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Kaydet (Commit) 82b56544 authored tarafından Michael Meeks's avatar Michael Meeks
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basegfx: accelerate Trapezoid subdivision by avoiding allocations. 

Allocate on the stack where possible, then more conservatively on
the heap. Unit test Trapezoid subdivision for good measure.

Change-Id: I83e63fd55fddcad149bb5279865670ebb18e0ab1
üst b178afc8
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Showing with 114 additions and 69 deletions
basegfx/source/polygon/b2dtrapezoid.cxx
Dosyayı görüntüle @ 82b56544
......@@ -193,6 +193,60 @@ namespace basegfx
{
namespace trapezoidhelper
{
// FIXME: templatize this and use it for TrDeEdgeEntries too ...
/// Class to allow efficient allocation and release of B2DPoints
class PointBlockAllocator
{
static const int nBlockSize = 32;
size_t nCurPoint;
B2DPoint *mpPointBase;
/// Special case the first allocation to avoid it.
B2DPoint maFirstStackBlock[nBlockSize];
std::vector< B2DPoint * > maBlocks;
public:
PointBlockAllocator() :
nCurPoint( nBlockSize ),
mpPointBase( maFirstStackBlock )
{
}
~PointBlockAllocator()
{
while(maBlocks.size() > 0)
{
delete [] maBlocks.back();
maBlocks.pop_back();
}
}
B2DPoint *allocatePoint()
{
if(nCurPoint >= nBlockSize)
{
mpPointBase = new B2DPoint[nBlockSize];
maBlocks.push_back(mpPointBase);
nCurPoint = 0;
}
return mpPointBase + nCurPoint++;
}
B2DPoint *allocatePoint(const B2DTuple &rPoint)
{
B2DPoint *pPoint = allocatePoint();
*pPoint = rPoint;
return pPoint;
}
/// This is a very uncommon case but why not ...
void freeIfLast(B2DPoint *pPoint)
{
// just re-use the last point if we can.
if ( nCurPoint > 0 && pPoint == mpPointBase + nCurPoint - 1 )
nCurPoint--;
}
};
// helper class to handle the complete trapezoid subdivision of a PolyPolygon
class TrapezoidSubdivider
{
......@@ -201,7 +255,8 @@ namespace basegfx
sal_uInt32 mnInitialEdgeEntryCount;
TrDeEdgeEntries maTrDeEdgeEntries;
::std::vector< B2DPoint > maPoints;
::std::vector< B2DPoint* > maNewPoints;
/// new points allocated for cuts
PointBlockAllocator maNewPoints;
void addEdgeSorted(
TrDeEdgeEntries::iterator aCurrent,
......@@ -349,22 +404,16 @@ namespace basegfx
const double fSimpleLengthB(aDeltaB.getX() + aDeltaB.getY());
const bool bAIsLonger(fSimpleLengthA > fSimpleLengthB);
B2DPoint* pNewPoint = bAIsLonger
? new B2DPoint(aEdgeA.getStart() + (fCutA * aDeltaA))
: new B2DPoint(aEdgeB.getStart() + (fCutB * aDeltaB));
bool bRetval(false);
? maNewPoints.allocatePoint(aEdgeA.getStart() + (fCutA * aDeltaA))
: maNewPoints.allocatePoint(aEdgeB.getStart() + (fCutB * aDeltaB));
bool bRetval = false;
// try to split both edges
bRetval = splitEdgeAtGivenPoint(aEdgeA, *pNewPoint, aCurrent);
bRetval |= splitEdgeAtGivenPoint(aEdgeB, *pNewPoint, aCurrent);
if(bRetval)
{
maNewPoints.push_back(pNewPoint);
}
else
{
delete pNewPoint;
}
if(!bRetval)
maNewPoints.freeIfLast(pNewPoint);
return bRetval;
}
......@@ -419,16 +468,12 @@ namespace basegfx
