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[pal] Use GEOS for linear referencing
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nyalldawson committed Jul 20, 2015
1 parent f6d2256 commit 3fdef5e
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Showing 3 changed files with 44 additions and 71 deletions.
31 changes: 3 additions & 28 deletions src/core/pal/feature.cpp
Expand Up @@ -500,9 +500,6 @@ namespace pal
double xrm = mFeature->label_x;
double yrm = mFeature->label_y;

double *d; // segments lengths distance bw pt[i] && pt[i+1]
double *ad; // absolute distance bw pt[0] and pt[i] along the line
double ll; // line length
double dist;
double bx, by, ex, ey;
int nbls;
Expand All @@ -528,24 +525,7 @@ namespace pal
x = line->x;
y = line->y;

d = new double[nbPoints-1];
ad = new double[nbPoints];

ll = 0.0; // line length
for ( i = 0; i < line->nbPoints - 1; i++ )
{
if ( i == 0 )
ad[i] = 0;
else
ad[i] = ad[i-1] + d[i-1];

d[i] = dist_euc2d( x[i], y[i], x[i+1], y[i+1] );
ll += d[i];
}

ad[line->nbPoints-1] = ll;


double ll = line->length(); // line length
nbls = ( int )( ll / xrm ); // ratio bw line length and label width

#ifdef _DEBUG_FULL_
Expand Down Expand Up @@ -580,9 +560,9 @@ namespace pal
while ( l < ll - xrm )
{
// => bx, by
line->getPoint( d, ad, l, &bx, &by );
line->getPointByDistance( l, &bx, &by );
// same but l = l+xrm
line->getPoint( d, ad, l + xrm, &ex, &ey );
line->getPointByDistance( l + xrm, &ex, &ey );

// Label is bigger than line ...
if ( l < 0 )
Expand Down Expand Up @@ -649,11 +629,6 @@ namespace pal
break;
}

//delete line;

delete[] d;
delete[] ad;

int nbp = positions.size();
*lPos = new LabelPosition *[nbp];
i = 0;
Expand Down
34 changes: 34 additions & 0 deletions src/core/pal/pointset.cpp
Expand Up @@ -942,6 +942,25 @@ namespace pal
GEOSGeom_destroy_r( geosctxt, centroidGeom );
}

void PointSet::getPointByDistance( double distance, double *px, double *py ) const
{
if ( !mGeos )
createGeosGeom();

if ( !mGeos )
return;

GEOSContextHandle_t geosctxt = geosContext();
GEOSGeometry *point = GEOSInterpolate_r( geosctxt, mGeos, distance );
if ( point )
{
const GEOSCoordSequence *coordSeq = GEOSGeom_getCoordSeq_r( geosctxt, point );
GEOSCoordSeq_getX_r( geosctxt, coordSeq, 0, px );
GEOSCoordSeq_getY_r( geosctxt, coordSeq, 0, py );
}
GEOSGeom_destroy_r( geosctxt, point );
}

const GEOSGeometry *PointSet::geos() const
{
if ( !mGeos )
Expand All @@ -950,6 +969,21 @@ namespace pal
return mGeos;
}

double PointSet::length() const
{
if ( !mGeos )
createGeosGeom();

if ( !mGeos )
return -1;

GEOSContextHandle_t geosctxt = geosContext();

double len = 0;
( void )GEOSLength_r( geosctxt, mGeos, &len );
return len;
}


} // end namespace

Expand Down
50 changes: 7 additions & 43 deletions src/core/pal/pointset.h
Expand Up @@ -123,57 +123,21 @@ namespace pal

int getNumPoints() const { return nbPoints; }

/** Iterate on line by real step of dl on x,y points.
* @param d array of distances between points
* @param ad absolute distance from pt0 to each point (ad0 = pt0->pt0)
* @param dl distance to traverse along line
/** Get a point a set distance along a line geometry.
* @param distance 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 )
{
int i;
double dx, dy, di;
double distr;

i = 0;
if ( dl >= 0 )
{
while ( i < nbPoints && ad[i] <= dl ) i++;
i--;
}

if ( i < nbPoints - 1 )
{
if ( dl < 0 )
{
dx = x[nbPoints-1] - x[0];
dy = y[nbPoints-1] - y[0];
di = sqrt( dx * dx + dy * dy );
}
else
{
dx = x[i+1] - x[i];
dy = y[i+1] - y[i];
di = d[i];
}

distr = dl - ad[i];
*px = x[i] + dx * distr / di;
*py = y[i] + dy * distr / di;
}
else // just select last point...
{
*px = x[i];
*py = y[i];
}
}
void getPointByDistance( double distance, double *px, double *py ) const;

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

/** Returns length of line geometry.
*/
double length() const;

protected:
mutable GEOSGeometry *mGeos;
mutable bool mOwnsGeom;
Expand Down

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