| 1 | -module(x_plane_data_raw). |
| 2 | |
| 3 | -export_type( |
| 4 | [ t/0 |
| 5 | , index/0 |
| 6 | , group_index/0 |
| 7 | , group_values/0 |
| 8 | , group/0 |
| 9 | , groups/0 |
| 10 | ]). |
| 11 | |
| 12 | -export( |
| 13 | [ of_bin/1 |
| 14 | ]). |
| 15 | |
| 16 | -type parsing_error() :: |
| 17 | packet_bad_header |
| 18 | | packet_bad_length |
| 19 | . |
| 20 | |
| 21 | -type group_index() :: |
| 22 | non_neg_integer(). |
| 23 | |
| 24 | -type group_values() :: |
| 25 | { float() |
| 26 | , float() |
| 27 | , float() |
| 28 | , float() |
| 29 | , float() |
| 30 | , float() |
| 31 | , float() |
| 32 | , float() |
| 33 | }. |
| 34 | |
| 35 | -type group() :: |
| 36 | {group_index(), group_values()}. |
| 37 | |
| 38 | % Packet index byte. Essentially a schema version. |
| 39 | -type index() :: |
| 40 | integer(). |
| 41 | |
| 42 | -type groups() :: |
| 43 | [group()]. |
| 44 | |
| 45 | -type t() :: |
| 46 | {index(), groups()}. |
| 47 | |
| 48 | -define(BYTE_SIZE_OF_EACH_BLOCK, 36). |
| 49 | -define(PACKET_HEADER, "DATA"). |
| 50 | |
| 51 | -spec of_bin(binary()) -> |
| 52 | {ok, t()} |
| 53 | | {error, parsing_error()} |
| 54 | . |
| 55 | of_bin(<<?PACKET_HEADER, _:8/integer, ContiguousBlocks/binary>>) |
| 56 | when byte_size(ContiguousBlocks) rem ?BYTE_SIZE_OF_EACH_BLOCK =/= 0 -> |
| 57 | {error, packet_bad_length}; |
| 58 | of_bin(<<?PACKET_HEADER, Index:8/integer, ContiguousBlocks/binary>>) -> |
| 59 | Groups = [group_of_bin(B) || B <- blocks_split(ContiguousBlocks)], |
| 60 | {ok, {Index, Groups}}; |
| 61 | of_bin(<<_/binary>>) -> |
| 62 | {error, packet_bad_header}. |
| 63 | |
| 64 | -spec blocks_split(binary()) -> |
| 65 | [binary()]. |
| 66 | blocks_split(<<>>) -> |
| 67 | []; |
| 68 | blocks_split(<<Block:?BYTE_SIZE_OF_EACH_BLOCK/bytes, Blocks/binary>>) -> |
| 69 | [Block | blocks_split(Blocks)]. |
| 70 | |
| 71 | -spec group_of_bin(binary()) -> |
| 72 | group(). |
| 73 | group_of_bin( |
| 74 | << Index:32/little-integer |
| 75 | , V1:32/little-float |
| 76 | , V2:32/little-float |
| 77 | , V3:32/little-float |
| 78 | , V4:32/little-float |
| 79 | , V5:32/little-float |
| 80 | , V6:32/little-float |
| 81 | , V7:32/little-float |
| 82 | , V8:32/little-float |
| 83 | >> |
| 84 | ) -> |
| 85 | Values = {V1, V2, V3, V4, V5, V6, V7, V8}, |
| 86 | {Index, Values}. |