I wanted to change the way some roads are presented on my maps. Here is how I did that.
The first step is to get current, like this:
Rename existing folder 'openstreetmap-carto' containing osm.xml to some recovery place.
Make new folder 'openstreetmap-carto'
cd there
git clone https://github.com/gravitystorm/openstreetmap-carto.git
This will make directory ../openstreetmap-carto/openstreetmap-carto.
cd there
./get-shapefiles.sh Time consuming
carto -l project.mml > osm.xml This will make the recent version of osm.xml
My maintenance issue was roads that became indistinct as zoom level was reduced, but still were important features in the wilds of Nevada to zoom 12. A zoom12 view may cover a 20x30 mile area over the ground and to be able to see where the roads are on that ground is useful. I wanted to change how a road entity was presented at some zoom level.
The first task is to determine what the entity type is:
1) Draw a box that the entity passes through. Use the max and min coordinates of that box in the SELECT below.
2) psql gis (postgres running of course)
then
SELECT *,St_AsText(way) FROM planet_osm_line where ST_Intersects(way, St_SetSRID(St_MakeBox2D(St_SetSRID(St_Point(-13348046.00, 4864100.00),900913)::geometry, St_SetSRID(St_Point(-13347721.00, 4863546.00),900913)),900913)::geometry) is true;
where the coordinates are of the box from 1).
3)If you are lucky a single row (or few) will be returned by query. From that you should be able to determine the type of the entity you are interested in. In the case at hand it was highway, residential. A miss classification given where it is.
Now that you know what you are looking for, the question becomes which of the 35,000+ lines in osm.xml affect the entity you looking at. There are 82 layers described there and 169 occurrences of the term ‘residential’. So, which ones are those that I seek?
To find out I wrote a small program to index osm.xml by two terms.
//////////////////////////////////////////////The header
#ifndef OSMXMLINDEX_H
#define OSMXMLINDEX_H
#include <QtGui/QtGui>
#include <QMainWindow>
#include <qlabel.h>
#include <qlineedit.h>
#include <qplaintextedit.h>
#include <qmessagebox.h>
class osmXmlIndex : public QMainWindow
{
Q_OBJECT
public:
osmXmlIndex(QApplication *);
~osmXmlIndex();
private:
QWidget *CentralWidget;
QLabel *LabelIndexTerm; //does not show
QLineEdit *LabelIndexEdit;
QLineEdit *LabelIndexEdi2;
QPlainTextEdit *IndexDisplay;
private slots:
void slotDisplayIndex(void);
};
#endif // OSMXMLINDEX_H
///////////////////////////////////////////////////////and the code
#include "osmxmlindex.h"
osmXmlIndex::osmXmlIndex(QApplication *App) : QMainWindow()
{
QWidget* w = new QWidget(this);
setCentralWidget(w);
CentralWidget = this;
setWindowTitle("osmIndex : Version 11/28/2015");
int wHeight = 950;
int wWidth = 1000;
setGeometry(10, 10, wWidth, wHeight);
LabelIndexTerm = new QLabel("Index Term",this);
LabelIndexTerm->setGeometry(10, 10, 70, 20);
LabelIndexTerm->setVisible(true);
LabelIndexEdit = new QLineEdit("",this);
LabelIndexEdit->setGeometry(90, 10, 200, 20);
LabelIndexEdit->setVisible(true);
connect(LabelIndexEdit, SIGNAL(returnPressed()), this, SLOT(slotDisplayIndex()));
LabelIndexEdi2 = new QLineEdit("",this);
LabelIndexEdi2->setGeometry(300, 10, 200, 20);
LabelIndexEdi2->setVisible(true);
connect(LabelIndexEdi2, SIGNAL(returnPressed()), this, SLOT(slotDisplayIndex()));
IndexDisplay = new QPlainTextEdit("",this);
IndexDisplay->setGeometry(0, 40, wWidth, wHeight - 40);
IndexDisplay->setVisible(true);
}
void osmXmlIndex::slotDisplayIndex(void)
{
IndexDisplay->clear();
int lineCount = 0, t1Count = 0, t2Count = 0;
QString rpt;
QString xmlFilePath;
QFile osmXmlFile("/home/RB/proj/Maps/MapWorking/openstreetmap-carto/openstreetmap-carto/osm.xml");
if (!osmXmlFile.open(QIODevice::ReadOnly | QIODevice::Text))
{
QMessageBox::information(this, tr("FTP"), tr("Unable to openFile "
"%1.").arg(xmlFilePath));
return;
}
while (!osmXmlFile.atEnd())
{
QString osmXmlData;
lineCount++;
osmXmlData = osmXmlFile.readLine();
if (osmXmlData.contains(LabelIndexEdit->text(), Qt::CaseInsensitive))
{
rpt = QString("%1").arg(lineCount, 6) + ": " + osmXmlData.left(osmXmlData.length()-1);
IndexDisplay->appendPlainText(rpt);
t1Count++;
continue;
}
if ((LabelIndexEdi2->text().length() > 0) && osmXmlData.contains(LabelIndexEdi2->text(), Qt::CaseInsensitive))
{
rpt = QString(" %1").arg(lineCount, 6) + ": " + osmXmlData.left(osmXmlData.length()-1);
IndexDisplay->appendPlainText(rpt);
t2Count++;
continue;
}
}
rpt = QString(" Term 1 count %1 : Term 2 count %2").arg( t1Count, 6).arg(t2Count, 6);
IndexDisplay->appendPlainText(rpt);
}
osmXmlIndex::~osmXmlIndex()
{
}
The output from that program looks like
.......
10628: <Layer name="line-barriers"
10666: <Layer name="cliffs"
10708: <Layer name="area-barriers"
10739: <Layer name="ferry-routes"
10852: <Filter>([int_tc_type] = 'residential')</Filter>
10858: <Filter>([int_tc_type] = 'residential')</Filter>
10864: <Filter>([int_tc_type] = 'residential')</Filter>
10870: <Filter>([int_tc_type] = 'residential')</Filter>
10876: <Filter>([int_tc_type] = 'residential')</Filter>
10916: <Layer name="turning-circle-casing"
10933: ('residential', 3),
10997: <Filter>([feature] = 'highway_residential')</Filter>
11001: <Layer name="highway-area-casing"
......
Were I working on a turning circle casing I would direct my interest to the vicinity of lines 10852, 10858, etc. (styles preceed their layers). And, thus I found the lines affecting the presentation I wanted to change
-RickBrown in Reno, NV
