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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#include "aqua/salmathutils.hxx"
#include <stdlib.h>
// =======================================================================
// =======================================================================
#define Swap( x, y ) { x ^= y; y ^= x; x ^= y; }
// =======================================================================
// =======================================================================
// Storage free swapping using XOR
void CSwap ( char &rX, char &rY )
{
Swap( rX, rY );
} // CSwap
// -----------------------------------------------------------------------
// Storage free swapping using XOR
void UCSwap ( unsigned char &rX, unsigned char &rY )
{
Swap( rX, rY );
} // UCSwap
// -----------------------------------------------------------------------
// Storage free swapping using XOR
void SSwap ( short &rX, short &rY )
{
Swap( rX, rY );
} // SSwap
// -----------------------------------------------------------------------
// Storage free swapping using XOR
void USSwap ( unsigned short &rX, unsigned short &rY )
{
Swap( rX, rY );
} // USSwap
// -----------------------------------------------------------------------
// Storage free swapping using XOR
void LSwap ( long &rX, long &rY )
{
Swap( rX, rY );
} // LSwap
// -----------------------------------------------------------------------
// Storage free swapping using XOR
void ULSwap ( unsigned long &rX, unsigned long &rY )
{
Swap( rX, rY );
} // ULSwap
// =======================================================================
// =======================================================================
// -----------------------------------------------------------------------
//
// This way of measuring distance is also called the "Manhattan distance."
// Manhattan distance takes advantage of the fact that the sum of the
// lengths of the three components of a 3D vector is a rough approxima-
// tion of the vector's length.
//
// -----------------------------------------------------------------------
unsigned long Euclidian2Norm ( const LRectCoorVector pVec )
{
unsigned long ndist = 0;
if ( pVec )
{
long nDX = 0;
long nDY = 0;
long nDZ = 0;
unsigned long nMax = 0;
unsigned long nMed = 0;
unsigned long nMin = 0;
// Find |x'-x|, |y'-y|, and |z'-z| from (x,y,z) and (x',y',z')
nDX = pVec[1].x - pVec[0].x;
nDY = pVec[1].y - pVec[0].y;
nDZ = pVec[1].z - pVec[0].z;
nMax = (unsigned long)abs( nDX );
nMed = (unsigned long)abs( nDY );
nMin = (unsigned long)abs( nDZ );
// Sort them (3 compares, 0-3 swaps)
if ( nMax < nMed )
{
Swap( nMax, nMed );
} // if
if ( nMax < nMin )
{
Swap( nMax, nMin );
} // if
// Approximate Euclidian distance:
//
// d = max + (11/32)*med + (1/4)*min
//
// with +/- 8% error, where the exact formulae for d is
//
// || (x',y',z') - (x,y,z) || = { |x'-x|^2 + |y'-y|^2 + |z'-z|^2 }^(1/2)
ndist = nMax + ( nMin >> 2UL )
+ ( ( ( nMed << 3UL ) + ( nMed << 1UL ) + nMed ) >> 5UL );
} // if
return ndist;
} // RGBDistance
// =======================================================================
// =======================================================================
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */