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fpvectorial: Improves the LAS reader, now reads the variable length records too
git-svn-id: trunk@33961 -
This commit is contained in:
sekelsenmat
parent
01385540aa
commit
a491e9260f
@ -31,22 +31,23 @@ uses
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fpvectorial;
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type
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// LAS data types
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laschar = Char; // or ShortInt
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// LAS data types introduced in LAS 1.0
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laschar = AnsiChar; // or ShortInt
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lasuchar = Byte;
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lasshort = Smallint;
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lasushort = Word;
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laslong = Integer;
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lasulong = Cardinal;
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lasdouble = double;
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//
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laslonglong = Int64;
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lasulonglong = QWord;
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lasdouble = double;
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// PUBLIC HEADER BLOCK
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TLASPublicHeaderBlock = packed record
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// PUBLIC HEADER BLOCK version 1.0
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TLASPublicHeaderBlock_1_0 = packed record
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FileSignatureLASF: array[0..3] of laschar;
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FileSourceID: lasushort;
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GlobalEncoding: lasushort;
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FileSourceID: lasushort; // Reserved in LAS 1.0
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GlobalEncoding: lasushort; // Reserved in LAS 1.0
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ProjectIDGUIDdata1: lasulong; // Optional
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ProjectIDGUIDdata2: lasushort; // Optional
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ProjectIDGUIDdata3: lasushort; // Optional
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@ -55,38 +56,87 @@ type
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VersionMinor: lasuchar;
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SystemIdentifier: array[0..31] of laschar;
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GeneratingSoftware: array[0..31] of laschar;
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FileCreationDayofYear: lasushort;
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FileCreationYear: lasushort;
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{Number of Variable Length Records
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Point Data Format ID (0-99 for spec)
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Point Data Record Length
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Number of point records
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Number of points by return
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X scale factor
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Y scale factor
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Z scale factor
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X offset
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Y offset
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Z offset
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Max X
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Min X
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Max Y
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Min Y
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Max Z
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Min Z
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Start of Waveform Data Packet Record
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Any field in the Public Header Block that is not required and is not used must be zero filled.}
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FileCreationDayofYear: lasushort; // Name in LAS 1.0 -> FlightDateJulian, but same meaning
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FileCreationYear: lasushort; // Name in LAS 1.0 -> Year, but same meaning
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HeaderSize: lasushort; // Name in LAS 1.0 -> OffsetToData
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OffsetToPointData: lasulong;
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NumberofVariableLengthRecords: lasulong;
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PointDataFormatID: lasuchar; // (0-99 for spec)
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PointDataRecordLength: lasushort;
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Numberofpointrecords: lasulong;
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Numberofpointsbyreturn: array[0..4] of lasulong;
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Xscalefactor: lasdouble;
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Yscalefactor: lasdouble;
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Zscalefactor: lasdouble;
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Xoffset: lasdouble;
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Yoffset: lasdouble;
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Zoffset: lasdouble;
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MaxX: lasdouble;
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MinX: lasdouble;
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MaxY: lasdouble;
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MinY: lasdouble;
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MaxZ: lasdouble;
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MinZ: lasdouble;
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end;
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// PUBLIC HEADER BLOCK Extension in Version 1.3
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TLASPublicHeaderBlock_1_3_Extension = packed record
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StartofWaveformDataPacket: lasulonglong;
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end;
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TLASVariableLengthRecord = packed record
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RecordSignatureAABB: lasushort;
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UserID: array[0..15] of laschar;
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RecordID: lasushort;
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RecordLengthAfterHeader: lasushort;
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Description: array[0..31] of laschar;
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end;
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TLASPointDataRecordFormat0 = packed record
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X: laslong;
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Y: laslong;
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Z: laslong;
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Intensity: lasushort;
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Flags: Byte;
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Classification: lasuchar;
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ScanAngleRank: lasuchar; // (-90 to +90) - is the left side
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FileMarker: lasuchar;
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UserBitField: lasushort;
