| // Copyright 2013 Google Inc. All Rights Reserved. |
| // |
| // 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. |
| // |
| // Helpers common across multiple parts of woff2 |
| |
| #include <algorithm> |
| |
| #include "./woff2_common.h" |
| |
| namespace woff2 { |
| |
| |
| uint32_t ComputeULongSum(const uint8_t* buf, size_t size) { |
| uint32_t checksum = 0; |
| for (size_t i = 0; i < size; i += 4) { |
| #if (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)) |
| uint32_t v = *reinterpret_cast<const uint32_t*>(buf + i); |
| checksum += (((v & 0xFF) << 24) | ((v & 0xFF00) << 8) | |
| ((v & 0xFF0000) >> 8) | ((v & 0xFF000000) >> 24)); |
| #elif (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)) |
| checksum += *reinterpret_cast<const uint32_t*>(buf + i); |
| #else |
| checksum += (buf[i] << 24) | (buf[i + 1] << 16) | |
| (buf[i + 2] << 8) | buf[i + 3]; |
| #endif |
| } |
| return checksum; |
| } |
| |
| size_t CollectionHeaderSize(uint32_t header_version, uint32_t num_fonts) { |
| size_t size = 0; |
| if (header_version == 0x00020000) { |
| size += 12; // ulDsig{Tag,Length,Offset} |
| } |
| if (header_version == 0x00010000 || header_version == 0x00020000) { |
| size += 12 // TTCTag, Version, numFonts |
| + 4 * num_fonts; // OffsetTable[numFonts] |
| } |
| return size; |
| } |
| |
| } // namespace woff2 |