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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 .
*/
// header for Point, Rectangle
// header for Polygon
// header for DBG_ASSERT
// header for XPolygon, XPolyPolygon
#include <bf_svx/xpoly.hxx>
// header for Line
#include <tools/line.hxx>
// for performance measurement
#include <rtl/logfile.hxx>
// Note: Enable the following to skip points in the resulting spline
// poly-polygon, if they have equal x-values rather than identical points.
// Unitl now, I think there are situations where the output might differ, if you
// do so, so it's not enabled by default.
// #define SPLINE_OPTIMIZE_POINTS
#include "calculat.hxx"
#include <algorithm>
#include <functional>
namespace binfilter {
using namespace ::std;
/*N*/ void SchCalculationHelper::IntersectPolygonWithRectangle( const XPolygon& rPolygon, const Rectangle& rRectangle, XPolyPolygon& aResult )
/*N*/ {
/*N*/ RTL_LOGFILE_CONTEXT_AUTHOR( context, "sch", "bm93744", "SchCalculationHelper::IntersectPolygonWithRectangle");
/*N*/
/*N*/ aResult.Clear();
/*N*/
/*N*/ if( rRectangle.IsInside( rPolygon.GetBoundRect() ) )
/*N*/ {
/*N*/ aResult.Insert( rPolygon );
/*N*/ OSL_TRACE( "IntersectPolygonWithRectangle: result has %d polygons", aResult.Count() );
/*N*/ return;
/*N*/ }
/*N*/
/*N*/ Point aFrom;
/*N*/ Point aTo;
/*N*/ USHORT nCount = rPolygon.GetPointCount();
/*N*/
/*N*/ // set last point to a position outside the rectangle, such that the first
/*N*/ // time clip2d returns true, the comparison to last will always yield false
/*N*/ Point aLast (rRectangle.TopLeft());
/*N*/ aLast.Move (-1, -1);
/*N*/ XPolygon aCurrentPoly;
/*N*/ USHORT nIdx = 0;
/*N*/
/*N*/ for (USHORT i=1; i<nCount; i++)
/*N*/ {
/*N*/ aFrom = rPolygon[i-1];
/*N*/ aTo = rPolygon[i];
/*N*/ if (clip2d (aFrom, aTo, rRectangle))
/*N*/ {
/*N*/ // compose an XPolygon of as many consecutive points as possible
/*N*/ if (aFrom == aLast)
/*N*/ {
/*N*/ if (aTo != aFrom)
/*N*/ aCurrentPoly.Insert (nIdx++, aTo, XPOLY_NORMAL);
/*N*/ }
/*N*/ else
/*N*/ {
/*N*/ // create an XPolygon and put it into the XPolyPolygon
/*N*/ if (aCurrentPoly.GetPointCount() > 0)
/*N*/ aResult.Insert (aCurrentPoly, XPOLYPOLY_APPEND);
/*N*/
/*N*/ // start new sequence
/*N*/ aCurrentPoly.SetPointCount (0);
/*N*/ aCurrentPoly.Insert (0, aFrom, XPOLY_NORMAL);
/*N*/ nIdx = 1;
/*N*/ if (aTo != aFrom)
/*N*/ aCurrentPoly.Insert (nIdx++, aTo, XPOLY_NORMAL);
/*N*/ }
/*N*/
/*N*/ aLast = aTo;
/*N*/ }
/*N*/ }
/*N*/ if (aCurrentPoly.GetPointCount() > 0)
/*N*/ aResult.Insert (aCurrentPoly, XPOLYPOLY_APPEND);
/*N*/
/*N*/ OSL_TRACE( "IntersectPolygonWithRectangle: result has %d polygons", aResult.Count() );
/*N*/ }
/*N*/ BOOL SchCalculationHelper::clip2d (Point & rPoint0,
/*N*/ Point & rPoint1,
/*N*/ const Rectangle & rRectangle)
/*N*/ {
/*N*/ // Direction vector of the line.
/*N*/ Point aD = rPoint1 - rPoint0;
/*N*/
/*N*/ if (aD.X()==0 && aD.Y()==0 && rRectangle.IsInside (rPoint0))
/*N*/ {
/*N*/ // Degenerate case of a zero length line.
/*N*/ return TRUE;
/*N*/ }
/*N*/ else
/*N*/ {
/*N*/ // Values of the line parameter where the line enters resp. leaves the rectangle.
/*N*/ double fTE = 0,
/*N*/ fTL = 1;
/*N*/
/*N*/ // Test wether at least a part lies in the four half-planes with respect to
/*N*/ // the rectangles four edges.
/*N*/ if (CLIPt (aD.X(), rRectangle.Left() - rPoint0.X(), fTE, fTL))
/*N*/ if (CLIPt (-aD.X(), rPoint0.X() - rRectangle.Right(), fTE, fTL))
/*N*/ if (CLIPt (aD.Y(), rRectangle.Top() - rPoint0.Y(), fTE, fTL))
/*N*/ if (CLIPt (-aD.Y(), rPoint0.Y() - rRectangle.Bottom(), fTE, fTL))
/*N*/ {
/*N*/ // At least a part is visible.
/*N*/ if (fTL < 1)
/*N*/ {
/*N*/ // ::com::pute the new end point.
/*N*/ rPoint1.X() = (long)(rPoint0.X() + fTL * aD.X() + 0.5);
/*N*/ rPoint1.Y() = (long)(rPoint0.Y() + fTL * aD.Y() + 0.5);
/*N*/ }
/*N*/ if (fTE > 0)
/*N*/ {
/*N*/ // ::com::pute the new starting point.
/*N*/ rPoint0.X() = (long)(rPoint0.X() + fTE * aD.X() + 0.5);
/*N*/ rPoint0.Y() = (long)(rPoint0.Y() + fTE * aD.Y() + 0.5);
/*N*/ }
/*N*/ return TRUE;
/*N*/ }
/*N*/
/*N*/ // Line is not visible.
/*N*/ return FALSE;
/*N*/ }
/*N*/ }
/*N*/ BOOL SchCalculationHelper::CLIPt (double fDenom,
/*N*/ double fNum,
/*N*/ double & fTE,
/*N*/ double & fTL)
/*N*/ {
/*N*/ double fT;
/*N*/
/*N*/ if (fDenom > 0) // Intersection enters: PE
/*N*/ {
/*N*/ fT = fNum / fDenom; // Parametric value at the intersection.
/*N*/ if (fT > fTL) // fTE and fTL crossover
/*N*/ return FALSE; // therefore reject the line.
/*N*/ else if (fT > fTE) // A new fTE has been found.
/*N*/ fTE = fT;
/*N*/ }
/*N*/ else if (fDenom < 0) // Intersection leaves: PL
/*N*/ {
/*N*/ fT = fNum / fDenom; // Parametric Value at the intersection.
/*N*/ if (fT < fTE) // fTE and fTL crossover
/*N*/ return FALSE; // therefore reject the line.
/*N*/ else if (fT < fTL) // A new fTL has been found.
/*N*/ fTL = fT;
/*N*/ }
/*N*/ else if (fNum > 0)
/*N*/ return FALSE; // Line lies on the outside of the edge.
/*N*/
/*N*/ return TRUE;
/*N*/ }
// --------------------------------------------------------------------------------
// Calculation of Splines
// ----------------------------------------
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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