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Merge remote-tracking branch 'origin/master' into papercuts

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timlinux committed Oct 27, 2014
2 parents 84c429d + 83d070e commit 531474d76ddcc6453c49ea9c7d44b079f6231c77
Showing with 46 additions and 24 deletions.
  1. +12 −1 src/core/qgsgeometry.cpp
  2. +34 −23 src/core/qgsmaptopixelgeometrysimplifier.cpp
@@ -284,6 +284,8 @@ static GEOSGeometry *createGeosLinearRing( const QgsPolyline& polyline )
}
else
{
// XXX [MD] this exception should not be silenced!
// this is here just because maptopixel simplification can return invalid linear rings
if ( polyline.count() == 3 ) //-> Avoid 'GEOS::IllegalArgumentException: Invalid number of points in LinearRing found 3 - must be 0 or >= 4'
return 0;

@@ -359,7 +361,16 @@ static GEOSGeometry *createGeosPolygon( const QgsPolygon& polygon )
for ( int i = 0; i < polygon.count(); i++ )
{
GEOSGeometry *ring = createGeosLinearRing( polygon[i] );
if ( ring ) geoms << ring;
if ( !ring )
{
// something went really wrong - exit
for ( int j = 0; j < geoms.count(); j++ )
GEOSGeom_destroy_r( geosinit.ctxt, geoms[j] );
// XXX [MD] we just silently return here - but we shouldn't
// this is just because maptopixel simplification can return invalid linear rings
return 0;
}
geoms << ring;
}

return createGeosPolygon( geoms );
@@ -61,7 +61,7 @@ inline static QgsRectangle calculateBoundingBox( QGis::WkbType wkbType, unsigned
}

//! Generalize the WKB-geometry using the BBOX of the original geometry
inline static bool generalizeWkbGeometry(
static bool generalizeWkbGeometryByBoundingBox(
QGis::WkbType wkbType,
unsigned char* sourceWkb, size_t sourceWkbSize,
unsigned char* targetWkb, size_t& targetWkbSize,
@@ -169,7 +169,7 @@ bool QgsMapToPixelSimplifier::simplifyWkbGeometry(
if (( simplifyFlags & QgsMapToPixelSimplifier::SimplifyEnvelope ) &&
isGeneralizableByMapBoundingBox( envelope, map2pixelTol ) )
{
isGeneralizable = generalizeWkbGeometry( wkbType, sourceWkb, sourceWkbSize, targetWkb, targetWkbSize, envelope, writeHeader );
isGeneralizable = generalizeWkbGeometryByBoundingBox( wkbType, sourceWkb, sourceWkbSize, targetWkb, targetWkbSize, envelope, writeHeader );
if ( isGeneralizable )
return true;
}
@@ -222,8 +222,8 @@ bool QgsMapToPixelSimplifier::simplifyWkbGeometry(
double* ptr = ( double* )targetWkb;
map2pixelTol *= map2pixelTol; //-> Use mappixelTol for 'LengthSquare' calculations.

bool isaUngenerizableSegment;
bool hasUngenerizableSegments = false; //-> To avoid replace the simplified geometry by its BBOX when there are 'long' segments.
bool isLongSegment;
bool hasLongSegments = false; //-> To avoid replace the simplified geometry by its BBOX when there are 'long' segments.

// Check whether the LinearRing is really closed.
if ( isaLinearRing )
@@ -249,44 +249,55 @@ bool QgsMapToPixelSimplifier::simplifyWkbGeometry(
memcpy( &x, sourceWkb, sizeof( double ) ); sourceWkb += sizeOfDoubleX;
memcpy( &y, sourceWkb, sizeof( double ) ); sourceWkb += sizeOfDoubleY;

isaUngenerizableSegment = false;
isLongSegment = false;

if ( i == 0 ||
!isGeneralizable ||
( isaUngenerizableSegment = ( calculateLengthSquared2D( x, y, lastX, lastY ) > map2pixelTol ) ) ||
( isLongSegment = ( calculateLengthSquared2D( x, y, lastX, lastY ) > map2pixelTol ) ) ||
( !isaLinearRing && ( i == 1 || i >= numPoints - 2 ) ) )
{
memcpy( ptr, &x, sizeof( double ) ); lastX = x; ptr++;
memcpy( ptr, &y, sizeof( double ) ); lastY = y; ptr++;
numTargetPoints++;

if ( isaUngenerizableSegment && !hasUngenerizableSegments )
{
hasUngenerizableSegments = true;
}
hasLongSegments |= isLongSegment;
}

r.combineExtentWith( x, y );
}
targetWkb = wkb2 + 4;

// Fix the topology of the geometry
if ( numTargetPoints <= ( isaLinearRing ? 2 : 1 ) && !hasUngenerizableSegments )
if ( numTargetPoints < ( isaLinearRing ? 4 : 2 ) )
{
unsigned char* targetTempWkb = targetWkb;
int targetWkbTempSize = targetWkbSize;

sourceWkb = sourcePrevWkb;
targetWkb = targetPrevWkb;
targetWkbSize = targetWkbPrevSize;
if ( generalizeWkbGeometry( wkbType, sourceWkb, sourceWkbSize, targetWkb, targetWkbSize, r, writeHeader ) )
return true;

targetWkb = targetTempWkb;
targetWkbSize = targetWkbTempSize;
// we simplified the geometry too much!
if ( !hasLongSegments )
{
// approximate the geometry's shape by its bounding box
// (rect for linear ring / one segment for line string)
unsigned char* targetTempWkb = targetWkb;
int targetWkbTempSize = targetWkbSize;

sourceWkb = sourcePrevWkb;
targetWkb = targetPrevWkb;
targetWkbSize = targetWkbPrevSize;
if ( generalizeWkbGeometryByBoundingBox( wkbType, sourceWkb, sourceWkbSize, targetWkb, targetWkbSize, r, writeHeader ) )
return true;

targetWkb = targetTempWkb;
targetWkbSize = targetWkbTempSize;
}
else
{
// Bad luck! The simplified geometry is invalid and approximation by bounding box
// would create artifacts due to long segments. Worst of all, we may have overwritten
// the original coordinates by the simplified ones (source and target WKB ptr can be the same)
// so we cannot even undo the changes here. We will return invalid geometry and hope that
// other pieces of QGIS will survive that :-/
}
}
if ( isaLinearRing )
{
// make sure we keep the linear ring closed
memcpy( &x, targetWkb + 0, sizeof( double ) );
memcpy( &y, targetWkb + sizeof( double ), sizeof( double ) );
if ( lastX != x || lastY != y )

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