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#9360R: enable ogr simplification for GDAL-OGR >= 1.11
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@ahuarte47
ahuarte47 committed Jan 21, 2014
1 parent 0c99423 commit f79dfa1
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Showing 4 changed files with 77 additions and 78 deletions.
4 changes: 2 additions & 2 deletions src/providers/ogr/qgsogrfeatureiterator.cpp
View file
Expand Up @@ -111,7 +111,7 @@ bool QgsOgrFeatureIterator::prepareSimplification( const QgsSimplifyMethod& simp
QgsSimplifyMethod::MethodType methodType = simplifyMethod.methodType();
Q_UNUSED( methodType);

#if defined(HAVE_OGR_GEOMETRY_CLASS)
#if defined(GDAL_VERSION_NUM) && defined(GDAL_COMPUTE_VERSION) && GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(1,11,0)
if ( methodType == QgsSimplifyMethod::OptimizeForRendering )
{
int simplifyFlags = QgsMapToPixelSimplifier::SimplifyGeometry | QgsMapToPixelSimplifier::SimplifyEnvelope;
Expand All @@ -134,7 +134,7 @@ bool QgsOgrFeatureIterator::prepareSimplification( const QgsSimplifyMethod& simp

bool QgsOgrFeatureIterator::providerCanSimplify( QgsSimplifyMethod::MethodType methodType ) const
{
#if defined(HAVE_OGR_GEOMETRY_CLASS)
#if defined(GDAL_VERSION_NUM) && defined(GDAL_COMPUTE_VERSION) && GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(1,11,0)
if ( methodType == QgsSimplifyMethod::OptimizeForRendering )
{
return true;
Expand Down
111 changes: 63 additions & 48 deletions src/providers/ogr/qgsogrgeometrysimplifier.cpp
View file
Expand Up @@ -25,6 +25,7 @@ QgsOgrAbstractGeometrySimplifier::~QgsOgrAbstractGeometrySimplifier()
/***************************************************************************/

#if defined(GDAL_VERSION_NUM) && GDAL_VERSION_NUM >= 1900

QgsOgrTopologyPreservingSimplifier::QgsOgrTopologyPreservingSimplifier( double tolerance )
: QgsTopologyPreservingSimplifier( tolerance )
{
Expand Down Expand Up @@ -59,10 +60,7 @@ bool QgsOgrTopologyPreservingSimplifier::simplifyGeometry( OGRGeometryH geometry

/***************************************************************************/

#if defined(HAVE_OGR_GEOMETRY_CLASS)

// Use OgrGeometry class to speed up simplification on provider side
#include <ogr_geometry.h>
#if defined(GDAL_VERSION_NUM) && defined(GDAL_COMPUTE_VERSION) && GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(1,11,0)

QgsOgrMapToPixelSimplifier::QgsOgrMapToPixelSimplifier( int simplifyFlags, double map2pixelTol )
: QgsMapToPixelSimplifier( simplifyFlags, map2pixelTol )
Expand All @@ -81,7 +79,7 @@ QgsOgrMapToPixelSimplifier::~QgsOgrMapToPixelSimplifier()
}

//! Returns a point buffer of the specified size
OGRRawPoint* QgsOgrMapToPixelSimplifier::mallocPoints( int numPoints )
QgsPoint* QgsOgrMapToPixelSimplifier::mallocPoints( int numPoints )
{
if ( mPointBufferPtr && mPointBufferCount < numPoints )
{
Expand All @@ -91,11 +89,41 @@ OGRRawPoint* QgsOgrMapToPixelSimplifier::mallocPoints( int numPoints )
if ( !mPointBufferPtr )
{
mPointBufferCount = numPoints;
mPointBufferPtr = ( OGRRawPoint* )OGRMalloc( mPointBufferCount * sizeof( OGRRawPoint ) );
mPointBufferPtr = ( QgsPoint* )OGRMalloc( mPointBufferCount * sizeof( QgsPoint ) );
}
return mPointBufferPtr;
}

