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author
homann
committedMar 18, 2007
Backport for measuring from trunk to 0.8. Not everything is ported, but the main functionality should at least be correct.
git-svn-id: http://svn.osgeo.org/qgis/branches/Release-0_8_0@6818 c8812cc2-4d05-0410-92ff-de0c093fc19c
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final-0_8_1Release-0_8_1
1 parent 185a7fc commit 1f23ba9

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3 files changed

+292
-95
lines changed

3 files changed

+292
-95
lines changed
 

‎src/core/qgsdistancearea.cpp

Lines changed: 223 additions & 56 deletions
Original file line numberDiff line numberDiff line change
@@ -17,27 +17,34 @@
1717
#include <cmath>
1818
#include <sqlite3.h>
1919
#include <QDir>
20-
#include <QSettings>
20+
#include <QString>
21+
#include <QLocale>
22+
#include <QObject>
2123

2224
#include "qgis.h"
2325
#include "qgspoint.h"
24-
#include "qgsproject.h"
2526
#include "qgscoordinatetransform.h"
2627
#include "qgsspatialrefsys.h"
2728
#include "qgsgeometry.h"
2829
#include "qgsdistancearea.h"
2930
#include "qgsapplication.h"
3031
#include "qgslogger.h"
3132

33+
// MSVC compiler doesn't have defined M_PI in math.h
34+
#ifndef M_PI
35+
#define M_PI 3.14159265358979323846
36+
#endif
37+
3238
#define DEG2RAD(x) ((x)*M_PI/180)
3339

3440

3541
QgsDistanceArea::QgsDistanceArea()
3642
{
3743
// init with default settings
44+
mProjectionsEnabled = FALSE;
3845
mCoordTransform = new QgsCoordinateTransform;
39-
setDefaultEllipsoid();
40-
setProjectAsSourceSRS();
46+
setSourceSRS(GEOSRS_ID); // WGS 84
47+
setEllipsoid("WGS84");
4148
}
4249

4350

@@ -47,27 +54,17 @@ QgsDistanceArea::~QgsDistanceArea()
4754
}
4855

4956

50-
void QgsDistanceArea::setSourceSRS(long srsid)
57+
void QgsDistanceArea::setProjectionsEnabled(bool flag)
5158
{
52-
QgsSpatialRefSys srcSRS;
53-
srcSRS.createFromSrsId(srsid);
54-
mCoordTransform->setSourceSRS(srcSRS);
59+
mProjectionsEnabled = flag;
5560
}
5661

5762

58-
void QgsDistanceArea::setProjectAsSourceSRS()
63+
void QgsDistanceArea::setSourceSRS(long srsid)
5964
{
60-
// This function used to only get the /ProjectSRSID if on-the-fly
61-
// projection was enabled (and used a default value in all other
62-
// cases). However, even if it was not, a valid value for
63-
// /ProjectSRSID is most likely available, and we now use it in all
64-
// cases (as it gives correct distances and areas even when
65-
// on-the-fly projection is turned off). The default of GEOSRS_ID
66-
// is still applied if all else fails.
67-
68-
int srsid = QgsProject::instance()->readNumEntry("SpatialRefSys","/ProjectSRSID",GEOSRS_ID);
69-
70-
setSourceSRS(srsid);
65+
QgsSpatialRefSys srcSRS;
66+
srcSRS.createFromSrsId(srsid);
67+
mCoordTransform->setSourceSRS(srcSRS);
7168
}
7269

7370

@@ -81,6 +78,14 @@ bool QgsDistanceArea::setEllipsoid(const QString& ellipsoid)
8178
const char *myTail;
8279
sqlite3_stmt *myPreparedStatement;
8380
int myResult;
81+
82+
// Shortcut if ellipsoid is none.
83+
if (ellipsoid == "NONE")
84+
{
85+
mEllipsoid = "NONE";
86+
return true;
87+
}
88+
8489
//check the db is available
8590
myResult = sqlite3_open(QString(QgsApplication::qgisUserDbFilePath()).latin1(), &myDatabase);
8691
if(myResult)
@@ -170,26 +175,6 @@ bool QgsDistanceArea::setEllipsoid(const QString& ellipsoid)
170175
}
171176