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end;
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TLASPointDataRecordFormat1 = packed record
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X: laslong;
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Y: laslong;
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Z: laslong;
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Intensity: lasushort;
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Flags: Byte;
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Classification: lasuchar;
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ScanAngleRank: lasuchar; // (-90 to +90) - is the left side
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FileMarker: lasuchar;
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UserBitField: lasushort;
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GPSTime: lasdouble;
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end;
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{ TvLASVectorialReader }
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TvLASVectorialReader = class(TvCustomVectorialReader)
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private
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// Stream position information
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InitialPos, PositionAfterPublicHeader: Int64;
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{$ifdef FPVECTORIALDEBUG_LAS}
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procedure DebugOutPublicHeaderBlock();
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{$endif}
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procedure ReadVariableLengthRecords(AStream: TStream);
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public
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PublicHeaderBlock: TLASPublicHeaderBlock;
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// Public Header
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PublicHeaderBlock_1_0: TLASPublicHeaderBlock_1_0;
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PublicHeaderBlock_1_3_Extension: TLASPublicHeaderBlock_1_3_Extension;
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// Variable Length Records
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VariableLengthRecords: array of TLASVariableLengthRecord;
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// Point Data
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PointsFormat0: array of TLASPointDataRecordFormat0;
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PointsFormat1: array of TLASPointDataRecordFormat1;
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{ General reading methods }
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procedure ReadFromStream(AStream: TStream; AData: TvVectorialDocument); override;
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end;
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@ -97,33 +147,116 @@ implementation
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procedure TvLASVectorialReader.DebugOutPublicHeaderBlock;
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begin
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WriteLn(Format('FileSignatureLASF = %s = %x %x %x %x',
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[PublicHeaderBlock.FileSignatureLASF,
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PublicHeaderBlock.FileSignatureLASF[0],
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PublicHeaderBlock.FileSignatureLASF[1],
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PublicHeaderBlock.FileSignatureLASF[2],
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PublicHeaderBlock.FileSignatureLASF[3]]));
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WriteLn(Format('FileSourceID = %x', [PublicHeaderBlock.FileSourceID]));
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WriteLn(Format('GlobalEncoding = %x', [PublicHeaderBlock.GlobalEncoding]));
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WriteLn(Format('ProjectIDGUIDdata1 = %x', [PublicHeaderBlock.ProjectIDGUIDdata1]));
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WriteLn(Format('ProjectIDGUIDdata2 = %x', [PublicHeaderBlock.ProjectIDGUIDdata2]));
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WriteLn(Format('ProjectIDGUIDdata3 = %x', [PublicHeaderBlock.ProjectIDGUIDdata3]));
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// WriteLn(Format('ProjectIDGUIDdata2 = %x', [ProjectIDGUIDdata2]));
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WriteLn(Format('VersionMajor = %x', [PublicHeaderBlock.VersionMajor]));
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WriteLn(Format('VersionMinor = %x', [PublicHeaderBlock.VersionMinor]));
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WriteLn(Format('SystemIdentifier = %s', [PublicHeaderBlock.SystemIdentifier]));
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WriteLn(Format('GeneratingSoftware = %s', [PublicHeaderBlock.GeneratingSoftware]));
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WriteLn(Format('FileCreationDayofYear = %x', [PublicHeaderBlock.FileCreationDayofYear]));
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WriteLn(Format('FileCreationYear = %x', [PublicHeaderBlock.FileCreationYear]));
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[string(PublicHeaderBlock_1_0.FileSignatureLASF),
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Ord(PublicHeaderBlock_1_0.FileSignatureLASF[0]),
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Ord(PublicHeaderBlock_1_0.FileSignatureLASF[1]),
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Ord(PublicHeaderBlock_1_0.FileSignatureLASF[2]),
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Ord(PublicHeaderBlock_1_0.FileSignatureLASF[3])]));
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WriteLn(Format('FileSourceID = $%x', [PublicHeaderBlock_1_0.FileSourceID]));
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WriteLn(Format('GlobalEncoding = $%x', [PublicHeaderBlock_1_0.GlobalEncoding]));
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WriteLn(Format('ProjectIDGUIDdata1 = $%x', [PublicHeaderBlock_1_0.ProjectIDGUIDdata1]));
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WriteLn(Format('ProjectIDGUIDdata2 = $%x', [PublicHeaderBlock_1_0.ProjectIDGUIDdata2]));
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WriteLn(Format('ProjectIDGUIDdata3 = $%x', [PublicHeaderBlock_1_0.ProjectIDGUIDdata3]));
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// WriteLn(Format('ProjectIDGUIDdata4 = %x', [ProjectIDGUIDdata2]));
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WriteLn(Format('VersionMajor = %d', [PublicHeaderBlock_1_0.VersionMajor]));
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WriteLn(Format('VersionMinor = %d', [PublicHeaderBlock_1_0.VersionMinor]));
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WriteLn(Format('SystemIdentifier = %s', [PublicHeaderBlock_1_0.SystemIdentifier]));
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WriteLn(Format('GeneratingSoftware = %s', [PublicHeaderBlock_1_0.GeneratingSoftware]));
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WriteLn(Format('FileCreationDayofYear = %d', [PublicHeaderBlock_1_0.FileCreationDayofYear]));
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WriteLn(Format('FileCreationYear = %d', [PublicHeaderBlock_1_0.FileCreationYear]));
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WriteLn(Format('HeaderSize = $%x', [PublicHeaderBlock_1_0.HeaderSize]));
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WriteLn(Format('OffsetToPointData = $%x', [PublicHeaderBlock_1_0.OffsetToPointData]));
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WriteLn(Format('NumberofVariableLengthRecords = $%x', [PublicHeaderBlock_1_0.NumberofVariableLengthRecords]));
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WriteLn(Format('PointDataFormatID = $%x', [PublicHeaderBlock_1_0.PointDataFormatID]));
