b9337e22ce
see https://gerrit.libreoffice.org/#/c/3367/ and Change-Id: I00c96fa77d04b33a6f8c8cd3490dfcd9bdc9e84a for details Change-Id: I199a75bc4042af20817265d5ef85b1134a96ff5a
257 lines
10 KiB
C++
257 lines
10 KiB
C++
/* -*- 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 .
|
|
*/
|
|
|
|
#ifndef _BGFX_RANGE_B2DCONNECTEDRANGES_HXX
|
|
#define _BGFX_RANGE_B2DCONNECTEDRANGES_HXX
|
|
|
|
#include <osl/diagnose.h>
|
|
#include <basegfx/range/b2drange.hxx>
|
|
#include <list>
|
|
#include <utility>
|
|
#include <algorithm>
|
|
|
|
|
|
namespace basegfx
|
|
{
|
|
/** Calculate connected ranges from input ranges.
|
|
|
|
This template constructs a list of connected ranges from the
|
|
given input ranges. That is, the output will contain a set of
|
|
ranges, itself containing a number of input ranges, which will
|
|
be mutually non-intersecting.
|
|
|
|
Example:
|
|
<code>
|
|
-------------------
|
|
| -------|
|
|
| | ||
|
|
| --- | ||
|
|
| | | -------| --------
|
|
| | +--------- | | |
|
|
| --+ | | | |
|
|
| | | | --------
|
|
| ---------- |
|
|
-------------------
|
|
</code
|
|
|
|
Here, the outer rectangles represent the output
|
|
ranges. Contained are the input rectangles that comprise these
|
|
output ranges.
|
|
|
|
@tpl UserData
|
|
User data to be stored along with the range, to later identify
|
|
which range went into which connected component. Must be
|
|
assignable, default- and copy-constructible.
|
|
*/
|
|
template< typename UserData > class B2DConnectedRanges
|
|
{
|
|
public:
|
|
/// Type of the basic entity (rect + user data)
|
|
typedef ::std::pair< B2DRange, UserData > ComponentType;
|
|
typedef ::std::list< ComponentType > ComponentListType;
|
|
|
|
/// List of (intersecting) components, plus overall bounds
|
|
struct ConnectedComponents
|
|
{
|
|
ComponentListType maComponentList;
|
|
B2DRange maTotalBounds;
|
|
};
|
|
|
|
typedef ::std::list< ConnectedComponents > ConnectedComponentsType;
|
|
|
|
|
|
/// Create the range calculator
|
|
B2DConnectedRanges() :
|
|
maDisjunctAggregatesList(),
|
|
maTotalBounds()
|
|
{
|
|
}
|
|
|
|
/** Query total bounds of all added ranges.
|
|
|
|
@return the union bound rect over all added ranges.
|
|
*/
|
|
B2DRange getBounds() const
|
|
{
|
|
return maTotalBounds;
|
|
}
|
|
|
|
/** Add an additional range.
|
|
|
|
This method integrates a new range into the connected
|
|
ranges lists. The method has a worst-case time complexity
|
|
of O(n^2), with n denoting the number of already added
|
|
ranges (typically, for well-behaved input, it is O(n)
|
|
though).
|
|
*/
|
|
void addRange( const B2DRange& rRange,
|
|
const UserData& rUserData )
|
|
{
|
|
// check whether fast path is possible: if new range is
|
|
// outside accumulated total range, can add it as a
|
|
// separate component right away.
|
|
const bool bNotOutsideEverything(
|
|
maTotalBounds.overlaps( rRange ) );
|
|
|
|
// update own global bounds range
|
|
maTotalBounds.expand( rRange );
|
|
|
|
// assemble anything intersecting with rRange into
|
|
// this new connected component
|
|
ConnectedComponents aNewConnectedComponent;
|
|
|
|
// as at least rRange will be a member of
|
|
// aNewConnectedComponent (will be added below), can
|
|
// preset the overall bounds here.
|
|
aNewConnectedComponent.maTotalBounds = rRange;
|
|
|
|
|
|
//
|
|
// STAGE 1: Search for intersecting maDisjunctAggregatesList entries
|
|
// =================================================================
|
|
//
|
|
|
|
// if rRange is empty, it will intersect with no
|
|
// maDisjunctAggregatesList member. Thus, we can safe us
|
|
// the check.
|
|
// if rRange is outside all other rectangle, skip here,
|
|
// too
|
|
if( bNotOutsideEverything &&
|
|
!rRange.isEmpty() )
|
|
{
|
|
typename ConnectedComponentsType::iterator aCurrAggregate;
|
|
typename ConnectedComponentsType::iterator aLastAggregate;
|
|
|
|
// flag, determining whether we touched one or more of
|
|
// the maDisjunctAggregatesList entries. _If_ we did,
|
|
// we have to repeat the intersection process, because
|
|
// these changes might have generated new
|
|
// intersections.