172177

173-
bool QgsDistanceArea::setDefaultEllipsoid()
174-
{
175-
QString defEll("WGS84");
176-
QString ellKey("/qgis/measure/ellipsoid");
177-
QSettings settings;
178-
QString ellipsoid = settings.readEntry(ellKey, defEll);
179-
180-
// Somehow/sometimes the settings file can have a blank ellipsoid
181-
// value. This is undesirable, so force a valid default value in
182-
// that case, and fix the problem by writing a valid value.
183-
if (ellipsoid.isEmpty())
184-
{
185-
ellipsoid = defEll;
186-
settings.writeEntry(ellKey, ellipsoid);
187-
}
188-
189-
return setEllipsoid(ellipsoid);
190-
}
191-
192-
193178
double QgsDistanceArea::measure(QgsGeometry* geometry)
194179
{
195180
unsigned char* wkb = geometry->wkbBuffer();
@@ -246,6 +231,7 @@ unsigned char* QgsDistanceArea::measureLine(unsigned char* feature, double* area
246231

247232
std::vector<QgsPoint> points(nPoints);
248233

234+
QgsDebugMsg("This feature WKB has " + QString::number(nPoints) + " points");
249235
// Extract the points from the WKB format into the vector
250236
for (unsigned int i = 0; i < nPoints; ++i)
251237
{
@@ -265,18 +251,32 @@ double QgsDistanceArea::measureLine(const std::vector<QgsPoint>& points)
265251
if (points.size() < 2)
266252
return 0;
267253

254+
double total = 0;
255+
QgsPoint p1, p2;
256+
268257
try
269258
{
270-
double total = 0;
271-
QgsPoint p1, p2;
272-
p1 = mCoordTransform->transform(points[0]);
273-
274-
for (int i = 1; i < points.size(); i++)
259+
if (mProjectionsEnabled && (mEllipsoid != "NONE"))
260+
p1 = mCoordTransform->transform(points[0]);
261+
else
262+
p1 = points[0];
263+
264+
for (std::vector<QgsPoint>::size_type i = 1; i < points.size(); i++)
275265
{
276-
p2 = mCoordTransform->transform(points[i]);
277-
total = computeDistanceBearing(p1,p2);
266+
if (mProjectionsEnabled && (mEllipsoid != "NONE"))
267+
{
268+
p2 = mCoordTransform->transform(points[i]);
269+
total += computeDistanceBearing(p1,p2);
270+
}
271+
else
272+
{
273+
p2 = points[i];
274+
total += measureLine(p1,p2);
275+
}
276+
278277
p1 = p2;
279278
}
279+
280280
return total;
281281
}
282282
catch (QgsCsException &cse)
@@ -291,9 +291,17 @@ double QgsDistanceArea::measureLine(const QgsPoint& p1, const QgsPoint& p2)
291291
{
292292
try
293293
{
294-
QgsPoint pp1 = mCoordTransform->transform(p1);
295-
QgsPoint pp2 = mCoordTransform->transform(p2);
296-
return computeDistanceBearing(pp1, pp2);
294+
QgsPoint pp1 = p1, pp2 = p2;
295+
if (mProjectionsEnabled && (mEllipsoid != "NONE"))
296+
{
297+
pp1 = mCoordTransform->transform(p1);
298+
pp2 = mCoordTransform->transform(p2);
299+
return computeDistanceBearing(pp1, pp2);
300+
}
301+
else
302+
{
303+
return sqrt((p2.x()-p1.x())*(p2.x()-p1.x()) + (p2.y()-p1.y())*(p2.y()-p1.y()));
304+
}
297305
}
298306
catch (QgsCsException &cse)
299307
{
@@ -328,14 +336,18 @@ unsigned char* QgsDistanceArea::measurePolygon(unsigned char* feature, double* a
328336

