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some labeling cleanups (fixes #1088)
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git-svn-id: http://svn.osgeo.org/qgis/trunk@8452 c8812cc2-4d05-0410-92ff-de0c093fc19c
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jef committed May 17, 2008
1 parent 813a85f commit b0c223c
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Showing 2 changed files with 116 additions and 142 deletions.
256 changes: 115 additions & 141 deletions src/core/qgslabel.cpp
View file
Expand Up @@ -14,7 +14,8 @@
* *
***************************************************************************/

#include <math.h> //needed for win32 build (ts)
#include <cmath>
#include <limits>

#include <QString>
#include <QFont>
Expand Down Expand Up @@ -45,10 +46,8 @@
static const char * const ident_ =
"$Id$";


QgsLabel::QgsLabel( const QgsFieldMap & fields )
{

mField = fields;
mLabelFieldIdx.resize ( LabelFieldCount );
for ( int i = 0; i < LabelFieldCount; i++ )
Expand Down Expand Up @@ -459,8 +458,8 @@ void QgsLabel::labelPoint ( std::vector<QgsPoint>& points, QgsFeature & feature
{
QgsGeometry* geometry = feature.geometry();
unsigned char *geom = geometry->wkbBuffer();
size_t geomlen = geometry->wkbSize();
QGis::WKBTYPE wkbType = geometry->wkbType();

QgsPoint point;

switch (wkbType)
Expand All @@ -472,10 +471,11 @@ void QgsLabel::labelPoint ( std::vector<QgsPoint>& points, QgsFeature & feature
case QGis::WKBPolygon25D:
case QGis::WKBPolygon:
{
labelPoint(point, geom);
labelPoint(point, geom, geomlen);
points.push_back(point);
}
break;

case QGis::WKBMultiPoint25D:
case QGis::WKBMultiPoint:
case QGis::WKBMultiLineString25D:
Expand All @@ -484,11 +484,15 @@ void QgsLabel::labelPoint ( std::vector<QgsPoint>& points, QgsFeature & feature
case QGis::WKBMultiPolygon:
// Return a position for each individual in the multi-feature
{
int numFeatures = (int)(*(geom + 5));
geom += 9; // now points to start of array of WKB's
for (int i = 0; i < numFeatures; ++i)
assert( 1+sizeof(wkbType)+sizeof(int)<=geomlen );
geom += 1+sizeof(wkbType);
int nFeatures = *(unsigned int *)geom;
geom += sizeof(int);

unsigned char *feature = geom;
for (int i = 0; i<nFeatures && feature; ++i)
{
geom = labelPoint(point, geom);
feature = labelPoint(point, feature, geom+geomlen-feature);
points.push_back(point);
}
}
Expand All @@ -498,156 +502,126 @@ void QgsLabel::labelPoint ( std::vector<QgsPoint>& points, QgsFeature & feature
}
}

unsigned char* QgsLabel::labelPoint ( QgsPoint& point, unsigned char* geom)
unsigned char* QgsLabel::labelPoint ( QgsPoint& point, unsigned char *geom, size_t geomlen)
{
// Number of bytes that ints and doubles take in the WKB format.
static const unsigned int sizeOfInt = 4;
static const unsigned int sizeOfDouble = 8;
// verify that local types match sizes as WKB spec
assert( sizeof(int) == 4 );
assert( sizeof(QGis::WKBTYPE) == 4 );
assert( sizeof(double) == 8 );

if(geom==NULL) {
QgsDebugMsg("empty wkb");
return NULL;
}

QGis::WKBTYPE wkbType;
unsigned char *geomend = geom+geomlen;

QGis::WKBTYPE wkbType;
bool hasZValue = false;
double *x, *y;
unsigned char *ptr;
int *nPoints;
// Upon return from this function, this variable will contain a
// pointer to the first byte beyond the current feature.
unsigned char *nextFeature = geom;
assert( geom+1+sizeof(wkbType)<=geomend );

memcpy(&wkbType, (geom+1), sizeof(wkbType));
geom++; // skip endianess
memcpy(&wkbType, geom, sizeof(wkbType));
geom += sizeof(wkbType);

switch (wkbType)
int dims = 2;

switch (wkbType)
{
case QGis::WKBPoint25D:
case QGis::WKBPoint:
{
case QGis::WKBPoint25D:
case QGis::WKBPoint:
assert( geom+2*sizeof(double)<=geomend );
double *pts = (double *)geom;
point.set( pts[0], pts[1] );
geom += 2*sizeof(double);
}
break;

case QGis::WKBLineString25D:
dims=3;
case QGis::WKBLineString: // Line center
{
assert( geom+sizeof(int)<=geomend );
int nPoints = *(unsigned int *)geom;
geom += sizeof(int);

assert( geom+nPoints*sizeof(double)*dims<=geomend );

// get line center
double *pts = (double *)geom;
double tl = 0.0;
for (int i = 1; i < nPoints; i++)
{
x = (double *) (geom + 5);
y = (double *) (geom + 5 + sizeof(double));
point.set(*x, *y);
nextFeature += 1 + sizeOfInt + sizeOfDouble*2;
double dx = pts[dims*i] - pts[dims*(i-1)];
double dy = pts[dims*i+1] - pts[dims*(i-1)+1];
tl += sqrt(dx*dx + dy*dy);
}
break;
case QGis::WKBLineString25D:
hasZValue = true;
case QGis::WKBLineString: // Line center
tl /= 2.0;