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WriteLn(Format('PointDataRecordLength = $%x', [PublicHeaderBlock_1_0.PointDataRecordLength]));
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WriteLn(Format('Numberofpointrecords = $%x', [PublicHeaderBlock_1_0.Numberofpointrecords]));
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WriteLn(Format('Numberofpointsbyreturn = %x %x %x %x %x',
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[PublicHeaderBlock_1_0.Numberofpointsbyreturn[0],
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PublicHeaderBlock_1_0.Numberofpointsbyreturn[1],
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PublicHeaderBlock_1_0.Numberofpointsbyreturn[2],
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PublicHeaderBlock_1_0.Numberofpointsbyreturn[3],
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PublicHeaderBlock_1_0.Numberofpointsbyreturn[4]
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]));
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WriteLn(Format('Xscalefactor = %f', [PublicHeaderBlock_1_0.Xscalefactor]));
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WriteLn(Format('Yscalefactor = %f', [PublicHeaderBlock_1_0.Yscalefactor]));
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WriteLn(Format('Zscalefactor = %f', [PublicHeaderBlock_1_0.Zscalefactor]));
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WriteLn(Format('Xoffset = %f', [PublicHeaderBlock_1_0.Xoffset]));
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WriteLn(Format('Yoffset = %f', [PublicHeaderBlock_1_0.Yoffset]));
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WriteLn(Format('Zoffset = %f', [PublicHeaderBlock_1_0.Zoffset]));
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WriteLn(Format('MaxX = %f', [PublicHeaderBlock_1_0.MaxX]));
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WriteLn(Format('MinX = %f', [PublicHeaderBlock_1_0.MinX]));
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WriteLn(Format('MaxY = %f', [PublicHeaderBlock_1_0.MaxY]));
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WriteLn(Format('MinY = %f', [PublicHeaderBlock_1_0.MinY]));
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WriteLn(Format('MaxZ = %f', [PublicHeaderBlock_1_0.MaxZ]));
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WriteLn(Format('MinZ = %f', [PublicHeaderBlock_1_0.MinZ]));
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WriteLn('');
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WriteLn(Format('LAS 1.0 header size = $%x', [SizeOf(TLASPublicHeaderBlock_1_0)]));
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WriteLn('');
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end;
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{$endif}
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procedure TvLASVectorialReader.ReadVariableLengthRecords(AStream: TStream);
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var
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i: Integer;
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NextPosition: Int64;
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begin
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NextPosition := PositionAfterPublicHeader;
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SetLength(VariableLengthRecords, PublicHeaderBlock_1_0.NumberofVariableLengthRecords);
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for i := 0 to PublicHeaderBlock_1_0.NumberofVariableLengthRecords - 1 do
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begin
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AStream.Position := NextPosition;
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{$ifdef FPVECTORIALDEBUG_LAS}
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WriteLn(Format('Variable Length Record #%d Position = $%x', [i, NextPosition]));
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WriteLn('');
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{$endif}
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AStream.Read(VariableLengthRecords[i], SizeOf(TLASVariableLengthRecord));
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NextPosition := AStream.Position+VariableLengthRecords[i].RecordLengthAfterHeader;
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{$ifdef FPVECTORIALDEBUG_LAS}
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WriteLn(Format('RecordSignatureAABB = $%x', [VariableLengthRecords[i].RecordSignatureAABB]));
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WriteLn(Format('UserID = %s', [VariableLengthRecords[i].UserID]));
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WriteLn(Format('RecordID = $%x', [VariableLengthRecords[i].RecordID]));
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WriteLn(Format('RecordLengthAfterHeader = $%x', [VariableLengthRecords[i].RecordLengthAfterHeader]));
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WriteLn(Format('Description = %s', [VariableLengthRecords[i].Description]));
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WriteLn('');
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{$endif}
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end;
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end;
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procedure TvLASVectorialReader.ReadFromStream(AStream: TStream;
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AData: TvVectorialDocument);
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begin
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AStream.Read(PublicHeaderBlock, SizeOf(TLASPublicHeaderBlock));
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// First read the header like if it was for LAS 1.0,
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// this will tell us the real version so then we read it again
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InitialPos := AStream.Position;
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AStream.Read(PublicHeaderBlock_1_0, SizeOf(TLASPublicHeaderBlock_1_0));
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{$ifdef FPVECTORIALDEBUG_LAS}
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DebugOutPublicHeaderBlock();
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{$endif}
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// First check the signature
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if PublicHeaderBlock_1_0.FileSignatureLASF <> 'LASF' then
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raise Exception.Create('[TvLASVectorialReader.ReadFromStream] Invalid file signoture while reading LAS file');
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// In LAS 1.3+ read the header extension
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// ToDo
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PositionAfterPublicHeader := AStream.Position;
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// Read the variable length records
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ReadVariableLengthRecords(AStream);
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// Read the point data
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AStream.Position := InitialPos + PublicHeaderBlock_1_0.OffsetToPointData;
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case PublicHeaderBlock_1_0.PointDataFormatID of
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0:
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begin
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end;
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1:
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begin
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end;
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end;
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end;
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initialization
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