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OpenGL vector map library - running on Android, iOS, Desktop and browser.
/*
* Copyright 2014 Hannes Janetzek
*
* This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
*
* This program is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with
* this program. If not, see mTagMap;
private final JsonFactory mJsonFactory;
private static final char[] FIELD_FEATURES = "features".toCharArray();
private static final char[] FIELD_GEOMETRY = "geometry".toCharArray();
private static final char[] FIELD_PROPERTIES = "properties".toCharArray();
private static final char[] FIELD_COORDINATES = "coordinates".toCharArray();
private static final char[] FIELD_TYPE = "type".toCharArray();
private static final char[] LINETRING = "LineString".toCharArray();
private static final char[] POLYGON = "Polygon".toCharArray();
private static final char[] POINT = "Point".toCharArray();
private static final char[] MULTI_LINESTRING = "MultiLineString".toCharArray();
private static final char[] MULTI_POLYGON = "MultiPolygon".toCharArray();
private static final char[] MULTI_POINT = "MultiPoint".toCharArray();
private ITileDataSink mTileDataSink;
private double mTileY, mTileX, mTileScale;
public GeoJsonTileDecoder(GeoJsonTileSource tileSource) {
mTileSource = tileSource;
mTagMap = new LinkedHashMap();
mJsonFactory = new JsonFactory();
mMapElement = new MapElement();
mMapElement.layer = 5;
}
@Override
public boolean decode(Tile tile, ITileDataSink sink, InputStream is) throws IOException {
mTileDataSink = sink;
mTileScale = 1 << tile.zoomLevel;
mTileX = tile.tileX / mTileScale;
mTileY = tile.tileY / mTileScale;
mTileScale *= Tile.SIZE;
JsonParser jp = mJsonFactory.createParser(new InputStreamReader(is));
for (JsonToken t; (t = jp.nextToken()) != null; ) {
if (t == FIELD_NAME) {
if (match(jp, FIELD_FEATURES)) {
if (jp.nextToken() != START_ARRAY)
continue;
while ((t = jp.nextToken()) != null) {
if (t == START_OBJECT)
parseFeature(jp);
if (t == END_ARRAY)
break;
}
}
}
}
return true;
}
private void parseFeature(JsonParser jp)
throws JsonParseException, IOException {
mMapElement.clear();
mMapElement.tags.clear();
mTagMap.clear();
for (JsonToken t; (t = jp.nextToken()) != null; ) {
if (t == FIELD_NAME) {
if (match(jp, FIELD_GEOMETRY)) {
if (jp.nextToken() == START_OBJECT)
parseGeometry(jp);
}
if (match(jp, FIELD_PROPERTIES)) {
if (jp.nextToken() == START_OBJECT)
parseProperties(jp);
}
continue;
}
if (t == END_OBJECT)
break;
}
//add tag information
mTileSource.decodeTags(mMapElement, mTagMap);
if (mMapElement.tags.size() == 0)
return;
mTileSource.postGeomHook(mMapElement);
if (mMapElement.type == GeometryType.NONE)
return;
//process this element
mTileDataSink.process(mMapElement);
}
private void parseProperties(JsonParser jp)
throws JsonParseException, IOException {
for (JsonToken t; (t = jp.nextToken()) != null; ) {
if (t == FIELD_NAME) {
String text = jp.getCurrentName();
t = jp.nextToken();
if (t == VALUE_STRING) {
mTagMap.put(text, jp.getText());
} else if (t == VALUE_NUMBER_INT) {
mTagMap.put(text, jp.getNumberValue());
}
continue;
}
if (t == END_OBJECT)
break;
}
}
private void parseGeometry(JsonParser jp)
throws JsonParseException, IOException {
boolean multi = false;
GeometryType type = GeometryType.NONE;
for (JsonToken t; (t = jp.nextToken()) != null; ) {
if (t == FIELD_NAME) {
if (match(jp, FIELD_COORDINATES)) {
if (jp.nextToken() != START_ARRAY)
continue;
if (multi) {
parseMulti(jp, type);
} else {
if (type == GeometryType.POLY)
parsePolygon(jp);
if (type == GeometryType.LINE)
parseLineString(jp);
if (type == GeometryType.POINT)
parseCoordinate(jp);
}
} else if (match(jp, FIELD_TYPE)) {
multi = false;
jp.nextToken();
if (match(jp, LINETRING))
type = GeometryType.LINE;
else if (match(jp, POLYGON))
type = GeometryType.POLY;
else if (match(jp, POINT))
type = GeometryType.POINT;
else if (match(jp, MULTI_LINESTRING)) {
type = GeometryType.LINE;
multi = true;
} else if (match(jp, MULTI_POLYGON)) {
type = GeometryType.POLY;
multi = true;
} else if (match(jp, MULTI_POINT)) {
type = GeometryType.POINT;
multi = true;
}
if (type == GeometryType.POINT)
mMapElement.startPoints();
}
continue;
}
if (t == END_OBJECT)
break;
}
}
private void parseMulti(JsonParser jp, GeometryType type)
throws JsonParseException, IOException {
for (JsonToken t; (t = jp.nextToken()) != null; ) {
if (t == END_ARRAY)
break;
if (t == START_ARRAY) {
if (type == GeometryType.POLY)
parsePolygon(jp);
else if (type == GeometryType.LINE)
parseLineString(jp);
else if (type == GeometryType.POINT)
parseCoordinate(jp);
;
} else {
//....
}
}
}
private void parsePolygon(JsonParser jp)
throws JsonParseException, IOException {
int ring = 0;
for (JsonToken t; (t = jp.nextToken()) != null; ) {
if (t == START_ARRAY) {
if (ring == 0)
mMapElement.startPolygon();
else
mMapElement.startHole();
ring++;
parseCoordSequence(jp);
mMapElement.removeLastPoint();
continue;
}
if (t == END_ARRAY)
break;
}
}
private void parseLineString(JsonParser jp)
throws JsonParseException, IOException {
mMapElement.startLine();
parseCoordSequence(jp);
}
private void parseCoordSequence(JsonParser jp)
throws JsonParseException, IOException {
for (JsonToken t; (t = jp.nextToken()) != null; ) {
if (t == START_ARRAY) {
parseCoordinate(jp);
continue;
}
if (t == END_ARRAY)
break;
}
}
private void parseCoordinate(JsonParser jp)
throws JsonParseException, IOException {
int pos = 0;
double x = 0, y = 0; //, z = 0;
for (JsonToken t; (t = jp.nextToken()) != null; ) {
if (t == VALUE_NUMBER_FLOAT || t == VALUE_NUMBER_INT) {
// avoid String allocation (by getDouble...)
char[] val = jp.getTextCharacters();
int offset = jp.getTextOffset();
int length = jp.getTextLength();
double c = ArrayUtils.parseNumber(val, offset, offset + length);
if (pos == 0)
x = c;
if (pos == 1)
y = c;
//if (pos == 2)
//z = c;
pos++;
continue;
}
if (t == END_ARRAY)
break;
}
mMapElement.addPoint((float) ((longitudeToX(x) - mTileX) * mTileScale),
(float) ((latitudeToY(y) - mTileY) * mTileScale));
}
private static final boolean match(JsonParser jp, char[] fieldName)
throws JsonParseException, IOException {
int length = jp.getTextLength();
if (length != fieldName.length)
return false;
char[] val = jp.getTextCharacters();
int offset = jp.getTextOffset();
for (int i = 0; i < length; i++) {
if (fieldName[i] != val[i + offset])
return false;
}
return true;
}
}