| 973 | } |
| 974 | |
| 975 | void LASwriteItemCompressed_POINT14_v3::write_gps_time(const U64I64F64 gps_time) |
| 976 | { |
| 977 | if (contexts[current_context].last_gpstime_diff[contexts[current_context].last] == 0) // if the last integer difference was zero |
| 978 | { |
| 979 | // calculate the difference between the two doubles as an integer |
| 980 | I64 curr_gpstime_diff_64 = gps_time.i64 - contexts[current_context].last_gpstime[contexts[current_context].last].i64; |
| 981 | I32 curr_gpstime_diff = (I32)curr_gpstime_diff_64; |
| 982 | if (curr_gpstime_diff_64 == (I64)(curr_gpstime_diff)) |
| 983 | { |
| 984 | enc_gps_time->encodeSymbol(contexts[current_context].m_gpstime_0diff, 0); // the difference can be represented with 32 bits |
| 985 | contexts[current_context].ic_gpstime->compress(0, curr_gpstime_diff, 0); |
| 986 | contexts[current_context].last_gpstime_diff[contexts[current_context].last] = curr_gpstime_diff; |
| 987 | contexts[current_context].multi_extreme_counter[contexts[current_context].last] = 0; |
| 988 | } |
| 989 | else // the difference is huge |
| 990 | { |
| 991 | U32 i; |
| 992 | // maybe the double belongs to another time sequence |
| 993 | for (i = 1; i < 4; i++) |
| 994 | { |
| 995 | I64 other_gpstime_diff_64 = gps_time.i64 - contexts[current_context].last_gpstime[(contexts[current_context].last+i)&3].i64; |
| 996 | I32 other_gpstime_diff = (I32)other_gpstime_diff_64; |
| 997 | if (other_gpstime_diff_64 == (I64)(other_gpstime_diff)) |
| 998 | { |
| 999 | enc_gps_time->encodeSymbol(contexts[current_context].m_gpstime_0diff, i+1); // it belongs to another sequence |
| 1000 | contexts[current_context].last = (contexts[current_context].last+i)&3; |
| 1001 | write_gps_time(gps_time); |
| 1002 | return; |
| 1003 | } |
| 1004 | } |
| 1005 | // no other sequence found. start new sequence. |
| 1006 | enc_gps_time->encodeSymbol(contexts[current_context].m_gpstime_0diff, 1); |
| 1007 | contexts[current_context].ic_gpstime->compress((I32)(contexts[current_context].last_gpstime[contexts[current_context].last].u64 >> 32), (I32)(gps_time.u64 >> 32), 8); |
| 1008 | enc_gps_time->writeInt((U32)(gps_time.u64)); |
| 1009 | contexts[current_context].next = (contexts[current_context].next+1)&3; |
| 1010 | contexts[current_context].last = contexts[current_context].next; |
| 1011 | contexts[current_context].last_gpstime_diff[contexts[current_context].last] = 0; |
| 1012 | contexts[current_context].multi_extreme_counter[contexts[current_context].last] = 0; |
| 1013 | } |
| 1014 | contexts[current_context].last_gpstime[contexts[current_context].last].i64 = gps_time.i64; |
| 1015 | } |
| 1016 | else // the last integer difference was *not* zero |
| 1017 | { |
| 1018 | // calculate the difference between the two doubles as an integer |
| 1019 | I64 curr_gpstime_diff_64 = gps_time.i64 - contexts[current_context].last_gpstime[contexts[current_context].last].i64; |
| 1020 | I32 curr_gpstime_diff = (I32)curr_gpstime_diff_64; |
| 1021 | |
| 1022 | // if the current gpstime difference can be represented with 32 bits |
| 1023 | if (curr_gpstime_diff_64 == (I64)(curr_gpstime_diff)) |
| 1024 | { |
| 1025 | // compute multiplier between current and last integer difference |
| 1026 | F32 multi_f = (F32)curr_gpstime_diff / (F32)(contexts[current_context].last_gpstime_diff[contexts[current_context].last]); |
| 1027 | I32 multi = I32_QUANTIZE(multi_f); |
| 1028 | |
| 1029 | // compress the residual curr_gpstime_diff in dependance on the multiplier |
| 1030 | if (multi == 1) |
| 1031 | { |
| 1032 | // this is the case we assume we get most often for regular spaced pulses |
nothing calls this directly
no test coverage detected