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Pascal: Change rate of turn from Byte to SmallInt #41

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35 changes: 27 additions & 8 deletions contrib/AISParser.pas
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@
{ AIVDM/AIVDO AIS Message Parser }
{ <center>Copyright 2006 by Brian C. Lane <bcl@brianlane.com><br> }
{ http://www.aisparser.com/ }
{ https://github.com/bcl/aisparser }
{ }
{ The Automatic Identification System (AIS) allows ships to be tracked in }
{ realtime based on information transmitted by each ship. They are equipped }
Expand Down Expand Up @@ -62,7 +63,7 @@

Interface

Uses Windows, Classes, SysUtils, StrUtils, Dialogs;
Uses Classes, SysUtils, StrUtils, Dialogs;

Const
MAX_NMEA_LENGTH = 255;
Expand Down Expand Up @@ -102,7 +103,7 @@
isrepeat: SmallInt; //!< 2 bits : Repeated
userid: LongInt; //!< 30 bits : UserID / MMSI
nav_status: SmallInt; //!< 4 bits : Navigational Status
rot: Byte; //!< 8 bits : Rate of Turn
rot: SmallInt; //!< 8 bits : Rate of Turn
sog: Integer; //!< 10 bits : Speed Over Ground
pos_acc: SmallInt; //!< 1 bit : Position Accuracy
longitude: LongInt; //!< 28 bits : Longitude in 1/10000 minute
Expand All @@ -124,7 +125,7 @@
isrepeat: SmallInt; //!< 2 bits : Repeated
userid: LongInt; //!< 30 bits : UserID / MMSI
nav_status: SmallInt; //!< 4 bits : Navigational Status
rot: Byte; //!< 8 bits : Rate of Turn
rot: SmallInt; //!< 8 bits : Rate of Turn
sog: Integer; //!< 10 bits : Speed Over ground
pos_acc: SmallInt; //!< 1 bit : Position Accuracy
longitude: LongInt; //!< 28 bits : Longitude in 1/10000 minute
Expand All @@ -146,7 +147,7 @@
isrepeat: SmallInt; //!< 2 bits : Repeated
userid: LongInt; //!< 30 bits : UserID / MMSI
nav_status: SmallInt; //!< 4 bits : Navigational Status
rot: Byte; //!< 8 bits : Rate of Turn
rot: SmallInt; //!< 8 bits : Rate of Turn
sog: Integer; //!< 10 bits : Speed Over Ground
pos_acc: SmallInt; //!< 1 bit : Position Accuracy
longitude: LongInt; //!< 28 bits : Longitude in 1/10000 minute
Expand Down Expand Up @@ -830,7 +831,7 @@

Function IsXDigit(C: Char): Boolean;
Begin
Result := C In ['0'..'9', 'A'..'F', 'a'..'f'];
Result := CharInSet( C, ['0'..'9', 'A'..'F', 'a'..'f'] );
End;

(* -----------------------------------------------------------------------
Expand Down Expand Up @@ -1172,10 +1173,13 @@

----------------------------------------------------------------------- *)
Function AIS2ASCII(C: Byte): Char;
var
Value: Byte;
Begin
Byte(Result) := C And $3f;
If Byte(Result) < $20 Then
Byte(Result) := Byte(Result) + $40;
Value := C and $3F; // Perform the bitwise AND operation
if Value < $20 then
Value := Value + $40;
Result := Char(Value); // Convert the Byte to Char for the Result
End;

(* -----------------------------------------------------------------------
Expand Down Expand Up @@ -1265,6 +1269,15 @@
Result := 0;
End;

Function ConvRoT( var RoT: SmallInt ): SmallInt;
Begin
// Interpret as signed 8-bit value (two's complement)
if RoT >= 128 then
Result := RoT - 256
else
Result := RoT;
End;

(* -----------------------------------------------------------------------
Assemble AIVDM/VDO sentences

Expand Down Expand Up @@ -1482,6 +1495,8 @@
// Convert the position to signed value
ConvPos(Msg.latitude, Msg.longitude);

ConvRoT( Msg.RoT );

Result := 0;
End;
End;
Expand Down Expand Up @@ -1539,6 +1554,8 @@
// Convert the position to signed value
ConvPos(Msg.latitude, Msg.longitude);

ConvRoT( Msg.RoT );

Result := 0;
End;
End;
Expand Down Expand Up @@ -1594,6 +1611,8 @@
// Convert the position to signed value
ConvPos(Msg.latitude, Msg.longitude);

ConvRoT( Msg.RoT );

Result := 0;
End;
End;
Expand Down