329337
// Extract the points from the WKB and store in a pair of
330338
// vectors.
331-
for (unsigned int jdx = 0; jdx < nPoints; jdx++)
339+
for (int jdx = 0; jdx < nPoints; jdx++)
332340
{
333341
x = *((double *) ptr);
334342
ptr += sizeof(double);
335343
y = *((double *) ptr);
336344
ptr += sizeof(double);
337345

338-
points[jdx] = mCoordTransform->transform(QgsPoint(x,y));
346+
points[jdx] = QgsPoint(x,y);
347+
if (mProjectionsEnabled && (mEllipsoid != "NONE"))
348+
{
349+
points[jdx] = mCoordTransform->transform(points[jdx]);
350+
}
339351
}
340352

341353
if (points.size() > 2)
@@ -359,14 +371,22 @@ unsigned char* QgsDistanceArea::measurePolygon(unsigned char* feature, double* a
359371

360372
double QgsDistanceArea::measurePolygon(const std::vector<QgsPoint>& points)
361373
{
374+
362375
try
363376
{
364-
std::vector<QgsPoint> pts(points.size());
365-
for (std::vector<QgsPoint>::size_type i = 0; i < points.size(); i++)
377+
if (mProjectionsEnabled && (mEllipsoid != "NONE"))
366378
{
367-
pts[i] = mCoordTransform->transform(points[i]);
379+
std::vector<QgsPoint> pts(points.size());
380+
for (std::vector<QgsPoint>::size_type i = 0; i < points.size(); i++)
381+
{
382+
pts[i] = mCoordTransform->transform(points[i]);
383+
}
384+
return computePolygonArea(pts);
385+
}
386+
else
387+
{
388+
return computePolygonArea(points);
368389
}
369-
return computePolygonArea(pts);
370390
}
371391
catch (QgsCsException &cse)
372392
{
@@ -376,6 +396,20 @@ double QgsDistanceArea::measurePolygon(const std::vector<QgsPoint>& points)
376396
}
377397

378398

399+
double QgsDistanceArea::getBearing(const QgsPoint& p1, const QgsPoint& p2)
400+
{
401+
QgsPoint pp1 = p1, pp2 = p2;
402+
if (mProjectionsEnabled && (mEllipsoid != "NONE"))
403+
{
404+
pp1 = mCoordTransform->transform(p1);
405+
pp2 = mCoordTransform->transform(p2);
406+
}
407+
408+
double bearing;
409+
computeDistanceBearing(pp1, pp2, &bearing);
410+
return bearing;
411+
}
412+
379413

380414
///////////////////////////////////////////////////////////
381415
// distance calculation
@@ -512,6 +546,11 @@ double QgsDistanceArea::computePolygonArea(const std::vector<QgsPoint>& points)
512546
double Qbar1, Qbar2;
513547
double area;
514548

549+
QgsDebugMsg("Ellipsoid: " + mEllipsoid);
550+
if ((! mProjectionsEnabled) || (mEllipsoid == "NONE"))
551+
{
552+
return computePolygonFlatArea(points);
553+
}
515554
int n = points.size();
516555
x2 = DEG2RAD(points[n-1].x());
517556
y2 = DEG2RAD(points[n-1].y());
@@ -556,3 +595,131 @@ double QgsDistanceArea::computePolygonArea(const std::vector<QgsPoint>& points)
556595
return area;
557596
}
558597

