// 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; size_t aligned_size = size & ~3; for (size_t i = 0; i < aligned_size; i += 4) { uint32_t v; memcpy(&v, buf + i, 4); #if (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)) checksum += (((v & 0xFF) << 24) | ((v & 0xFF00) << 8) | ((v & 0xFF0000) >> 8) | ((v & 0xFF000000) >> 24)); #elif (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)) checksum += v; #else checksum += (buf[i] << 24) | (buf[i + 1] << 16) | (buf[i + 2] << 8) | buf[i + 3]; #endif } // treat size not aligned on 4 as if it were padded to 4 with 0's if (size != aligned_size) { uint32_t v = 0; for (size_t i = aligned_size; i < size; ++i) { v |= buf[i] << (24 - 8 * (i & 3)); } checksum += v; } 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