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extern/draco/dracoenc/src/draco/core/varint_encoding.h
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| // Copyright 2016 The Draco Authors. | |||||
| // | |||||
| // Licensed under the Apache License, Version 2.0 (the "License"); | |||||
| // you may not use this file except in compliance with the License. | |||||
| // You may obtain a copy of the License at | |||||
| // | |||||
| // http://www.apache.org/licenses/LICENSE-2.0 | |||||
| // | |||||
| // Unless required by applicable law or agreed to in writing, software | |||||
| // distributed under the License is distributed on an "AS IS" BASIS, | |||||
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |||||
| // See the License for the specific language governing permissions and | |||||
| // limitations under the License. | |||||
| // | |||||
| #ifndef DRACO_CORE_VARINT_ENCODING_H_ | |||||
| #define DRACO_CORE_VARINT_ENCODING_H_ | |||||
| #include <type_traits> | |||||
| #include "draco/core/bit_utils.h" | |||||
| #include "draco/core/encoder_buffer.h" | |||||
| namespace draco { | |||||
| // Encodes a specified integer as varint. Note that different coding is used | |||||
| // when IntTypeT is an unsigned data type. | |||||
| template <typename IntTypeT> | |||||
| bool EncodeVarint(IntTypeT val, EncoderBuffer *out_buffer) { | |||||
| if (std::is_unsigned<IntTypeT>::value) { | |||||
| // Coding of unsigned values. | |||||
| // 0-6 bit - data | |||||
| // 7 bit - next byte? | |||||
| uint8_t out = 0; | |||||
| out |= val & ((1 << 7) - 1); | |||||
| if (val >= (1 << 7)) { | |||||
| out |= (1 << 7); | |||||
| if (!out_buffer->Encode(out)) | |||||
| return false; | |||||
| if (!EncodeVarint<IntTypeT>(val >> 7, out_buffer)) | |||||
| return false; | |||||
| return true; | |||||
| } | |||||
| if (!out_buffer->Encode(out)) | |||||
| return false; | |||||
| } else { | |||||
| // IntTypeT is a signed value. Convert to unsigned symbol and encode. | |||||
| const typename std::make_unsigned<IntTypeT>::type symbol = | |||||
| ConvertSignedIntToSymbol(val); | |||||
| if (!EncodeVarint(symbol, out_buffer)) | |||||
| return false; | |||||
| } | |||||
| return true; | |||||
| } | |||||
| } // namespace draco | |||||
| #endif // DRACO_CORE_VARINT_ENCODING_H_ | |||||