|
|
bool bSomeAggregatesChanged;
|
|
|
|
// loop, until bSomeAggregatesChanged stays false
|
|
do
|
|
{
|
|
// only continue loop if 'intersects' branch below was hit
|
|
bSomeAggregatesChanged = false;
|
|
|
|
// iterate over all current members of maDisjunctAggregatesList
|
|
for( aCurrAggregate=maDisjunctAggregatesList.begin(),
|
|
aLastAggregate=maDisjunctAggregatesList.end();
|
|
aCurrAggregate != aLastAggregate; )
|
|
{
|
|
// first check if current component's bounds
|
|
// are empty. This ensures that distinct empty
|
|
// components are not merged into one
|
|
// aggregate. As a matter of fact, they have
|
|
// no position and size.
|
|
|
|
if( !aCurrAggregate->maTotalBounds.isEmpty() &&
|
|
aCurrAggregate->maTotalBounds.overlaps(
|
|
aNewConnectedComponent.maTotalBounds ) )
|
|
{
|
|
// union the intersecting
|
|
// maDisjunctAggregatesList element into
|
|
// aNewConnectedComponent
|
|
|
|
// calc union bounding box
|
|
aNewConnectedComponent.maTotalBounds.expand( aCurrAggregate->maTotalBounds );
|
|
|
|
// extract all aCurrAggregate components
|
|
// to aNewConnectedComponent
|
|
aNewConnectedComponent.maComponentList.splice(
|
|
aNewConnectedComponent.maComponentList.end(),
|
|
aCurrAggregate->maComponentList );
|
|
|
|
// remove and delete aCurrAggregate entry
|
|
// from list (we've gutted it's content
|
|
// above). list::erase() will update our
|
|
// iterator with the predecessor here.
|
|
aCurrAggregate = maDisjunctAggregatesList.erase( aCurrAggregate );
|
|
|
|
// at least one aggregate changed, need to rescan everything
|
|
bSomeAggregatesChanged = true;
|
|
}
|
|
else
|
|
{
|
|
aCurrAggregate++;
|
|
}
|
|
}
|
|
}
|
|
while( bSomeAggregatesChanged );
|
|
}
|
|
|
|
//
|
|
// STAGE 2: Add newly generated connected component list element
|
|
// =============================================================
|
|
//
|
|
|
|
// add new component to the end of the component list
|
|
aNewConnectedComponent.maComponentList.push_back(
|
|
ComponentType( rRange, rUserData ) );
|
|
|
|
// do some consistency checks (aka post conditions)
|
|
OSL_ENSURE( !aNewConnectedComponent.maComponentList.empty(),
|
|
"B2DConnectedRanges::addRange(): empty aggregate list" );
|
|
OSL_ENSURE( !aNewConnectedComponent.maTotalBounds.isEmpty() ||
|
|
(aNewConnectedComponent.maTotalBounds.isEmpty() &&
|
|
aNewConnectedComponent.maComponentList.size() == 1),
|
|
"B2DConnectedRanges::addRange(): empty ranges must be solitary");
|
|
|
|
// add aNewConnectedComponent as a new entry to
|
|
// maDisjunctAggregatesList
|
|
maDisjunctAggregatesList.push_back( aNewConnectedComponent );
|
|
}
|
|
|
|
/** Apply a functor to each of the disjunct component
|
|
aggregates.
|
|
|
|
@param aFunctor
|
|
Functor to apply. Must provide an operator( const ConnectedComponents& ).
|
|
|
|
@return a copy of the functor, as applied to all aggregates.
|
|
*/
|
|
template< typename UnaryFunctor > UnaryFunctor forEachAggregate( UnaryFunctor aFunctor ) const
|
|
{
|
|
return ::std::for_each( maDisjunctAggregatesList.begin(),
|
|
maDisjunctAggregatesList.end(),
|
|
aFunctor );
|
|
}
|
|
|
|
private:
|
|
// default: disabled copy/assignment
|
|
B2DConnectedRanges(const B2DConnectedRanges&);
|
|
B2DConnectedRanges& operator=( const B2DConnectedRanges& );
|
|
|
|
/** Current list of disjunct sets of connected components
|
|
|
|
Each entry corresponds to one of the top-level rectangles
|
|
in the drawing above.
|
|
*/
|
|
ConnectedComponentsType maDisjunctAggregatesList;
|
|
|
|
/** Global bound rect over all added ranges.
|
|
*/
|
|
B2DRange maTotalBounds;
|
|
};
|
|
}
|
|
|
|
#endif /* _BGFX_RANGE_B2DCONNECTEDRANGES_HXX */
|
|
|
|
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|