tdf#130150 Improve clipping in PDF export
For more info and discusson please have a look
at the task. It reverts the change from tdf#99680
which did a wrong paradigm change in how clip in
Region(s) is defined and tries to fix the
underlying error in a more correct way.
This includes problems noted in tdf#44388 and
tdf#113449.
This is a decent improvement, but - due to dealing
with numerical problems - not yet the whole healing.
Still thinking about how to solve this for good.
Adapted PdfExportTest::testTdf99680() and
PdfExportTest::testTdf99680_2() as needed, empty
clip regions are allowed again. Added comments, too.
Had to change solvePolygonOperationAnd to work
on ranges if both inputs *are* ranges. The AND-case
is then completely solvable. Also increased geometry
for transformations of clip geometries - may help
later.
Change-Id: I2370447597faa6efb81d58ee31c63654e304262e
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89874
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
diff --git a/basegfx/source/polygon/b2dpolygontools.cxx b/basegfx/source/polygon/b2dpolygontools.cxx
index c194a38..1cb6158 100644
--- a/basegfx/source/polygon/b2dpolygontools.cxx
+++ b/basegfx/source/polygon/b2dpolygontools.cxx
@@ -331,15 +331,15 @@ namespace basegfx::utils
const B2DPoint aPreviousPoint(aCurrentPoint);
aCurrentPoint = aCandidate.getB2DPoint(a);
// cross-over in Y?
const bool bCompYA(fTools::more(aPreviousPoint.getY(), rPoint.getY()));
const bool bCompYB(fTools::more(aCurrentPoint.getY(), rPoint.getY()));
// cross-over in Y? tdf#130150 use full precision, no need for epsilon
const bool bCompYA(aPreviousPoint.getY() > rPoint.getY());
const bool bCompYB(aCurrentPoint.getY() > rPoint.getY());
if(bCompYA != bCompYB)
{
// cross-over in X?
const bool bCompXA(fTools::more(aPreviousPoint.getX(), rPoint.getX()));
const bool bCompXB(fTools::more(aCurrentPoint.getX(), rPoint.getX()));
// cross-over in X? tdf#130150 use full precision, no need for epsilon
const bool bCompXA(aPreviousPoint.getX() > rPoint.getX());
const bool bCompXB(aCurrentPoint.getX() > rPoint.getX());
if(bCompXA == bCompXB)
{
@@ -355,7 +355,8 @@ namespace basegfx::utils
(aPreviousPoint.getX() - aCurrentPoint.getX()) /
(aPreviousPoint.getY() - aCurrentPoint.getY()));
if(fTools::more(fCompare, rPoint.getX()))
// tdf#130150 use full precision, no need for epsilon
if(fCompare > rPoint.getX())
{
bRetval = !bRetval;
}
diff --git a/basegfx/source/polygon/b2dpolypolygoncutter.cxx b/basegfx/source/polygon/b2dpolypolygoncutter.cxx
index ad185f4..6263c78 100644
--- a/basegfx/source/polygon/b2dpolypolygoncutter.cxx
+++ b/basegfx/source/polygon/b2dpolypolygoncutter.cxx
@@ -984,6 +984,42 @@ namespace basegfx::utils
}
else
{
// tdf#130150 shortcut & precision: If both are simple ranges,
// solve based on ranges
if(basegfx::utils::isRectangle(rCandidateA) && basegfx::utils::isRectangle(rCandidateB))
{
// *if* both are ranges, AND always can be solved
const basegfx::B2DRange aRangeA(rCandidateA.getB2DRange());
const basegfx::B2DRange aRangeB(rCandidateB.getB2DRange());
if(aRangeA.isInside(aRangeB))
{
// 2nd completely inside 1st -> 2nd is result of AND
return rCandidateB;
}
if(aRangeB.isInside(aRangeA))
{
// 2nd completely inside 1st -> 2nd is result of AND
return rCandidateA;
}
// solve by intersection
basegfx::B2DRange aIntersect(aRangeA);
aIntersect.intersect(aRangeB);
if(aIntersect.isEmpty())
{
// no overlap -> empty polygon as result of AND
return B2DPolyPolygon();
}
// create polygon result
return B2DPolyPolygon(
basegfx::utils::createPolygonFromRect(
aIntersect));
}
// concatenate polygons, solve crossovers and throw away all sub-polygons
// with a depth of < 1. This means to keep all polygons where at least two
// polygons do overlap.
diff --git a/vcl/qa/cppunit/pdfexport/pdfexport.cxx b/vcl/qa/cppunit/pdfexport/pdfexport.cxx
index d55e09a..706c4ca 100644
--- a/vcl/qa/cppunit/pdfexport/pdfexport.cxx
+++ b/vcl/qa/cppunit/pdfexport/pdfexport.cxx
@@ -823,15 +823,17 @@ void PdfExportTest::testTdf99680()
aZCodec.Decompress(rObjectStream, aUncompressed);
CPPUNIT_ASSERT(aZCodec.EndCompression());
// Make sure there are no empty clipping regions.
