin
     18 
     19 #ifndef MINIKIN_INTERNAL_H
     20 #define MINIKIN_INTERNAL_H
     21 
     22 #include <hb.h>
     23 #include <utils/Log.h>
     24 #include <utils/Mutex.h>
     25 
     26 #include "minikin/HbUtils.h"
     27 #include "minikin/MinikinFont.h"
     28 
     29 namespace minikin {
     30 
     31 #ifdef ENABLE_ASSERTION
     32 #define MINIKIN_ASSERT(cond, ...) LOG_ALWAYS_FATAL_IF(!(cond), __VA_ARGS__)
     33 #else
     34 #define MINIKIN_ASSERT(cond, ...) ((void)0)
     35 #endif
     36 
     37 #define MINIKIN_NOT_REACHED(...) MINIKIN_ASSERT(false, __VA_ARGS__);
     38 
     39 constexpr uint32_t MAX_UNICODE_CODE_POINT = 0x10FFFF;
     40 
     41 constexpr uint32_t VS1 = 0xFE00;
     42 constexpr uint32_t VS16 = 0xFE0F;
     43 constexpr uint32_t VS17 = 0xE0100;
     44 constexpr uint32_t VS256 = 0xE01EF;
     45 
     46 // Returns variation selector index. This is one unit less than the variation selector number. For
     47 // example, VARIATION SELECTOR-25 maps to 24.
     48 // [0x00-0x0F] for U+FE00..U+FE0F
     49 // [0x10-0xFF] for U+E0100..U+E01EF
     50 // INVALID_VS_INDEX for other input.
     51 constexpr uint16_t INVALID_VS_INDEX = 0xFFFF;
     52 uint16_t getVsIndex(uint32_t codePoint);
     53 
     54 // Returns true if the code point is a variation selector.
     55 // Note that this function returns false for Mongolian free variation selectors.
     56 bool isVariationSelector(uint32_t codePoint);
     57 
     58 // An RAII accessor for hb_blob_t
     59 class HbBlob {
     60 public:
     61     HbBlob(const HbFaceUniquePtr& face, uint32_t tag)
     62             : mBlob(hb_face_reference_table(face.get(), tag)) {}
     63     HbBlob(const HbFontUniquePtr& font, uint32_t tag)
     64             : mBlob(hb_face_reference_table(hb_font_get_face(font.get()), tag)) {}
     65 
     66     inline const uint8_t* get() const {
     67         return reinterpret_cast<const uint8_t*>(hb_blob_get_data(mBlob.get(), nullptr));
     68     }
     69 
     70     inline size_t size() const { return (size_t)hb_blob_get_length(mBlob.get()); }
     71 
     72     inline operator bool() const { return size() > 0; }
     73 
     74 private:
     75     HbBlobUniquePtr mBlob;
     76 };
     77 
     78 }  // namespace minikin
     79 
     80 #endif  // MINIKIN_INTERNAL_H
     81