if(fTools::more(aSplit.getX(), aRange.getMinimum())
&& fTools::less(aSplit.getX(), aRange.getMaximum()))
{
// cut is in XRange of horizontal edge, potenitally needed cut
B2DPoint* pNewPoint = new B2DPoint(aSplit);
// cut is in XRange of horizontal edge, potentially needed cut
B2DPoint* pNewPoint = maNewPoints.allocatePoint(aSplit);
if(splitEdgeAtGivenPoint(aCompare, *pNewPoint, aCurrent))
if(!splitEdgeAtGivenPoint(aCompare, *pNewPoint, aCurrent))
{
maNewPoints.push_back(pNewPoint);
}
else
{
delete pNewPoint;
maNewPoints.freeIfLast(pNewPoint);
}
}
}
......@@ -551,17 +596,6 @@ namespace basegfx
}
}
~TrapezoidSubdivider()
{
// delete the extra points created for cuts
const sal_uInt32 nCount(maNewPoints.size());
for(sal_uInt32 a(0); a < nCount; a++)
{
delete maNewPoints[a];
}
}
void Subdivide(B2DTrapezoidVector& ro_Result)
{
// This is the central subdivider. The strategy is to use the first two entries
......@@ -671,28 +705,20 @@ namespace basegfx
{
if(bLeftIsLonger)
{
B2DPoint* pNewPoint = new B2DPoint(aLeftEnd);
B2DPoint* pNewPoint = maNewPoints.allocatePoint(aLeftEnd);
if(splitEdgeAtGivenPoint(aLeft, *pNewPoint, aCurrent))
if(!splitEdgeAtGivenPoint(aLeft, *pNewPoint, aCurrent))
{
maNewPoints.push_back(pNewPoint);
}
else
{
delete pNewPoint;
maNewPoints.freeIfLast(pNewPoint);
}
}
else
{
B2DPoint* pNewPoint = new B2DPoint(aRightEnd);
B2DPoint* pNewPoint = maNewPoints.allocatePoint(aRightEnd);
if(splitEdgeAtGivenPoint(aRight, *pNewPoint, aCurrent))
{
maNewPoints.push_back(pNewPoint);
}
else
if(!splitEdgeAtGivenPoint(aRight, *pNewPoint, aCurrent))
{
delete pNewPoint;
maNewPoints.freeIfLast(pNewPoint);
}
}
}
......@@ -780,28 +806,26 @@ namespace basegfx
aCompare.getStart().getX() <= aSplitRight.getX())
{
// is inside, correct and restart loop
B2DPoint* pNewLeft = new B2DPoint(aSplitLeft);
B2DPoint* pNewLeft = maNewPoints.allocatePoint(aSplitLeft);
if(splitEdgeAtGivenPoint(aLeft, *pNewLeft, aCurrent))
{
maNewPoints.push_back(pNewLeft);
bDone = true;
}
else
{
delete pNewLeft;
maNewPoints.freeIfLast(pNewLeft);
}
B2DPoint* pNewRight = new B2DPoint(aSplitRight);
B2DPoint* pNewRight = maNewPoints.allocatePoint(aSplitRight);
if(splitEdgeAtGivenPoint(aRight, *pNewRight, aCurrent))
{
maNewPoints.push_back(pNewRight);
bDone = true;
}
else
{
delete pNewRight;
maNewPoints.freeIfLast(pNewRight);
}
}
}
......@@ -837,28 +861,20 @@ namespace basegfx
{
if(bLeftIsLonger)
{
B2DPoint* pNewPoint = new B2DPoint(aLeftEnd);
B2DPoint* pNewPoint = maNewPoints.allocatePoint(aLeftEnd);
if(splitEdgeAtGivenPoint(aLeft, *pNewPoint, aCurrent))
if(!splitEdgeAtGivenPoint(aLeft, *pNewPoint, aCurrent))
{
maNewPoints.push_back(pNewPoint);
}
else
{
delete pNewPoint;
maNewPoints.freeIfLast(pNewPoint);
}
}
else
{
B2DPoint* pNewPoint = new B2DPoint(aRightEnd);
B2DPoint* pNewPoint = maNewPoints.allocatePoint(aRightEnd);
if(splitEdgeAtGivenPoint(aRight, *pNewPoint, aCurrent))
{
maNewPoints.push_back(pNewPoint);
}
else
if(!splitEdgeAtGivenPoint(aRight, *pNewPoint, aCurrent))
{
delete pNewPoint;
maNewPoints.freeIfLast(pNewPoint);
}
}
}
......
