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| import org.geotools.data.simple.SimpleFeatureIterator;
import org.geotools.data.simple.SimpleFeatureSource;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.grid.GridFeatureBuilder;
import org.geotools.grid.Grids;
import org.geotools.referencing.crs.DefaultGeographicCRS;
import org.locationtech.jts.geom.*;
import org.locationtech.jts.operation.buffer.BufferOp;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import java.util.LinkedList;
import java.util.List;
/**
* 网格创建工具类
* 默认使用84坐标系
*
* @author chenchuancheng github.com/meethigher
* @since 2022/5/15 21:36
*/
public class GridCreator {
/**
* 坐标系
* 默认使用84坐标系
*/
private CoordinateReferenceSystem crs;
/**
* 构建器
*/
private GridFeatureBuilder gridFeatureBuilder;
/**
* 边长
*/
private Double sideLen;
/**
* 区域
*/
private Geometry geometry;
public GridCreator(Double sideLen, Geometry geometry) {
this(DefaultGeographicCRS.WGS84, null, sideLen, geometry);
}
public GridCreator(CoordinateReferenceSystem crs, Double sideLen, Geometry geometry) {
this(crs, null, sideLen, geometry);
}
public GridCreator(GridFeatureBuilder gridFeatureBuilder, Double sideLen, Geometry geometry) {
this(DefaultGeographicCRS.WGS84, gridFeatureBuilder, sideLen, geometry);
}
public GridCreator(CoordinateReferenceSystem crs, GridFeatureBuilder gridFeatureBuilder, Double sideLen, Geometry geometry) {
this.crs = crs;
this.gridFeatureBuilder = gridFeatureBuilder;
this.sideLen = sideLen;
this.geometry = geometry;
}
/**
* LineSting拆分方格逻辑
*
* @param geometry
* @return
*/
private List<String> linestringSplit(Geometry geometry) {
List<String> list = new LinkedList<>();
Coordinate[] coordinates = geometry.getCoordinates();
for (int i = 0; i < coordinates.length; i++) {
if ((i + 1) > geometry.getCoordinates().length - 1) {
break;
} else {
Coordinate start = coordinates[i];
Coordinate end = coordinates[i + 1];
double deltaY = (end.y - start.y);
double deltaX = (end.x - start.x);
//加该判断是为了针对奇葩问题。比如手一抖，连续点了好几个一样的点。
//至于特殊情况，像π、π/2，通过Math.atan取绝对值就够了
if (!(deltaX == 0 && deltaY == 0)) {
double degree = Math.atan(deltaY / deltaX);
//如果距离不足sideLen时，至少保证有一个点被渲染
Geometry grid = GeoUtils.rotateGeometry(GeoUtils.createPoint(start.getX(), start.getY()).buffer(sideLen / 2, 1, BufferOp.CAP_SQUARE),
GeoUtils.createPoint(start.getX(), start.getY()), degree, false);
list.add(grid.toText());
//此处选用1/2的原因，看图。只要<俺>到<终点>的距离大于边长的一半，就给再补一个块出来
// ____________
//| __|__俺__|_终点
//|_____|_____|
while (GeoUtils.createLine(start, end).getLength() > sideLen * 1 / 2) {
double x = sideLen * Math.cos(degree);
double y = sideLen * Math.sin(degree);
double realX;
double realY;
/*如果线的走向是往西，需要取相反数*/
if (end.x >= start.x) {
realX = (start.x + x);
realY = (start.y + y);
} else {
realX = (start.x - x);
realY = (start.y - y);
}
Point point = GeoUtils.createPoint(realX, realY);
grid = GeoUtils.rotateGeometry(GeoUtils.createPoint(point.getX(), point.getY()).buffer(sideLen / 2, 1, BufferOp.CAP_SQUARE),
GeoUtils.createPoint(point.getX(), point.getY()), degree, false);
list.add(grid.toText());
start = new Coordinate(point.getX(), point.getY());
}
}
}
}
return list;
}
/**
* Polygon拆分方格逻辑
*
* @param geometry
* @return
*/
private List<String> polygonSplit(Geometry geometry) {
//以东西为x轴，南北为y轴，获取包含此几何图形中最小和最大x和y值
//如果是一条斜线，就重组x、y坐标构成一个矩形。
Envelope envelopeInternal = geometry.getEnvelopeInternal();
double maxX = envelopeInternal.getMaxX();
double minX = envelopeInternal.getMinX();
double maxY = envelopeInternal.getMaxY();
double minY = envelopeInternal.getMinY();
/**
* 多加一块的原因有两个
* 1. 如果sideLen超过了最大的差值，此时会缺块
* 2. 如果区域多出来了一部分，不足以用sideLen进行分块，此时也会缺块
*/
if ((maxX - minX) < sideLen || (maxX - minX) % sideLen < sideLen) {
maxX += sideLen;
}
if ((maxY - minY) < sideLen || (maxY - minY) % sideLen < sideLen) {
maxY += sideLen;
}
try {
//构建边界，使用84坐标系即可。
ReferencedEnvelope gridBounds =
new ReferencedEnvelope(minX, maxX, minY, maxY, DefaultGeographicCRS.WGS84);
SimpleFeatureSource grid;
if (gridFeatureBuilder == null) {
grid = Grids.createSquareGrid(gridBounds, sideLen);
} else {
grid = Grids.createSquareGrid(gridBounds, sideLen, -1, gridFeatureBuilder);
}
List<String> gridList = new LinkedList<>();
SimpleFeatureIterator iterator = grid.getFeatures().features();
while (iterator.hasNext()) {
SimpleFeature feature = iterator.next();
Geometry defaultGeometry = (Geometry) feature.getDefaultGeometry();
gridList.add(defaultGeometry.toString());
}
return gridList;
} catch (Exception e) {
return null;
}
}
/**
* 创建方格
*
* @return 方格的wkt集合
*/
public List<String> create() {
if (geometry == null) {
return null;
}
if (geometry instanceof LineString) {
return linestringSplit(geometry);
} else {
return polygonSplit(geometry);
}
}
}
|
