74 lines
2.0 KiB
C++
74 lines
2.0 KiB
C++
// Copyright (c) 2014 OPEN CASCADE SAS
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//
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// This file is part of Open CASCADE Technology software library.
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//
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// This library is free software; you can redistribute it and/or modify it under
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// the terms of the GNU Lesser General Public License version 2.1 as published
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// by the Free Software Foundation, with special exception defined in the file
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// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
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// distribution for complete text of the license and disclaimer of any warranty.
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//
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// Alternatively, this file may be used under the terms of Open CASCADE
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// commercial license or contractual agreement.
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#ifndef _Graphic3d_BufferRange_HeaderFile
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#define _Graphic3d_BufferRange_HeaderFile
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#include "Graphic3d_Vec.hxx"
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#include "Standard_Integer.hxx"
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//! Range of values defined as Start + Length pair.
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struct Graphic3d_BufferRange
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{
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Standard_Integer Start; //!< first element within the range
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Standard_Integer Length; //!< number of elements within the range
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//! Empty constructor.
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Graphic3d_BufferRange()
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: Start(0),
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Length(0)
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{
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}
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//! Constructor.
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Graphic3d_BufferRange(Standard_Integer theStart, Standard_Integer theLength)
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: Start(theStart),
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Length(theLength)
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{
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}
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//! Return TRUE if range is empty.
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Standard_Boolean IsEmpty() const { return Length == 0; }
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//! Return the Upper element within the range
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Standard_Integer Upper() const { return Start + Length - 1; }
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//! Clear the range.
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void Clear()
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{
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Start = 0;
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Length = 0;
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}
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//! Add another range to this one.
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void Unite(const Graphic3d_BufferRange& theRange)
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{
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if (IsEmpty())
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{
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*this = theRange;
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return;
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}
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else if (theRange.IsEmpty())
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{
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return;
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}
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const Standard_Integer aStart = Min(Start, theRange.Start);
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const Standard_Integer aLast = Max(Upper(), theRange.Upper());
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Start = aStart;
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Length = aLast - aStart + 1;
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}
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};
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#endif // _Graphic3d_BufferRange_HeaderFile
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