Implement UDP data parsing.

[erlang-x-plane-data.git] / src / x_plane_datum.erl

diff --git a/src/x_plane_datum.erl b/src/x_plane_datum.erl
new file mode 100644 (file)
index 0000000..cd55c2f
--- /dev/null
+++ b/src/x_plane_datum.erl
@@ -0,0 +1,134 @@
+-module(x_plane_datum).
+
+-include("x_plane_datum_defaults.hrl").
+-include("include/x_plane_data.hrl").
+
+-export_type(
+    [ t/0
+    , label/0
+    , anonymous/0
+    , identified/0
+    , parsing_error/0
+    ]).
+
+-export(
+    [ of_bin/1  % Use default max index
+    , of_bin/2  % Specify max index
+    ]).
+
+-type parsing_error() ::
+      {block_structure_invalid, binary()}
+    | {block_index_byte_out_of_range, anonymous()}
+    .
+
+-type anonymous() ::
+    { non_neg_integer()
+    , float()
+    , float()
+    , float()
+    , float()
+    , float()
+    , float()
+    , float()
+    , float()
+    }.
+
+-type label() ::
+      speeds
+    | pitch_roll_heading
+    | lat_lon_alt
+    .
+
+-type identified() ::
+      #x_plane_datum_speeds{}
+    | #x_plane_datum_pitch_roll_heading{}
+    | #x_plane_datum_lat_lon_alt{}
+    .
+
+-type t() ::
+      {non_neg_integer() , anonymous()}
+    | {label()           , identified()}
+    .
+
+-spec of_bin(binary()) ->
+    hope_result:t(t(), parsing_error()).
+of_bin(<<Block/binary>>) ->
+    of_bin(Block, ?DEFAULT_MAX_INDEX).
+
+-spec of_bin(binary(), non_neg_integer()) ->
+    hope_result:t(t(), parsing_error()).
+of_bin(<<Block/binary>>, MaxIndex) ->
+    case anonymous_of_bin(Block, MaxIndex)
+    of {ok, Anonymous} ->
+            IdentifiedOrIndexed = identify_or_index(Anonymous),
+            {ok, IdentifiedOrIndexed}
+    ;   {error, _}=Error ->
+            Error
+    end.
+
+-spec anonymous_of_bin(binary(), non_neg_integer()) ->
+    hope_result:t(anonymous(), parsing_error()).
+anonymous_of_bin(
+    << Index:32/little-integer
+     ,    V1:32/little-float
+     ,    V2:32/little-float
+     ,    V3:32/little-float
+     ,    V4:32/little-float
+     ,    V5:32/little-float
+     ,    V6:32/little-float
+     ,    V7:32/little-float
+     ,    V8:32/little-float
+    >>,
+    MaxIndex
+) ->
+    Anonymous = {Index, V1, V2, V3, V4, V5, V6, V7, V8},
+    if Index > 0 andalso Index =< MaxIndex ->
+        {ok, Anonymous}
+    ;  true ->
+        {error, {block_index_byte_out_of_range, Anonymous}}
+    end;
+anonymous_of_bin(<<Block/binary>>, _) ->
+    % This case shouldn't possible with a correct packet length, but we want to
+    % allow for possibility of using this module independently of it's parent,
+    % data module.
+    {error, {block_structure_invalid, Block}}.
+
+-spec identify_or_index(anonymous()) ->
+    t().
+identify_or_index({3, V1, V2, V3, V4, _, V6, V7, V8}) ->
+    Datum =
+        #x_plane_datum_speeds
+        { vind_kias   = V1
+        , vind_keas   = V2
+        , vtrue_ktas  = V3
+        , vtrue_ktgs  = V4
+
+        , vind_mph    = V6
+        , vtrue_mphas = V7
+        , vtrue_mphgs = V8
+        },
+    {speeds, Datum};
+identify_or_index({17, V1, V2, V3, V4, _, _, _, _}) ->
+    Datum =
+        #x_plane_datum_pitch_roll_heading
+        { pitch_deg  = V1
+        , roll_deg   = V2
+        , hding_true = V3
+        , hding_mag  = V4
+        },
+    {pitch_roll_heading, Datum};
+identify_or_index({20, V1, V2, V3, V4, V5, V6, V7, V8}) ->
+    Datum =
+        #x_plane_datum_lat_lon_alt
+        { lat_deg   = V1
+        , lon_deg   = V2
+        , alt_ftmsl = V3
+        , alt_ftagl = V4
+        , on_runwy  = V5
+        , alt_ind   = V6
+        , lat_south = V7
+        , lat_west  = V8
+        },
+    {lat_lon_alt, Datum};
+identify_or_index({Index, _, _, _, _, _, _, _, _}=Anonymous) ->
+    {Index, Anonymous}.