OString aEmptyRegion("0 0 m h W* n");
auto pStart = static_cast<const char*>(aUncompressed.GetData());
const char* pEnd = pStart + aUncompressed.GetSize();
auto it = std::search(pStart, pEnd, aEmptyRegion.getStr(), aEmptyRegion.getStr() + aEmptyRegion.getLength());
CPPUNIT_ASSERT_EQUAL_MESSAGE("Empty clipping region detected!", it, pEnd);
// tdf#130150 See infos in task - short: tdf#99680 was not the
// correct fix, so empty clip regions are valid - allow again in tests
// Make sure there are no empty clipping regions.
// OString aEmptyRegion("0 0 m h W* n");
// auto it = std::search(pStart, pEnd, aEmptyRegion.getStr(), aEmptyRegion.getStr() + aEmptyRegion.getLength());
// CPPUNIT_ASSERT_EQUAL_MESSAGE("Empty clipping region detected!", it, pEnd);
// Count save graphic state (q) and restore (Q) operators
// and ensure their amount is equal
auto pStart = static_cast<const char*>(aUncompressed.GetData());
const char* pEnd = pStart + aUncompressed.GetSize();
size_t nSaveCount = std::count(pStart, pEnd, 'q');
size_t nRestoreCount = std::count(pStart, pEnd, 'Q');
CPPUNIT_ASSERT_EQUAL_MESSAGE("Save/restore graphic state operators count mismatch!", nSaveCount, nRestoreCount);
@@ -862,15 +864,17 @@ void PdfExportTest::testTdf99680_2()
aZCodec.Decompress(rObjectStream, aUncompressed);
CPPUNIT_ASSERT(aZCodec.EndCompression());
// Make sure there are no empty clipping regions.
OString aEmptyRegion("0 0 m h W* n");
auto pStart = static_cast<const char*>(aUncompressed.GetData());
const char* pEnd = pStart + aUncompressed.GetSize();
auto it = std::search(pStart, pEnd, aEmptyRegion.getStr(), aEmptyRegion.getStr() + aEmptyRegion.getLength());
CPPUNIT_ASSERT_EQUAL_MESSAGE("Empty clipping region detected!", it, pEnd);
// tdf#130150 See infos in task - short: tdf#99680 was not the
// correct fix, so empty clip regions are valid - allow again in tests
// Make sure there are no empty clipping regions.
// OString aEmptyRegion("0 0 m h W* n");
// auto it = std::search(pStart, pEnd, aEmptyRegion.getStr(), aEmptyRegion.getStr() + aEmptyRegion.getLength());
// CPPUNIT_ASSERT_EQUAL_MESSAGE("Empty clipping region detected!", it, pEnd);
// Count save graphic state (q) and restore (Q) operators
// and ensure their amount is equal
auto pStart = static_cast<const char*>(aUncompressed.GetData());
const char* pEnd = pStart + aUncompressed.GetSize();
size_t nSaveCount = std::count(pStart, pEnd, 'q');
size_t nRestoreCount = std::count(pStart, pEnd, 'Q');
CPPUNIT_ASSERT_EQUAL_MESSAGE("Save/restore graphic state operators count mismatch!", nSaveCount, nRestoreCount);
diff --git a/vcl/source/gdi/pdfwriter_impl.cxx b/vcl/source/gdi/pdfwriter_impl.cxx
index 27a299d..f5efd31 100644
--- a/vcl/source/gdi/pdfwriter_impl.cxx
+++ b/vcl/source/gdi/pdfwriter_impl.cxx
@@ -9641,8 +9641,15 @@ void PDFWriterImpl::updateGraphicsState(Mode const mode)
if ( rNewState.m_aClipRegion.count() )
{
m_aPages.back().appendPolyPolygon( rNewState.m_aClipRegion, aLine );
aLine.append( "W* n\n" );
}
else
{
// tdf#130150 Need to revert tdf#99680, that breaks the