// find line center
double l = 0.0;
for (int i=1; i < nPoints; i++)
{
double dx, dy, tl, l;
ptr = geom + 5;
nPoints = (int *)ptr;
if(hasZValue)
{
nextFeature += 1 + sizeOfInt*2 + (*nPoints)*sizeOfDouble*3;
}
else
{
nextFeature += 1 + sizeOfInt*2 + (*nPoints)*sizeOfDouble*2;
}
ptr = geom + 1 + 2 * sizeof(int);
double dx = pts[dims*i] - pts[dims*(i-1)];
double dy = pts[dims*i+1] - pts[dims*(i-1)+1];
double dl = sqrt(dx*dx + dy*dy);

tl = 0;
for (int i = 1; i < *nPoints; i++)
if ( l+dl > tl )
{
if(hasZValue)
{
dx = ((double *)ptr)[3*i] - ((double *)ptr)[3*i-3];
dy = ((double *)ptr)[3*i+1] - ((double *)ptr)[3*i-2];
}
else
{
dx = ((double *)ptr)[2*i] - ((double *)ptr)[2*i-2];
dy = ((double *)ptr)[2*i+1] - ((double *)ptr)[2*i-1];
}
tl += sqrt(dx*dx + dy*dy);
}
tl /= 2;
double k = (tl-l)/dl;

l = 0;
for (int i = 1; i < *nPoints; i++)
{
double dl;
if(hasZValue)
{
dx = ((double *)ptr)[3*i] - ((double *)ptr)[3*i-3];
dy = ((double *)ptr)[3*i+1] - ((double *)ptr)[3*i-2];
}
else
{
dx = ((double *)ptr)[2*i] - ((double *)ptr)[2*i-2];
dy = ((double *)ptr)[2*i+1] - ((double *)ptr)[2*i-1];
}
dl = sqrt(dx*dx + dy*dy);

if ( l+dl > tl )
{
l = tl - l;
double k = l/dl;

if(hasZValue)
{
point.setX ( ((double *)ptr)[3*i-3] + k * dx );
point.setY ( ((double *)ptr)[3*i-2] + k * dy );
}
else
{
point.setX ( ((double *)ptr)[2*i-2] + k * dx );
point.setY ( ((double *)ptr)[2*i-1] + k * dy );
}
break;
}
l += dl;
point.set( pts[dims*(i-1)] + k * dx,
pts[dims*(i-1)+1] + k * dy);
break;
}

l += dl;
}
break;

case QGis::WKBPolygon25D:
hasZValue = true;
case QGis::WKBPolygon:
geom += nPoints*sizeof(double)*dims;
}
break;

case QGis::WKBPolygon25D:
dims = 3;
case QGis::WKBPolygon: // centroid of outer ring
{
assert( geom+sizeof(int)<=geomend);
int nRings = *(unsigned int *)geom;
geom += sizeof(int);

for (int i=0; i<nRings; ++i)
{
double sx, sy;
ptr = geom + 1 + 2 * sizeof(int); // set pointer to the first ring
nPoints = (int *) ptr;
ptr += 4;
sx = sy = 0;
for (int i = 0; i < *nPoints-1; i++)
{
if(hasZValue)
{
sx += ((double *)ptr)[3*i];
sy += ((double *)ptr)[3*i+1];
}
else
{
sx += ((double *)ptr)[2*i];
sy += ((double *)ptr)[2*i+1];
}
}
point.setX ( sx/(*nPoints-1) );
point.setY ( sy/(*nPoints-1) );
// Work out a pointer to the next feature after this one.
int numRings = (int)(*(geom+1+sizeOfInt));
unsigned char* nextRing = nextFeature + 1 + 2*sizeOfInt;
for (int i = 0; i < numRings; ++i)
{
int numPoints = (int)(*nextRing);
// get the start of the next ring
if(hasZValue)
{
nextRing += sizeOfInt + numPoints*sizeOfDouble*3;
}
else
{
nextRing += sizeOfInt + numPoints*sizeOfDouble*2;
}
assert( geom+sizeof(int)<=geomend );
int nPoints = *(unsigned int *)geom;
geom += sizeof(int);

assert( geom+nPoints*sizeof(double)*dims<=geomend );

if( i==0 ) {
double sx=0.0, sy=0.0;
double *pts = (double*) geom;
for (int j=0; j<nPoints-1; j++) {
sx += pts[dims*j];
sy += pts[dims*j+1];
}
point.set( sx/(nPoints-1),
sy/(nPoints-1) );
}
nextFeature = nextRing;
}
break;

default:
// To get here is a bug because our caller should be filtering
// on wkb type.
break;
geom += nPoints*sizeof(double)*dims;
}
}
return nextFeature;
break;

default:
// To get here is a bug because our caller should be filtering
// on wkb type.
QgsDebugMsg("unsupported wkb type");
return NULL;
}

return geom;
}

static int _elementFieldIndex(QDomElement& el)
Expand Down
2 changes: 1 addition & 1 deletion src/core/qgslabel.h
View file
Expand Up @@ -133,7 +133,7 @@ class CORE_EXPORT QgsLabel
void labelPoint ( std::vector<QgsPoint>&, QgsFeature & feature );

/** Get label point for the given feature in wkb format. */
unsigned char* labelPoint( QgsPoint& point, unsigned char* wkb);
unsigned char* labelPoint( QgsPoint& point, unsigned char* wkb, size_t wkblen);

/** Color to draw selected features */
QColor mSelectionColor;
Expand Down

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