basegfx/test/basegfx2d.cxx
Dosyayı görüntüle @ 82b56544
......@@ -30,6 +30,7 @@
#include <basegfx/polygon/b2dpolypolygontools.hxx>
#include <basegfx/polygon/b2dpolygonclipper.hxx>
#include <basegfx/polygon/b2dpolypolygon.hxx>
#include <basegfx/polygon/b2dtrapezoid.hxx>
#include <basegfx/range/b2irange.hxx>
#include <basegfx/range/b2ibox.hxx>
#include <basegfx/range/b1drange.hxx>
......@@ -51,6 +52,7 @@ using namespace ::basegfx;
namespace basegfx2d
{
extern double getRandomOrdinal( const ::std::size_t n );
class b2dsvgdimpex : public CppUnit::TestFixture
{
......@@ -858,13 +860,39 @@ public:
CPPUNIT_TEST_SUITE_END();
}; // class b2dpolygontools
class b2dpolypolygon : public CppUnit::TestFixture
{
public:
// insert your test code here.
void EmptyMethod()
void testTrapezoidHelper()
{
B2DPolygon aPolygon;
// provoke the PointBlockAllocator to exercise the freeIfLast path
for(int i = 0; i < 16 * 10; i++)
{
B2DPoint aPoint(getRandomOrdinal(1000), getRandomOrdinal(1000));
aPolygon.append(aPoint);
}
// scatter some duplicate points in to stress things more.
for(int i = 0; i < 16 * 10; i++)
{
aPolygon.insert(getRandomOrdinal(aPolygon.count() - 1),
aPolygon.getB2DPoint(getRandomOrdinal(aPolygon.count() - 1)));
}
B2DPolygon aPolygonOffset;
// duplicate the polygon and offset it slightly.
for(size_t i = 0; i < aPolygon.count(); i++)
{
B2DPoint aPoint(aPolygon.getB2DPoint(i));
aPoint += B2DPoint(0.5-getRandomOrdinal(1),0.5-getRandomOrdinal(1));
}
B2DPolyPolygon aPolyPolygon;
aPolyPolygon.append(aPolygon);
aPolyPolygon.append(aPolygonOffset);
B2DTrapezoidVector aVector;
basegfx::tools::trapezoidSubdivide(aVector, aPolyPolygon);
CPPUNIT_ASSERT_MESSAGE("more than zero sub-divided trapezoids",
aVector.size() > 0);
}
// Change the following lines only, if you add, remove or rename
......@@ -872,7 +900,7 @@ public:
// because these macros are need by auto register mechanism.
CPPUNIT_TEST_SUITE(b2dpolypolygon);
CPPUNIT_TEST(EmptyMethod);
CPPUNIT_TEST(testTrapezoidHelper);
CPPUNIT_TEST_SUITE_END();
}; // class b2dpolypolygon
......
basegfx/test/boxclipper.cxx
Dosyayı görüntüle @ 82b56544
......@@ -38,11 +38,12 @@
using namespace ::basegfx;
extern double getRandomOrdinal( const ::std::size_t n );
namespace basegfx2d
{
/// Gets a random ordinal [0,n)
inline double getRandomOrdinal( const ::std::size_t n )
double getRandomOrdinal( const ::std::size_t n )
{
// use this one when displaying polygons in OOo, which still sucks
// great rocks when trying to import non-integer svg:d attributes
......
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