598+
double QgsDistanceArea::computePolygonFlatArea(const std::vector<QgsPoint>& points)
599+
{
600+
// Normal plane area calculations.
601+
double area = 0.0;
602+
int i, size;
603+
604+
size = points.size();
605+
606+
// QgsDebugMsg("New area calc, nr of points: " + QString::number(size));
607+
for(i = 0; i < size; i++)
608+
{
609+
// QgsDebugMsg("Area from point: " + (points[i]).stringRep(2));
610+
// Using '% size', so that we always end with the starting point
611+
// and thus close the polygon.
612+
area = area + points[i].x()*points[(i+1) % size].y() - points[(i+1) % size].x()*points[i].y();
613+
}
614+
// QgsDebugMsg("Area from point: " + (points[i % size]).stringRep(2));
615+
area = area / 2.0;
616+
return fabs(area); // All areas are positive!
617+
}
618+
619+
QString QgsDistanceArea::textUnit(double value, int decimals, QGis::units u, bool isArea)
620+
{
621+
QString unitLabel;
622+
623+
624+
switch (u)
625+
{
626+
case QGis::METERS:
627+
if (isArea)
628+
{
629+
if (fabs(value) > 1000000.0)
630+
{
631+
unitLabel = QObject::tr(" km2");
632+
value = value / 1000000.0;
633+
}
634+
else if (fabs(value) > 1000.0)
635+
{
636+
unitLabel = QObject::tr(" ha");
637+
value = value / 10000.0;
638+
}
639+
else
640+
{
641+
unitLabel = QObject::tr(" m2");
642+
}
643+
}
644+
else
645+
{
646+
if (fabs(value) == 0.0)
647+
{
648+
// Special case for pretty printing.
649+
unitLabel=QObject::tr(" m");
650+
651+
}
652+
else if (fabs(value) > 1000.0)
653+
{
654+
unitLabel=QObject::tr(" km");
655+
value = value/1000;
656+
}
657+
else if (fabs(value) < 0.01)
658+
{
659+
unitLabel=QObject::tr(" mm");
660+
value = value*1000;
661+
}
662+
else if (fabs(value) < 0.1)
663+
{
664+
unitLabel=QObject::tr(" cm");
665+
value = value*100;
666+
}
667+
else
668+
{
669+
unitLabel=QObject::tr(" m");
670+
}
671+
}
672+
break;
673+
case QGis::FEET:
674+
if (isArea)
675+
{
676+
if (fabs(value) > (528.0*528.0))
677+
{
678+
unitLabel = QObject::tr(" sq mile");
679+
value = value / (5280.0*5280.0);
680+
}
681+
else
682+
{
683+
unitLabel = QObject::tr(" sq ft");
684+
}
685+
}
686+
else
687+
{
688+
if (fabs(value) > 528.0)
689+
{
690+
unitLabel = QObject::tr(" mile");
691+
value = value / 5280.0;
692+
}
693+
else
694+
{
695+
if (fabs(value) == 1.0)
696+
unitLabel=QObject::tr(" foot");
697+
else
698+
unitLabel=QObject::tr(" feet");
699+
}
700+
}
701+
break;
702+
case QGis::DEGREES:
703+
if (isArea)
704+
{
705+
unitLabel = QObject::tr(" sq.deg.");
706+
}
707+
else
708+
{
709+
if (fabs(value) == 1.0)
710+
unitLabel=QObject::tr(" degree");
711+
else
712+
unitLabel=QObject::tr(" degrees");
713+
}
714+
break;
715+
case QGis::UNKNOWN:
716+
unitLabel=QObject::tr(" unknown");
717+
default:
718+
std::cout << "Error: not picked up map units - actual value = "
719+
<< u << std::endl;
720+
};
721+
722+
723+
return QLocale::system().toString(value, 'f', decimals) + unitLabel;
724+
725+
}

‎src/core/qgsdistancearea.h

Lines changed: 19 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -32,7 +32,7 @@ General purpose distance and area calculator
3232
(both cases transform the coordinates from source SRS to the ellipse coords)
3333
- returned values are in meters resp. square meters
3434
*/
35-
class QgsDistanceArea
35+
class CORE_EXPORT QgsDistanceArea
3636
{
3737

3838
public:
@@ -43,19 +43,23 @@ class QgsDistanceArea
4343
//! Destructor
4444
~QgsDistanceArea();
4545

46+
//! sets whether coordinates must be projected to ellipsoid before measuring
47+
void setProjectionsEnabled(bool flag);
48+
49+
//! returns projections enabled flag
50+
bool projectionsEnabled() { return mProjectionsEnabled; }
51+
4652
//! sets source spatial reference system (by QGIS SRS)
4753
void setSourceSRS(long srsid);
48-
//! sets project's SRS as source
49-
void setProjectAsSourceSRS();
54+
5055
//! returns source spatial reference system
5156
long sourceSRS() { return mSourceRefSys; }
5257
//! What sort of coordinate system is being used?
5358
bool geographic() { return mCoordTransform->sourceSRS().geographicFlag(); }
5459