// rule that an set but empty clip-region clips everything
// aka draws nothing -> nothing is in an empty clip-region
aLine.append( "0 0 m h " ); // NULL clip, i.e. nothing visible
}
aLine.append( "W* n\n" );
rNewState.m_aMapMode = aNewMapMode;
SetMapMode( rNewState.m_aMapMode );
@@ -9787,8 +9794,12 @@ void PDFWriterImpl::setMapMode( const MapMode& rMapMode )
void PDFWriterImpl::setClipRegion( const basegfx::B2DPolyPolygon& rRegion )
{
basegfx::B2DPolyPolygon aRegion = LogicToPixel( rRegion, m_aGraphicsStack.front().m_aMapMode );
aRegion = PixelToLogic( aRegion, m_aMapMode );
// tdf#130150 improve coordinate manipulations to double precision transformations
const basegfx::B2DHomMatrix aCurrentTransform(
GetInverseViewTransformation(m_aMapMode) * GetViewTransformation(m_aGraphicsStack.front().m_aMapMode));
basegfx::B2DPolyPolygon aRegion(rRegion);
aRegion.transform(aCurrentTransform);
m_aGraphicsStack.front().m_aClipRegion = aRegion;
m_aGraphicsStack.front().m_bClipRegion = true;
m_aGraphicsStack.front().m_nUpdateFlags |= GraphicsStateUpdateFlags::ClipRegion;
@@ -9798,16 +9809,26 @@ void PDFWriterImpl::moveClipRegion( sal_Int32 nX, sal_Int32 nY )
{
if( m_aGraphicsStack.front().m_bClipRegion && m_aGraphicsStack.front().m_aClipRegion.count() )
{
Point aPoint( lcl_convert( m_aGraphicsStack.front().m_aMapMode,
m_aMapMode,
this,
Point( nX, nY ) ) );
aPoint -= lcl_convert( m_aGraphicsStack.front().m_aMapMode,
m_aMapMode,
this,
Point() );
// tdf#130150 improve coordinate manipulations to double precision transformations
basegfx::B2DHomMatrix aConvertA;
if(MapUnit::MapPixel == m_aGraphicsStack.front().m_aMapMode.GetMapUnit())
{
aConvertA = GetInverseViewTransformation(m_aMapMode);
}
else
{
aConvertA = LogicToLogic(m_aGraphicsStack.front().m_aMapMode, m_aMapMode);
}
basegfx::B2DPoint aB2DPointA(nX, nY);
basegfx::B2DPoint aB2DPointB(0.0, 0.0);
aB2DPointA *= aConvertA;
aB2DPointB *= aConvertA;
aB2DPointA -= aB2DPointB;
basegfx::B2DHomMatrix aMat;
aMat.translate( aPoint.X(), aPoint.Y() );
aMat.translate(aB2DPointA.getX(), aB2DPointA.getY());
m_aGraphicsStack.front().m_aClipRegion.transform( aMat );
m_aGraphicsStack.front().m_nUpdateFlags |= GraphicsStateUpdateFlags::ClipRegion;
}
@@ -9822,9 +9843,14 @@ void PDFWriterImpl::intersectClipRegion( const tools::Rectangle& rRect )
void PDFWriterImpl::intersectClipRegion( const basegfx::B2DPolyPolygon& rRegion )
{
basegfx::B2DPolyPolygon aRegion( LogicToPixel( rRegion, m_aGraphicsStack.front().m_aMapMode ) );
aRegion = PixelToLogic( aRegion, m_aMapMode );
// tdf#130150 improve coordinate manipulations to double precision transformations
const basegfx::B2DHomMatrix aCurrentTransform(
GetInverseViewTransformation(m_aMapMode) * GetViewTransformation(m_aGraphicsStack.front().m_aMapMode));
basegfx::B2DPolyPolygon aRegion(rRegion);
aRegion.transform(aCurrentTransform);
m_aGraphicsStack.front().m_nUpdateFlags |= GraphicsStateUpdateFlags::ClipRegion;
if( m_aGraphicsStack.front().m_bClipRegion )
{
basegfx::B2DPolyPolygon aOld( basegfx::utils::prepareForPolygonOperation( m_aGraphicsStack.front().m_aClipRegion ) );
