Skip to content
Permalink
Browse files

[pal] Use GEOS for calculating minimum distances between geometries

Also more cleanups, fixes for geos handling
  • Loading branch information
nyalldawson committed Jul 20, 2015
1 parent 323fa2c commit 42bef4e02e6d7c284fb1aeed7eb06b1d18f4aba2
@@ -227,9 +227,7 @@ namespace pal

void PolygonCostCalculator::update( PointSet *pset )
{
double rx, ry;
pset->getDist( px, py, &rx, &ry );
double d = dist_euc2d_sq( px, py, rx, ry );
double d = pset->minDistanceToPoint( px, py );
if ( d < dist )
{
dist = d;
@@ -1365,9 +1365,11 @@ namespace pal

if ( mOwnsGeom ) // delete old geometry if we own it
GEOSGeom_destroy_r( ctxt, mGeos );
GEOSPreparedGeom_destroy_r( ctxt, mPreparedGeom );
// set up new geometry
mGeos = gTmp;
mOwnsGeom = true;
mPreparedGeom = 0;

deleteCoords();
qDeleteAll( mHoles );
@@ -145,24 +145,6 @@ namespace pal
&& cross_product( x3, y3, x4, y4, x1, y1 ) * cross_product( x3, y3, x4, y4, x2, y2 ) < 0 );
}

/*
* \brief Intersection bw a line and a segment
* \return true if the point exist false otherwise
*/
bool computeLineSegIntersection( double x1, double y1, double x2, double y2, // 1st line
double x3, double y3, double x4, double y4, // 2nd segment
double *x, double *y )
{
double cp1, cp2;
cp1 = cross_product( x1, y1, x2, y2, x3, y3 );
cp2 = cross_product( x1, y1, x2, y2, x4, y4 );

if ( cp1 * cp2 <= 0 )
return computeLineIntersection( x1, y1, x2, y2, x3, y3, x4, y4, x, y );

return false;
}

/*
* \brief compute the point wherre two lines intersects
* \return true if the ok false if line are parallel
@@ -69,14 +69,6 @@ namespace pal
bool isSegIntersects( double x1, double y1, double x2, double y2, // 1st segment
double x3, double y3, double x4, double y4 ); // 2nd segment

/*
* \brief Intersection bw a line and a segment
* \return true if the point exist false otherwise
*/
bool computeLineSegIntersection( double x1, double y1, double x2, double y2, // 1st line
double x3, double y3, double x4, double y4, // 2nd segment
double *x, double *y );

/*
* \brief compute the point wherre two lines intersects
* \return true if the ok false if line are parallel
@@ -378,7 +378,7 @@ namespace pal
while ( !featureParts->isEmpty() )
{
FeaturePart* fpart = featureParts->takeFirst();
const GEOSGeometry* geom = fpart->getGeometry();
const GEOSGeometry* geom = fpart->geos();
double chopInterval = fpart->getFeature()->repeatDistance();
if ( chopInterval != 0. && GEOSGeomTypeId_r( geosctxt, geom ) == GEOS_LINESTRING )
{
@@ -154,13 +154,29 @@ namespace pal
void PointSet::createGeosGeom() const
{
GEOSContextHandle_t geosctxt = geosContext();
GEOSCoordSequence *coord = GEOSCoordSeq_create_r( geosctxt, nbPoints, 2 );

bool needClose = false;
if ( x[0] != x[ nbPoints - 1] || y[0] != y[ nbPoints - 1 ] )
{
needClose = true;
}

GEOSCoordSequence *coord = GEOSCoordSeq_create_r( geosctxt, nbPoints + ( needClose ? 1 : 0 ), 2 );
for ( int i = 0; i < nbPoints; ++i )
{
GEOSCoordSeq_setX_r( geosctxt, coord, i, x[i] );
GEOSCoordSeq_setY_r( geosctxt, coord, i, y[i] );
}