//! Returns a point buffer of the specified envelope
QgsPoint* QgsOgrMapToPixelSimplifier::getEnvelopePoints( const QgsRectangle& envelope, int& numPoints, bool isaLinearRing )
{
QgsPoint* points = NULL;

double x1 = envelope.xMinimum();
double y1 = envelope.yMinimum();
double x2 = envelope.xMaximum();
double y2 = envelope.yMaximum();

if ( isaLinearRing )
{
numPoints = 5;
points = mallocPoints( numPoints );
points[0].set( x1, y1 );
points[1].set( x2, y1 );
points[2].set( x2, y2 );
points[3].set( x1, y2 );
points[4].set( x1, y1 );
}
else
{
numPoints = 2;
points = mallocPoints( numPoints );
points[0].set( x1, y1 );
points[1].set( x2, y2 );
}
return points;
}

//////////////////////////////////////////////////////////////////////////////////////////////
// Helper simplification methods

Expand Down Expand Up @@ -138,52 +166,29 @@ bool QgsOgrMapToPixelSimplifier::simplifyOgrGeometry( QGis::GeometryType geometr
}

//! Simplifies the OGR-geometry (Removing duplicated points) when is applied the specified map2pixel context
bool QgsOgrMapToPixelSimplifier::simplifyOgrGeometry( OGRGeometry* geometry, bool isaLinearRing )
bool QgsOgrMapToPixelSimplifier::simplifyOgrGeometry( OGRGeometryH geometry, bool isaLinearRing )
{
OGRwkbGeometryType wkbGeometryType = wkbFlatten( geometry->getGeometryType() );
OGRwkbGeometryType wkbGeometryType = wkbFlatten( OGR_G_GetGeometryType( geometry ) );

// Simplify the geometry rewriting temporally its WKB-stream for saving calloc's.
if ( wkbGeometryType == wkbLineString )
{
OGRLineString* lineString = ( OGRLineString* )geometry;
int numPoints = OGR_G_GetPointCount( geometry );

int numPoints = lineString->getNumPoints();
if (( isaLinearRing && numPoints <= 5 ) || ( !isaLinearRing && numPoints <= 4 ) )
return false;

OGREnvelope env;
lineString->getEnvelope( &env );
OGR_G_GetEnvelope( geometry, &env );
QgsRectangle envelope( env.MinX, env.MinY, env.MaxX, env.MaxY );

// Can replace the geometry by its BBOX ?
if (( mSimplifyFlags & QgsMapToPixelSimplifier::SimplifyEnvelope ) && canbeGeneralizedByMapBoundingBox( envelope ) )
{
OGRRawPoint* points = NULL;
QgsPoint* points = getEnvelopePoints( envelope, numPoints, isaLinearRing );

double x1 = envelope.xMinimum();
double y1 = envelope.yMinimum();
double x2 = envelope.xMaximum();
double y2 = envelope.yMaximum();

if ( isaLinearRing )
{
numPoints = 5;
points = mallocPoints( numPoints );
points[0].x = x1; points[0].y = y1;
points[1].x = x2; points[1].y = y1;
points[2].x = x2; points[2].y = y2;
points[3].x = x1; points[3].y = y2;
points[4].x = x1; points[4].y = y1;
}
else
{
numPoints = 2;
points = mallocPoints( numPoints );
points[0].x = x1; points[0].y = y1;
points[1].x = x2; points[1].y = y2;
}
lineString->setPoints( numPoints, points );
lineString->flattenTo2D();
setGeometryPoints( geometry, points, numPoints );
OGR_G_FlattenTo2D( geometry );

return true;
}
Expand All @@ -192,27 +197,29 @@ bool QgsOgrMapToPixelSimplifier::simplifyOgrGeometry( OGRGeometry* geometry, boo
QGis::GeometryType geometryType = isaLinearRing ? QGis::Polygon : QGis::Line;
int numSimplifiedPoints = 0;