5560
//! sets ellipsoid by its acronym
5661
bool setEllipsoid(const QString& ellipsoid);
57-
//! sets ellipsoid which has been specified in preferences
58-
bool setDefaultEllipsoid();
62+
5963
//! returns ellipsoid's acronym
6064
const QString& ellipsoid() { return mEllipsoid; }
6165

@@ -76,6 +80,11 @@ class QgsDistanceArea
7680

7781
//! measures polygon area
7882
double measurePolygon(const std::vector<QgsPoint>& points);
83+
84+
//! compute bearing - in radians
85+
double getBearing(const QgsPoint& p1, const QgsPoint& p2);
86+
87+
static QString textUnit(double value, int decimals, QGis::units u, bool isArea);
7988

8089
protected:
8190

@@ -104,6 +113,8 @@ class QgsDistanceArea
104113
105114
*/
106115
double computePolygonArea(const std::vector<QgsPoint>& points);
116+
117+
double computePolygonFlatArea(const std::vector<QgsPoint>& points);
107118

108119
/**
109120
precalculates some values
@@ -116,6 +127,9 @@ class QgsDistanceArea
116127
//! used for transforming coordinates from source SRS to ellipsoid's coordinates
117128
QgsCoordinateTransform* mCoordTransform;
118129

130+
//! indicates whether we will transform coordinates
131+
bool mProjectionsEnabled;
132+
119133
//! id of the source spatial reference system
120134
long mSourceRefSys;
121135

‎src/gui/qgsmeasure.cpp

Lines changed: 50 additions & 34 deletions
Original file line numberDiff line numberDiff line change
@@ -20,11 +20,15 @@
2020
#include "qgscontexthelp.h"
2121
#include "qgsdistancearea.h"
2222
#include "qgsmapcanvas.h"
23+
#include "qgsmaprender.h"
2324
#include "qgsmaptopixel.h"
2425
#include "qgsrubberband.h"
26+
#include "qgsspatialrefsys.h"
27+
#include "qgsproject.h"
2528

2629
#include "QMessageBox"
2730
#include <QSettings>
31+
#include <QLocale>
2832
#include <iostream>
2933

3034

@@ -50,7 +54,7 @@ QgsMeasure::QgsMeasure(bool measureArea, QgsMapCanvas *mc, Qt::WFlags f)
5054
mTable->setNumRows(1);
5155
mTable->setText(0, 0, QString::number(0, 'f',1));
5256

53-
mTable->horizontalHeader()->setLabel( 0, tr("Segments (in meters)") );
57+
//mTable->horizontalHeader()->setLabel( 0, tr("Segments (in meters)") );
5458
//mTable->horizontalHeader()->setLabel( 1, tr("Total") );
5559
//mTable->horizontalHeader()->setLabel( 2, tr("Azimuth") );
5660

@@ -94,9 +98,7 @@ void QgsMeasure::activate()
9498
"If so, the results from line or area measurements will be "
9599
"incorrect.</p>"
96100
"<p>To fix this, explicitly set an appropriate map coordinate "
97-
"system using the <tt>Settings:Project Properties</tt> menu."),
98-
QMessageBox::Ok,
99-
QMessageBox::NoButton);
101+
"system using the <tt>Settings:Project Properties</tt> menu."));
100102
mWrongProjectProjection = true;
101103
}
102104
}
@@ -177,12 +179,11 @@ void QgsMeasure::addPoint(QgsPoint &point)
177179
editTotal->setText(formatDistance(mTotal));
178180

179181

180-
int row = mPoints.size()-2;
181-
mTable->setText(row, 0, QString::number(d, 'f',1));
182-
//mTable->setText ( row, 1, QString::number(mTotal) );
182+
int row = mPoints.size()-2;
183+
mTable->setText(row, 0, QLocale::system().toString(d, 'f', 2));
183184
mTable->setNumRows ( mPoints.size() );
184185