//close ring if needed
if ( needClose )
{
GEOSCoordSeq_setX_r( geosctxt, coord, nbPoints, x[0] );
GEOSCoordSeq_setY_r( geosctxt, coord, nbPoints, y[0] );
}

mGeos = GEOSGeom_createPolygon_r( geosctxt, GEOSGeom_createLinearRing_r( geosctxt, coord ), 0, 0 );

mOwnsGeom = true;
}

@@ -180,7 +196,7 @@ namespace pal
{
GEOSContextHandle_t geosctxt = geosContext();

if ( mOwnsGeom )
if ( mGeos && mOwnsGeom )
{
GEOSGeom_destroy_r( geosctxt, mGeos );
mGeos = NULL;
@@ -625,44 +641,6 @@ namespace pal
}
}


PointSet* PointSet::createProblemSpecificPointSet( double bbmin[2], double bbmax[2], bool *inside )
{
#ifdef _DEBUG_FULL_
std::cout << "CreateProblemSpecific:" << std::endl;
#endif
PointSet *shape = new PointSet();
shape->x = new double[nbPoints];
shape->y = new double[nbPoints];
shape->nbPoints = nbPoints;
shape->type = type;

shape->xmin = xmin;
shape->xmax = xmax;
shape->ymin = ymin;
shape->ymax = ymax;

*inside = true;

for ( int i = 0; i < nbPoints; i++ )
{
shape->x[i] = this->x[i];
shape->y[i] = this->y[i];

// check whether it's not outside
if ( x[i] < bbmin[0] || x[i] > bbmax[0] || y[i] < bbmin[1] || y[i] > bbmax[1] )
*inside = false;
}

shape->holeOf = NULL;
shape->parent = NULL;

return shape;
}




CHullBox * PointSet::compute_chull_bbox()
{
int i;
@@ -830,74 +808,47 @@ namespace pal
return finalBb;
}

double PointSet::getDist( double px, double py, double *rx, double *ry )
double PointSet::minDistanceToPoint( double px, double py, double *rx, double *ry )
{
if ( nbPoints == 1 || type == GEOS_POINT )
{
if ( rx && ry )
{
*rx = x[0];
*ry = y[0];
}
return dist_euc2d_sq( x[0], y[0], px, py );
}

int a, b;
int nbP = ( type == GEOS_POLYGON ? nbPoints : nbPoints - 1 );
if ( !mGeos )
createGeosGeom();

double best_dist = DBL_MAX;
double d;
if ( !mGeos )
return 0;

for ( a = 0; a < nbP; a++ )
{
b = ( a + 1 ) % nbPoints;

double px2, py2;
px2 = px - y[b] + y[a];
py2 = py + x[b] - x[a];
double ix, iy;

// (px,py)->(px2,py2) is a line perpendicular to a->b
// Check the line p->p2 cross the segment a->b
if ( computeLineSegIntersection( px, py, px2, py2,
x[a], y[a], x[b], y[b],
&ix, &iy ) )
{
d = dist_euc2d_sq( px, py, ix, iy );
}
else
{
double d1 = dist_euc2d_sq( x[a], y[a], px, py );
double d2 = dist_euc2d_sq( x[b], y[b], px, py );
if ( d1 < d2 )
{
d = d1;
ix = x[a];
iy = y[a];
}
else
{
d = d2;
ix = x[b];
iy = y[b];
}
}
GEOSContextHandle_t geosctxt = geosContext();

if ( d < best_dist )
{
best_dist = d;
if ( rx && ry )
{
*rx = ix;
*ry = iy;
}
}
} // end for (a in nbPoints)
GEOSCoordSequence *coord = GEOSCoordSeq_create_r( geosctxt, 1, 2 );
GEOSCoordSeq_setX_r( geosctxt, coord, 0, px );
GEOSCoordSeq_setY_r( geosctxt, coord, 0, py );
GEOSGeometry* geosPt = GEOSGeom_createPoint_r( geosctxt, coord );