OGRRawPoint* points = mallocPoints( numPoints );
QgsPoint* points = mallocPoints( numPoints );
double* xptr = ( double* )points;
double* yptr = xptr + 1;
lineString->getPoints( points );
OGR_G_GetPoints( geometry, xptr, 16, yptr, 16, NULL, 0 );

if ( simplifyOgrGeometry( geometryType, xptr, 16, yptr, 16, numPoints, numSimplifiedPoints ) )
{
lineString->setPoints( numSimplifiedPoints, points );
lineString->flattenTo2D();
if (( isaLinearRing && numSimplifiedPoints <= 4 ) || ( !isaLinearRing && numSimplifiedPoints <= 1 ) )
points = getEnvelopePoints( envelope, numSimplifiedPoints, isaLinearRing );

setGeometryPoints( geometry, points, numSimplifiedPoints );
OGR_G_FlattenTo2D( geometry );
}
return numSimplifiedPoints != numPoints;
}
}
else if ( wkbGeometryType == wkbPolygon )
{
OGRPolygon* polygon = ( OGRPolygon* )geometry;
bool result = simplifyOgrGeometry( polygon->getExteriorRing(), true );
bool result = simplifyOgrGeometry( OGR_G_GetGeometryRef( geometry, 0 ), true );

for ( int i = 0, numInteriorRings = polygon->getNumInteriorRings(); i < numInteriorRings; ++i )
for ( int i = 1, numInteriorRings = OGR_G_GetGeometryCount( geometry ); i < numInteriorRings; ++i )
{
result |= simplifyOgrGeometry( polygon->getInteriorRing( i ), true );
result |= simplifyOgrGeometry( OGR_G_GetGeometryRef( geometry, i ), true );
}

if ( result )
Expand All @@ -222,12 +229,11 @@ bool QgsOgrMapToPixelSimplifier::simplifyOgrGeometry( OGRGeometry* geometry, boo
}
else if ( wkbGeometryType == wkbMultiLineString || wkbGeometryType == wkbMultiPolygon )
{
OGRGeometryCollection* collection = ( OGRGeometryCollection* )geometry;
bool result = false;

for ( int i = 0, numGeometries = collection->getNumGeometries(); i < numGeometries; ++i )
for ( int i = 0, numGeometries = OGR_G_GetGeometryCount( geometry ); i < numGeometries; ++i )
{
result |= simplifyOgrGeometry( collection->getGeometryRef( i ), wkbGeometryType == wkbMultiPolygon );
result |= simplifyOgrGeometry( OGR_G_GetGeometryRef( geometry, i ), wkbGeometryType == wkbMultiPolygon );
}

if ( result )
Expand All @@ -239,6 +245,15 @@ bool QgsOgrMapToPixelSimplifier::simplifyOgrGeometry( OGRGeometry* geometry, boo
return false;
}

//! Load a point array to the specified LineString geometry
void QgsOgrMapToPixelSimplifier::setGeometryPoints( OGRGeometryH geometry, QgsPoint* points, int numPoints )
{
double* xptr = ( double* )points;
double* yptr = xptr + 1;

OGR_G_SetPoints( geometry, numPoints, xptr, 16, yptr, 16, NULL, 0 );
}

//////////////////////////////////////////////////////////////////////////////////////////////

//! Simplifies the specified geometry
Expand All @@ -248,7 +263,7 @@ bool QgsOgrMapToPixelSimplifier::simplifyGeometry( OGRGeometryH geometry )

if ( wkbGeometryType == wkbLineString || wkbGeometryType == wkbPolygon )
{
return simplifyOgrGeometry( (OGRGeometry*) geometry, wkbGeometryType == wkbPolygon );
return simplifyOgrGeometry( geometry, wkbGeometryType == wkbPolygon );
}

return false;
Expand Down
37 changes: 11 additions & 26 deletions src/providers/ogr/qgsogrgeometrysimplifier.h
View file
Expand Up @@ -18,29 +18,9 @@
#define QGSOGRGEOMETRYSIMPLIFIER_H

#include "qgsmaptopixelgeometrysimplifier.h"
#include <ogr_api.h>
#include "qgspoint.h"

