RVGeo

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Features

• Geospatial Drawing: Draw points, lines, polygons, rectangles, and circles on a map.
• Advanced Visualizations: Create Delaunay triangulations, Voronoi diagrams, convex hulls, and more.
• Grid and Contour Visualization: Render grids, contours, and heatmaps from geospatial data.
• Geospatial Analysis: Perform operations like polygon intersection, point-in-polygon checks, and area calculations.
• Customizable Styling: Customize the appearance of drawn elements with colors, opacity, and stroke weights.
• Integration with Maps: Seamlessly integrate with mapping libraries like Baidu Maps (BMapGL).

Installation

npm install rvgeo

Quick Start

1. Setup the Map

Initialize a map using a mapping library like Baidu Maps (BMapGL):

const map = new BMapGL.Map("allmap");
map.centerAndZoom(new BMapGL.Point(-105.7220660521329, 39.0119712026557), 8);
map.enableScrollWheelZoom(true);

2. Draw Points

Draw multiple points and their centroid on the map:

const points = mockPoints(30, myMBR1); // Generate random points
const multiPoint = new RVGeo.MultiPoint(points);

drawPoint2BLMap(multiPoint.centroid(), map); // Draw centroid
drawMultiPoint2BLMap(multiPoint, map, innerIcon(0)); // Draw points

3. Draw a Delaunay Triangulation

Visualize a Delaunay triangulation from a set of points:

const delaunay = RVGeo.Delaunator.from(multiPoint.toXY());
const triangles = RVGeo.fillIndexArray(delaunay.getTriangleIndices(), multiPoint.coordinates);
drawTriangleEdge2BLMap(triangles, map, { strokeColor: 'blue' });

4. Draw a Voronoi Diagram

Generate and draw a Voronoi diagram:

const voronoi = new RVGeo.Voronoi(delaunay);
const clippedVoronoi = voronoi.cutVoronoiByMBR(myMBR1);
drawEdgeMap2BLMap(clippedVoronoi, map, { strokeColor: "green", strokeWeight: 2, strokeOpacity: 0.5 }, true);

Examples

Example 1: Drawing Multiple Points and Their Centroid

function example1() {
  removeAllOverlay(map);
  let icon = innerIcon(0);
  drawPoint2BLMap(mps.centroid(), map);
  drawMultiPoint2BLMap(mps, map, icon);
}

Example 2: Drawing a Delaunay Triangulation

function example2() {
  removeAllOverlay(map);
  let del = RVGeo.Delaunator.from(mps.toXY());
  let trs = RVGeo.fillIndexArray(del.getTriangleIndices(), mps.coordinates);
  drawTriangleEdge2BLMap(trs, map, { strokeColor: 'blue' });
}

Example 3: Drawing a Voronoi Diagram

function example5() {
  removeAllOverlay(map);
  let voronoi = new RVGeo.Voronoi(delaunay);
  let clippedVoronoi = voronoi.cutVoronoiByMBR(myMBR1);
  drawEdgeMap2BLMap(clippedVoronoi, map, { strokeColor: "green", strokeWeight: 2, strokeOpacity: 0.5 }, true);
}

API Reference

Core Functions

• drawPoint2BLMap(point, map, options): Draw a point on the map.
• drawMultiPoint2BLMap(multiPoint, map, icon): Draw multiple points on the map.
• drawLineString2BLMap(lineString, map, options): Draw a line string on the map.
• drawPolygon2BLMap(polygon, map, options): Draw a polygon on the map.
• drawTriangleEdge2BLMap(triangles, map, options): Draw triangle edges on the map.
• drawVoronoi2BLMap(voronoi, map, options): Draw a Voronoi diagram on the map.

Geospatial Analysis

• RVGeo.convexHull(points): Compute the convex hull of a set of points.
• RVGeo.intersectionPolygon(polygon1, polygon2): Compute the intersection of two polygons.
• RVGeo.pointInEdge(point, lineStart, lineEnd): Check if a point lies on a line segment.

Grid and Contour Visualization

• drawGrid2d(canvas, data, rect, statistics, colorBand): Draw a 2D grid on a canvas.
• drawCountour(canvas, contour, rect, color): Draw contours on a canvas.

Contributing

We welcome contributions! If you'd like to contribute, please follow these steps:

1. Fork the repository.
2. Create a new branch for your feature or bugfix.
3. Submit a pull request with a detailed description of your changes.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Happy mapping! 🌍