return best_dist;
int type = GEOSGeomTypeId_r( geosctxt, mGeos );
const GEOSGeometry* extRing = 0;
if ( type != GEOS_POLYGON )
{
extRing = mGeos;
}
else
{
//for polygons, we want distance to exterior ring (not an interior point)
extRing = GEOSGetExteriorRing_r( geosctxt, mGeos );
}
GEOSCoordSequence *nearestCoord = GEOSNearestPoints_r( geosctxt, extRing, geosPt );
double nx;
double ny;
( void )GEOSCoordSeq_getX_r( geosctxt, nearestCoord, 0, &nx );
( void )GEOSCoordSeq_getY_r( geosctxt, nearestCoord, 0, &ny );
GEOSGeom_destroy_r( geosctxt, geosPt );

if ( rx )
*rx = nx;
if ( ry )
*ry = ny;

return dist_euc2d_sq( px, py, nx, ny );
}


void PointSet::getCentroid( double &px, double &py, bool forceInside ) const
{
if ( !mGeos )
@@ -932,6 +883,15 @@ namespace pal
GEOSGeom_destroy_r( geosctxt, centroidGeom );
}

const GEOSGeometry *PointSet::geos() const
{
if ( !mGeos )
createGeosGeom();

return mGeos;
}


} // end namespace

#endif
@@ -44,18 +44,6 @@ namespace pal
class Projection;
class LabelPosition;

typedef struct _cross
{
int pt;
double d;
double x;
double y;
int seg; // seg{0,1,2,3}
int nextCorner; // pt{0,1,2,3}
int way;

} Crossing;

class PointSet;

typedef struct _cHullBox
@@ -70,18 +58,6 @@ namespace pal
} CHullBox;



inline bool ptrCrossingCompare( Crossing * a, Crossing * b )
{
return a == b;
}

inline bool crossingDist( void *a, void *b )
{
return (( Crossing* ) a )->d > (( Crossing* ) b )->d;
}


class CORE_EXPORT PointSet
{
friend class FeaturePart;
@@ -95,10 +71,6 @@ namespace pal
PointSet( int nbPoints, double *x, double *y );
virtual ~PointSet();

/** Returns the point set's GEOS geometry.
*/
const GEOSGeometry* getGeometry() const { return mGeos; }

PointSet* extractShape( int nbPtSh, int imin, int imax, int fps, int fpe, double fptx, double fpty );

/** Tests whether point set contains a specified point.
@@ -108,27 +80,23 @@ namespace pal
*/
bool containsPoint( double x, double y ) const;

PointSet* createProblemSpecificPointSet( double bbmin[2], double bbmax[2], bool *inside );

CHullBox * compute_chull_bbox();


/** Split a concave shape into several convex shapes.
*/
static void splitPolygons( QLinkedList<PointSet *> &shapes_toProcess,
QLinkedList<PointSet *> &shapes_final,
double xrm, double yrm, const QString &uid );



/** Return the minimum distance bw this and the point (px,py). Optionally, store the nearest point in (rx,ry).
/** Returns the minimum distance between the point set geometry and the point (px,py)
* Optionally, the nearest point is stored in (rx,ry).
* @param px x coordinate of the point
* @param py y coordinate of the points
* @param rx pointer to x coorinates of the nearest point (can be NULL)
* @param ry pointer to y coorinates of the nearest point (can be NULL)
* @returns minimum distance
*/
double getDist( double px, double py, double *rx, double *ry );
double minDistanceToPoint( double px, double py, double *rx = 0, double *ry = 0 );

void getCentroid( double &px, double &py, bool forceInside = false ) const;

@@ -151,7 +119,7 @@ namespace pal
* @param dl distance to traverse along line
* @param px final x coord on line
* @param py final y coord on line
*/
*/
inline void getPoint( double *d, double *ad, double dl,
double *px, double *py )
{
@@ -192,6 +160,10 @@ namespace pal
}
}

/** Returns the point set's GEOS geometry.
*/
const GEOSGeometry* geos() const;

protected:
mutable GEOSGeometry *mGeos;
mutable bool mOwnsGeom;

0 comments on commit 42bef4e

Please sign in to comment.
You can’t perform that action at this time.