185-
mTable->setText(row + 1, 0, QString::number(0, 'f',1));
186+
mTable->setText(row + 1, 0, QLocale::system().toString(0.0, 'f', 2));
186187
mTable->ensureCellVisible(row + 1,0);
187188
}
188189

@@ -225,7 +226,8 @@ void QgsMeasure::mouseMove(QgsPoint &point)
225226
QgsPoint p1 = tmpPoints[last], p2 = tmpPoints[last+1];
226227

227228
double d = mCalc->measureLine(p1,p2);
228-
mTable->setText(last, 0, QString::number(d, 'f',1));
229+
//mTable->setText(last, 0, QString::number(d, 'f',1));
230+
mTable->setText(last, 0, QLocale::system().toString(d, 'f', 2));
229231
editTotal->setText(formatDistance(mTotal + d));
230232
}
231233
}
@@ -289,37 +291,37 @@ void QgsMeasure::on_btnHelp_clicked()
289291
QString QgsMeasure::formatDistance(double distance)
290292
{
291293
QString txt;
292-
if (distance < 1000)
293-
{
294-
txt = QString::number(distance,'f',0);
295-
txt += " m";
296-
}
297-
else
298-
{
299-
txt = QString::number(distance/1000,'f',1);
300-
txt += " km";
301-
}
302-
return txt;
294+
QString unitLabel;
295+
296+
QGis::units myMapUnits = mCanvas->mapUnits();
297+
return QgsDistanceArea::textUnit(distance, 2, myMapUnits, false);
303298
}
304299

305300
QString QgsMeasure::formatArea(double area)
306301
{
307-
QString txt;
308-
if (area < 10000)
309-
{
310-
txt = QString::number(area,'f',0);
311-
txt += " m2";
312-
}
313-
else
314-
{
315-
txt = QString::number(area/1000000,'f',3);
316-
txt += " km2";
317-
}
318-
return txt;
302+
QGis::units myMapUnits = mCanvas->mapUnits();
303+
return QgsDistanceArea::textUnit(area, 2, myMapUnits, true);
319304
}
320305

321306
void QgsMeasure::updateUi()
322307
{
308+
309+
QGis::units myMapUnits = mCanvas->mapUnits();
310+
switch (myMapUnits)
311+
{
312+
case QGis::METERS:
313+
mTable->horizontalHeader()->setLabel( 0, tr("Segments (in meters)") );
314+
break;
315+
case QGis::FEET:
316+
mTable->horizontalHeader()->setLabel( 0, tr("Segments (in feet)") );
317+
break;
318+
case QGis::DEGREES:
319+
mTable->horizontalHeader()->setLabel( 0, tr("Segments (in degrees)") );
320+
break;
321+
case QGis::UNKNOWN:
322+
mTable->horizontalHeader()->setLabel( 0, tr("Segments") );
323+
};
324+
323325
if (mMeasureArea)
324326
{
325327
mTable->hide();
@@ -335,8 +337,22 @@ void QgsMeasure::updateUi()
335337

336338
void QgsMeasure::updateProjection()
337339
{
338-
mCalc->setDefaultEllipsoid();
339-
mCalc->setProjectAsSourceSRS();
340+
// set ellipsoid
341+
QSettings settings;
342+
QString ellipsoid = settings.readEntry("/qgis/measure/ellipsoid", "WGS84");
343+
mCalc->setEllipsoid(ellipsoid);
344+
345+
// set source SRS and projections enabled flag
346+
mCalc->setProjectionsEnabled(QgsProject::instance()->readNumEntry("SpatialRefSys","/ProjectionsEnabled",0));
347+
int srsid = QgsProject::instance()->readNumEntry("SpatialRefSys","/ProjectSRSID",GEOSRS_ID);
348+
349+
mCalc->setSourceSRS(srsid);
350+
351+
int myRed = settings.value("/qgis/default_measure_color_red", 180).toInt();
352+
int myGreen = settings.value("/qgis/default_measure_color_green", 180).toInt();
353+
int myBlue = settings.value("/qgis/default_measure_color_blue", 180).toInt();
354+
mRubberBand->setColor(QColor(myRed, myGreen, myBlue));
355+
340356
}
341357

342358
//////////////////////////

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