/* TODO:
* Disable OGR-simplification on provider side because of OGRGeometry class
* (GDAL C++ API) is not available in current QGIS builds.
* This simplification is ~5-10% faster than simplification on QGIS side
* (for very complex polygons up to ~20%).
*
* While GDAL C API has not published the needed method 'OGR_G_SetPoints()'
* to rewrite the geometry of a LineString/LinearRing in one single call,
* we can not enable the OGR-simplification to change the current disabled
* references of OGRGeometry* (GDAL C++ API) to OGRGeometryH (GDAL C API).
*
* Search in 'qgsogrgeometrysimplifier.cpp' : lineString->setPoints(...);
* We can not use 'OGR_G_SetPoint(...)' because of each call reallocs the
* point array of the geometry and it is very-very slow.
*
#if defined(__cplusplus)
#define HAVE_OGR_GEOMETRY_CLASS 1
class OGRGeometry;
class OGRRawPoint;
#endif
*/
#include <ogr_api.h>

/**
* Abstract base class for simplify OGR-geometries using a specific algorithm
Expand Down Expand Up @@ -72,7 +52,7 @@ class QgsOgrTopologyPreservingSimplifier : public QgsOgrAbstractGeometrySimplifi
};
#endif

#if defined(HAVE_OGR_GEOMETRY_CLASS)
#if defined(GDAL_VERSION_NUM) && defined(GDAL_COMPUTE_VERSION) && GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(1,11,0)
/**
* OGR implementation of GeometrySimplifier using the "MapToPixel" algorithm
*
Expand All @@ -87,17 +67,22 @@ class QgsOgrMapToPixelSimplifier : public QgsOgrAbstractGeometrySimplifier, QgsM

private:
//! Point memory buffer for optimize the simplification process
OGRRawPoint* mPointBufferPtr;
QgsPoint* mPointBufferPtr;
//! Current Point memory buffer size
int mPointBufferCount;

//! Simplifies the OGR-geometry (Removing duplicated points) when is applied the specified map2pixel context
bool simplifyOgrGeometry( QGis::GeometryType geometryType, double* xptr, int xStride, double* yptr, int yStride, int pointCount, int& pointSimplifiedCount );
//! Simplifies the OGR-geometry (Removing duplicated points) when is applied the specified map2pixel context
bool simplifyOgrGeometry( OGRGeometry* geometry, bool isaLinearRing );
bool simplifyOgrGeometry( OGRGeometryH geometry, bool isaLinearRing );

//! Returns a point buffer of the specified size
OGRRawPoint* mallocPoints( int numPoints );
QgsPoint* mallocPoints( int numPoints );
//! Returns a point buffer of the specified envelope
QgsPoint* getEnvelopePoints( const QgsRectangle& envelope, int& numPoints, bool isaLinearRing );

//! Load a point array to the specified LineString geometry
static void setGeometryPoints( OGRGeometryH geometry, QgsPoint* points, int numPoints );

public:
//! Simplifies the specified geometry
Expand Down
3 changes: 1 addition & 2 deletions src/providers/ogr/qgsogrprovider.cpp
View file
Expand Up @@ -45,7 +45,6 @@ email : sherman at mrcc.com
#include "qgsgeometry.h"
#include "qgscoordinatereferencesystem.h"
#include "qgsvectorlayerimport.h"
#include "qgsogrgeometrysimplifier.h"

static const QString TEXT_PROVIDER_KEY = "ogr";
static const QString TEXT_PROVIDER_DESCRIPTION =
Expand Down Expand Up @@ -1496,7 +1495,7 @@ int QgsOgrProvider::capabilities() const
}

// supports geometry simplification on provider side
#if defined(HAVE_OGR_GEOMETRY_CLASS)
#if defined(GDAL_VERSION_NUM) && defined(GDAL_COMPUTE_VERSION) && GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(1,11,0)
ability |= QgsVectorDataProvider::SimplifyGeometries;
#endif
#if defined(GDAL_VERSION_NUM) && GDAL_VERSION_NUM >= 1900
Expand Down

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